26 September 2005

Rita makes landfall...

In the early morning hours on Saturday (around 3am local), Rita crossed the coastline as a powerful Category 3 hurricane, near Sabine, TX on the TX/LA border.  Cameron, LA got the eastern eyewall and was severely damaged, as was Lake Charles, LA.
You can view a radar loop that I made of this landfall at http://einstein.atmos.colostate.edu/~mcnoldy/tropics/rita/Rita_23-24Sep05.gif

Also, photojournalist Allan Detrich recorded a sound file during the eyewall passage in Beaumont, TX... you can listen to this short clip at http://einstein.atmos.colostate.edu/~mcnoldy/tropics/rita/rita.WAV.  In terms of rainfall, New Orleans got 6.3", Beaumont received about 9"; Center, TX got 10.5"; and the largest total is in Bunkie, LA at 16".

Elsewhere, nothing is of immediate concern as shear seems to dominate many of the classic formation zones.  However, there are active waves out there, so if conditions improve, something could form fairly quickly.

Please visit my tropical Atlantic headquarters.

23 September 2005

Rita less than 24 hours from the coast...

At 15Z, Rita was located at 27.4N 91.9W, about 200 miles from Sabine TX.  Aircraft-measured intensity is 115kts and 929mb.  It is in the midst of an eyewall replacement cycle, so the intensity may fluctuate +/- 10-15 kts.   Hurricane Warnings are in effect from Port O'Connor TX eastward to Morgan City LA.

Landfall is still expected to occur between Galveston TX and Cameron LA, perhaps near the small coastal town of Sabine TX.  Intensity is a great forecast problem, but should be CAT 3/4 barring any unforeseen changes.  The majority of hurricane conditions leading up to landfall will occur during the early morning hours on Saturday, then landfall itself should be around sunrise-ish.  Hurricane-force winds will be felt about 85 miles to the east and west of the landfall point, including Houston and Lake Charles.  The following map shows the potential storm surge from Rita:  http://www.fema.gov/hltdata/attachments/u1_sabine_slosh.jpg

My friend and photojournalist Allan Detrich is in Beaumont TX with reporter Dennis Roddy from the Pittsburgh Post-Gazette.  They are at the Civic Center there, and report that the city is a ghost town, barely anyone to be seen, gas is very hard to come by, and winds are ~15mph and picking up slowly.  Sites along the coast are already seeing water levels rise several feet: this site shows the tidal gauge data from Sabine, TX, which is right on the coast at the TX/LA state border.
http://tidesonline.nos.noaa.gov/plotcomp.shtml?station_info=8770570+Sabine+Pass+North,+TX+&flag=0

You can also follow the storm via the Lake Charles radar at http://radar.weather.gov/radar/latest/DS.p20-r/si.klch.shtml or via the Houston radar at http://radar.weather.gov/radar/latest/DS.p20-r/si.khgx.shtml

Part 2 of issues with Rita is that the steering flow is forecast to be basically non-existant once it's inland a bit, leaving it to rain for days over TX/LA/AR/OK... possibly dumping over 2 FEET of rain.  And of course, the usual threat of tornadoes exists associated with the hurricane.

Philippe is STILL hanging on as a tropical storm, barely recognizable as a tropical entity.  As of 15Z today, it was located at 31.1N 63.2W (just southeast of Bermuda) and the estimated intensity was 35kts and 1005mb.  It is heading north, and has prompted Bermuda to issue a Tropical Storm Warning.

Elsewhere, something that spun off of Philippe is presently halfway between Bermuda and Puerto Rico and could be worth watching over the next few days.  Also, a large tropical wave that exited Africa yesterday morning is located at about 12N 28W and bears watching... although the vertical shear is VERY high over it now, the low-level energy should persist and could develop when conditions improve.

Please visit my tropical Atlantic headquarters.

22 September 2005

Rita breaks the 900 barrier...

At 03Z today, Hurricane Rita's central pressure bottomed out at 897mb, nudging past the rarely-broken 900mb threshold.  Only 3 other storms have achieved this intensity: Gilbert 1988 (888mb), Labor Day 1935 (892mb), and Allen 1980 (899mb).  This occurred just 24 days after Katrina reached its peak intensity of 902mb, and virtually at the same location.

