31 August 2005

Lee forms in the central Atlantic...

TD13 has regenerated and was upgraded to TS Lee today at 21Z.  However, it does not look very healthy and will likely be back down to a TD in 2-3 days.  It's located at 30.5N 49.7W and heading NNE at 12kts.  The intensity estimated by satellite is 35kts and 1007mb.

The strong tropical wave 1200 miles east of the Lesser Antilles is STILL looking impressive, with an obvious surface circulation and persistent deep convection.  This is the wave that exited Africa on August 27.  I honestly don't know why this is not being classified as TD14 yet, but from my experience, it should be.  It's presently at about 19N 42W and heading NW at 10kts.  The next name on deck is Maria.

And lastly, a new tropical wave has exited Africa and is already showing signs of a broad circulation.  This will be watched closely for signs of development over the next few days.

The NTC as of the end of the month is now 110.2%, compared to a normal 31% or so for this date.  Recall that a value of 100% corresponds to an entire average season.  So 2005 is already 10% above an entire normal season, and the climatologically active part of the season is still ahead of us.


Please visit my tropical Atlantic headquarters.

30 August 2005

Katrina still devastating parts of the coast...

36 hours after landfall, the people in New Orleans emergency shelters 
are being evacuated as levee after levee is breached by flood waters and 
the shelters are filling with water.  Water from the Mississippi River 
and from Lake Pontchartrain is now pouring into the city, bringing the 
water level up to at least 25 feet in parts of the city.  Also, as time 
goes by, we start to get more reports from the coast of Mississippi and 
realize how complete and extensive the destruction really is.  Gulfport 
and Biloxi are in very bad shape to say the least, and strong tornadoes 
generated by Katrina's spiral bands have ravaged parts of Georgia.  This 
is very similar to Hurricane Camille in 1969, but Katrina was LARGER.

The death toll from the storm is now around 70, but there are a LOT of 
people unaccounted for, so that number could rise drastically in the 
coming days and weeks.  Nearly all communication and transportation is 
cut off, so information out of the area and assistance into the area are 
greatly hindered.   I'll once again provide a link to the American Red 
Cross for donations: https://www.redcross.org/donate/donation-form.asp.  

Although Gulfport was hit very hard by the eastern eyewall, New Orleans 
may end up being the worst off, as the city sits submerged for weeks or 
even months without power, water, or sewer services.  The ultimate 
doomsday forecast that was made for the city has sadly come to fruition.

The terrorist attacks on the US in 2001 had a total cost of about $40 
billion.  Hurricane Andrew in 1992 cost $42 billion.  All four big 
hurricanes in 2004 (Charley, Frances, Jeanne, and Ivan) added up to 
about $46 billion.  Hurricane Katrina could potentially be twice those 
values.

For those who are interested, I have created radar loops of Katrina's 
two landfalls: the first on Thursday afternoon near Miami, and the 
second on Monday morning near New Orleans.
http://einstein.atmos.colostate.edu/~mcnoldy/tropics/katrina/Katrina_25Aug05.gif
http://einstein.atmos.colostate.edu/~mcnoldy/tropics/katrina/Katrina_29Aug05.gif

The tropical wave I mentioned yesterday over the central Atlantic 
between Africa and the Lesser Antilles has remained unchanged.  There is 
still a disorganized broad surface circulation and a more impressive 
anticyclone aloft.  It's located roughly at 14N 38W and tracking W at 
10kts.  Conditions still appear favorable for gradual development.
Please visit my tropical Atlantic headquarters.

29 August 2005

Katrina hits coastal LA and MS hard...

At about 11Z today, Katrina made landfall on the Mississippi River delta 
in southeast LA as a potent CAT4 hurricane.  Maximum sustained winds 
were estimated to be 120kts with a MSLP of 920mb.  Then it proceded 
north... the western eyewall hitting New Orleans, and the eastern 
eyewall hitting Gulfport and Biloxi.  There are already reports of 
significant flooding and damage all along the coast in LA, MS, and AL -- 
from New Orleans to Pensacola.  It's still too early to get a complete 
picture of what has transpired this morning, but it will be an extremely 
costly disaster.  Cities as far east as Mobile, AL had levees topped and 
flood waters racing into the city.  Buoys just offshore reported waves 
of 40+ ft ahead of the storm.

