12 December 2003

2003 Tropical Atlantic Activity Summary


The hurricane season is over, so it is time for my annual Season Summary. I sent out about 65 updates to this mailing list (which has grown from about 4 subscribers in 1996 to 240 subscribers in 2003, not to mention the updates being posted on several websites) over the past 9 months; now it's time for the final one. This report is structured in the following manner: 1) the Saffir-Simpson Scale, 2) Lifetimes and Intensities, 3) Climatology and Statistics, and 4) Landfall.
As usual, my data (which in large part comes from The National Hurricane Center and Unisys Weather) and typing could contain errors, so if you see a mistake, please point it out to me.

1. Saffir-Simpson Scale of Tropical Cyclone Intensity

CATEGORY            WINDS (mph)   PRESSURE (millibars)
------------------- ----------    ------------------
depression          23- 39        N/A
tropical storm      40- 73        N/A
1                   74- 95        > 980
2                   96-110        965-979
3                  111-130        945-964
4                  131-155        920-944
5                     >156        < 919

2. Lifetimes and Intensities
----------------------------------------------------
NAME       DATES OF          MAX WIND    MIN PRES
         ACTIVITY         (kts)        (mb)
---------- ---------------- ------------ -------------
ANA        21 APR - 24 APR        45        996 (N)
TD2        11 JUN - 12 JUN        30       1008
BILL       29 JUN - 01 JUL        50        997 (N)
CLAUDETTE  08 JUL - 16 JUL        70        981 (N,H)
DANNY      16 JUL - 20 JUL        65       1005 (N,H)
TD6        19 JUL - 21 JUL        30       1008
TD7        25 JUL - 26 JUL        30       1016
ERIKA      14 AUG - 17 AUG        65        986 (N,H)
TD9        21 AUG - 22 AUG        30       1008
FABIAN     27 AUG - 08 SEP       125        939 (N,H,M)
GRACE      30 AUG - 31 AUG        35       1007 (N)
HENRI      03 SEP - 08 SEP        45        997 (N)
ISABEL     06 SEP - 19 SEP       140        920 (N,H,M)
TD14       08 SEP - 10 SEP        30       1007
JUAN       25 SEP - 29 SEP        90        970 (N,H)
KATE       25 SEP - 07 OCT       110        952 (N,H,M)
LARRY      02 OCT - 06 OCT        50        993 (N)
MINDY      10 OCT - 14 OCT        40       1002 (N)
NICHOLAS   13 OCT - 23 OCT        60        990 (N)
ODETTE     04 DEC - 07 DEC        55        993 (N)
PETER      09 DEC - 11 DEC        60        990 (N)

In the previous chart, the N, H, and M that follows some storms denote what statistic they contributed to; Named storm (TS+), Hurricane (CAT1+), Major hurricane (CAT3+).
The winds and pressures reflect the data as posted in the operational advisories, NOT the final “best-track” data that will be available from the NHC in the post-season timeframe.

3. Climatology and Statistics
----------------------------------------------------
The average annual number of tropical disturbances (for the period 1950-2000) is:
9.6 named storms
5.9 hurricanes
2.3 major hurricanes

This year, the numbers were near the average:
16 named storms (12 in 2002)
7 hurricanes (4 in 2002)
3 major hurricanes (2 in 2002)

A fairly unique aspect of the past season was the early start and late end to the activity. Ana formed in late April, nearly six weeks before the official beginning of hurricane season. Then two storms formed in June and four in July; also unusually active so early in the season. For the second consecutive year, no storms formed during November. Then Odette and Peter both formed in December, after the official end of hurricane season.

Although there were 16 named storms, which is already above average, there were also 5 Tropical Depressions that never got named. TD2, TD6, TD7, TD9, and TD14 were scattered across the basin and across the season. Perhaps of most interest was TD14 which formed out at 22°W, east of the Cape Verde Islands; this is remarkable because it’s only 500km off the African coast. If large-scale conditions had been just a bit more favorable, it’s possible that all of these unnamed Depressions would have made it to Tropical Storm strength and 2003 would have been a close match for the amazing 1933 season (21 named storms and 10 hurricanes).

Curiously, the Caribbean Sea was completely devoid of any hurricane activity all season. Only TD9, Claudette, and Odette passed through the Caribbean, and they were all below hurricane strength. The Gulf of Mexico was also nearly devoid of hurricane activity, but Claudette and Erika both became hurricanes briefly on the western periphery of the Gulf. This is in stark contrast to 2002 where the Caribbean was home to two major hurricanes and the central Gulf was crowded with overlapping storm tracks.

For the first time since October 1998 (Mitch), a Category 5 hurricane occurred in the Atlantic. Hurricane Isabel was not only a CAT5 storm, but maintained that intensity for a total of 192 hours while passing well north of the Lesser Antilles!

The three intense hurricanes (Fabian, Isabel, and Kate) were also notable because they maintained that intensity for so long. Fabian contributed 6.5 Intense Hurricane Days, Isabel contributed 8.0, and Kate contributed 1.5. Kate was rather typical, but Fabian and Isabel were among the longest-lived intense hurricanes to ever stir up the Atlantic basin. This is the only time that two intense hurricanes each surpassed 6 “intense hurricane days” since 1900.

There were a total of 75.75 “named storm days” (days during which a storm with 35kt+ winds was present). 31.75 of those days were "hurricane days", and 16.25 of those days were "intense hurricane days". This is 171% of the climatological mean, i.e., this season was over 2/3 more active than the "normal" season. The average numbers (for the period 1950-2000) are 49.1 named storm days, 24.5 hurricane days, and 5.0 intense hurricane days. You can compare this season and recent past seasons at

Here is a summary of the season (VERY brief):

Ana formed in late April near Bermuda from a subtropical Low. The Low gradually acquired tropical characteristics as it tracked eastward with a mid-latitude disturbance. This was the first April tropical cyclone in the Atlantic ever.

Bill also did not begin as a tropical wave, but developed in the southern Gulf of Mexico. It tracked northward into the central Louisiana coast, causing coastal flooding and several tornadoes.

The third storm of the season was the first to have purely tropical origins. Claudette formed south of Hispaniola and tracked westward across the Caribbean Sea, nipping the northeast tip of the Yucat√°n Peninsula, then continuing northwest across the Gulf. The storm briefly intensified to a hurricane just prior to making landfall north of Corpus Christi, TX. The winds were slow to spin down after landfall, and maintained TS strength for over a day, dumping 5” of rain on parts of Texas.

Danny formed from a tropical wave, but the first advisory was only written when the storm was at 31°N. It completed an arc over the north central Atlantic, never affecting anything.

Erika would be the last of the storms with non-tropical origins… forming from a surface Low along a cold front just northwest of Key West, FL. It tracked westward and briefly reached hurricane strength before making landfall in northeast Mexico.

Fabian formed out at 31°W and became the first major hurricane of the season at about 50°W. The storm followed a track around the periphery of the subtropical High. This included the eyewall passing directly over Bermuda as a Category 3 hurricane, causing tremendous damage to the tiny island.

Grace was short-lived, but formed from a tropical wave. It became a Depression in the central Gulf and headed northwest toward the US coast, making landfall at nearly the same place as Claudette. Although only a Tropical Storm, Grace released 6” of rainfall over TX and LA.

Henri formed in the northeast Gulf from a tropical wave, but was immediately steered eastward across the central Florida peninsula, dumping 10” of rain in FL.

Isabel formed from a tropical wave out at 34°W and followed a classic track across the basin. It became the second major hurricane of the season at 41°W, then more notably, attained Category 5 status at 55°W… the first CAT5 in five years. This monster hurricane gradually weakened as it approached the US mainland, heading directly for North Carolina. Isabel made landfall between Capes Lookout and Hatteras as a CAT2 storm, then weakened to a CAT1 as it tracked inland across NC. It weakened further to a Tropical Storm as it passed over central Virginia and western Pennsylvania, finally dissipating over Lake Erie. This was a very destructive hurricane, with major storm surge flooding (6-8’ at places), 20” of inland rainfall, and causing widespread flooding and power outages in NC, VA, WV, MD, PA, and NY. Considering the impact this minimal hurricane and then tropical storm had on property and life along its path, it’s very fortunate that it weakened so much before making landfall; had it made landfall as a CAT4 or CAT5, it would have been catastrophic, surpassing the impact of Hurricane Andrew ’92 because of the large population it passed over.

Juan was yet another storm with tropical wave origins and a path of destruction. It formed southeast of Bermuda and tracked due north into Nova Scotia as a CAT2 hurricane. The eyewall went directly over Halifax causing extensive damage with 95kt gusts and large storm surge along the coast. This is the first time in 110 years that Halifax was directly hit by a hurricane eyewall.

Kate would become the third and last major hurricane of the season. It formed from a tropical wave in the central deep tropics, then tracked north, then northeast toward the Azores, then west toward Bermuda, then north toward Greenland. Although she lasted 12 days, the length of the track if straightened out would be the longest of the season.

