03 December 2004

2004 Tropical Atlantic Activity Summary

The 2004 hurricane season is over, so it is time for my annual Season Summary. I sent out about 60 updates to this mailing list (which I’m proud to say has grown from about 4 subscribers in 1996 to 270 subscribers in 2004, not to mention the updates being posted on several websites) over the past 4 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) Statistics and Storm Summaries, and 4) Landfall.
Thanks to the National Hurricane Center and Unisys Weather for the data, and a special thanks to Jonathan Vigh and Phil Klotzbach at CSU for valuable discussion and assistance throughout the season. The data presented here are the most current available to me, but could be altered in the post-season timeframe as more information becomes available.

1. Saffir-Simpson Scale of Tropical Cyclone Intensity

Depression        < 35          N/A
Tropical Storm   35-63          N/A
1                64-82        > 980
2                83-95        965-979
3               96-113        945-964
4              114-135        920-944
5                > 135        < 919

2. Lifetimes and Intensities

NAME      ACTIVE            VMAX (kts) MSLP (mb)

ALEX      31 JUL – 06 AUG     105       957 (N,H,M)
BONNIE    03 AUG – 12 AUG      55      1001 (N)
CHARLEY   09 AUG – 15 AUG     130       941 (N,H,M)
DANIELLE  13 AUG – 21 AUG      95       964 (N,H)
EARL      13 AUG – 16 AUG      45      1009 (N)
FRANCES   25 AUG – 07 SEP     125       935 (N,H,M)
GASTON    27 AUG – 01 SEP      65       985 (N,H)
HERMINE   29 AUG – 31 AUG      50      1002 (N)
IVAN      02 SEP – 24 SEP     145       910 (N,H,M)
TD 10     07 SEP – 09 SEP      30      1009
JEANNE    13 SEP – 27 SEP     105       950 (N,H,M)
KARL      16 SEP – 24 SEP     120       938 (N,H,M)
LISA      19 SEP – 03 OCT      65       987 (N)
MATTHEW   08 OCT – 10 OCT      40       997 (N)
NICOLE    10 OCT – 11 OCT      45       988 (N)
OTTO      30 NOV – 02 DEC      45       993 (N)

In the previous chart, the N, H, and M denote what statistic they contributed to; Named storm (TS+), Hurricane (CAT1+), Major hurricane (CAT3+). VMAX is the maximum sustained wind speed and MSLP is the minimum sea-level pressure, both at peak intensity.
3. Statistics and Storm Summaries


Named Storm Days refers to the number of days during which a storm with 35kt+ winds was present. If there are two named storms active during a given day, 2 NSD are accrued, etc. The Hurricane Days value is similar but for storms with 65kt+ winds, and Major Hurricanes Days is for storms with winds 100kt+.

NTC is the Net Tropical Cyclone activity, which is a benchmark that combines the number of storms and the longevity of them (all 12 of the parameters in the table above). The climatological values used here are for the 1950-2000 timeframe. You can learn more about NTC and compare this season to recent past seasons at

A fairly unique aspect of the past season was the late start and early end to the activity. Nearly all of the active portion of the season fit in 10 consecutive weeks, but those 10 weeks were extremely active. Alex formed on 31 July which is the latest formation date since 2000. The outlier was Otto which formed on the last day of the official hurricane season, 30 November. Otto also dissipated on 2 December, after the official end of the season. Three of the past four years have had activity beyond the end of the season.

Following Mitch in October 1998 and Isabel in 2003, Hurricane Ivan joined the ranks of recent Category 5 hurricanes in the Atlantic. Hurricane Ivan was not only a CAT5 storm, but maintained that intensity for a total of 60 hours. Even more noteworthy is that it set the all-time Atlantic record for time spent as a major hurricane at 240 hours (old record was set in 1926 at 222 hours).

Two of the six intense hurricanes (Frances and Ivan) were also notable because they maintained that intensity for so long. Frances contributed 7.25 Intense Hurricane Days, and Ivan contributed 10.00. Combined, Frances and Ivan were the longest-lived intense hurricanes to ever stir up the Atlantic basin with a total of 414 hours and comprised 49% of the season’s NTC.

The NTC reached an amazing 233.1% of the climatological mean, i.e., this season was 2.3 times more active than the "normal" season. If this sounds like a lot, it IS. 2004 had the highest NTC in recorded history, surpassing the amazing years of 1950, 1926, 1995, and 1933.

Here is a brief summary of the individual storms:

Alex formed off the northeast FL coast and headed north along the coast toward the Outer Banks of NC where it reached its peak intensity and caused some damage, although the center of the eye technically never passed over land. It was the strongest hurricane in the Atlantic north of 38°.

Bonnie began as a tropical wave that organized into a Depression, but fell apart for a few days, finally regenerating north of the Yucatan peninsula. The weak Tropical Storm hit the Florida peninsula on August 12 and caused minimal damage.

Charley formed from a tropical wave near Trinidad, then continued through the Caribbean. It passed around Jamiaca and directly over Cuba. It then rapidly intensified only a few hours before making landfall on the Florida peninsula in Charlotte Harbor to a compact Category 4 hurricane. The central pressure fell 24mb in the 6 hours prior to landfall, one of the most rapid falls ever. It crossed directly over Orlando and Daytona Beach, exited over the Atlantic, then hit the NC/SC border, and exited into the Atlantic again, only to hit Long Island, NY before dissipating near Nova Scotia. Charley was the first major hurricane to strike Florida since 1995 and the strongest to strike Florida since 1992. This was also the second costliest hurricane in US history, only behind Andrew 1992.

Danielle formed from a tropical wave very far east… at 23°W. This was the further east that a tropical storm has existed since Alberto in 2000. It recurved very early (by 41°W) and dissipated over open water.

Earl also developed from a tropical wave. It formed rather far south (9°N) and was also moving very quickly to the west. This rapid motion inhibited forming a closed Low and it degenerated to an open wave in the central Caribbean.

Frances was the fifth storm with tropical wave origins, and formed at 36°W. It quickly intensified to a hurricane and major hurricane and tracked over the northern Bahama islands. It made two US landfalls: as a CAT2 near Stuart, FL and as a TS near St. Marks, FL.

Gaston had origins similar to Alex; a Low off the northeast Florida coast. It meandered slowly for a few days, then hit SC as a minimal hurricane, dissipated inland and then reintensified off the Delmarva peninsula before heading out into the open ocean.

Hermine was the third system with non-tropical origins, forming in the mid-latitudes west of Bermuda. It tracked due north and made landfall in MA, but with minimal damage.

Ivan was a classic and infamous hurricane with tropical wave origins. It formed at 29°W and tracked along the southern periphery of the basin, gradually gaining strength as time progressed. It passed directly over Grenada, destroying 80-90% of the structures on the island. It then passed very near Jamaica, the Cayman Islands, and western Cuba. It made US landfall at Palm Shores, AL. The death toll between Grenada, Jamaica, Caymans, Cuba, and the US is over 100. Ivan was the longest-lived major hurricane in Atlantic history (10 days), and had the lowest central pressure (910mb) since Mitch 1998 (905mb).

Jeanne was another remarkable hurricane with tropical wave origins. It formed near Guadeloupe and tracked over Puerto Rico and then stalled over Hispaniola, causing immense flooding problems, completely burying entire communities under mudslides and making it the deadliest storm of the season by far. It eventually moved away from the island and headed north, doing a clockwise loop and heading toward the US. Like Frances, it passed over the northern Bahama islands and made US landfall near Stuart, FL.

Karl was the 8th storm with tropical origins, although it followed an irregular track. It formed at 33°W and recurved by 49°W, taking a course almost due north through the basin. Under nearly ideal conditions, it strengthened to a CAT4 storm and eventually became extratropical in the far north central Atlantic.