The storm has since moved inland and weakened to a CAT1 hurricane as of 
this writing.  Further weakening will occur, but now the primary threat 
is from inland flooding, and that is a risk for the next several days in 
the southeast and Ohio Valley.  Visit 
http://www.spc.noaa.gov/products/wwa/ to check out the most current 
watches and warnings.  Remember that tornadoes and flash floods are big 
dangers from hurricanes that have made landfall... even quite far from 
where it made landfall.

As of 19Z, Hurricane Katrina was located at 31.4N 89.6W (near 
Hattiesburg, MS) and tracking N at 15kts.  The intensity is 80kts and 
the MSLP is 955mb.  On its forecast track, it will be passing over TN, 
KY, and OH over the next couple of days.

If you wish to help the Katrina victims, the American Red Cross has a 
donation form at https://www.redcross.org/donate/donation-form.asp

Due to excessive shear in the critical formative stage, TD13 has 
dissipated into an open wave and is no longer forecast to intensify.  It 
will be watched for signs of regeneration though.  However, a relatively 
new wave has exited the African coast and is located near 10N 32W, just 
southwest of the Cape Verde Islands.  It shows signs of development and 
conditions should be favorable for gradual organization.
Please visit my tropical Atlantic headquarters.

28 August 2005

Katrina catastrophe imminent...

Since my last update on Friday, Katrina has done the unimaginable, and 
rapidly intensified to a monstrous Category 5 hurricane right off the US 
coast.  To make matters more dire, it is headed for one of the most 
vulnerable cities in the US: New Orleans.

The storm experienced a phenomenal period of rapid intensification, with 
pressure drops of 27 mb/3hr and 36 mb/12hr.  As of this writing, the 
storm is STILL strengthening, currently holding the 4th lowest pressure 
ever recorded in the Atlantic.  As of 21Z today, aircraft recon found 
maximum sustained winds of 145kts and a minimum central pressure of 
902mb.  It is located at 26.9N 89.0W and tracking NW at 10kts.  This 
puts it 225 miles south of New Orleans.  It is forecast to gradually 
turn more to the north and maintain CAT 4/5 intensity, with fluctuations 
primarily due to concentric eyewall cycles.  The best estimate for time 
of landfall is around 5am CDT on Monday.  As an aside, this makes the 
first time there have been 3 CAT5s in 3 consecutive years (Isabel '03, 
Ivan '04, and Katrina '05).

A mandatory evacuation has been ordered for all of New Orleans, as well 
as some other coastal cities in LA and MS.  The storm surge from this 
hurricane could reach 25-30 feet, with wind gusts to 200mph or even 
higher.  I wanted to share an excerpt from the forecast discussion out 
of the New Orleans NWS office: 
"MOST OF THE AREA WILL BE UNINHABITABLE FOR WEEKS...PERHAPS LONGER. 
AT LEAST ONE HALF OF WELL CONSTRUCTED HOMES WILL HAVE ROOF AND WALL 
FAILURE. ALL GABLED ROOFS WILL FAIL...LEAVING THOSE HOMES SEVERELY 
DAMAGED OR DESTROYED.  POWER OUTAGES WILL LAST FOR WEEKS...AS MOST 
POWER POLES WILL BE DOWN AND TRANSFORMERS DESTROYED.  WATER SHORTAGES 
WILL MAKE HUMAN SUFFERING INCREDIBLE BY MODERN STANDARDS." 


The President has already declared Lousiana and Mississippi 
federal disaster areas to expedite funding and recovery efforts once the storm 
passes.  A Hurricane Warning is in effect from western LA to the FL panhandle.  
Aside from the devastating eyewall, areas to the east of landfall can expect 
VERY large waves, perhaps upwards of 40 feet, along with 1-2 feet of rain.