Since then the storm has weakened a BIT, and is presently at 915mb and ~140kts.  Given that such a high intensity is so hard to achieve, let alone maintain, the storm is expected to weaken further over the next 24-36 hours prior to landfall.  BUT, keep in mind that a storm at 907mb has a looong way to weaken before it's not major, so landfall will almost certainly be as a CAT3/4 hurricane.  It's moving WNW at 8kts, but this motion will become NW with time as the steering ridge to its north shifts eastward.  The latest position is 25.4N 88.7W, or about 225 miles due south of the mouth of the Mississippi River.

Landfall is becoming a more ominous event, and is expected to occur in the early morning hours on Saturday as a major hurricane.  The latest official track forecast and model guidance have shifted eastward a bit, now placing the prime target just east of Galveston Bay.  Hurricane Warnings are in place now from Matagorda Bay TX eastward to Atchafalaya Bay LA, and evacuations are underway in many cities within the warning area (also in New Orleans with fears of the rainfall breaking the patched levees).  Hurricane-force winds now extend 75 miles from the center.

Looking beyond landfall, the steering flow is forecast to dwindle, leaving Rita to stall over TX/OK/AR/LA, perhaps dumping upwards of 2 feet of rain over the area.  This has to potential to be a very catastrophic storm.  The eyewall is only one part of the storm... the coast has to contend with a large storm surge, and places inland have to contend with rain-induced flooding and spiral band-spawned tornadoes.

Philippe is still a tropical storm, with estimated intensity at 35kts and 1005mb.  It is quickly losing tropical characteristics and today will likely be its last day as a tropical system.  The transitioning system is heading north toward the north-central Atlantic.

The season's NTC stands at 175% now; only ten years since 1900 have had higher seasonal NTCs, and this season isn't over yet.

Please visit my tropical Atlantic headquarters.

21 September 2005

Rita reaches Category 5 intensity...

Hurricane Rita has been very well observed by aircraft today, having four planes in it simultaneously at times.  And based on the data collected by the planes, Rita was upgraded to a CAT5 hurricane at the 21Z advisory today.   The maximum sustained winds are 145kts (maybe higher now?) and the central pressure has plumetted to 904mb and still falling.  This is a big storm, with hurricane-force winds extending 50 miles from the center... this will only grow with time.

Landfall is of course the big concern with this storm (otherwise, it would just be a beautiful vortex over the open ocean!).  Computer model guidance has gradually clustered more around the Port Lavaca area, or roughly halfway between Corpus Christi and Galveston/Houston.  The timing should place Rita near the coast late Friday night into early Saturday morning.  A Hurricane Watch has just been issued for basically the entire TX coast, and evacuations are well underway in Houston, Galveston, Corpus Christi, Port Lavaca, and other smaller towns in between.  A worst-case scenario that people are preparing for is that the storm comes in just south of Galveston, driving Galveston Bay into parts of Houston.

Please visit my tropical Atlantic headquarters.

Rita intensifies very quickly, headed for Texas...

Phillipe has weakened to a tropical storm and will likely struggle to 
maintain that status as it's pounded by strong westerly wind shear.  
It's located  northeast of the Leeward Islands and barely looks tropical
anymore.  Latest intensity estimate is 45kts and 1000mb.

Rita, on the other hand, has strengthened immensely since my last update 
on Monday afternoon.  It became the 9th hurricane of the season on 
Tuesday morning, and continued to strengthen rapidly as it became the 
5th major hurricane of the season early Wednesday morning.  This trend 
continues, and Rita is nearly a CAT5 hurricane now.  The latest central 
pressure as of this writing is 920mb, which means the pressure has 
fallen 28mb in the last 6 hours, and 58mb in the last 24 hours.  One 
wonders how much further it will fall, and will it exceed Katrina's peak 
intensity of 902mb?