Lisa formed from the wave immediately behind Karl, and was never far behind. The track was nearly identical too. However, being the smaller and later to form, Lisa was always suppressed by Karl’s strong outflow.

Matthew was the 4th system to form in the mid latitudes. It formed from a Low in the Bay of Campeche and became a Depression in the central Gulf of Mexico. Under strong vertical wind shear, it never got well organized before making landfall in central LA and dissipating inland.

Nicole was never truly tropical, but was a sub-tropical storm. It formed near Bermuda and headed northeast for a short time before becoming completely extratropical.

Lastly, Otto formed in the north central part of the basin very late in the season. It began as an extratropical Low that gradually acquired tropical characteristics.

Of the 15 named storms, 9 had tropical wave origins, and 6 had extratropical or subtropical origins.

4. Landfall

There were eight landfalling storms this year... all of which made landfall on the U.S. There were two major hurricane landfalls in Florida… the last U.S. major landfall before this year was Bret in 1999, and the last time TWO major hurricanes made Florida landfall in the same year was 1950. The last time there were 8 landfalling named storms was 1916. Of the 10 costliest hurricanes to hit the US, 2004 is responsible for 4 of them, and all 4 rank in the top 6 (Andrew ’92 and Hugo ’89 are in there too).

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). A row in italics means there was not a direct hit, but close enough to cause damage.


ALEX         8/3  1700   85  near Cape Hatteras, NC, USA (1 death, $5 million)
BONNIE       8/4  1000   30  St. Lucia, Windward Islands
            8/12  1500   45  Apalachicola, FL, USA (3 deaths)
CHARLEY     8/12  0300   65  near Jamaica (1 death)
8/13  0400   90  Guira de Melena, La Habana, Cuba (4 deaths)
            8/13  2000   70  Punta Gorda, FL, USA (30 deaths, $14 billion)
            8/14  1400   70  Cape Romain, SC, USA
            8/14  1600   65  Myrtle Beach, SC, USA
            8/15  0900   35  Fire Island, NY, USA (1 death)
FRANCES      9/3  0900  105  Eleuthera, Bahamas (extensive)
             9/4  0600   90  Grand Bahama, Bahamas (extensive)
             9/5  0500   90  Stuart, FL, USA (33 deaths, $9 billion)
             9/6  1800   55  St. Marks, FL, USA
GASTON      8/29  1300   65  Awendaw, SC, USA ($130 million)
HERMINE     8/31  0600   35  New Bedford, MA, USA
IVAN         9/7  2000  105  Grenada, Windward Islands (40 deaths, extensive)
            9/11  0300  135  near Jamaica (19 deaths, extensive)
            9/12  1200  135  near Grand Cayman (extensive) ~10 deaths
            9/13  2100  140  near Cabo San Antonio, Pinar Del Rio, Cuba(extensive)
            9/16  0700  115  Gulf Shores, AL, USA (52 deaths, $12 billion)
            9/24  0000   40  Lake Charles, LA, USA
JEANNE      9/14  0400   30  Guadeloupe, Leeward Islands
            9/15  1600   60  Puerto Rico, USA (2 deaths, $200 million)
            9/16  1100   70  Dominican Republic & Haiti (3000+ deaths, extensive)
            9/18  1200   40  Great Inagua, Bahamas (extensive)
            9/25  1200  100  Great Abaco, Bahamas (9 deaths, extensive)
            9/26  0400  105  Stuart, FL, USA (9 deaths, $7 billion)
            9/27  0300   45  St. Marks, FL, USA
MATTHEW    10/10  1100   35  Houma, LA, USA

Hurricane Season 2005 begins June 1; the first names in the lineup are Arlene, Bret, and Cindy. New names for the season are Franklin and Lee, which replace Floyd and Lenny whose names were retired in 1999. As an aside, there will likely be several new names in the 2010 list because of the death and devastation caused by so many of this year’s storms (namely Charley, Frances, Ivan, and Jeanne).

Please visit my tropical Atlantic headquarters.

01 December 2004

Otto weakening...

Convection near the center of the circulation is much weaker today, and
less symmetric.  TS Otto reached a peak intensity around 09Z today at
45kts and 993mb, but has since weakened to 35kts and 999mb.  It has been
drifting to the east to southeast at about 5kts. 

Three of the last four years have gone into "overtime", or post-season
activity.  The storms in recent history that have been active past
November 30 are Olga '01, Odette '03, Peter '03, and Otto '04. 
Something magical about the "O" storms in December??

As I mentioned about two weeks ago, Gaston was officially upgraded to a
hurricane prior to landfall, and that increase in the number of
hurricanes was enough to nudge 2004 into first place in terms of NTC
(Net Tropical Cyclone activity).  Before Otto, NTC was 230.8%, and as of
the 21Z advisory today, the NTC is 232.9%... breaking the old record of
229.6% set back in 1950 by an even larger margin.  Keep in mind that
100% is a climatologically average season.

Once Otto dissipates, I will send out my season summary, done in the
same fashion since 1996!

Please visit my tropical Atlantic headquarters.

30 November 2004

Otto forms in the central Atlantic...

On the last day of the official hurricane season, Tropical Storm Otto
formed in the north central part of the basin, about 800 miles east of
Bermuda.  It began several days ago as an upper Low which transitioned
to a surface Low, gradually acquiring subtropical characteristics, and
over the last couple of days acquired tropical characterisitics.  i.e.,
relatively deep and persistent convection near the center of the
circulation and a warm core aloft.  This is the 15th named storm of the

At 21Z today, Otto was located at 31.8N 51.0W and tracking N at 4kts. 
Satellite-estimated intensity is 40kts and 997mb.  Over the next 2-3
days, the storm is forecast to drift to the east and slowly weaken in
the face of increasing vertical wind shear.

Please visit my tropical Atlantic headquarters.

19 November 2004

Gaston upgraded to a hurricane...

No, I'm not living in the past, but post-analysis of radar and surface
observations of Tropical Storm Gaston indicate that indeed it was a 65kt
hurricane just prior to landfall in SC on 29 August.  This brings the
season up to 9 hurricanes -- 6 of which made it to CAT3 or higher.
I attached a radar image of Gaston at landfall.

With this, 2004 has just become the most active season in the Atlantic
since 1900, in terms of NTC (Net Tropical Cyclone activity).  This
quantity is a function of numbers of storms and longevity of them.  The
percentages are relative to a climatological average season (100%).

2004: 230.8%
1950: 229.6%
1926: 228.6%
1995: 221.9%
1933: 216.5%

As I've done for the past 8 years, I'll be sending out a season summary
when the season is officially over in 12 days.  There are certainly
plenty of interesting and record-setting characteristics of 2004.

Please visit my tropical Atlantic headquarters.

11 October 2004

Matthew makes landfall, Nicole forms and passes by Bermuda...

Matthew, the storm that formed in the Gulf on Friday afternoon, was slow
to get organized, and hovered at the Depression/Storm boundary during
the entire northward trek toward the Gulf coast.  At 12Z on Sunday, TS
Matthew made landfall as a poorly organized storm near Houma, LA, 40
miles west of New Orleans.  It dumped about a foot of rain on LA and MS,
causing severe flooding, before dissipating inland.  This storm brought
the season's NTC up to 225.2%, still in third place behind 1926 and

Then on Sunday morning at 09Z, an area of interest near Bermuda for many
days was upgraded to Subtropical Storm Nicole.  Although it does receive
a name (a new convention started in 2002), a subtropical system is
fundamentally different from a tropical one... best described as a
hybrid between a tropical and extratropical storm.  The closest approach
to Bermuda was 55 miles, and did give the island a bit of inclement
weather, but I haven't heard of any damage reports.  Nicole never
transitioned to purely tropical, and is now extratropical.  Whether or
not Nicole will count toward NTC is still being debated, but if so, the
new value would be 227.5%.