Larry was a slow-motion system. Thirteen days after exiting Africa as an easterly tropical wave, it became a Depression in the Bay of Campeche. Then it slowly drifted south through the Bay and into Mexico.

Mindy lasted only a few days… formed from a tropical wave north of Hispaniola and tracked northward then eastward before dissipating.

Nicholas was the named storm to develop the furthest south, at 9°N, and so obviously, also from a tropical wave. It tracked northwest from the deep tropics, then dissipated northeast of the Lesser Antilles due to strong vertical wind shear.

Odette formed from a tropical disturbance and was very slow to organize as it drifted over the Bay of Campeche and parts of central America. Four days after the official end of hurricane season, it was upgraded to a depression, then a tropical storm shortly after, based on aircraft flights into the storm. It slowly headed northeastward toward Hispaniola and reached 55kts just prior to landfall, dumping 10” of rain over Jamaica, Haiti, and the Dominican Republic. Odette was the first named storm to form in the Caribbean during December since records began in 1871.

Lastly, Peter formed from a subtropical Low west-northwest of the Cape Verdes. This small storm was very quick to spin up, and already had an eye by the first advisory, but operationally was not made a hurricane (could be upgraded in the post-season re-analysis). Peter was absorbed by a mid-latitude trough just one day after forming. This was the first time since 1887 that two named storms formed during December in the Atlantic.


On September 6-8, there were three active named storms... Fabian, Henri, and Isabel. There were many examples of two named storms being present at the same time. Also of great interest is the large number of storms with easterly tropical wave origins; 12 out of 16!

The 2003 season, with 16 named storms, ranks #3 in recorded history for activity in the Atlantic, only behind 1995 (19 named storms) and 1933 (21 named storms).
4. Landfall
----------------------------------------------------
There were ten landfalling storms this year... six of which made landfall on the U.S. Although Ana and Fabian did not technically make landfall, they passed close enough to Bermuda to make a significant impact. There were no major hurricane landfalls anywhere during the season… the last U.S. major landfall was Bret 1999.

The first column is the storm name, second column is the date of landfall, third column is the approximate time of landfall (UTC or Zulu), fourth column is maximum sustained winds (kts) at landfall, and the fifth column is the nearest location to landfall (preliminary storm-related deaths and damages are shown in parentheses).

STORM     DATE & TIME   WIND   LOCATION
--------- ------------- ------ ---------------
ANA       4/21           35    near Bermuda (2 deaths)
BILL      6/30 1800      50    Point au fer Island, LA, USA (4 deaths, $30 million)
CLAUDETTE 7/11 1000      80    Puerto Morelos, Quintana Roo, Mexico
          7/15 1500      70    Matagorda Island, TX, USA (3 deaths, $180 million)
TD7       7/26 0600      30    Sapelo Island, GA, USA
ERIKA     8/16 1100      65    Boca San Rafael, Tamaulipas, Mexico (2 deaths)
FABIAN     9/5          105    near Bermuda (8 deaths, $300 million+)
GRACE     8/31 1500      30    Port O’Connor, TX, USA
HENRI      9/6 1000      25    Clearwater, FL, USA
ISABEL    9/18 1700      70    Atlantic, NC, USA (30+ deaths, $1 billion+)
JUAN      9/29 0300      85    Pennant Point, Nova Scotia, Canada (4 deaths, extensive)
LARRY     10/5 0300      50    Comalcalco, Tabasco, Mexico (5 deaths)
ODETTE    12/6 2300      55    Cabo Beata, Jaragua, Dominican Republic


Hurricane Season 2004 begins June 1; the first names in the lineup are Alex, Bonnie, and Charlie. New names for the season are Gaston and Matthew, which replace Georges and Mitch whose names were retired in 1998. As an aside, there will likely be several new names in the 2009 list because of the death and devastation caused by so many of this year’s storms.


Please visit my tropical Atlantic headquarters.

09 December 2003

TS Peter forms in the central Atlantic...

Tropical Storm Peter, the 16th named storm of the season, has formed
from a subtropical Low WNW of the Cape Verde Islands at 15Z today.  Not
only was it VERY rare to have TS Odette form on Dec 4, but then to have
TS Peter form on Dec 9 is perhaps unprecedented (more to follow once I
get some stats, hopefully).

At 17Z, TS Peter was located at 20.3N 37.1W (800 miles WNW of the Cape
Verde Islands) and tracking NNE at 10kts.  Intensity is estimated to be
60kts and 990mb and already has an eye-like feature, so could be
upgraded to the 8th hurricane of 2003 later today.

The storm is expected to track northeast and be absorbed by a trough,
turning extratropical by Thursday.  So.... this will change the season
stats once again and once it's over I'll send out ANOTHER revised season
summary!  Sorry for the multiple summaries, but I don't think anyone
would have foreseen our season lasting into the middle of December!


Please visit my tropical Atlantic headquarters.

05 December 2003

Odette gets stronger...

Since yesterday morning, TS Odette has gotten better organized and more
intense, despite fairly high vertical shear.  The center has been hard
to track accurately... either it's masked by the CDO or it reforms under
new deep convection.  Regardless, it's only drifting northeast.

At 15Z today, Odette was located at 14.2N 74.2W and moving toward the
ENE at 4kts.  Aircraft-measured intensity is 45kts and 993mb and she
still appears to be getting better organized.  SSTs are still very warm
(28.5C), and the oceanic heat content is very high in this part of the
Caribbean, but vertical shear is not letting up much.  An aside... the
environmental SLP is about 1012mb now at this latitude, which is lower
than it would be in the summer; this helps explain the 993mb MSLP of
Odette and only 45kt winds.

A Tropical Storm Warning is in effect for Jamaica, Haiti, and much of
the Dominican Republic; a Tropical Storm Watch is in effect for the
eastern islands of the Bahamas.  Odette is forecast to strengthen some
more, but most likely not reach hurricane intensity.  She has now
contributed 1.0 additional Named Storm Days to the 2003 season, bringing
the total to 73.0.


Please visit my tropical Atlantic headquarters.

04 December 2003

TD20 forms in the western Caribbean...

At 15Z today, the area of disturbed weather I mentioned yesterday was
upgraded to Tropical Depression 20.  This was based on surface
observations in the area and the presentation on satellite.  An aircraft
will fly into the system later today to confirm or deny Tropical Storm
status.  If sustained winds in the surface circulation are at least
35kts, it will become TS Odette, the 15th named storm of the season
(although the season is officially over).

At 15Z, TD20 was located at 13.3N 76.3W and tracking NNE at 9kts. 
Intensity is 30kts and 1005mb.  The storm is expected to strenghten,
probably becoming a TS this afternoon, and to accelerate northward with
time.  This time of year, it would be very difficult for a tropical
system to survive outside of the deep tropics, so it should make the
extratropical transition during the weekend. 

A Tropical Storm Warning is in effect for all of the Haiti coast, and
Tropical Storm Watches are in effect for portions of the southern
Dominican Republic coast and the eastern islands of the Bahamas. 
Jamaica and Cuba could begin experiencing adverse weather today and
warnings might be issued for those areas as well.


Please visit my tropical Atlantic headquarters.

03 December 2003

Post-season activity might be brewing...

For nearly a week, I've been watching an area of disturbed weather in
the Bay of Campeche and over central America.  It has drifted a bit more
north into the west central Caribbean Sea now, and showing signs of
organization.

There is a broad circulation centered at about 13N 77W with significant
divergence aloft.  It is over 29C ocean temperatures, and in this part
of the basin, the warm water is deep, resulting in a high oceanic heat
content to fuel a potential storm.  Vertical shear could be the major
inhibiting factor (not a surprise in December especially)... strong
southwesterly flow aloft could keep it from organizing further.

A recon aircraft might investigate the system on Thursday to check for a
closed surface circulation.  If so, it would be come TD20, and if it
gets named, it will be Odette.

Recall this season started with Ana in the last week of April.  Only
fitting to maybe get Odette in the first week of December!  Officially,
hurricane season runs from June 1 to November 30.  I'll keep you posted
if anything happens with this.


Please visit my tropical Atlantic headquarters.

23 October 2003

Nicholas finally absorbed...

At 21Z today, the final advisory was written on Nicholas, 10 days after
the first one was written.  Last position was at 24.3N 56.8W with 25kt
winds.  He has been absorbed by a mid-latitude trough.

Unless something else forms in the remaining five weeks of the official
season (which is certainly possible), the next update will be my final
season summary.

As of now, the season stands at:
14    Named Storms
72.00 Named Storm Days
6     Hurricanes
31.50 Hurricane Days
3     Intense Hurricanes
16.25 Intense Hurricane Days (2nd highest EVER!)


Please visit my tropical Atlantic headquarters.