Elsewhere, TD13 has formed from the area of disturbed weather in the deep 
tropics between the Lesser Antilles and Africa.  It is located at 15.4N 
46.8W.  Initial intensity is estimated to be 25kts and 1007mb.  This is 
from a wave that exited Africa on August 25.  The longer range forecast 
for this is to head northwest (north of the Leeward Islands) and 
gradually strengthen to hurricane intensity by later this week.  This 
should be upgraded to TS Lee sometime tomorrow.
 
 


Please visit my tropical Atlantic headquarters.

26 August 2005

Katrina slams southern FL and intensifying...

At about 23Z yesterday, Katrina made landfall as a CAT1 hurricane on 
North Miami Beach, FL.  The storm was highly asymmetric, and nearly all 
of the rainfall occurred on the south side, quite extreme in some 
places.  Wind gusts to nearly 85kts were observed at several places, and 
radar-estimated rainfall totals in southern FL are 10-20" along the 
south side of the track.  So far, this hurricane has killed 4 people, 
and left 5 missing at sea.

The hurricane barely noticed that it was over land, since the land is 
flat and mostly swampy.  Then, a peculiar turn to the southwest allowed 
the storm to spend just 7 hours over the peninsula before exiting into 
the Gulf.  It responded well to the transition and is now strengthening 
very quickly.  The pressure at first landfall was 985mb, and shortly 
after landfall was 971mb (usually is the other way around!).  Conditions 
over the Gulf are ideal for rapid intensification -- the SSTs will 
remain above 30C and the northerly shear that has been affecting it is 
expected to relax.

At 15Z today, the center of Hurricane Katrina was located at 25.1N 82.2W 
and crawling W at 6kts.  Intensity measured by aircraft is 85kts and 
971mb, making it a CAT2 storm.  The forecast is for continued 
strengthening, reaching at least CAT3 by the end of the weekend, and 
then hitting the FL panhandle (perhaps between Pensacola and Panama 
City) on Monday morning.  Ahh, the Sunshine State...

Elsewhere, the same circulation and area of disturbed weather I've 
mentioned lately in the deep tropics east of the Lesser Antilles 
struggles to get organized (it exited Africa on Aug 19).  It still has 
persistent deep convection, but it is still well separated from the 
low-level center.  It's located at about 20N 46W.
Please visit my tropical Atlantic headquarters.

25 August 2005

Katrina bearing down on FL, nearly a hurricane...

The storm has gradually intensified and slowed down, now moving west at 
just 5kts, with further slowing expected prior to landfall.  That should 
put the eyewall ashore around 10pm EDT, probably at or near Fort 
Lauderdale, FL (it would be their first direct hit since 1964).  It's 
crossing over the Florida Current, a channel in the ocean floor with a 
constant re-supply of warm water (30.5C+).  Based on experience and some 
objective models, there still exists a decent chance of rapid 
intensification in the next few hours before the eyewall hits land.  A 
competing factor seems to be some dry air on the north and west sides 
of the storm.

A buoy just east of Cape Canaveral is now reporting 9ft waves, and 
growing rapidly (their normal non-storm wave height is about 1.5ft).  
The core is still far enough from land (40 miles or so) that the strong 
winds have not reached Fort Lauderdale as of this writing... they are 
currently reporting sustained winds of 15kts, gusting to 25kts.  At 16Z 
today, TS Katrina was located at 26.2N 79.4W and tracking W at 5kts.  
It is being monitored constantly by aircraft and by ground-based radar, 
and the latest intensity is 55kts and 990mb (fell 7mb in 2 hours).  A 
Hurricane Warning is in effect for all of the southeastern FL peninsula, 
and a Tropical Storm Watch is in effect for the Keys and the 
southwestern FL peninsula.  I suspect the central FL panhandle will have 
a hurricane watch issued later today or early tomorrow for them.