Elsewhere in the basin, vertical wind shear dominates and will keep
things quiet for a while.  The next number/name on deck is 17/Otto.

Please visit my tropical Atlantic headquarters.

08 October 2004

Matthew forms in the Gulf of Mexico...

After several days of slow "brewing", a large area of disturbed weather
in the Bay of Campeche was upgraded to TS Matthew based on an aircraft
recon flight into it today.  This is the 13th named storm of the
season.  The center was at 24.2N 93.8W and tracking E at 9kts.  The
maximum sustained winds are 35kts and the MSLP is 1001mb.

The forecast is tricky because of its proximity to a large mid-latitude
trough that is imposing hefty vertical shear over it.  It should
maintain intensity or perhaps strengthen a bit (thanks to baroclinic
enhancement) as it heads generally NE, probably hitting the Florida
panhandle late Sunday night.

For those who have an interest in keeping track of NTC (Net Tropical
Cyclone activity), the season is up to 224.8% as of 21Z today... still
3rd place overall since 1900.

Please visit my tropical Atlantic headquarters.

01 October 2004

Lisa becomes a hurricane...

After nearly 10 full days as a Tropical Storm, Lisa was finally upgraded
to a minimal hurricane at 21Z today, the 8th of the season.  This
upgrade was based solely on satellite appearance, which has become more
symmetric and convective the past few hours.  Current position is 38.4N
45.1W and tracking NE at 19kts.  She will soon become a strong
extratropical cyclone and that will be the end of this long-lived
storm.  Intensity is estimated at 65kts and 987mb, but should quickly
deteriorate as she heads north.

In terms of NTC (Net Tropical Cyclone activity), 2004 has now beat 1961,
1933, and 1995 with a value of 222.3%.  The years remaining in second
place are 1926 (229%) and in first place 1950 (230%).  But the key to
remember is that there are still two more months until the hurricane
season offically ends, so the all-time NTC record could fall this year.

Please visit my tropical Atlantic headquarters.

28 September 2004

Jeanne drenching the eastern seaboard, Lisa still a TS...

So far 9 deaths have been blamed on Jeanne in the US, and about 1500 in
Haiti and Dominican Republic (with 900+ still missing).  Although not
producing tornadoes as prolifically as Ivan did, Jeanne has produced a
few, but the main story is RAIN... 1-2 feet at places.  Heavy rain over
the same areas that saw rain from Charley, Frances, and Ivan.

Of the big landfalls this year, Jeanne has been the least deadly in the
US, but the most deadly overall.  Charley, Frances, and Ivan were
responsible for 82 US fatalities combined.  Sadly, some long-dead are
coming back to the surface too; the rain-soaked earth in the southeast
is letting buried coffins in cemetaries come to the surface, creating a
rather unpleasant clean-up job.  The worst of the weather associated
with Jeanne is now hitting MD, PA, NJ, and NY, where Tornado and Flood
Watches/Warnings cover those states.

Despite forecasters' urge to strengthen the storm, Lisa has remained a
strongly-sheared Tropical Storm, no threat to land.  The convection has
been displaced from the low-level center for days now, so until that
corrects itself, it will not be able to intensity much, if at all.  At
15Z, TS Lisa was located at 25.0N 47.1W and moving N at 10kts. 
Satellite-estimated intensity is 45kts and 1000mb.

Elsewhere, there is a tropical wave at about 30W that is not very well
organized at the moment, but should be watched for development over the
next few days.  A couple of reliable computer models favor it, while the
rest do not.

As of this afternoon, the season's NTC (Net Tropical Cyclone activity)
is 218%.  In other words, this measure shows that more than twice the
activity of an entire average season has already occured.  This puts
2004 in 4th place since 1900, only behind 1995 (222%), 1926 (229%), and
1950 (230%).  Two more months until the official end of hurricane
season.  A remarkable facet of this season is that out of the 7
hurricanes we've had, 6 of them have made it to CAT3 or higher.  On top
of that, they have generally maintained that intensity for 1.8x longer
than the typical major hurricane.

Please visit my tropical Atlantic headquarters.

26 September 2004

Jeanne slams Florida, Lisa still no threat to land...

At about midnight local time, Jeanne made landfall near Port St. Lucie, FL as a 100kt CAT3 hurricane, very close to where CAT2 Hurricane Frances made landfall three weeks prior.  I attached a radar image from landfall as seen from the Melbourne radar.

Jeanne has since moved inland across the peninsula and will move over the panhandle later tonight.  It's too early to get an idea of the damage, but from the preliminary reports, it sounds very severe.  It is now a weakening 55kt Tropical Storm and the central Low pressure will continue to fill as it tracks northward over the southeast US states.

Lisa remains poorly organized, and is currently a 45kt TS.  With weaker vertical shear in the forecast however, she is expected to become a minimal hurricane in a few days, but still out in the open Atlantic, far from any land.  At 21Z, TS Lisa was located at 19.7N 46.1W.

For the first time in almost two months, there is nothing on the immediate horizon in terms of formation, so once Jeanne is over with in a day or two, Lisa will still be churning up the central Atlantic, and maybe all will be quiet for a brief time during this historical season.

Please visit my tropical Atlantic headquarters.

25 September 2004

Jeanne just hours from landfall, Lisa strengthens slightly...

As feared, Jeanne has intensified to a CAT3 hurricane, the 6th of the season, and is still seemingly growing stronger.  The center of the eye  is between the Bahamas and the FL coast now, and should make landfall near Vero Beach around midnight local time.  This is nearly identical to the track of Frances, who made landfall there 3 weeks ago.  That stretch of land is certainly living up to its claim of the most frequently-hit spot on the entire US coastline this year.  However, I think this is the first year to have 4 hurricane landfalls in FL during the same year.

At 21Z, Hurricane Jeanne was located at 27.1N 78.8W and tracking W at 12kts.  Maximum sustained winds are 100kts and the MSLP is 950mb. Although currently a CAT3, it could easily reach CAT4 status by landfall.  Hurricane Warnings/Watches cover basically all of the FL coastline, and into the southern GA coast.

At 09Z today, Lisa was upgraded to a Tropical Storm again, and now has an intensity of 35kts and 1002mb.  The vertical wind shear is quite high, and the forecast track is similar to Karl's... heading north into the open Atlantic, no threat to land at all.

Please visit my tropical Atlantic headquarters.

24 September 2004

Ivan makes another landfall, Jeanne heading for Florida, Karl becomes extratropical, and Lisa weakens...

At about 02Z this morning, Ivan made another US landfall, this time as a
Tropical Storm just south of Lake Charles, LA.  It has since moved
inland over TX and has produced 3-4" of rain, but quite insignificant
compared to its first US landfall.  As far as I know, the death toll
associated with Ivan is only around 120 people in the Caribbean and US

Jeanne, on the other hand, has been terribly deadly, with about 1200
fatalities reported so far, and another 1300 still missing in Hispaniola
alone (mass graves have been dug for the human and animal corpses, so
it's BAD).  She has now completed a small loop and is heading west
directly toward the Florida peninsula.  Now that forward motion has
resumed and shear has lessened, it should intensify steadily.

As of 21Z, Jeanne was located at 26.4N 73.5W and tracking W at 10kts. 
Maximum sustained winds are 85kts and MSLP is 965mb.  As shear decreases
and SST increases, it is forecast to strengthen to a CAT3 storm by
landfall... expected Sunday morning between Cape Canaveral and West Palm

A Tropical Storm Warning is in effect for the central Bahamas.  Tropical
Storm Watch for most of the western FL peninsula.  Hurricane Watch for
the extreme northern FL and GA coast.  And Hurricane Warnings for the
western Bahamas and almost all of the eastern FL peninsula.  Nearly 1/2
million evacuations have already been ordered on the FL peninsula...