21 October 2003

Nicholas still out there...

It's been a while since my last update, but very little has transpired. 
Since 10/14, TD19 was upgraded to TS Nicholas on 10/15, and never
reached hurricane intensity.  The steering flow has been relatively weak
and the vertical shear has been moderately high, resulting in a
quasi-stationary storm that has struggled to maintain organization.

At 15Z today, TS Nicholas was located at 18.5N 51.5W and tracking W at
7kts.  Intensity is back up to 45kts and MSLP has been dropped to
1002mb.  From the satellite perspective, the storm has made a noticeable
comeback in deep convection, although the shear is still apparent.  The
forecast is for a northward turn and gradual weakening.

Nicholas has accumulated 6.75 Named Storm Days, and 1-2 more are
probably in store.  I believe this brings the season total up to 69.75
NSD so far (the climatological seasonal average is about 49).  Another
note on climatology... this season is ALREADY 62% more active than the
average season, and there's still another five weeks left ("activity"
defined as a function of Named Storms, Named Storm Days, Hurricanes,
Hurricane Days, Intense Hurricanes, and Intense Hurricane Days).  The
last year that was this active was 1999.  See
http://einstein.atmos.colostate.edu/~mcnoldy/tropics/NTC.html for a look
at some recent past seasons.


Please visit my tropical Atlantic headquarters.

14 October 2003

Mindy dissipates, TD19 nearly a TS...

At 03Z today, the final advisory was written on Mindy as she completed
the extratropical transition and is now fully absorbed by a trough.  She
never reached hurricane strength, but did accumulate 2.0 Named Storm
Days.

TD19 continues to organize east of the Lesser Antilles.  This morning's
infrared satellite imagery shows a very cold CDO, with cloud tops as
cold as -85C at times.  The low-level center, although somewhat
challenging to find, is approximately under the CDO.  As of 15Z, TD19
was at 10.8N 41.4W and tracking WNW at 8kts.  Intensity is estimated to
be 30kts and 1006mb.  This will likely be upgraded to TS Nicholas at the
21Z advisory today, and could reach hurricane strength during the
weekend.  The track forecast recurves the storm by about 47W, sneaking
north through a weakness in the subtropical ridge.  However, if the
ridge does not break down according to the models, the track will be
forced more westerly.  Just something to keep an eye on.

Elsewhere, there is an area of disturbed weather over the western
Caribbean Sea, right by Honduras and Nicaragua.  Conditions are
favorable for development, but proximity to land could hinder it.  If it
continues a westward drift, it stands a better chance of developing in
the EastPac.


Please visit my tropical Atlantic headquarters.

13 October 2003

Mindy weakens, TD19 forms...

At 21Z yesterday, Mindy weakened to a Depression, and continues to be
absorbed into a midlatitude trough.  She is very poorly organized, and
as of 21Z was loacted at 26.1N 67.7W and tracking E at 8kts.  Intensity
is estimated to be 25kts and 1007mb.  The forecast is for continued
dissipation.

The tropical wave I mentioned on the 11th has become better organized
and was upgraded to TD19 at 21Z today.   It's at 9.6N 38.7W and moving W
at 7kts.  Maximum sustained winds are 25kts and the MSLP is 1008mb. 
Conditions appear favorable for further development, and this should
become TS Nicholas by Tuesday afternoon.  Vertical shear may inhibit the
storm from reaching hurricane strength.  It formed far enough south that
it could enter the Caribbean in the long term, unlike many of the last
few storms that recurved rather far east.  Also, this is very late in
the season for a Cape Verde storm to form, but it's obviously possible!


Please visit my tropical Atlantic headquarters.

11 October 2003

TS Mindy forms over Hispaniola...

The area of disturbed weather I had been mentioning since Oct 6 was upgraded to
Tropical Storm Mindy at 21Z yesterday.  She remains disorganized though, and
will not have long to wait until she's picked up by a trough.  She's already in
moderate shear, and it should pick up a bit today too, making it even
questionable if this weak TS will survive.  As of 15Z, Mindy was at 22.2N 71.6W
and tracking NW at 12kts.  Intensity is 35kts and 1007mb (weakened a bit from
her peak intensity so far of 40kts and 1002mb).  The forecast track takes her
over the extreme south islands of the Bahamas, then recurving and heading for
Bermuda by Monday.

Elsewhere, a tropical wave is located southwest of the Cape Verde islands and
conditions are marginally favorable for slow development.  It's moving west at
12kts and has a 1006mb Low.  Although being sheared now, this could improve with
time and makes this something worth watching.  Normally, the Cape Verde season
would be over by now, but there are bound to be outliers.


Please visit my tropical Atlantic headquarters.

07 October 2003

Kate becoming extratropical...

The mid-latitude trough is rapidly absorbing Kate, and she's barely
discernable as a tropical system anymore.  She is gradually losing
centralized deep convection and now has a front extending southward from
the Low.  As of 15Z today, TS Kate was located at 45.5N 48.0W and
tracking NNE at 38kts.  Intensity is estimated to be 60kts and 987mb. 
During the rest of the week, she's expected to zip quickly
northeastward, passing south of Iceland then north of England, heading
for Norway as a potent early Fall storm.  However, Kate has joined the
ranks of Fabian and Isabel as 2003's Atlantic major hurricanes.  It's
very likely that the 21Z advisory today will be the last written on
Kate.  She has 5.75 Hurricane Days and 1.5 Intense Hurricane Days to her
name, and probably will end up with 9.75 Named Storm Days.

I'm still watching the tropical wave east of the Lesser Antilles.  It
has made little if any progress since yesterday, but conditions are
still favorable for development.  Again, should this organize, the next
number and name are TD18 and Mindy.


Please visit my tropical Atlantic headquarters.

06 October 2003

Kate back to CAT1 hurricane, Larry made landfall...

Since Friday morning (time of the last update), Kate reached a peak
intensity of 110kts and 952mb on Saturday afternoon, just shy of CAT4
status.  She accumulated 1.5 Intense Hurricane Days, and so far has 8.5
Named Storm Days and 5.25 Hurricane Days.  The track has not been very
deviant from the forecast... she has made the expected northward bend as
she recurves in response to a midlatitude trough.  As of 15Z today,
Hurricane Kate was at 36.1N 55.2W and tracking NNE at 19kts.  Current
intensity is 75kts and 979mb.  The future is not very surprising; she
will gradually lose tropical characteristics, weaken, and get whisked
northeastward by the trough, probably giving Iceland a bit of a show by
Thursday.

Tropical Storm Larry never reached hurricane strength, and never found a
real steering flow.  He drifted VERY slowly and erratically south into
Mexico, making landfall around 03Z on 10/5.  Advisories on Larry have
ceased, as his remnants continue to drift into the Gulf of Tehuantepec.

Elsewhere, a tropical wave is located at about 12N 45W and could slowly
organize over the next couple days, as conditions appear favorable. 
There is already a broad area of cyclonic vorticity, divergence aloft,
and it's heading into an area of very high oceanic heat content (not
only warm water, but deep warm water).  The next number/name on deck is
18/Mindy.


Please visit my tropical Atlantic headquarters.

03 October 2003

Kate now a CAT2, Larry heading for Mexico...

Kate's satellite presentation continues to improve, and therefore, so
does her intensity.  She has a large and symmetric eye, a CDO being
maintained over the eyewall at about -62C (the approx temperature of the
tropopause there), and healthy outflow.  MSLP has fallen 13mb in the
past 24 hours... not rapid, but noticable.  As of 15Z, Hurricane Kate
was located at 29.5N 48.3W and tracking W at 9kts.  Intensity is
estimated at 95kts and 966mb, making her a strong CAT2 storm.  The
forecast is for further intensificiation, possibly becoming the third
major hurricane of the season in the next 12-24 hours.  The westward
trek is expected to continue through the weekend, then make a turn to
the north in response to an advancing midlatitude trough... possibly
affecting Newfoundland early next week.

TS Larry is still not very well organized, and still in very weak
steering flow, but has begun to drift south toward land.  Presently,
there is very deep convection just east of the center, with cloud tops
as cold as -90C at times.  At 15Z today, Larry was at 20.0N 94.6W and
creeping SW at 2kts.  Maximum winds are 50kts and MSLP is 997mb.  There
are frequent aircraft recon flights into the storm, so this intensity is
not satellite-estimated.  A Tropical Storm Warning and Hurricane Watch
are in effect for much of the coast along the Bay of Campeche.  Larry is
forecast to continue drifting slowly south, heading toward Chivela Pass,
Mexico (home of the famous Tehuantepec gap winds!).  He is forecast to
slowly intensify, almost reaching hurricane strength as he makes
landfall early next week.


Please visit my tropical Atlantic headquarters.

02 October 2003

Kate strengthens, Larry forms in the Gulf...