It is about to pass over a deep warm eddy in the central Gulf, which 
should give it another boost in intensity.  Then ~12 hours after that, 
it MIGHT pass over a cool eddy and could weaken the storm a bit.  Keep 
in mind the surface temperature of the water is still a toasty 
28.0-29.5C along its projected track, but the DEPTH of that warm water 
can play a role too.
http://www.aoml.noaa.gov/phod/dataphod1/work/HHP/NEW/2005263go.jpg

The last official advisory at 15Z had the intensity at 120kts and 944mb, 
but that is already far too weak.  The motion is toward the W at 11kts, 
and environmental conditions are ideal for further strengthening.  The 
forecast calls for the hurricane to maintain CAT4/5 intensity through 
landfall, which raises the age-old questions of when and where.  
Landfall is expected to occur in the early morning hours on Saturday, 
roughly halfway between Galveston/Houston and Corpus Christi, or near 
Port Lavaca.  Although Hurricane Watches are not yet posted for the TX 
coast, mandatory evacuations are already being carried out in the areas 
I just mentioned, particularly vulnerable Galveston and populated 
Houston.  Hurricane Katrina refugees who moved from one costal city to 
another coastal city in the peak of hurricane season are being moved 
again out of harm's way (not a big surprise).  This time, the evacuees 
are moving inland.
Please visit my tropical Atlantic headquarters.

19 September 2005

Philippe and Rita both strengthening...

Philippe was upgraded to a hurricane -- the 9th of the season -- at 03Z 
today based on satellite presentation.  It is a minimal hurricane with 
65kt sustained winds, but it is forecast to intensify, perhaps reaching 
CAT3 status in a few days.  The good news is that it is in the central 
Atlantic and will remain there, heading north.  At 15Z, it was located 
at 17.4N 56.3W, or about 5 degrees east of the Leeward Islands.

TD18 was upgraded to TS Rita at 21Z yesterday, and the storm is 
apparently starting a rapid intensification phase now, with structural 
improvements every hour.  A plane is en route as I write this and I 
suspect it will find that Rita is now a hurricane.  As of 15Z, TS Rita 
was located at 23.0N 75.2W (over Great Exuma Island in the Bahamas) and 
tracking WNW at 10kts.  The estimated intensity was 55kts and 994mb, but 
that will be updated with actual observations once the aircraft 
penetrates the storm in the near future.  The SSTs in the storm's 
immediate path are very warm, 30C+, with a strong ridge to the north 
providing minimal wind shear and westward steering flow.

More and more computer models favor a major hurricane hitting the 
Florida Keys on Tuesday afternoon/evening, which would be devastating, 
since mandatory evacuations have only begun this morning.  Furthermore, 
the storm will then enter the Gulf of Mexico and has no obvious factors 
to keep it from becoming even stronger.  As of now, the landfall 
position is anywhere from the central TX coast eastward to eastern LA, 
and although intensity is not accurately known out that far, it should 
be rather strong.  This landfall on the Gulf Coast is expected to occur 
late Friday into early Saturday, depending on the exact track.

A Hurricane Warning is in place for some of northwestern Cuba, Andros 
Island in the Bahamas, and all of the southern tip of Florida.  
Mandatory evacuation orders are in place for the Florida Keys, and 
voluntary evacuations are occuring further north toward Miami.
http://www.nhc.noaa.gov/refresh/graphics_at3+shtml/153924.shtml?3day
 
 
 
Please visit my tropical Atlantic headquarters.

18 September 2005

Ophelia dissipates, Philippe and TD18 form...

Late Saturday night, the NHC wrote the final advisory on Ophelia, as she was zipping off past Newfoundland into the north central Atlantic and becoming an extratropical cyclone.

The large tropical wave I have been discussing in the central deep tropics was upgraded to TD17 on Saturday morning, and then upgraded again to TS Philippe on Saturday night.  Although forecast to become a major hurricane, it is also expected to turn to the north and recurve by 65W, never affecting land.  As of 15Z today, Philippe was located at 15.2N 55.7W and tracking NNW at 6kts.  Satellite-estimated intensity is 45kts and 1000mb.