The final advisory was written on Karl this afternoon, nearly at 50N! 
He has become absorbed by the mid-latitude trough and is now a potent
extratropical storm destined to give Iceland a rough ride in a couple

Lisa has been a Tropical Depression since the update I sent out
yesterday, and that's entirely due to strong northerly shear.  There has
been active deep convection, but none of it is over the low-level
circulation!  The interaction with the strong tropical wave has
basically ended, with Lisa the victorious vortex.  Still way out at
about 15N 45W, she's forecast to head quickly to the north as a strong
TS, folling almost in Karl's footsteps.

Please visit my tropical Atlantic headquarters.

23 September 2004

Ivan regenerates, Jeanne heading for US coast, Karl and Lisa still over open ocean...

At 23Z last night, the remnants of the once-great Ivan regenerated in
the north central Gulf of Mexico.  After making landfall in Alabama, the
low-level center passed over GA, NC, VA, MD, then offshore and moved
south, crossing over Florida on Monday, then finally to where it is
now.  Yes this is unusual, but the whole season has been, so it's no
surprise.  TS Ivan is now just a few miles off the southwest LA coast
and should make landfall (again) shortly, then head inland over
southeast TX.  Latest intensity was 40kts and 1003mb, and tracking NW at

Jeanne has just about completed her little loop northeast of the Bahamas
and is set to head toward the US coast.  Satellite presentation has been
improving throughout the day, and it's also been upgraded to a CAT2
storm.  Further intensification is likely before making landfall on the
FL peninsula (most likely) on Sunday morning.  At 21Z, Hurricane Jeanne
was located at 25.9N 70.3W and heading WNW at 7kts.  Maximum sustained
winds are up to 90kts and the MSLP is 966mb.

Karl is rapidly being absorbed by a mid-latitude trough, but still a
CAT2 hurricane out near 36N 42W.  This hurricane which has been in the
picture for a full week now is close to becoming extratropical.

Lisa is still a TS, and having trouble organizing as it interacts with
the strong tropical wave immediately east of it.  The forecast however,
is for gradual strengthening and a turn to the north just like Karl.

Please visit my tropical Atlantic headquarters.

22 September 2004

Jeanne, Karl, and Lisa still churning up the Atlantic...

Jeanne is now a CAT2 hurricane, and is in the process of making a small
loop, eventually heading back toward the west, and forecast to hit the
southeast US in a few days as a hurricane.  As of 21Z today, Hurricane
Jeanne was located about 500 miles east of the Bahamas with an intensity
of 85kts and 967mb.

Karl has been a CAT3/4 hurricane for a while, until this morning when it
was downgraded to a CAT2.  Further weakening is expected as it merges
with a strong mid-latitude system and makes the extratropical
trasition.  Latest intensity is 90kts and 970mb.

Lisa, the one that formed immediately east of Karl, has not moved too
far, and is having great difficulty intensifying; however, only
partially because of Karl's outflow.  The wave just a few degrees to her
east has become much better organized and is in fact looking healthier
than Lisa.  The ensuing binary interaction will be interesting to watch,
and see which vortex is victorious.  Lisa is still a Tropical Storm with
45kt maximum sustained winds and 997mb MSLP.

A fragment of Ivan dropped down along the east coast, crossed Florida,
and is now in the central Gulf of Mexico.  It has persistent deep
convection, but is strongly sheared right now.  However, if the shear
decreases, Ivan could make a comeback, but would almost certainly get a
new name.  IF it becomes something of note, it could affect LA or TX in
the next few days.

Please visit my tropical Atlantic headquarters.

20 September 2004

Jeanne a hurricane again, Karl still a major hurricane, TD13 upgraded...

At 21Z today, TS Jeanne was upgraded to a hurricane again, based on
aircraft recon (recall the last time she was a hurricane was 4.5 days
ago as she made landfall on Hispaniola, and has since killed over 250
people on that island).  Current location is 27.4N 71.2W and heading NE
at 6kts.  The storm is under weak steering flow, and that makes the
forecast track very challenging, so for the most part, the long-range
forecast is for it to basically stall, but maintain hurricane
intensity.  Maximum sustained winds are now 75kts and MSLP is 983mb.

Karl is still a major hurricane, and not a threat to land.  Presently at
18.6N 47.1W and tracking NW at 10kts, a sharp recurve to the north is
expected soon.  Latest satellite-estimated intensity is 105kts and

At 12Z this morning, TD13 was upgraded to TS Lisa, the 12th named storm
of the season.  As of 21Z, Lisa was at 13.8N 36.8W and moving W at
10kts.  Still VERY close behind Karl, the intensity is a remarkable
55kts and 994mb.  This is an interesting case of tropical cyclogenesis
in the immediate neighborhood of a major hurricane.  Unlike her big
brother Karl, Lisa is expected to continue heading west *slowly* maybe
reaching the Lesser Antilles in 8-10 days.

Elsewhere, there's a borad impressive tropical wave just behind Lisa at
about 26W that will be watched for further organization.

So, although there are 2 hurricanes and a tropical storm out there, none
of them will be affecting land in the near future, if at all.

Please visit my tropical Atlantic headquarters.

19 September 2004

Jeanne strengthens, Karl a major hurricane, TD13 forms...

Since exiting the coast of Hispaniola as a small disorganized Depression, Jeanne is now a much bigger, more organized Tropical Storm.  However, despite the improvement, there is still minimal convection near the inner core, so intensification will hold off until that occurs.  As of 21Z today, TS Jeanne was located at 24.5N 72.3W and heading. Winds are 45kts and MSLP is 996mb.  Gradual strengthening is forecast over the next 3 days, followed by weakening due to increasing vertical wind shear.  The forecast track keeps Jeanne well away from the US.

Karl was upgraded to the 5th major hurricane of the season at 03Z today, and is now a CAT4 storm.  Environmental conditions are basically ideal, and maximum sustained winds are estimated at 115kts, and the MSLP at 944mb.  It is forecast to reach 125kts, same intensity as Charlie and Frances at their peak intensities.  The storm is located at 17.0N 44.0W and tracking WNW at 9kts.  This large hurricane should begin heading due north through a weakness in the subtropical ridge within a day or so.

At 21Z today, TD13 formed immediately east of Karl (about 850 miles). Latest intensity is 30kts and 1004mb.  Due to the proximity to Karl, the system will suffer from strong vertical shear, and the steering flow is virually identical, so the forecast track is very similar.  If and when this Depression gets named, it will be TS Lisa.

Please visit my tropical Atlantic headquarters.

17 September 2004

Ivan still decaying, Jeanne weakens, Karl forms...

The large circulation of Ivan's remnants are still producing heavy rain
and tornadoes over much of the eastern US.  The total death toll is at
about 75 people in the Caribbean and US.  Also of great interest is that
Ivan has set the all-time record for amount of time spent as a major
hurricane: 10 days.  This will certainly be one of the most memorable
storms in history, joining the ranks of Camille '69, Frederic '79, Allen
'80, Hugo '89, Andrew '92, and Opal '95.

Jeanne had stalled over Hispaniola, but is now starting to drift WNW
over the open ocean.  This basically shredded the integrity of the
former hurricane, and is now a Tropical Depression, with all convection
to the east of the low-level center.  So far 6 deaths have resulted from
the flooding in Puerto Rico and Dominican Republic.  As of 21Z, TD
Jeanne was at 20.2N 71.8W with maximum sustained winds of 1002mb.  The
forecast is for slow weakening, but perhaps not even reaching hurricane
strength again.  Still, residents from FL to NC should watch its
progress closely.

At 03Z today, TD12 was upgraded to TS Karl, and it's still on an
intensifying trend.  Latest intensity is 55kts and 994mb.  Convection
and banding have improved, and Karl is expected to become the 7th
hurricane of the season within 12-18 hours (then perhaps the 5th major
hurricane within 3 days).  The good news is that it will almost
certainly recurve into the open ocean well before reaching even the
Lesser Antilles, let alone the US.