Hurricane Kate appears very healthy on satellite imagery.  Outflow is
not ideal, but there is a defined eye and cold cloud tops over the
eyewall.  As of 15Z she was at 30.0N 44.1W and heading WSW at 8kts. 
Intensity is estimated at 75kts and 979mb.  She is forecast to continue
westward and to intensify further, perhaps to a CAT2 hurricane by
tomorrow.  At this time, it appears she is no risk to land, perhaps
Newfoundland in about a week if anything.  As as aside... something to
keep in mind when viewing an IR image of Kate: the cloud tops may not
appear as intense as what you might see in a hurricane at lower
latitudes.  However, a lower tropopause at higher latitudes means that
the cloud top temps CAN'T get as cold, but the tops are still hitting
the tropopause.

The disturbance in the southern Gulf was finally upgraded to TS Larry at
03Z today based on satellite estimates and aircraft recon... the 12th
named storm of the season.  At 15Z today, TS Larry was located at 21.0N
93.5W and stationary.  Maximum sustained winds are 45kts and the MSLP is
1003mb.  The forecast is for very gradual strengthening and to remain
nearly stationary.  Although poorly organized now, SSTs and vertical
shear are favorable for development.  However, if and when he
intensifies and winds increase, being stationary will only stir up more
cool water from below, inhibiting intensificiation.  We could be
watching Larry in the southern Gulf for many days to come.


Please visit my tropical Atlantic headquarters.

01 October 2003

Kate still a TS, Gulf system still brewing...

Kate has made the westward turn as forecast, and continues to maintain
strong Tropical Storm intensity.  As of 15Z, she was located at 32.2N
40.2W and tracking W at 10kts.  Intensity is estimated to be 60kts and
991mb.  The forecast is for slight strengthening, re-achieving hurricane
strength later today as vertical shear continues to relax.  She does
appear to be forming an eye on both visible and infrared satellite
imagery.

For the 6th day, we're watching a large disturbance make its way into
the southern Gulf of Mexico.  It still has very deep and persistent
convection, along with a broad circulation and 1006mb central pressure
at about 22N 93W.  However, recent aircraft recon reveals a non-tropical
structure.  It will continue to be monitored closely for tropical
development. Again, this would be TD17/Larry if it forms.


Please visit my tropical Atlantic headquarters.

30 September 2003

Kate becomes a hurricane, Gulf is getting active...

At 03Z today, Kate briefly reached hurricane strength, making her the
6th of the season.  She has since been downgraded back to a Tropical
Storm, but with a forecast of reaching hurricane strength again.  She is
still very heavily sheared, but SSTs are sufficient and shear is
forecast to lessen with time.  At 15Z, she was located at 32.0N 35.4W
and crawling N at 5kts.  Intensity is estimated to be 55kts and 992mb. 
She is forecast to reach hurricane intensity again tomorrow evening and
also make a turn toward the
west.                                                                    

The southern Gulf of Mexico is getting more interesting every day. 
Recall the area of disturbed weather that I first mentioned last
Thursday in the western Caribbean... same thing, it's just been very
slow to get organized and in weak steering flow.  It has a 1008mb Low,
and is located at about 22N 92N and drifting slowly to the WNW. 
Although still disorganized, deep convection (cold cloud tops) has been
persistent.  As is typical for this time of the season, the southern tip
of a cold front extends into the Gulf and is currently playing a
hindering role in the development of this system (they can also assist
formation at times either by baroclinic enhancement and/or by
introducing vorticity).  Should this develop, it will be TD17/Larry.


Please visit my tropical Atlantic headquarters.

29 September 2003

Juan hits Nova Scotia, Kate still in open waters...

Since Friday, Juan had reached a peak intensity of 90kts and 970mb,
following a northerly course.  He made landfall at 03Z today as a CAT1
hurricane on Nova Scotia and has since lost all tropical
characteristics.  He accumulated 3.75 Named Storm Days and 2.75
Hurricane Days.

At 21Z on 9/27, TD16 was upgraded to TS Kate, the 11th named storm of
the season.  She recurved at 45W and is presently heading NE toward the
Azores.  Satellite-estimated intensity has been slowly increasing, and
as of 15Z was 60kts and 991mb.  She could easily become a hurricane
later today, despite rather hefty vertical shear.  The 15Z location was
28.8N 37.6W and tracking NE at 17kts.  The forecast track is rather
interesting because the NE journey comes to an end and she heads back to
the NW.

Elsewhere, the area of disturbed weather I mentioned last Thursday and
Friday is STILL out there festering near the Gulf of Mexico and
Caribbean Sea border.  There is evidence of a broad-scale circulation,
and once over the Gulf, conditions could be favorable enough for this to
finally become a Depression.


Please visit my tropical Atlantic headquarters.

26 September 2003

TD15 becomes Hurricane Juan, TD16 forms...

TD15 which formed southeast of Bermuda yesterday morning has rapidly
intensified, and is now Hurricane Juan.  The central pressure fell 19mb
in the past 24 hours, and the winds increased by 35kts.  Also, he
developed a small eye which has since covered over with convective
debris.  As of 15Z today, Juan was at 32.2N 62.0W and moving slowly N at
7kts.  Maximum sustained winds are 65kts with a MSLP of 987mb.  He is
expected to strengthen a bit more, then rapidly degenerate as he nears
Nova Scotia on Sunday, being absorbed into a midlatitude trough and make
an extratropical transition.  Juan is the 5th hurricane of the season.

At 21Z yesterday, the area of disturbed weather east of the Lesser
Antilles was upgraded to TD16, and it is slowly organizing.  At 15Z
today, it was located at 15.9N 40.7W and tracking NW at 13kts. 
Intensity is a weak 30kts and 1007mb.  It's battling some shear, and
deep convection has been sparce.  It's forecast to continue gradually
intensifying, reaching TS status later today, but falling short of
hurricane strength because of the increasing shear.  The track should be
generally northwestward, recurving by 50W.

Elsewhere, the area I've been mentioning in the western Caribbean Sea
continues to fester... environmental pressures are falling and
convection is becoming more concentrated.  The focus of action is at
about 17N 84W.


Please visit my tropical Atlantic headquarters.

25 September 2003

TD15 forms near Bermuda...

Over the past few days, there have been three areas of interest in the
Atlantic.  One in the deep tropics east of the Cape Verdes, one in the
western Caribbean, and one south of Bermuda.  As the headline suggests,
the area south of Bermuda is the one that developed first, and became
the 15th depression of the season today.

At 15Z, TD15 formed at 29.5N 61.0W and heading NE at 6kts.  Intensity is
estimated at 30kts and 1006mb.  Given favorable conditions, it is
expected to quickly reach TS status, but probably not make it to
hurricane strength.  Its name will be Juan when it does get named.  The
track forecast is basically due north, zipping east of Bermuda then up
to Nova Scotia.

Elsewhere, the area of disturbed weather east of the Lesser Antilles is
indeed getting better organized and is a rather large circulation. 
Located at about 12N 37W, it's tracking W at 12kts.  This could become
TD16 in the next day or two... SST is 28C+ and the vertical shear is
fairly low (next name on deck is Kate, assuming TD15 becomes Juan).  The
western Caribbean disturbance is still not looking very organized, but
conditions are improving for development.


Please visit my tropical Atlantic headquarters.

21 September 2003

another Isabel report

Here is another very thorough report from former CSU Atmos student Zach Eitzen,
now in Hampton, VA.

Also since the last report was mailed out, I heard from my dad, Bill McNoldy, in
Reading, PA.  He reported that winds were pretty breezy, rain was moderate, but
his area still lost power for nearly a day.

Brian


-------- Original Message --------

I have weathered my first hurricane, and I'd have to say that I was impressed,
even though sustained winds here were generally "only" up to 50 mph, and the
peak 
gust here in Hampton was around 83 mph. Me, my cat, my car, and my apartment are
all okay, although there was considerable damage to the apartment complex that I
live in. A fair bit of vinyl siding was blown off, and three chimneys came down,
as well. We lost power for 48 hours, and phone service for about 30 hours. The
water is currently unsafe to drink, but I have plenty of bottled water for now.

Strangely, the phone service went out yesterday morning, under sunny skies with
only breezy conditions. I am thankful that services were restored so quickly -
many people will have to wait a lot longer.

My apartment is at the lofty elevation of 15 feet, so I didn't need to worry 
about storm surge, but there was considerable flooding in Poquoson and other
locales along the Chesapeake Bay, even up to Baltimore. I was very impressed
with the amount of wind damage/power outages so far inland. I've included a map
of power outages that I took from the local power company on Friday morning
(while I still had phone service but no power). As Isabel came ashore, there
appeared to be a concentric eyewall, but the max winds were in the outer
eyewall, at a fairly large radius from the center of circulation.

For some pictures of the damage, I've included a couple of local news 
channel "email your pictures to us" sites:
http://www.wvec.com/blog/isabel/
http://wavy.com/Global/story.asp?S=1448226


Please visit my tropical Atlantic headquarters.