Another interesting question is, what happens after tonight's landfall?  
Although there is rather large divergence among model forecasts, the NHC 
shows the storm crossing westward over the peninsula, exiting into the 
Gulf, then recurving to the north and hitting the central FL panhandle 
early Monday morning as a hurricane.  Again, there is the chance it 
could be rather intense if it has the time.
Please visit my tropical Atlantic headquarters.

23 August 2005

Jose hits Mexico, TD12 forms over the Bahamas...

As expected, TS Jose made landfall on the Mexican coast and has since 
weakened considerably inland.

Of much greater concern is TD12.  Although one can make a very strong 
case for it being the remnants of TD10, the NHC called it TD12... it was 
upgraded to a Depression this afternoon based on an aircraft recon 
flight into it.  The center is not exactly easy to find, as there 
appears to be at least a couple of them.  However, the convection is 
very intense, the SSTs are incredibly warm, and the vertical shear is 
minimal.  This will likely be upgraded to TS Katrina in the next 12-18 
hours.

At 21Z, TD12 was located at 23.2N 75.5W and tracking NW at 7kts.  The 
maximum sustained winds are 30kts and the MSLP is 1007mb.  This motion 
is expected to continue for a couple days, then turn west as a ridge 
builds to its north.  What this means is that it should turn directly 
into the southern tip of Florida as it intensifies.  Then, after 
crossing the tip of the peninsula, it should enter the Gulf and be under 
ideal conditions for rapid intensification.  If you're in FL or along 
the northern Gulf coast, be sure to check out the track forecast!  This 
is a small system, and has the ability intensify very quickly.

Further east, the large circulation I've been mentioning is still out 
there at about 18N 37W, but the convection is all displaced east of the 
low-level center.  It's seemingly very close to being upgraded to TD13 
if the convection persists.
Please visit my tropical Atlantic headquarters.

22 August 2005

TS Jose forms in Bay of Campeche...

From what I can tell, the wave that was ahead (west) of ex-TD10 crossed 
the Yucatan Peninsula last night and emerged over the Bay of Campeche 
this morning.  It very promptly organized and was upgraded to TD11.  
Over the next few hours, it continued to organize and intensify, and an 
aircraft recon flight into it found that it was indeed a tropical storm, 
and was upgraded to TS Jose this afternoon... the earliest 10th named 
storm ever in the Atlantic (by one day).  At 22Z, TS Jose was located at 
19.6N 95.4W and tracking W at 5kts.  Intensity measured by aircraft was 
45kts and 1002mb.  It should make landfall on Mexico later this evening 
as a tropical storm and then rapidly deteriorate inland.

The remnants of TD10 are still easily trackable, now near Hispaniola.  
The wave is very weak, but still has sporadic convection and nice 
curvature in visible satellite imagery.  It will continue to be 
monitored closely, because it's heading for Florida, so IF it 
regenerates, things could get interesting.

Elsewhere, a very large wave exited Africa on August 20, and is now at 
about 16N 34W.  It's a bit far north for the classic track across the 
deep tropics, so if it forms, would likely recurve somewhere in the 
central Atlantic.  It's also lacking deep convection at this time, but 
conditions should remain favorable in the foreseeable future and this 
could become TD12 in the next couple of days.  The next name on deck is 
Katrina.
Please visit my tropical Atlantic headquarters.

Atlantic Earliest "N-th" Storm Records

From Gary Padgett:
 
Back in July I looked up the earliest occurrences of Atlantic
TCs number 6 - 12 within a season.     Dennis, Emily, Franklin,
Gert, Harvey and Irene all set new records for the earliest
4th, 5th, 6th, 7th, 8th and 9th tropical storms, respectively.
 