As of 21Z today, the season is 66% more active than an entire full
hurricane season, and there are still 10 weeks to go.

Please visit my tropical Atlantic headquarters.

2004's place in history

From Phil Klotzbach:

First of all, after double-checking the numbers,  Ivan has the most intense hurricane days of a single storm on record with 10.0, extending back to 1900.  The second place storm was the Miami 1926 storm (Storm 4 of that year) with 9.25 IHD, and in third place was Donna from 1960 with 9 IHD.
Here are my calculations for the months of August and September (up to 15Z on September 17) and for the season as a whole.  I'd be interested to see how they compare with the numbers that you guys have calculated.  I have put in parentheses its all-time rank if ranks in the top 10 all-time since 1950.


NS: 8 (Rank: 1)
H: 4 (Rank: T-2)
IH: 3 (Rank: 1)
NSD: 32 (Rank: 3)
HD: 14.75 (Rank: 4)
IHD: 5.25 (Rank: 5)
NTC: 85.3 (Rank: 1)


NS: 3
H: 2
IH: 1
NSD: 24.25
HD: 16.5
IHD: 13 (Rank: 3)
NTC: 80.9 (Rank: 9)


NS: 11
H: 6
IH: 4 (Rank: T-8)
NSD: 56.25
HD: 31.25
IHD: 18.25 (Rank: 2)
NTC: 166.2 (Rank: 9)

This season has been quite remarkable so far.  We already have the 2nd most intense hurricane days for a season on record... the only year with more was 1961 with 21.5 IHD.  I'll try to run some more calculations in the next few days.

Please visit my tropical Atlantic headquarters.

16 September 2004

Ivan makes landfall, Jeanne makes landfall, TD12 forms...

At about 07Z today, "Ivan the Terrible" made landfall at Gulf Shores,
AL, a fairly small town on the east side of Mobile Bay, and just a few
miles west of the FL panhandle.  Locations from Gulfport, MS to Fort
Walton Beach all suffered substantial damage, while locations further
inland were enduring deadly tornadoes spawned in Ivan's rainbands. 
Intensity at landfall was about 100kts, but post-landfall analysis of
observations and damage will pinpoint that better.  So far 36 tornadoes
have been reported in FL, GA, and SC since landfall, causing at LEAST 12
fatalities and 15 injuries.

Ivan has weakened to a Tropical Storm now, and is near Birmingham, AL. 
Intensity is 50kts and 980mb, with a heading of NNE at 12kts.  It will
continue to move NE over TN, then perhaps loop back E then SE toward SC
and interact with Jeanne in about 6 days.  Stranger things have
happened.  I'll close today's discussion of Ivan with some relevant
remarks made today:
"I've been through a lot of hurricanes, but this is the most ungodly
thing I've ever seen"  -- Robert Randle, Gulf Breeze deputy police

"This couldn't be much worse."  -- John Fogg, mayor of Pensacola

"It would be easier to say what's NOT damaged,"  -- Ted Roy, Escambia
County sheriff's department.

I found this quote on CNN's website which I thought was very fitting:
"In the eye of a hurricane, you learn things other than of a scientific
nature. You feel the puniness of man and his works. If a true definition
of humility is ever written, it might well be written in the eye of a
hurricane."  -- Edward Murrow, reporting on Hurricane Edna 1954

Now on to Jeanne.  Jeanne was upgraded to the 6th hurricane of the
season at 12Z today, then made landfall on the Dominican Republic and
went on to actually form an open eye while over the mountainous island. 
At 21Z, it was downdraged to a Tropical Storm again, but that should be
temporary.  It is now expected to head back over water and toward the
Bahamas.  The SE US coast should be watching this one very closely, as
it could be another hurricane landfall in about 5 days.  Current
intensity is 60kts and 990mb.

Elsewhere, that large tropical wave I've mentioned that past couple of
days is now TD12, based on satellite presentation.  It's out at 11.4N
32.8W and heading W at 14kts.  Maximum sustained winds are 30kts and
MSLP is 1007mb, but it's forecast to quickly become Tropical Storm Karl,
then a hurricane in about 2 days.  The latest thinking is that it will
recurve into the central open Atlantic, but I have to wonder how likely
that is given the current location south of 12N.  Something to watch... 

Please visit my tropical Atlantic headquarters.

15 September 2004

Gulf Coast prepares for a hard hit, Puerto Rico takes a direct hit...

Ivan is now just 120 miles from the coast, or about 8.5 hours (21Z fix
had it at 28.4N 88.3W).   Heavy rainbands have moved onshore, and the
eyewall will move onshore in perhaps 6 hours.  The exact location of
landfall will not matter since this is such a large strong storm. 
However, Mobile is forecast to take the center of the eye during the
early morning hours on Thursday.  Buoys in the gulf ahead of Ivan have
reported waves up to 50 feet high.

Recent aircraft recon suggests that Ivan is intensifying.  The pressure
has fallen noticeably, and the objective satellite techniques all show
an intensifying trend.  But as of now, the maximum sustained winds are
held constant at 115kts.  MSLP is 933mb.  Ivan should make landfall as a
CAT4 hurricane, and unfortunately, that means the damage will be
widespread and extreme.  Storm surge flooding, rainfall flooding,
tornadoes, and hurricane-related winds will result in a very scary night
tonight as he makes landfall.

Jeanne made landfall on Puerto Rico at about 18Z as a strengthening
Tropical Storm.  Current intensity is 60kts and 991mb.  It is expected
to exit the island, then head WNW past Hispaniola then into the
Bahamas.  It's presently at 18.4N 66.5W and tracking WNW at 8kts.  This
motion is expected to continue.  Again, residents along the southeast US
coast should keep a close eye on Jeanne in the coming week.

The strong tropical wave I mentioned yesterday has become better
organized, and is presently at about 10N 28W (south of the Cape
Verdes).  It's moving WNW at about 16kts and has a 1010mb Low associated
with it.  Given the warm SSTs and low shear, this should become TD12
within 18-24 hours.  The next name on the list is Karl.  

Please visit my tropical Atlantic headquarters.

Ivan nearing Gulf Coast, Jeanne nearing Puerto Rico...

Ivan is still a mighty CAT4 hurricane at is takes aim at the northern Gulf Coast.  Evacuations are being rushed, especially in New Orleans where they are particularly vulnerable.  The city exists 5 feet below sea level, protected by dikes.  A direct hit or even a near-miss would result in the costliest disaster in US history as the entire city fills with perhaps 15+ feet of water.  The 09Z forecast track takes the eye into Mobile, AL, which is still quite bad, for Mobile and places far east and west of it due to the storm's large eyewall.  Latest position is 165 miles away from landfall, or about 13 hours.

TS Jeanne is currently very near hurricane-strength at 60kts and 991mb.  The center of the circulation is just a few miles off the southeast coast of Puerto Rico, with evidence of an eyewall forming.  She will almost certainly be upgraded to the 6th hurricane of the season within the next 12 hours.  The forecast is for slight strengthening beyond Puerto Rico, but still facing the outflow/shear from Ivan.  In a couple of days, conditions should improve as it heads over the Bahamas and intensifies, heading toward the US coast... at this point, anywhere from FL to NC should be watchful.

Please visit my tropical Atlantic headquarters.

14 September 2004

Ivan still a CAT4, TD11 becomes TS Jeanne...

At 06Z today, Ivan was downgraded to a still-powerful CAT4 hurricane as
it entered the Gulf of Mexico.  It now has a very large eye and is
heading for a patch of high oceanic heat content which could allow it to
intensify yet again.