19 September 2003

another update on Isabel's aftermath

Thanks to John Snowden III for sharing his experience and observations from
NC...


-------- Original Message --------
Date: Sat, 20 Sep 2003 00:58:22 +0000

Brian,

I have some photos of storm damage.  Will be getting more.

I'm on the Board of Directors for our local Red Cross chapter.

The "center" of Isabel passed about 50 miles to the west of where I rode out 
the storm (Elizabeth City, NC).  Sustained winds were 70 mph with gusts to 95 
mph.

My dad recorded a barometric pressure of 28.98 Thursday afternoon (he was 
located about 30 miles further east toward the Outer Banks).

I drove from E. City east to Currituck County this morning.  The damage was 
progressively "less" as you drove east.  Lots of trees down on roads, power 
line, phone lines and houses.

Telephone and power poles were pushed over (some broken, others simply 
displaced the ground and went over).  Road signs were snapped off.  Billboards 
that did not have panels removed were broken off. Portions of rooves were 
stripped of tarpaper and shingles.  Some metal rooves were peeled right off.
Vinyl siding was stripped off some houses.

Vehicles blown off the road.

Ground water was so high, lots of trees were uprooted.

Surprisingly light damage to single and double wide trailers (I saw one where 
the roof was peeled right off).

2-3 feet of soundside flooding due to southwest wind.

Of the 2.0 million customers of Dominion Power in NC and Va, 1.8 million were 
without power during the height of the storm.

In E. City, there was structurral damage to older buildings, toppled chimneys, 
building facades that were ripped off.  Further west in Hertford, NC & Edenton, 
NC (closer to the storms eye) 75% of residences were damaged to some extent.

Some of the Red Cross workers I spoke with said it looked like a war zone the 
closer you were to the path of the eye.

The height of the storm for us was 2 - 4 pm, Thursday.  Then by 7 pm Thursday 
things had died off significantly.  There was a lot more wind out in front of 
the storm than behind it.

I lived in Greenville, NC through Bertha, Fran and Floyd.  This was pretty 
impressive, just from the extent of the wind field, and considerable build up 
to the storm.  If it had been slower moving, it would have been really bad.

I'll send links to pictures when I can upload them to my website.

/John


Please visit my tropical Atlantic headquarters.

Isabel's aftermath...

Isabel came ashore with notable fury yesterday, eroding beaches,
toppling trees, washing out road networks, downing power lines, and
collapsing buildings.  Geoff Mackley was at Cape Hatteras, NC for
Isabel's landfall, and reports that all services are cut and the storm
surge was major (http://www.rambocam.com/isabel03.html).  Jason and
Sarah Kline in Downingtown, PA report downed trees, limbs and leaves all
over everything, and are still without power.

So far, I'm aware of 15 deaths caused by the storm, scattered across NC,
VA, MD, NJ, PA, NY, and RI as well as about 5 million people without
power.  The U.S. government will remain closed for the second
consecutive day, and some of the affected states' governments will also
be closed today.  States of emergency have been declared in NC, VA, DE,
MD, PA, and NJ.

Isabel is presently over Lake Erie and just about to cross into Canada. 
At 15Z, she was at 42.0N 80.7W and racing N at 26kts, and becoming
absorbed into a midlatitude trough.  She is now just a Tropical
Depression with 30kt sustained winds and a MSLP of 997mb.  The name will
undoubtedly be retired after this season, just for the damage and deaths
she caused, but as far as hurricane records go, she accumulated a total
of 13.25 Named Storm Days, 11.25 Hurricane Days, and 8.0 Intense
Hurricane Days.  She was also one of the longest-lived CAT5 hurricanes
in Atlantic basin history.

One good thing to come from this storm is the preparedness.  Models and
official forecasts were very accurate in both placement and timing of
the hurricane, letting evacuations be well-placed and watches/warnings
be timely and precise.  All affected states had plenty of preparation
time and got exactly what was expected.  This was a great case for
hurricane forecasters, and the outcome is a prepared public.  People
living on or near the coast will never avoid the property damage
associated with landfalls, but success comes in reducing the death toll.


Please visit my tropical Atlantic headquarters.

18 September 2003

Isabel making landfall...

Just as forecast, Hurricane Isabel is making landfall between Cape
Lookout and Cape Hatteras.  No big surprises yet; she is producing large
surf, a hefty 8' storm surge, strong winds, and torrential rain... just
like any other landfalling hurricane.  In addition, tornadoes are a very
real threat in the hurricane as she moves ashore.

Watches and warnings abound along a vast stretch of the Atlantic
seaboard.  Areas included are SC, NC, VA, WV, MD, DE, NJ, PA, NY, and
CT.  A Hurricane Warning is in effect from Cape Fear, NC to
Chincoteague, VA as well as the southern Chesapeake Bay.  Tropical Storm
Warnings are in effect from Chincoteague, VA to Moriches Inlet, NY, and
then from Cape Fear, NC to South Santee River, SC, as well as the
northern Chesepeake Bay and Delaware Bay.
A Tornado Watch is in effect for eastern NC, VA, and parts of MD and
DE.  Flood and Flash Flood Watches are issued for parts of NC, VA, WV,
MD, NY, and basically all of PA.  High Wind Warnings are issued for much
of the same areas.  The best thing you can do if you live in any of the
states I mentioned is to keep tuned to a reliable local radio station or
TV station, and/or to have a NOAA Hazard Radio in your house for the
latest information.  Avoid mudslide/rockslide-prone areas and of course,
never attempt to cross a flooded street no matter how convenient a path
home it might be.

As of this writing, the center of the eye is about 50 miles east of Cape
Lookout, NC.  At 15Z she was located at 34.4N 75.7W and tracking NW at
16kts.  Intensity is 85kts and 956mb, and this will rapidly dwindle as
she moves inland... but the danger from tornadoes and flooding will
not.  The forecast track is still unchanged, and should cross over VA
late tonight into Friday morning, then over PA from Friday morning
through Friday evening.

The links I sent in a separate mailing to the radar and surface
observations will still come in handy if you wish to monitor the storm
as she moves in.

Please visit my tropical Atlantic headquarters.

P.S.  Any updates that anyone has who's experiencing Isabel's wrath
first-hand would be greatly appreciated.  I'd be happy to include them
in future mailings.

17 September 2003

Isabel taking aim at NC coast...

Since yesterday at this time, the storm has remained basically the same,
perhaps organizing a bit more.  She's still a CAT2 hurricane, and a
significant change in intensity is unlikely before landfall.

As of 15Z today, Isabel was located at 30.0N 72.6W and tracking NNW at
8kts.  Maximum sustained winds are 95kts with gusts to 115kts, and the
MSLP is 957mb.  The combined effects of wind-driven water plus the dome
of water under the Low pressure is expected to result in a storm surge
of 7-11' in northern NC and much of VA, and 4-7' in the Chesapeake Bay. 
And along with the 130mph wind gusts, rainfall could be nearly 12"
during the course of her passage.  Inland flooding could be a serious
threat for NC, VA, MD, DE, WV, NJ, and PA through Friday evening. 

The wind field associated with Isabel is very large, and hurricane-force
winds extend as far out as 115 miles from the eye, and
tropical-storm-force winds extend as much as 315 miles from the eye. 
So, the exact location of where the eye crosses the coastline is not
important.  Conditions will become rough well before the eye reaches the
coast, and rather far from that location as well.

A Hurricane Warning is in effect from Cape Fear, NC to Chincoteague,
VA.  A  Hurricane Warning is also in effect for the southern Chesapeake
Bay.  Tropical Storm Warnings extend from Cape Fear, NC to South Santee
Rover, SC and then from Chincoteauge, VA to Sandy Hook, NJ.  TS Warnings
also for the northern Chesapeake Bay and tidal Potomac River.  You can
find the latest warning graphic at
http://www.nhc.noaa.gov/ftp/graphics/AT13/refresh/AL1303W+GIF/170948W.gif

Parts of NC and VA have already been declared states of emergency to
expedite disaster relief teams and Red Cross assistance (however, CNN
reports that the Red Cross Disaster Relief Fund is empty).  There are
some mandatory evacuation orders in place along the NC coast, and
numerous optional evacuations.  The extent of mandatory evacuations
could grow today just to make sure threatened residents stay safe.

Landfall is expected midday Thursday near Cape Lookout, NC.  Winds and
storm surge will be worse to the north of the eyewall.  She is then
expected to pass over VA early Friday morning and over central PA midday
Friday.  Winds could still be brisk, but rainfall will most likely be
the key player by this time.


Please visit my tropical Atlantic headquarters.

16 September 2003

Isabel weakens in the face of shear...