And the area of disturbed weather I mentioned on Friday near Puerto Rico was upgraded to TD18 on Saturday night and continues to get better organized by the hour.  It is currently located at 22.0N 72.2W (over the far eastern Bahamas) and tracking W at 10kts.  The estimated intensity is 30kts and 1008mb, but aircraft recon missions are planned for it to get a better handle on actual intensity.  This should become TS Rita later today.

A Hurricane Watch is in effect for the western Bahamas and for the Florida Keys.  A Tropical Storm Warning is in effect for the eastern Bahamas.  This storm is forecast to pass between Cuba abd Florida and enter the Gulf on Wednesday as a powerful hurricane.  The latest computer model guidance shows a westward track, heading toward TX/Mexico, but all eyes should be on it anywhere along the Gulf, and certainly southern Florida.

Elsewhere, there's an area of interest in the deep tropics, near 11N 37W.  This is forecast to move westward toward the Lesser Antilles and gradually strenghten.  It's currently poorly organized, but conditions should improve.  The next number/name on deck is 19/Stan.

I should also point out that the Eastern Pacific basin presently has three named storms as well (Jova, Kenneth, and Lidia), so someone must have turned on a switch!

Please visit my tropical Atlantic headquarters.

16 September 2005

Ophelia creeping away from the US coast...

Category 1 Hurricane Ophelia pounded the NC coast for over 40 hours as 
it moved VERY slowly along the coastline.  It never actually made 
landfall, but the western eyewall remained over land the whole time.  I 
suspect we'll hear more about the flooding and coastal 
erosion/destruction in the coming days.  It's nothing like what Katrina 
did, but not negligible either.  You can view a couple of radar loops of 
the slow transit at:
http://einstein.atmos.colostate.edu/~mcnoldy/tropics/ophelia/Ophelia_13-14Sep05.gif
http://einstein.atmos.colostate.edu/~mcnoldy/tropics/ophelia/Ophelia_14-15Sep05.gif

Last night, Ophelia was downgraded to a tropical storm and is still 
sitting just east of the NC/VA border.  The latest intensity is 50kts 
and 996mb.  The forecast track takes it NNE, just clipping by Cape Cod 
and perhaps hitting Nova Scotia on Saturday night.

Elsewhere, that large tropical wave I mentioned a couple days ago is 
still there, moving slowly westward, and is not in any rush to get 
better organized.  It must still be watched very closely, because of the 
potential track if it develops.

And lastly, an area of disturbed weather has been festering at the 
trailing edge of an old cold front, just north of Puerto Rico.  This has 
been gradually getting better organized, but again, it's in no hurry.  
Either one of these systems could become TD17 (and TD18?) over the 
weekend.
Please visit my tropical Atlantic headquarters.

14 September 2005

Ophelia pounding the NC coast...

Hurricane Ophelia has still not technically made landfall as of 22Z, but 
the western eyewall is raking the coast, exposing every coastal 
community in NC to the eyewall for hours due to its slow motion.  Aside 
from the torrential rains which may total 20" in some places, a 10' 
storm surge can be expected in the bays of eastern NC.

As of 22Z, Ophelia was located at 34.2N 77.0W, or approximately 40 miles 
form the coast.  Keep in mind that center position is the location of 
the center of the large eye, so hurricane-force winds already can be 
found inland.  Intensity is 75kts and 979mb, with perhaps a bit more 
strengthening in the next 12-24 hours.  You can follow its progress via 
radar imagery at 
http://weather.noaa.gov/radar/latest/DS.p19r0/si.kmhx.shtml

Elsewhere, a large tropical wave that exited Africa on September 8 is 
making its way westward across the deep tropics.  Currently at about 7N 
45W, it's taking a very far south track, reminiscent of Ivan 2004.  
Conditions do appear favorable for gradual intensification, and this 
should become TD 17, and the next name on deck is Philippe.
Please visit my tropical Atlantic headquarters.

13 September 2005

Ophelia heading toward US east coast...

My last update was sent on Thursday, but very little has happened since 
then.  Maria and Nate are long gone, absorbed by a mid-latitude trough.  
Ophelia has drifted or remained stationary day after day, now heading 
NNW at 3kts toward the NC coast as a minimal hurricane.