The 21Z position was 24.2N 86.6W and motion was NNW at 8kts.  Maximum
sustained winds are 120kts and MSLP is 929mb.  The forecast is slowly
becoming more certain as it gets closer, and the region between New
Orleans and western FL panhandle look like the highest risk areas now. 
The official NHC forecast takes it into Mobile, AL as a CAT3 storm in
the early morning hours on Thursday.  Hurricane Warnings cover a stretch
of land from Grande Isle, LA to Apalachicola, FL, and evacuations have
already begun in many places contained in that warning.  Personal
intuition tells me that New Orleans should be especially cautious.

At 15Z today, TD11 was upgraded to TS Jeanne, the 10th named storm of
the season.  It crossed directly over Guadeloupe as a strengthening TD,
so conditions wouldn't have been TOO bad there.

As of 21Z, she's at 16.8N 63.9W and tracking WNW at 9kts.  Intensity is
50kts and 998mb.  The forecast is for gradual intensification, passing
directly over Puerto Rico as a hurricane, then skipping north of
Dominican Republic and into the Bahamas in 5 days.  Residents from FL to
NC should be watching Jeanne closely.

Elsewhere, there is an impressive tropical wave in the deep tropics near
25W.  This circulation will be monitored for future development.

Please visit my tropical Atlantic headquarters.

13 September 2004

Ivan passing by Cuba as CAT5 storm, TD11 forms...

At 03Z today, Ivan was upgraded to a CAT5 hurricane for the third time. 
The latest aircraft recon found maximum sustained winds of 140kts and
the MSLP is 912mb (910mb was found since the advisory).

It's presently just a few miles off the western tip of Cuba and heading
northwest through the Yucatan Channel.  A Gulf Coast landfall is
inevitable; the obvious question is WHERE.  The primary threat region
appears to be between New Orleans and Tampa, with the FL panhandle in
the highest risk zone.  Timing would place it near the US coast
Wednesday night.  Luckily, the Keys residents who evacuated earlier are
being allowed back in due to the unexpected westerly track over the
weekend (always better returning home after a miss than a hit!).  

This major storm has killed at least 62 people so far: 17 on Jamaica, 37
in Grenada, 4 in Venezuela, and 4 in Dominican Republic.  Ivan has now
spent more time as a major hurricane than Frances, and is possibly on
its way to breaking the all-time record.

At 21Z, a disturbance just east of the Lesser Antilles was upgraded to
TD11.  It exited the African coast on Sept 7 and is now nearing
Guadeloupe in the southern Leeward Island chain.  As of 21Z, TD11 was
located at 16.0N 60.4W and tracking WNW at 10kts.  It's expected to
track over or near the British Virgin Islands, US Virgin Islands, Puerto
Rico, perhaps parts of Hispaniola, then the Bahamas.

Current intensity is 30kts and 1010mb.  The immense outflow from Ivan
will likely keep pretty high shear over TD11 for the next couple days,
but further intensification is forecast once the shear and landmasses
are in the past.  If named, this will be TS Jeanne.

Please visit my tropical Atlantic headquarters.

11 September 2004

Ivan now past Jamaica, heading for Cayman Islands...

Around midnight local time last night, very powerful Ivan approached the Jamaican coast, and miraculously turned to the west, keeping the eyewall JUST offshore.  After passing the island, it resumed its WNW course.  So although I'm sure the destruction due to flooding and some high winds on Jamaica will be hefty (7 deaths already reported there), they really got incredibly lucky.  On the flip side, this also allowed Ivan to continuously intensify, since the inner core remained over extremely warm water.  My preliminary count has the death toll at already about 40 people, from Grenada, Venezuela, Dominican Republic, Barbados, and Jamaica.

At 21Z today, it was upgraded its strongest intensity yet based on aircraft recon.  It's at 145kts and 914mb... one of the stronger hurricanes to ever exist in the Atlantic, and still strengthening perhaps.  It is forecast to hit western Cuba as a CAT5 early Monday morning.  First though, it looks like it will pass directly over Grand Cayman early Sunday morning, also as a CAT5.  Present location is about 140 miles ESE of Grand Cayman, and heading WNW at 8kts.

Although the current forecast track takes it into the central FL panhandle early Wednesday, I personally believe it's simply too early to pinpoint a location... there are some uncertain variables that make this too questionable so far out.  Anyone on the panhandle, western peninsula, and the Keys should be preparing for this.  Also of great importance is the trough that's steering it northward will also weaken it a bit before it hits the US due to increasing vertical wind shear.

Please visit my tropical Atlantic headquarters.

10 September 2004

Ivan aircraft recon...

Although Hurricane Ivan looked slightly ragged last night and much of
today, it appears to now be taking full advantage of the increasing
oceanic heat content and could be at the onset of another rapid
intensification phase.  The frequency of in-situ measurements made by
aircraft is wonderful.  Here I'll include a table of some parameters
throughout the day when aircraft were in the storm:

TIME (UTC)   MSLP (mb)   EYE DIAM (nm)   ODT T#
1023         934         20              5.3
1105         934         20              5.3
1738         940         16              5.7
1913         937         16              5.8
2037         933         15              6.0
2215                                     6.2

So, you'll notice the eye has been contracting throughout the day which
will also lead to intensifcation.  The Objective Dvorak Technique
T-numbers are using just infrared satellite imagery, and are a function
of cold cloud tops over the eyewall and a warm eye... the higher the
number, the stronger the storm, objectively.

Please visit my tropical Atlantic headquarters.

Ivan very near Jamaica...

During the night and early morning hours, Ivan went through an eyewall
replacement cycle, and was hit by light northwesterly wind shear, and
weakened to 120kts as a result, but still a CAT4 hurricane.  The latest
satellite imagery shows gradual strengthening again, with the coldest
cloud tops wrapping around a clearing eye.

As of 21Z, Hurricane Ivan was located at 17.0N 76.2W and tracking WNW at
11kts.  Aircraft-measured intensity is 120kts and 937mb.  The storm is
just now entering enhanced SSTs and oceanic heat content as it nears
Jamaica and then again between Jamaica and Cuba.  The very dangerous
storm is just 80 miles away from Jamaica, and is expected to hit it
head-on tonight (around 1-2am local time) as a CAT4 storm... even
stronger than Gilbert '88 which was totally devastating.  Major
hurricane-force winds could ravage the island for up to 8 hours.

The death toll has already reached 25, and it hasn't even hit Jamaica,
Cuba, or the US yet.  But hopefully enough precautions and evacuations
have taken place that people will be safe.  The Florida Keys are
presently being evacuated.

The forecast is certainly of great interest to a LOT of people.  It
looks more and more apparent that Florida is indeed the target of yet
another tropical assault.  Jamaica will be hit late tonight, then
western-central Cuba on Sunday evening, then it should be very close to
the FL Keys midday Monday.  It is too early to give an exact landfall
location in mainland FL, aside from saying the panhandle and western
peninsula.  Intensity at US landfall will depend on what effects Cuba
has on it, so we'll have to wait until early Monday perhaps to see that.

Please visit my tropical Atlantic headquarters.

09 September 2004

Ivan taking aim on Jamaica...

Mighty Hurricane Ivan maintained CAT5 status until 21Z when it was
downgraded slightly to a strong CAT4.  At this very high strength,
intensity fluctuations are perfectly normal as it responds to minor
changes in oceanic heat content and as it undergoes eyewall replacement
cycles.  It now has maximum sustained winds of 130kts and a MSLP of
921mb.  It's 350 miles ESE of Jamaica and is headed WNW at 13kts;
landfall is expected on Jamaica Friday afternoon/evening.  If it does
indeed hit them head-on at CAT4 intensity, it would be devastating. 
Some of you may recall Hurricane Gilbert '88 who hit the island as a
CAT3 and was incredibly destructive.