During the past 24 hours, Isabel has encountered fairly significant
vertical wind shear, on the order of 20kts from the southwest.  This is
very evident in satellite imagery.  SSTs under the storm continue to be
plenty warm at about 29C, but her slow forward motion could be
responsible for some degree of upwelling.  She's also been ingesting
some drier air from the western side which has snuffed convection out a
bit.

At 15Z today, Hurricane Isabel was located at 27.4N 71.2W and tracking
NNW at 7kts.  Intensity has dropped quite a bit to 90kts and 959mb,
making her a CAT2 storm.  That is still a strong hurricane, but there's
the possibility that she COULD reintensify before landfall if the shear
lets up at all.  The hurricane-force winds extend 80 miles on the
northwest quadrant, so the exact location of where the eyewall makes
landfall is not so important; it's a large storm.

A Hurricane Watch has been issued for a large stretch of the Atlantic
seaboard, from Little River Inlet, SC to Chincoteague, VA.  These
watches will probably be upgraded to warnings at the 21Z advisory today
or 03Z tomorrow.  Precautions are already being completed, such as
moving ships out to sea to avoid being battered at port, coastal
evacuations, inland shelters being established and manned, and
positioning of emergency managers, utility repair workers, and Red Cross
personnel.  It's likely that many more evacuations will be made
mandatory by Wednesday morning.  Although Isabel has weakened a bit
recently, she still poses a very significant threat, in terms of winds,
storm surge, high surf, and rainfall.

NHC's forecast places landfall near Cape Lookout, NC on Thursday
mid-morning, then tracking inland over central VA and PA.  The passage
over VA is expected early Friday morning, and then midday Friday for
PA.  

Please visit my tropical Atlantic headquarters.

P.S.  The aircraft reconaissance data that we enjoy so much is something
we shouldn't take for granted.  First of all, the Atlantic basin is the
only one in the world with routine recon flights, thanks to both NOAA
and the US Air Force.  And this past Sunday, for the first time since
1989, there was a close call which thankfully didn't result in an
accident.  As Pete Black of the NHC describes, "While climbing back to
altitude on Sunday after the second stepped descent, less than a minute
after the 200 ft run, the inboard engine on the right side flamed out
with two small exhaust explosions, and had to be shut down. Thank God
the aircraft was back to 1500 ft at the time and that it was late in the
flight, as the aircraft was able to continue climbing to safe altitude
and return to St Croix, where they were greeted by the airport fire
department lining the field after the aircraft commander declared an
emergency."  The plane and all crew returned safely, but not without a
bit of a scare.

15 September 2003

More 2003 Hurricane Season Fun Trivia

From Phil Klotzbach:

We have now had 14 IHD this season.  This ranks us 4th all-time for IHD since 1950.  2003 now trails only 1961, 1950 and 1999 for intense hurricane days.  Since we will likely get 2-3 more IHD for Isabel, that will pass us by both 1999 and 1950 leaving us behind only 1961 which had a whopping 20.75 intense hurricane days.

We have also had 12.75 IHD during September.  This ranks us 2nd all-time for IHD since 1950.  2003 now only trails 1961 which had 15.75 IHD.  We will likely be very close to passing 1961 by the time Isabel makes landfall. 
This is the first time since 1900 that we have had two intense hurricanes that have each lasted longer than 6 intense hurricane days (Fabian and Isabel). 
Our seasonal NTC is already up to 115.

Please visit my tropical Atlantic headquarters.

Isabel still a CAT4, bypassing the Bahamas...

Since Saturday's update, not too much has changed.  Isabel remains a
powerful CAT4 hurricane, and has been slowly tracking WNW.  For quite a
while, she achieved a large eye and broad symetric eyewall, in a
configuration known as an annular hurricane.  She's now departing from
that stable configuration, and the cloud tops are cooling as asymetries
lead to pockets of deeper convection in the eyewall.  Although this
means slight weakening in the near future, it opens the door for future
intensification.  SSTs will continue to be plenty warm (~29C), and shear
is becoming more noticable, but should decrease again over the next
couple days.

At 15Z today, Isabel was located at 25.2N 69.4W and tracking WNW at 7kts
(this is about 6 degrees due east of Eleuthera Island, Bahamas). 
Intensity has fallen a bit to 120kts and 945mb.  She has already
accumulated 7.25 Intense Hurricane Days, and several more are most
likely in her future.

U.S. landfall is not out of the question, and it appears that NC (Cape
Lookout to Cape Hatteras area) will receive the initial hit, then she is
forecast to track inland over eastern VA and central PA.  Conditions
could be favorable enough for Isabel to hit eastern NC as a major
hurricane on Thursday morning.  All coastal residents should be
monitoring this storm very closely.  Inland flooding is always a huge
concern with landfalling hurricanes, and with central PA lying right
along the forecast track, the flooding situation already in place in
eastern PA could be severely aggravated toward the end of the week. 


Please visit my tropical Atlantic headquarters.

13 September 2003

Isabel drops to CAT4, but possibly reintensifying...

At 09Z today, intensity was dropped to 130kts, or just below the CAT5
threshold.  This could have been caused by Fabian's cool wake and/or by another
eyewall replacement cycle.  However, all imagery now shows a trend toward
becoming more intense and symetric.  At this strength, oscillations in intensity
are very typical, and wind fluctuations of ±15kts will continue to happen.

As of 15Z, Isabel was located at 22.2N 61.5W and tracking W at 9kts.  Maximum
sustained winds are 130kts with a MSLP of 935mb.  Another aircraft is in the
storm as I type this, and will give in-situ obs for the 21Z advisory.  She is
forecast to remain an intense hurricane at least for another 5 days as she
approaches the US east coast.  The question will be... where along the coast
will she hit, or will she recurve just shy of it?  The date of a potential
landfall looks be approx next Friday (9/19), but that's still 6 days out and
models are not all that reliable so far out.


Please visit my tropical Atlantic headquarters.

12 September 2003

Isabel becomes a CAT5 hurricane...

At 21Z yesterday, Isabel became the first Category 5 hurricane in the
Atlantic since Mitch 1998.  A few hours after reaching this level, she
underwent an eyewall replacement cycle and now has a larger eye, still
clear, and showing some wonderful features (mesovortices) as described
in http://einstein.atmos.colostate.edu/~mcnoldy/papers/KMS2002_MWR.pdf 
(coincidentally, Hurricane Erin '01 also had some beautiful mesovortices
in her eye on 9/11)

At 15Z today, Isabel was located at 21.6N 57.8W and tracking slowly W at
8kts.  Intensity is 140kts and 924mb.  NHC's forecast does not keep her
at CAT5 status, but rather just a bump down to 135kts (CAT4).  However,
keep in mind that a CAT5 is an extreme, and few forecasters are willing
to forecast extremes.  From this point on, aircraft will be flying the
storm to get in-situ intensity measurements; up until now, it's all been
satellite estimates.  I would not be surprised if the aircraft currently
in there finds a much lower pressure, perhaps 912mb or so.

Her track has shifted to due west now, and will be crossing over the
"remnants" of Fabian's cool wake Saturday afternoon, which could
temporarily disrupt the intensity.  However, on the west side of the
wake, SSTs are warmer than they are now, so rapid recovery is likely.

Given the ideal conditions, it's not impossible that Isabel could
accumulate a large number of hours as a CAT5.  Since 1947, there have
been only 20 hurricanes to reach CAT5 strength, and only 6 have lasted
longer than 24 hours as a CAT5.  It's very difficult for a storm to
maintain this intensity for very long because it pushes the envelope of
what our atmosphere can provide.  Any flaw in conditions such as
decreased SST, increased vertical shear, change in direction, etc
usually causes a drop in intensity.

Again, for some stunning 1-minute imagery of Isabel, visit
http://www.cira.colostate.edu/ramm/rmsdsol/RSOMAIN.HTML and hit the GOES
East Visible Floater Loop link.  This marks the 4th consecutive day of
GOES-12 SRSO on Isabel.  (GOES-12 is the satellite, and SRSO is Super
Rapid Scan Operations, meaning 1-minute imagery over a small predefined
area, such as a hurricane)


Please visit my tropical Atlantic headquarters.

11 September 2003

Isabel a very strong CAT4 hurricane...

Since this time yesterday, Isabel's MSLP has fallen and additional 18mb
and sustained winds have increased by 15kts.  After a brief period of
shear and internal reorganization, she has now taken on the most classic
of appearances, rivaling anything else in recent memory.  The outflow
channels are well-established, the eye is clear and hard-edged, and the
eyewall forms a thick symmetric band of -75C cloud tops.  As of 15Z
today, Hurricane Isabel was located at 21.4N 54.5W and tracking W at
8kts.  Intensity is 130kts and 930mb.  The CAT5 transition occurs at
140kts and about 920mb, so she's just borderline, and with SSTs of 28.3C
and increasing, it's not out of the realm of possibility over the next
couple days to see the basin's first CAT5 hurricane since Mitch '98.