At 21Z, Ophelia was located at 32.7N 77.9W, or about 100 miles east of 
Charleston.  Aircraft-measured intensity is 65kts and 985mb.  It should 
maintain this intensity as it scrapes the coastline and Outer Banks.  A 
Hurricane Warning is in effect for most of NC and the northern half of 
SC.  Hurricane Watches cover the remainder of NC and SC.  You can track 
the hurricane via radar at 
http://weather.noaa.gov/radar/latest/DS.p19r0/si.kltx.shtml

21 years ago today, Hurricane Diana made landfall on the NC coast.  And 
17 years ago today, the Atlantic's most intense hurricane on record 
(Gilbert) hit the Cayman Islands.  The season's NTC stands at 144.8%, 
which still leaves it as the 17th highest NTC overall since 1900.  Keep 
in mind it's only mid-September though!
Please visit my tropical Atlantic headquarters.

08 September 2005

a tropical tidbit to reflect on

"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


Please visit my tropical Atlantic headquarters.

Maria, Nate, and Ophelia are all hurricanes...

Maria stubbornly refuses to become a truly extratropical cyclone, and 
is still clinging onto hurricane status.  At 21Z, the storm was located 
at 39.5N 46.8W and moving NE at 10kts... this is uncharacteristically 
slow for such a high latitude!!  Satellite-estimated intensity is 65kts 
and 982mb.  Although it will remain a powerful cyclone, the next 1-2 
days will see the full transition from tropical to extratropical.

Nate has changed very little in the past 24 hours, but has passed to 
the south of Bermuda and is now safely out of their way.  It remains a 
CAT1 hurricane with sustained winds of 75kts and a central pressure of 
982mb.  As of 21Z, it's at 31.8N 62.0W and tracking NE at 14kts.

Ophelia, sitting at exactly the same spot it was 24 hours ago, was 
recently upgraded to a hurricane, the seventh of the season.  It is 
intensifying just dozens of miles east of Cape Canaveral, and shows no 
signs of moving soon.  However, with the warm Gulf Stream flowing 
underneath it, a constant supply of energy is available.  The latest 
intensity is 65kts and 985mb.  You can track it easily from Melbourne's 
radar at http://www.srh.noaa.gov/radar/latest/DS.p19r0/si.kmlb.shtml.  
In the near term, it is expected to gradually drift toward the NE, but 
the US coast should not let it's guard down... several models project 
that it could loop back around and hit the coast.

The season's NTC is climbing rapidly now, and stands at an impressive 
140%, high for any year, but it's only September 8!  In fact, going back 
to 1900, only 16 years have had higher NTCs for the entire season, so 
it will be interesting to see how many of those will be surpassed by 
the end of the 2005 season.
 
 
Please visit my tropical Atlantic headquarters.

07 September 2005

Maria, Nate, and Ophelia ring in the peak of the season...

Maria had briefly weakened to a Tropical Storm overnight, but jumped 
back to CAT1 status during the day, and is decidedly in the early-mid 
stages of ET transition.  At 21Z, Hurricane Maria was located at 36.9N 
50.4W and accelerating to the NE.  Satellite-estimated intensity is 
70kts and 980mb.  Advisories should cease on this storm within 24 hours 
as it's absorbed by a mid-latitude trough.

Nate has strengthened into the 6th hurricane of the season, and has a 
beautiful eye in satellite imagery.  Though only a CAT1 now, there is a 
good chance that it will reach CAT2, and possibly even CAT3 within the 
next day.  It's located just south of Bermuda, and slowly intensifying.  
Latest intensity estimate is 75kts and 979mb, but an aircraft is 
scheduled to investigate it later tonight for a true measurement.  
Nate's fate is nearly identical to Maria's... being scooped up by the 
same mid-latitude trough and becoming an extratropical cyclone.