The forecast calls for maintaining CAT4/5 intensity as it heads over
Jamaica on Friday afternoon, western Cuba on Sunday evening, then
perhaps weaken slightly as it heads for Florida Monday evening or
Tuesday afternoon, depending on how far north it makes it before hitting
land.  Hurricane warnings are in effect for Jamaica and the Cayman
Islands, and Hurricane watches are up for virtually all of Cuba.  No
watches or warnings yet for the US.

In other news, TD10 formed from a tiny weak circulation near the Azores
Islands in the far northeast Atlantic.  It lasted for 12 hours (09-21Z
today) before NHC ceased writing advisories on it.  It was highly
sheared and no longer convectively active.

Please visit my tropical Atlantic headquarters.

Ivan rapidly intensifies...

Ivan has undergone rapid intensification during the afternoon and night on Wednesday.  At 06Z on Thursday, the already-terrible Ivan was upgraded to a Category 5 hurricane, the first of the season.  The last CAT5 was Isabel '03, then before that was Mitch '98.

Ending at 06Z, the pressure fell 13mb in 3 hours and 24mb in 12 hours. Winds have reached 140kts (160mph) and the central pressure is now 925mb.  This extreme intensity is difficult to maintain for very long, so it could easily drop back down to a CAT4, but still very dangerous.

It is presently located north of the tiny islands of Aruba, Bonaire, and Curacao off the Venezuelan coast.  The official forecast takes it directly over Jamaica on Friday afternoon, western Cuba on Sunday afternoon, and the southwest Florida peninsula on Monday evening... all as a CAT4.  Keep in mind the later forecast times become increasingly uncertain.

Please visit my tropical Atlantic headquarters.

07 September 2004

Frances decays inland, Ivan thrashes the Windwards...

At 03Z today, NHC issued the final advisory on Frances, now a large
weakening swirl centered over Atlanta.  However, she will not be
forgotten.  Over 3 million people are still without power, and 16 people
have died in the Bahamas, Florida, and Georgia.  The storm was a
hurricane for 10 full days, and a major hurricane for 7.25 of those

Ivan is gradually regaining intensity, and became a CAT3 again at 09Z
today.  As of 21Z, it was at 12.0N 62.0W and moving quickly to the west
at 16kts.  Aircraft-measured intensity is 105kts and 956mb.  Given
nearly ideal conditions, Ivan is forecast to intensify further, reaching
CAT4 within 6-12 hours.

The northern eyewall and eye passed directly over the island of Grenada
at 22Z today.  Grenada is the southernmost island in the Windward Island
chain with a population of nearly 100,000.  Since that only occurred
only one hour ago as of this writing, no damage reports are in, but they
will be significant.  I don't usually do this, but I included an
attachment showing a visible satellite image, taken near local sunset,
just as Ivan was passing over Grenada... looks peaceful from space, but
remember under those pretty clouds are sustained winds of 120mph.
The forecast track is very easy in the short term, but extremely
challenging in the long term.  Over the next couple of days, Ivan will
continue heading W to WNW outside the periphery of the subtropical
ridge.  Beyond then, it's too hard to say if the ridge will decay at
all, or to what degree.  This affects the track immensely: a weaker
ridge means it will nudge northward, toward the Greater Antilles and
perhaps Florida; a stronger ridge means it will keep heading WNW toward
the Yucatan Peninsula.  It's simply too early to tell.  

The tropical wave I mentioned yesterday is still heading west, and
presently located at about 16N 37W.  It shows signs of development, and
should become TD10 very soon.  If it gets named, it would be Jeanne. 
Given its position so far north at 37W, it would most likely recurve
before reaching the Lesser Antilles, but will be monitored closely.

Please visit my tropical Atlantic headquarters.

06 September 2004

Frances makes landfall (again), and powerful Ivan heading for Lesser Antilles...

Frances exited the Florida peninsula near Tampa as a Tropical Storm, and
tracked across the northeastern Gulf of Mexico, never regaining
hurricane strength.  It made landfall again near St. Marks in the
Florida panhandle at 2pm EDT as a strong Tropical Storm.  But the heavy
rain spans from near Tampa to central GA.  There are already 11 tornado
reports today in FL, GA, and SC associated with Frances' rainbands. 
Tornado, Flood, Flash Flood, and Tropical Storm Watches/Warnings cover
much of FL, GA, AL, and SC.  At 21Z, the center of TS Frances was
inland, about 75 miles northeast of Apalachicola, and moving NNW at
7kts.  Maximum sustained winds have dropped to 40kts and the MSLP is up
to 982mb.

After Ivan's extremely rapid intensification on Sunday (30mb in 6
hours), the inner core basically collapsed and the storm weakened as a
result.  This was part of an eyewall replacement cycle, which as of this
writing, is still occuring.  Once complete, the central pressure should
drop fairly quickly again.  It is still 300 miles east of the Windward
Islands, and is heading directly for Barbados.  As of 21Z, Hurricane
Ivan is located at 11.6N 55.3W and tracking WNW at 19kts.  Intensity
measured by aircraft was 90kts and 968mb.  Further strengthening is very
likely, and it should be upgraded to a CAT3 storm again within 6-12
hours.  The Lesser Antilles can expect the worst weather midday Tuesday.

The forecast track takes Ivan over Hispaniola (a mountainous island
between Cuba and Puerto Rico comprised of Haiti and the Dominican
Republic) midday Thursday, then PERHAPS knocking on Florida's door early
this weekend.  The southeastern FL peninsula is climatologically the
most frequently hit slice of land along the entire US coastline, and
this year is certainly validating and enhancing that statistic.

Elsewhere, a healthy tropical wave is located in the far eastern
Atlantic, at about 12N 32W.  It exited Africa last Friday (4 days behind
Ivan), and is moving W at 12kts. Conditions appear favorable for
development over the next day or two; the next number/name on deck is

As of the 21Z advisories today, this season's activity is already 19%
higher than an entire average season, and we haven't yet reached the
climatological peak!

I'd like to thank Jonathan Vigh for sending the updates in my absence. 
The ten days I was gone were host to a lot of activity (Frances, Gaston,
Hermine, Ivan), so it was no small chore.  I hope you all enjoyed his
expert analysis and commentary!

Please visit my tropical Atlantic headquarters.

Frances exits stage left, another storm that may be known as 'Ivan the Terrible'...

From Jonathan Vigh: 
Hurricane Frances was downgraded to Tropical Storm Frances at 5 pm EDT. What
is remarkable about this fact is that she made it nearly to the other side
of Florida before being downgraded. Lumbering along at 5-7 mph, her large
circulation has been very slow to weaken. Frances has now affected nearly
the entire Florida Peninsula, bringing at tropical storm force gusts all the
way from the Lower Keys up to Jacksonville. Hurricane-force gusts have been
felt along Florida's east coast from Palm Beach county all the way up to
Saint Augustine. There have not been very many reports of peak winds yet,
but there have been anecdotal reports (or estimates) by the media and others
of 100+ mph winds right along the coast. Port Canaveral reported a 124 mph
gust, but it is not known at what height this measurement was taken. Winds
almost always increase rapidly with height just above the ground, so if this
was measured on a tall tower it would not be representative of the actual
winds (the standard height to take wind measurements is 10 meters). Inland,
Orlando's main airport reported gusts as high as 69 mph (in contrast, they
had gusts to at least 105 mph in Charley), and wind gusts of 95 mph were
reported around and on Lake Okechobee. 