Phil Klotzbach (CSU) reports the following: "As of the 15Z advisory
today, we have already had 8.75 IHD this month which puts us in a tie
for sixth place all-time with 1995.  The maximum number of IHD for
September is 15.75 set in 1961.  Isabel alone could very likely put us
at or very close to that record."

NHC's 5-day track forecast places her just northeast of the Bahamas by
Tuesday morning, and if she recurves into the US east coast, it would be
about 7-8 days from today... just something to keep a close eye on as
the days go by.

If you wish to be astounded with high resolution (1km spatial and 1min
temporal) visible satellite imagery from GOES-12, please visit
http://www.cira.colostate.edu/ramm/rmsdsol/RSOMAIN.HTML and click on the
GOES-EAST Visible Floater link.


Please visit my tropical Atlantic headquarters.

10 September 2003

Little change since yesterday...

Isabel is still a CAT4 hurricane and is making slow progress WNW toward
the Leeward Islands.  Intensity is still 115kts and the MSLP is 948mb. 
The interesting part will of course be her long-range track forecast. 
It appears that the Bahamas are under the gun in a week, then from there
it's even harder to predict.

TD14 has also changed little, and in fact is getting less organized. 
It's still very near the Cape Verde Islands and is losing its surface
circulation and deep convection.  Latest intensity is 25kts and 1010mb.


Please visit my tropical Atlantic headquarters.

09 September 2003

Isabel a CAT4 storm, TD14 struggles to organize...

Both Fabian and Henri have become extratropical and no longer have
advisories being written for them.

Isabel continues to get better organized and became a CAT 4 hurricane
today at 03Z.  She already has accumulated 1.25 Intense Hurricane Days
and isn't even to 50W yet.  As of 15Z, she was located at 19.6N 46.9W
and tracking WNW at 12kts.  Maximum sustained winds are up to 115kts and
the MSLP is down to 948mb. The outflow pattern remains very symmetric,
and the eye, although clouded over a bit this morning, is clearing and
small.

She's expected to strengthen even further, just shy of CAT5 status, and
keep a general west track, ending up a bit north of the Leeward Islands
during the weekend.  Although way too far out to say with any certainty,
a U.S. landfall is not out of the question and people living along the
coasts should keep an eye on Isabel in the coming 7-10 days.

TD14 is still near the Cape Verde Islands, but is poorly organized. 
Intensity estimates as of 15Z were 30kts and 1007mb.  Conditions appear
favorable for development, so it could become TS Juan today or tomorrow.


Please visit my tropical Atlantic headquarters.

08 September 2003

fun tidbits for current Atlantic storms

From Phil Klotzbach: 
 
Here are some fun facts that I've been looking at this morning.  As of 
today's 15Z advisory:

Fabian was classified as a hurricane until 49.8 degrees North... this is 
the farthest north that a system has been classified as a hurricane 
since Helene, 1988 (50.2N)

Fabian had 6.75 intense hurricane days, the most since Edouard (7.5 IHD) 
in 1996

Isabel became an intense hurricane at 42.6W... this is the farthest east 
that a storm has become an intense hurricane since Isaac (2000) which 
became intense at 35.0W

TD 14 just became a tropical depression at 22.1W... this is the farthest 
east that a storm has become a tropical depression since Alberto (2000) 
which became a TD at 18.0W

September has already had 5.75 IHD... this is the most IHD in September 
since 1999 and also puts it in a tie for 9th since 1950 with 1953, 1955 
and 1967.

The season has had 7 IHD which is also the most since 1999... this puts 
2003 in a tie with 1966 for the 15th most IHD since 1950

With Isabel likely accumulating 3 to 4 more IHD , we will likely be in 
the top 10 for seasonal IHD by September 10... not bad for halfway 
through the season!


Please visit my tropical Atlantic headquarters.

Fabian becomes extratropical, Henri still barely hanging on, Isabel becomes major hurricane, TD14 forms in far east Atlantic...

Although still packing hurricane-force winds, Fabian has enough
extratropical characteristics to officially drop him as a tropical
cyclone.  These include a lack of centralized deep convection, cold-core
aloft, and a front extending southward from the Low.  He will remain a
very powerful extratropical cyclone in the north central Atlantic, and
influencing Greenland, Iceland, and major shipping lanes.  The last
advisory placed him at 49.8N 39.2W and zipping off to the NE at 34kts. 
Intensity was estimated at 65kts and 980mb.  Fabian accumulated 11 Named
Storm Days, 10 Hurricane Days, and 6.5 Intense Hurricane Days.

TD Henri is very disorganized, yet refuses to dissipate.  Shear from an
advancing frontal boundary will soon destroy the system and it will
merge with the front.  At 15Z, TD Henri was located at 32.7N 75.6W and
moving NE at 7kts.  Winds are 30kts and the MSLP is 1006mb.  I suspect
any mention of him tomorrow will be in the form of an obituary.

Hurricane Isabel continues to rapidly intensify, and is now the second
major hurricane of the season.  She reached CAT3 status at 15Z today at
17.2N 42.6W.  This is VERY far east to reach major hurricane status, and
she is forecast to reach CAT4 status by this evening.  The MSLP fell
25mb in the previous 24 hour period, and 43mb in the past 48 hours. 
Intensity as of 15Z was 100kts and 962mb.  The track forecast will take
her just north of the Lesser Antilles by the weekend.  Considering the
location, motion, and intensity, the number of Intense Hurricane Days
this season could easily be doubled by Isabel. (as an aside, the average
number of IHD is 4.7; in 2002 there were 2.5, this year we could hit
15!)

At 15Z today, the tropical wave I first mentioned on Saturday has been
upgraded to TD14... the amazing part is how far EAST it made this step! 
It was located at 11.8N 22.1W and drifting W at 3kts.  22.1W is still
east of the Cape Verde Islands!!  Notice however, that both Isabel and
TD14 were nearly stalled as they exited Africa, giving them time to
fester before heading west; this gives them the edge on developing
abnormally far east.  It is expected to become TS Juan later today, but
the track will most likely not follow Fabian and Isabel, but rather
recurve early, perhaps by 40W.  He could become a hurricane by mid-week,
not affecting any land.

Remember, September 10 is the climatological peak of the entire season,
with a sharp increase in activity as we approach that date, so this
queue of 3 named storms we've been maintaining is helping to reinforce
the climatological records!


Please visit my tropical Atlantic headquarters.

07 September 2003

Fabian STILL a hurricane, Henri nearly a TS again, Isabel now a hurricane, tropical wave nearing Depression status...

Fabian is now at 11 Named Storm Days (as well as 10 Hurricane Days and 6.5
Intense Hurricane Days) and is still a tropical cyclone, but the extratropical
transition is beginning as evident by a frontal structure forming on the
southeast end of the Low.  This will almost certainly be the last update with
Fabian as a hurricane, and the last with him as a purely tropical system.  At
21Z, Hurricane Fabian was at 43.4N 49.3W and tracking NE at 27kts (the forward
speed is due to the impeding trough).  Winds are still 75kts and the central
pressure is up to 972mb.  Toward the middle part of this week, Fabian could make
a powerful impact on southern Greenland.

TD Henri has made very little progess over the past 24 hours, and is still very
disorganized.  The official forecast calls for him reach TS status again, but
shear could hinder that from ever happening.  The 21Z position and intensity are
31.6N 77.6W and 30kts.  He should keep heading NE away from the US mainland.

Isabel has very rapidly organized and is now a hurricane.  The MSLP fell 18mb in
the 24 hours ending at 15Z today.  As of 21Z she was at 15.2N 39.1W and tracking
WNW at 13kts.  Maximum sustained winds have increased to 70kts and the MSLP has
fallen to 984mb.  The forecast is for continued strengthening, becoming a major
hurricane by Tuesday afternoon, and the track should closely follow in Fabian's
footsteps when he was near the Lesser Antilles.  She does have an eye and
sustained cloud tops colder than -70C, along with symmetric outflow.

The easterly wave in the east Atlantic I've been mentioning is getting better
organized every day and appears to be very close to becoming a Depression.  The
1010mb Low is located at approx 12N 22W and drifting slowly W at 5kts, much like
Isabel did (notice how far east this is though!!).  There is an elongated
surface circulation as seen by SeaWinds, and persistent deep convection, and a
more symmetric mid-level circulation.  This could become TD14 today or tomorrow,
then TS Juan either tomorrow or Tuesday.


Please visit my tropical Atlantic headquarters.

06 September 2003

Fabian hit Bermuda, Henri hit Florida, TS Isabel forms in the deep tropics...

Fabian made nearly a direct hit on Bermuda Friday afternoon at about 5pm EDT as
a strong CAT3 hurricane.  The center actually passed just west of them, giving
the tiny island the worst possible conditions for the longest possible time. 
Preliminary reports indicate widespread damage and four deaths.  As of 21Z
today, Hurricane Fabian is still very strong at 95kts and 960mb.  He was located
at 37.5N 59.3W and tracking NE at 20kts.  He is not forecast to begin the
extratropical transition until Monday morning, giving him more time to rack up
Named Storm Days and Hurricane Days.  He ended up accumulating 6.5 Intense
Hurricane Days.