TD16 was upgraded to TS Ophelia at 06Z today.  This beats the date for 
the earliest 15th named storm by a whopping 9 days!  If I'm not 
mistaken, that means 11 of our 15 named storms this season have set the 
new record for earliest formation date.  If Philippe forms before Sept 
27th, we'll have another to add to the record list.  This storm is 
particularly intersting because it's literally just 80 miles off the 
Florida coast!  It is basically stationary, and being subject to 
moderate southeasterly wind shear.  However, it has the warm Gulf Stream 
directly under it, and plenty of time, as it is forecast to remain 
nearly stationary for the next few days.  This is one that people from 
FL to NC need to be watching rather closely.  Current intensity is 45kts 
and 996mb.  The primary threat now is the very heavy surf being 
generated along the southeastern coast.
Please visit my tropical Atlantic headquarters.

06 September 2005

Maria, Nate, and TD16 keep the season going...

TD14 formed last Thursday, was upgraded to Maria on Friday, then had a much more productive weekend than forecasters had anticipated.  Maria became the season's 5th hurricane on Saturday morning, and the season's 4th major hurricane on Monday night.  It is currently a Category 2 storm with 85kt winds and a central pressure of 975mb, located at 33.8N 55.6W.  It is feeling the effects of an upper-level trough and will begin the extratropical transition today as it's whisked out to the north central Atlantic... the hurricane graveyard.

An upper-level Low to the west of Maria developed a surface Low and became TD15 on Monday afternoon.  It was upgraded to TS Nate late last night and is looking very impressive on satellite imagery.  Nate, like Maria, is forecast to remain well out in the Atlantic and be taken out by the same upper-level trough.  However, Bermuda has all eyes on this storm, as it could hit the island as a hurricane.  I'd image that after Fabian '03, they're not looking forward to the visit.  As of 15Z today, TS Nate was stationary at 28.7N 66.7W.  Estimated intensity is 50kts and 997mb.  Further strengthening is forecast and Nate should become the 6th hurricane of the season.  This is the earliest date for the 14th named storm, beating the old record by four days.

Lastly, a new Tropical Depression formed over northwestern Bahamas this morning... TD16.  It is expected to intensify and head toward the FL/GA coast over the next couple of days.  Residents there should be alert to this storm as it is so close to land.  Conditions appear favorable for gradual intensification, and it's expected to become TS Ophelia later today or tomorrow.  At 15Z, it was located basically over Grand Bahama Island.  It's also stationary, but should begin drifting to the NNW with time.  Tropical Storm Warnings are in place for northwest Bahamas and the central portion of Florida's east coast.

With this latest flurry of activity, the NTC for the season stands at 128%, which is quite phenomenal for Sept 6!

Please visit my tropical Atlantic headquarters.

02 September 2005

Lee dissipates, Maria forms...

Since my last update on Wednesday, Lee had quickly dissipated due to excessive vertical shear.  It is now a barely noticeable low-level swirl over the north central Atlantic.

However, that hefty tropical wave I mentioned was finally upgraded to TD14 on Thursday morning, and then upgraded to TS Maria this morning.  It will have a track and fate nearly identical to Lee, so it is no threat to land.  It is not forecast to reach hurricane intensity.  As of 15Z today, TS Maria is located at 21.3N 50.0W and tracking WNW at 8kts.  Satellite-estimated intensity is 35kts and 1007mb.

Maria is the earliest 13th named storm on record, crushing the old record by 6 days.  So far, every storm from Dennis through Maria has broken the record for earliest N-th storm, with the exception of Lee, who lagged Luis 1995 by two days.  If Nate forms before September 10, it will also hold the record for the earliest 14th named storm.  The season's NTC is now at 112% as of 15Z this morning, and we're just now entering the climatological peak of the season.

The wave that had just exited Africa on Wednesday has continued to trek westward and is presently near 7N 38W.  It's presently lacking deep convection, but the wave is holding together and actually has a 1008mb Low embedded within it.  The longer range track would take it very near the Leeward Islands in 5 days.  The SSTs should be at least 29C, and variable wind shear will allow for periods of strengthening and weakening, but given the overall current and future conditions, it should be free to intensify to a powerful hurricane by early next week, if not sooner.  This will likely become TD15, then the next name on deck is Nate.  This is the type of track that the US east coast needs to be on alert for.


Please visit my tropical Atlantic headquarters.