Most of the damage so far seems consistent with a cat 1/2 hurricane. It is
likely that the most severe damage occurred on barrier islands which have
not been surveyed yet. Needless to say, Frances hit Florida hard. Unlike
Charley, where damage was extreme, but mostly confined to a 10-mile wide
swath, Frances left spotty damage across the entire state, but a general
swath of moderate damage about 100 miles across, mostly along the coast (not
very many people live inland in the path taken by the eye after landfall).
Beach erosion has been considerable. Frances has also been much less deadly
than Charley (so far -- however, many storm deaths happen afterwards due to
accidents, electrocutions, carbon monoxide poisoning, and the like). 2 were
reported killed in the Bahamas and 2 or 3 deaths are blamed on the storm in
Florida so far. Power is out to over 2 million households and businesses.
The total damage will likely be in the billions, but it is unclear whether
it will be more or less than Charley. 

But wait, the story is not done -- no, not even yet has Frances relinquished
her desire to cause grief to the state of Florida. She is just now emerging
out into the Gulf of Mexico north of Tampa and will have 12-18 hours over
open water before making a second landfall, possibly near Apalachicola. She
is forecast to restrengthen to a minimal hurricane by this time, so more
trouble is ahead. Since she is so broad, the actual point of landfall
doesn't matter very much and winds and more heavy rains will spread far
inland over Georgia and Alabama afterwards. The bend of Florida is very
susceptible to storm surge flooding, so this will be a factor as well.
Hurricane warnings are in effect from south of Tampa all the way to Destin.
Tropical Storm Warnings are in effect for nearly the rest of Florida except
the southeast coast.   

At 03Z, Frances was at 28.3N  82.7W, moving west-northwest at 7 kt with
sustained winds of 55 kt and a central pressure of 976 mb.

If anyone is getting hurricane fatigue, they may want to skip the next
section. Unfortunately, Africa has given birth to a monster. Just a few days
ago, cute little Ivan rolled off the coast with an interesting umbilical
cord stretching back to the motherland. Now, just a few days later, Ivan is
poised to become one of the strongest storms ever seen in the Atlantic.
Here's a brief recap of the amazing developments of the past day:

Sun 03Z 991 mb 60 kt
Sun 09Z 987 mb 65 kt Ivan becomes 5th Atlantic hurricane of the year
Sun 15Z 980 mb 75 kt Ivan rapidly strengthening
Sun 17Z 960 mb 100 kt Ivan becomes the 4th major hurricane of the season
Sun 21Z 950 mb 110 kt Ivan is now perhaps the strongest hurricane on record at such a low latitude in the Atlantic basin (preliminary)
Sun 03Z 948 mb 115 kt Ivan now a cat. 4 hurricane

It should be noted that all of these intensity measurements are based
completely on satellite estimates. A plane is scheduled to investigate Ivan
about 24 hours from now. By then, it may in all likelihood be a cat. 5
hurricane, as there is not much of anything that would bring a stop to its
rapid intensification. It wouldn't hurt to say a prayer for the safety of
the Hurricane Hunters and NOAA scientists that fly into these storms. 16
years ago, the first plane to investigate Hurricane Hugo was nearly lost
(you can read the story at:

The potential effects of Ivan could be indeed terrible. The first island in
the path is Barbados, where appoximately 278,000 people live. Under the
current track forecast, the storm may pass between Saint Lucia (pop.
164,000) and St. Vincent and the Grandines (pop. 117,000), sparing either
the deadly core (hurricane-force winds are only 35 miles across). Of course,
a slight deviation could produce a direct hit for either of these island
groups. The confidence in this forecast is quite high, and Barbados should
prepare as best as possible for a direct hit from a cat. 5 hurricane 36
hours from now. After passing the windward islands, the forecast track of
Ivan takes it over Hispanola, one of the poorest and most vulnerable areas
you could find (just this year, extreme flooding from an early season
tropical disturbance killed approximately 2000 people there). The extreme
rains are caused by mountains that reach up to 10,414 feet (and the
deforestation). Hispanola has torn apart many mighty storms in the past
(David, Cleo, Inez). It is still too early to say if this will tame Ivan, or
whether Ivan will even pose a threat to the United States. Regardless of the
ultimate effects of Ivan on the U.S., trouble is rapidly approaching the

At 03Z, Ivan was at 10.8N  49.4W, moving west-northwest at 18 kt, with
estimated maximum sustained winds at 115 kt and estimated minimum central
pressure of 948 mb. 

Please visit my tropical Atlantic headquarters.

04 September 2004

Frances crawls ashore east Florida coast, Ivan strengthens...

From Jonathan Vigh: 
Yesterday, Hurricane Frances was lashing Grand Bahama Island on her way
towards Florida. Today, she was still crossing that island! A C-MAN station
on the west part of the island was in the eye for approximately 10 hours
today. The eastern part of the eyewall has finally crossed over that end of
the island and the wind has picked back up to gusts of 80 kts. Currently,
Frances is coming ashore between West Palm Beach and Fort Pierce. Her exact
point of landfall doesn't matter very much because her eye is 70 miles
across! Yesterday's episode of vertical wind shear and dry air disrupted her
core long enough to let the wind field spread out. Storms often have trouble
regrouping once they have a broad wind field because it is hard to spin up
the central part of the storm. The shear appears to have let up somewhat
today, and deep thunderstorms have wrapped all the way around the center of
Frances, forming a very large eye. Within the eye, a weak circulation
appears to be trying to organize as well, but it is doubtful that this will
have much of an effect before landfall. One mechanism which could possibly
help tighten up the core of Frances (leading to intensification) is the
friction with the Florida coast. As the eyewall has been starting to move
onshore this evening, the eye deformed a bit, becoming elliptical for a
while. The greater friction over land may have helped contract the eye by be
helping to squash the eye in the east-west direction, which may help it
contract. On her current pace, the eye of Frances should be completely
onshore in 5-12 hours. This will bring a halt to any possible
intensification -- for a little while. If the eye remains at the current
size, when the eastern end finally moves onshore, the western end will be
most of the way to the other side of Florida!  

Sometime tomorrow morning, Frances should start moving at a more respectable
pace as a trough weakens the ridge that has been blocking her path. She is
likely to finish crosssing Florida by tomorrow night and reemerge out into
the Gulf of Mexico as a tropical storm (this means that most of Florida's
west coast will get tropical storm conditions, including Tampa which was
missed by Charley three weeks ago). Some restregthening is possible, and
then Frances will likely make her 2nd (and final) landfall in the Florida
Panhandle. By the time this event is over, nearly all of Florida will likely
have experienced at least tropical storm force winds and large amounts of

Many of the reporting stations in the immediate vicinity of landfall have
stopped reporting, likely due to power outages. Most of the wind reports
thusfar have been fairly consistent with a category 1 hurricane, but there
have been very few reports since the eyewall actually started moving onshore
a few hours ago. Up till this afternoon, the highest wind report was 91 mph
at Juper River Inlet and 90 mph near West Palm Beach. The outer rainbands
have also packed a punch, causing scattered damage and some power outages as
far south as Miami, as far west as Tampa, and as far north as Orlando and
Daytona Beach. At least 1.1 million customers are now without power and this
number will rapidly grow as the night goes on. 

At 03Z, Frances was at 27.1N  79.7W, moving west-northwest at 5 kt with
maximum susatined winds at 90 kt, and a minimum central pressure of 960 mb. 

Frances will still be with us for several more days, but five days from now,
Ivan may take the spotlight. The storm strenthened today, looking better and
better in the satellite imagery. Ivan is nearly to hurricane stength, and
with low shear and warm waters for at least the next 3 days, there is not
much to keep the storm from steadily strengthening. The forecast calls for
Ivan to cross the central Windward Islands in a little over 3 days, possibly
hitting Hispanola at 5 days as a major hurricane. It is still too soon to
say, but Ivan may pose an additional threat to storm-weary Florida in a
little over a week from now. 

At 03Z, Ivan was at 9.4N  42.4W, moving westward at 16 kt, with estimated
maximum sustained winds at 60 kt and a minimum central pressure of 991 mb.

For other information including preliminary wind and damage reports, see

Please visit my tropical Atlantic headquarters.