TS Henri made landfall near Tampa, FL Friday afternoon (9/5) at about 7pm EDT as
a disorganized Tropical Depression, but has since exited the peninsula and is
back over open water... forecast to reintensify to a minimal TS again.  The
satellite presentation was very poor on Friday evening, but is slowly getting
better organized.  As of 21Z, he was at 29.4N 79.7W (80mi east of Daytona Beach)
and tracking ENE at 15kts.  Maximum sustained winds are 30kts and the MSLP is
1007mb.  

At 09Z today, the tropical wave I've been mentioning since this past Tuesday was
upgraded directly to Tropical Storm Isabel, the 9th named storm of the season. 
In contrast to Henri, Isabel's satellite presentation is remarkable.  She was
located at 13.4N 35.4W as of 21Z today.  Intensity was 45kts and 1000mb.  The
NHC forecast is for continued strengthening, reaching hurricane status by Monday
morning, and tracking toward the northern Lesser Antilles later this week.

Elsewhere, a new and impressive tropical wave has just exited the African coast
and is presently at about 12N 20W and tracking W at 7kts.  Given the favorable
conditions and present appearance, it seems likely this 1010mb Low will organize
and become TD14/Juan in the near future.


Please visit my tropical Atlantic headquarters.

05 September 2003

Fabian nearly at Bermuda, TD12 becomes TS Henri, and Cape Verde wave getting better organized...

As of 15Z today, Hurricane Fabian is still a major hurricane, and just
95 nautical miles south of Bermuda.  At its distance and speed, landfall
will occur by 6pm EDT today as a major hurricane.  Needless to say, the
Hurricane Warning is still in effect for Bermuda.  Latest position was
30.8N 65.4W and tracking N at 15kts.  Intensity is 105kts and 951mb.  It
is expected to continue north making a direct hit on Bermuda later today
with sustained winds of 105kts and gusts to 130kts.  They are
anticipating up to 10" of rain and 10' storm surge.  Winds are already
affecting the island and taking down tree limbs.

The northeast quadrant of the storm could have hurricane-force winds
extending 100 nautical miles from the center.  Shortly after passing by
Bermuda, the mid-latitude trough will pick it up and shear it apart, and
the extra-tropical transition will commence.  Fabian has now racked up
5.75 Intense Hurricane Days, and will tie 3rd place in the record books
at 21Z today, just as he's hitting Bermuda.

At 09Z today, TD12 was upgraded to TS Henri, the 7th named storm of the
season.  At 15Z, Henri (pronounced ahn-ree, not hen-ree... it's a
spanish name) was located at 28.3N 83.9W and moving at 7kts.  Aircraft
recon indicates max winds of 40kts now, and a MSLP of 997mb. 
Southwesterly vertical shear will probably inhibit much further
intensification as he drifts toward the Florida coast today.  Landfall
is expected very late tonight into the early morning hours of Saturday
as a Tropical Storm.  A TS Warning is in effect from Englewood to the
Aucilla River.  Given that he'll be over land and in some shear, the
forecast for maintaining intensity then weakening by the end of the
weekend.  You can monitor the progress of Henri as he approaches the
coast from Tallahassee's radar
(http://www.srh.noaa.gov/radar/latest/DS.p20-r/si.ktlh.shtml) or Tampa's
radar (http://www.srh.noaa.gov/radar/latest/DS.p20-r/si.ktbw.shtml).

The tropical wave I've been mentioning for the past 4 days or so
continues to head west and get better organized.  It's now at about 13N
29W, or 400 miles WSW of the Cape Verdes and tracking W at 7kts.  The
embedded Low is now down to 1009mb and development into TD13 is likely
today.  The satellite presentation in both IR and VIS is rather
impressive, and an active microwave scatterometer (SeaWinds) did find a
closed but elongated surface circulation during a 08Z overpass. 
Although the models favor this system, the location of the subtropical
High is pretty far east, so any Cape Verde storms that do form will be
recurved like Fabian, if not sooner.


Please visit my tropical Atlantic headquarters.

04 September 2003

Fabian still a major hurricane, TD12 forms, eastern Atlantic very interesting...

As of 15Z today, Hurricane Fabian has accumulated 4.75 Intense Hurricane
Days.  Previous record holders are Gert '99 (6), Edouard '96 (7.5), and
Luis '95 (8).  It seems probable that Fabian will surpass Gert, but
probably not Edouard or Luis, leaving him in third place.  For
comparison, there were a TOTAL of 2.5 Intense Hurricane Days during the
entire 2002 season.

Also as of 15Z, Fabian was located at 25.2N 64.0W and tracking NNW at
10kts.  The eye is 25nm in diameter now, and intensity is 105kts and
944mb.  Some fluctuations in intensity are likely as he begins the
recurvature process, then significant weakening once he interacts with
the approaching trough.  A Hurricane Warning is in effect for Bermuda;
they are anticipating a direct hit on Friday evening with sustained
winds of 110kts and gusts to 135kts.  Very large swells from this storm
should begin reaching the US east coast later today and Friday.

After passing Bermuda, Fabian will interact with a trough and make the
extra-tropical transition, losing his tropical characteristics and
zipping off to the north central Atlantic.  Baroclinic enhancement can
sometimes temporarily intensity the storm, but at the same time, its
demise is never far behind.

At 21Z yesterday, TD12 formed in the eastern Gulf from that area of
disturbed weather I'd been talking about for a few days.  Although still
poorly organized, it's nearly stationary and in very favorable
conditions, likely leading to further development.  At 15Z today, TD12
was at 27.9N 87.1W and has 30kt sustained winds and a 1010mb MSLP.  It
is forecast to become a named storm early Friday as it drifts northeast
toward the FL panhandle.  A Tropical Storm Warning is in effect from
Englewood to Indian Pass, FL and landfall is expected to hit early
Saturday morning.  Should this get named, its name will be Henri.

The tropical wave I mentioned yesterday near the Cape Verde Islands is
still there and still a candidate for development.  It's at about 12N
27W and has a 1010mb Low that's tracking very slowly westward.  The next
number/name on deck is 13/Isabel (assuming TD12 goes to Henri).


Please visit my tropical Atlantic headquarters.

03 September 2003

Fabian still maintaining intensity...

As of 15Z today, Hurricane Fabian was located at 22.4N 62.7W and
tracking NW at 8kts.  Maximum sustained winds are 115kts and the MSLP is
945mb.  The forecast is for very gradual weakening and a recurve close
to Bermuda.  It is likely that Bermuda will experience the worst part of
the storm Friday afternoon into early Saturday morning.

During the night, it appears that the storm underwent an eyewall
replacement cycle.  A clear eye was distorted/missing for several hours
and now the eye that's present is noticeably larger.  It's very common
for intense hurricanes to undergo these eyewall replacement cycles; it's
merely the storm's way of reorganizing itself to maximize efficiency
(smart little critters).  The new eye is about 30 nautical miles in
diameter (55km) rather than the 20nm eye it had yesterday.

The area of disturbed weather I mentioned near the Yucatan is now in the
eastern Gulf and although not terribly well organized at the moment,
conditions are favorable so it's still an area of interest.

The easterly wave near the Cape Verde Islands continues to slowly get
better organized and is presently at about 12N 23W.  It has a 1008mb Low
embedded in it.  There's also an easterly wave to its west at about 14N
35W which is tracking W at 5kts.  These two are close enough to possibly
merge into a single vorticity center, as some computer models indicate.


Please visit my tropical Atlantic headquarters.

02 September 2003

Fabian still a CAT4 hurricane...

Hurricane Fabian's intensity has changed little in the past 48 hours,
and is still a Category 4 storm (with 3.0 Intense Hurricane Days racked
up so far).  The eye is very small at 20 nautical miles in diameter, and
there is some evidence of slight westerly vertical wind shear.

At 15Z today, Fabian was located at 20.3N 60.4W and tracking WNW at
9kts.  Intensity is 120kts and 945mb.  It is expected to slowly weaken
over the next few days, but still be a major hurricane.  The forecast
track has remained basically unchanged, still recurving just west of
Bermuda.  I suspect Bermuda will be in for a rough ride on Friday
especially if it ends up on the front-right quadrant of a major
hurricane.

The area of disturbed weather I mentioned yesterday in the western
Caribbean has lost much of its deep convection, but the broad
circulation is still present and conditions are favorable for
development... assuming convection comes back.

There is a new Low that formed within a tropical wave west of the Cape
Verde Islands at about 14N 33W.  It has made some progress today in
organization and will be watched this week for development.


Please visit my tropical Atlantic headquarters.