Following is an updated table for TCs 10 - 21:
 
Number     Number of            Earliest                 2nd Earliest                        3rd Earliest 
 of TS      Occurrences
-------------------------------------------------------------------------------------------------------------------------------------------------
10th TS         many             23 Aug 1995 (Jerry)       26 Aug 1933                   28 Aug 1936
11th TS         many             28 Aug 1933                 28 Aug 1936                   28 Aug 1995 (Karen)
12th TS         many             29 Aug 1995 (Luis)        31 Aug 1933                     7 Sep 1936
13th TS           17                 8 Sep 1933                  8 Sep 1936                    13 Sep 1995 (Marilyn)
14th TS           13               10 Sep 1933                 10 Sep 1936                    27 Sep 1995 (Noel)
15th TS             7               16 Sep 1933                 19 Sep 1936                    30 Sep 1995 (Opal)
16th TS             6               27 Sep 1933                   5 Oct 1995 (Pablo)           9 Oct 1936
17th TS             4               28 Sep 1933                   9 Oct 1995 (Roxanne)     21 Nov 1969 (Martha)
18th TS             3                1 Oct 1933                   21 Oct 1995 (Sebastien)    4 Dec 1887
19th TS             3               25 Oct 1933                  27 Oct 1995 (Tanya)          7 Dec 1887
20th TS             1               26 Oct 1933
21st TS             1               15 Nov 1933
 
All the above is based on the current Best Track file, which has been re-analyzed for the
years 1851 - 1910.   Information for 1911 onward will be subject to revision, and this
could affect stats for some of the busier seasons, especially 1916, 1933 and 1936.
 
 
Please visit my tropical Atlantic headquarters.

17 August 2005

Irene becoming extratropical...

Since my last update two days ago, Irene had briefly reached Category 2 
intensity, but is now rapidly losing tropical characteristics as it is 
affected by the mid-latitude jet.  It has been downgraded to a Tropical 
Storm with maximum sustained winds of 60kts and a central pressure of 
990mb.  It's located at 38.5N 56.3W and zipping off to the northeast at 
18kts.

The remnants of TD10 have continued to drift WNW and although struggling 
to overcome shear, appears to be making a comeback, and could be 
re-upgraded to TD10 in the near future.  It's presently at about 18N 
56W... a few hundred miles east of the Leeward Islands.

As of today at 21Z, the season's NTC stands at 81%.
Of historical note, today is the 36th anniversary of Hurricane Camille's 
deadly and devastating landfall on the MS coast.
Please visit my tropical Atlantic headquarters.

15 August 2005

Irene becomes 3rd hurricane, TD10 comes and goes...

On Sunday night, Irene was upgraded to a hurricane, the third of the 
season.  Since then, the satellite presentation has been quite nice, and 
it's not outlandish to think that it could become a CAT2 storm before 
transitioning to extratropical over the central north Atlantic.  At 21Z, 
Hurricane Irene was located at 36.7N 66.0W and tracking ENE at 10kts.  
The latest satellite imagery suggests that the motion is perhaps even E 
at 10kts.  Estimated intensity is 80kts and 980mb.

TD10 formed in the deep tropics over the weekend, but was in a high-
shear environment.  Only four advisories were written before NHC decided 
to downgrade it to a low-level circulation.  HOWEVER, within about 12 
hours, it will be crossing a low-shear zone, and if it takes advantage 
of that, it could regenerate and become interesting again.

I've descibed the NTC Activity index before, and as of now, the season 
stands at about 79%, which is quite phenomenal for the second week of 
August!  Typically, the bulk of the season is still coming in the next 
two months!
Please visit my tropical Atlantic headquarters.

12 August 2005

Irene nearly a hurricane...

Over the past 24 hours, Irene has become increasingly better organized, 
and is now just shy of becoming the 3rd hurricane of the season.  
Intensity as measured by an aircraft was 60kts and 997mb.  It is located 
at 28.7N 67.5W and heading NW at 9kts.  This motion is expected to slow 
down, then make a turn to the north then northeast, but weak steeering 
flow could make this is a long process, and Irene could thus be a 
hurricane for quite a while.

Currently, there is persistent deep convection over the center, the 
outer rainbands are weakening, and the outflow aloft is improving, 
helping this young tropical cyclone to breathe better.  The shear and 
SST environment are favorable for further development, and I don't see 
any reason why this will not become Hurricane irene later tonight.

Elsewhere, there's a potent tropical wave in the deep tropics at about 
12N 43W.  It exited the African coast on the morning of August 8 and has 
now had 4 days to organize a broad circulation.  This could become TD10 
or TS Jose over the weekend.
Please visit my tropical Atlantic headquarters.

11 August 2005

Irene making a comeback...

It has been a week since my last update, and since then Harvey came and 
went, finally making the transition to an extratropical cyclone over the 
north Atlantic, never having made it to a hurricane.  And TD9 that I 
mentioned in that update had briefly become TS Irene for a day, then 
weakened back to a TD, but over the past couple of days is making a 
genuine effort at looking impressive.  Now back to a TS and forecast to 
become a hurricane, Irene is between Puerto Rico and Bermuda and heading 
northwest.  It had been battling dry Saharan air that sometimes lingers 
over the ocean, as well as vertical wind shear.

As of 21Z today, TS Irene was located at 25.7N 63.9W and tracking WNW at 
13kts.  The maximum sustained winds are 45kts and the central pressure 
is 1000mb.  Conditions continue to improve and it is expected to reach 
hurricane intensity by Friday night.  The forecast track is most 
interesting... it could nip the US coast near Cape Hatteras or recurve 
before hitting.  At any rate, the closest approach should occur sometime 
on Tuesday.
Please visit my tropical Atlantic headquarters.

04 August 2005

TD8 becomes TS Harvey, TD9 forms in deep tropics...

Since my last update on Tuesday, TD8 has gotten much better organized, 
has become completely tropical in nature, and was upgraded to TS Harvey 
on Wednesday morning.  It passed just south of Bermuda as a moderately 
strong tropical storm, and is now not far from being a minimal hurricane.  
As of 21Z today, satellite-based intensity estimates are 55kts and 994mb.  
It's east of Bermuda and heading ENE into the open ocean.  

Over the past week, I've been watching a large easterly wave trek across 
Africa and out into the eastern Atlantic.  It entered the Atlantic on 
Monday morning and has been drifting westward since then, gradually 
getting better organized 
(http://einstein.atmos.colostate.edu/~mcnoldy/tropics/hovmoller/atlantic/).  
Today at 21Z it was upgraded to TD9 and has everything in its favor to 
quickly become Irene, the 9th named storm of the season, by tomorrow.  
It's located at 12.7N 34.5W and tracking W at 10kts.  Intensity is 25kts 
and 1009mb and is forecast to become a hurricane during the weekend.
Please visit my tropical Atlantic headquarters.

02 August 2005

TD8 forms off the US east coast...

Sorry for the lack of updates the past week, I was on vacation.  During 
that week, Franklin meandered off the east coast of the US and then 
zipped off into the north central Atlantic, racking up 8 "named storm 
days", and Gert formed and followed a nearly identical track and 
intensity as Bret, collecting just 1 named storm day, neither making it 
to hurricane intensity.

Today at 21Z, a somewhat subtropical-looking disturbance was upgraded to 
TD #8, and is headed generally toward Bermuda.  The deep convection is 
quite removed from the low-level center, and there's an upper Low to the 
southwest of the surface Low.  All-in-all, it doesn't look very tropical 
to me!  It's located at 28.5N 68.7W and moving N at 11kts.  Satellite-
estimated intensity is 30kts and 1009mb.  It is forecast to gradually 
intensity to a weak tropical storm, at which point it would be named 
Harvey.  A Tropical Storm Warning is in effect for Bermuda, and it 
should pass very near the island tomorrow night.

Elsewhere, there's a healthy easterly wave at about 11N 24W, tracking 
slowly westward at 5kts.  Although not real impressive now, conditions 
are favorable for it to develop.  This wave's origins can be tracked 
back to far eastern Africa on July 26... so it took about 8 days to get 
to its current location near the Cape Verde Islands.

The NTC for 2005 stands at 68.4% as of this afternoon.  The average NTC 
for this time of year is somewhere around 8%.
 
 
Please visit my tropical Atlantic headquarters.