ATL: TROPICAL DEPRESSION ANA (02L)

[vacanechaser]

12z CMC takes 99L on a westward track.

http://moe.met.fsu.edu/cgi-bin/cmctc2.c ... =Animation

yes it does... i noticed the 0z ecmwf does the same but sort of loses it once into the caribbean..



Jesse V. Bass III
http://www.vastormphoto.com
Hurricane Intercept Research Team

[Aric Dunn]

[cycloneye]

First GFDL plots

WHXX04 KWBC 091721
CHGQLM
ATTENTION...NATIONAL HURRICANE CENTER

NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR

TROPICAL DEPRESSION INVEST 99L

INITIAL TIME 12Z AUG 9

DISCLAIMER ... THIS INFORMATION IS PROVIDED AS GUIDANCE. IT
REQUIRES INTERPRETATION BY HURRICANE SPECIALISTS AND SHOULD
NOT BE CONSIDERED AS A FINAL PRODUCT. PLEASE SEE THE TPC/NHC
OFFICIAL FORECAST.


FORECAST STORM POSITION

HOUR LATITUDE LONGITUDE HEADING/SPEED(KT)

0 13.4 20.7 280./13.0
6 13.9 21.6 301./10.5
12 14.4 23.0 290./14.1
18 14.8 24.4 285./13.9
24 15.1 25.9 281./14.8
30 15.3 27.5 277./15.9
36 15.4 28.6 275./10.2
42 15.7 29.7 286./11.8
48 15.9 31.1 278./13.0
54 16.0 32.4 274./12.4
60 16.1 33.4 278./ 9.6
66 16.5 34.4 292./10.4
72 16.7 35.7 277./12.4
78 16.9 37.1 277./13.9
84 17.1 38.4 279./12.4
90 17.5 39.7 288./13.3
96 17.6 41.1 276./13.8
102 17.9 42.4 282./12.5
108 18.3 43.5 289./10.7
114 18.9 44.3 306./ 9.5
120 19.4 44.9 309./ 8.0
126 20.0 45.9 301./10.7

[njweather]

Any thoughts on SAL?

[jinftl]

Looking extremely healthy....shear and SAL don't seem to be big players at this point....i would speculate development this far east would more than likely suggest a fish storm...but a storm nonetheless (what we have all been waiting for)

[cycloneye]

Code Orange

229
ABNT20 KNHC 091730
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT SUN AUG 9 2009

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

AN AREA OF LOW PRESSURE...ASSOCIATED WITH A TROPICAL WAVE...IS
CENTERED JUST TO THE SOUTHEAST OF THE SOUTHERN CAPE VERDE ISLANDS
AND CONTINUES TO SHOW SOME SIGNS OF ORGANIZATION. CONDITIONS
APPEAR FAVORABLE FOR THIS SYSTEM TO BECOME A TROPICAL DEPRESSION
DURING THE NEXT COUPLE OF DAYS AS IT MOVES GENERALLY WESTWARD AT 10
TO 15 MPH. THERE IS A MEDIUM CHANCE...30 TO 50 PERCENT...OF THIS
SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.
REGARDLESS OF DEVELOPMENT...SHOWERS AND THUNDERSTORMS WITH LOCALLY
GUSTY WINDS COULD AFFECT PORTIONS OF THE CAPE VERDE ISLANDS OVER
THE NEXT DAY OR SO.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BERG/PASCH

[jinftl]

should stay south of the area of SAL for now...would have to hit 18N or so to hit it....there has been a definite decrease in th extent and strength of SAL over the basin....this image is very different than what we had been seeing, esp at lower 'storm-forming' latitudes. This is to be expected in August.

Any thoughts on SAL?

[vacanechaser]

should stay south of the area of SAL for now...would have to hit 18N or so to hit it....there has been a definite decrease in th extent and strength of SAL over the basin....this image is very different than what we had been seeing, esp at lower 'storm-forming' latitudes. This is to be expected in August.

Any thoughts on SAL?

yep.. and looking at that image, the sal does not appear to be to strong at this time either... have seen storms develop in worse conditions!!


Jesse V. Bass III
http://www.vastormphoto.com
Hurricane Intercept Research Team

[cycloneye]

The loop of the 12z GFDL has a 70kt cane at one point of the loop.

http://moe.met.fsu.edu/cgi-bin/gfdltc2. ... =Animation

12z HWRF has a moderate tropical storm.

http://moe.met.fsu.edu/cgi-bin/hwrftc2. ... =Animation

[Nimbus]

Do you suppose the NHC is waiting to upgrade this to a TD because they want to get a better handle on the future track? The last wave that came off Africa looked quite impressive at this longitude but it went poof once it got a little further west. This wave seems to have a little stronger pulse and more moisture to work with. The models will do a better job if they have been initialized with a clear LLC position and with a longer history of the strengthening/weakening trend.

[jinftl]

TWC on-board with development....in latest Tropical Update said this is the strongest system to move off of africa this season so far and it could become ana in the next few days.

[dixiebreeze]

http://manati.orbit.nesdis.noaa.gov/sto ... _at_0.html


Scat

[Macrocane]

The models are showing stronger disturbances coming off from Africa, I think we have reached that time of the year when conditions are improving for development. Earlier a quikscat showed a closed circulation trying to form, IMO this has a good chance of becoming Ana I think it will be a weak to moderate tropical storm but this is just an UNOFFICIAL OPINION.

[SEASON_CANCELED]

http://manati.orbit.nesdis.noaa.gov/storm_at_image21/latest_at_0.html


Scat

They really need to rename that.

[jinftl]

From Dr. Jeff Master's blog this morning:

A strong tropical wave with a high amount of spin moved off the coast of Africa yesterday, and has a good chance of becoming the first named storm of the 2009 Atlantic hurricane season. The wave was designated 99L by NHC Sunday morning. Wind shear is moderate, about 10 knots, and sea surface temperatures are moderately warm, about 27 - 28°C. There is a large area of dry air to 99L's north, but this is not currently interfering with the storm's organization. This morning's QuikSCAT pass showed a nearly closed surface circulation, stretched out along two axes.

The storm can now be classified as tropical depression using the satellite-based Dvorak classification technique, but the surface circulation will have to show better definition before 99L can be classified as a tropical depression. Top winds were in the 20 - 30 mph range, as estimated by QuikSCAT and the Dvorak satellite estimates.

Wind shear is expected to be low, 5 - 10 knots, tonight through Tuesday. SSTs will remain relatively constant at 27°C, so conditions favor development. NHC has given 99L a moderate (30 - 50% chance) of developing into a tropical depression by Tuesday morning, which is a reasonable forecast. The UKMET, GFS, and NOGAPS models all develop 99L into a tropical depression 1 - 4 days from now. The dry air of the Saharan Air Layer may become a problem for 99L 2 -4 days from now, as the storm moves slightly north of due west. It is too early to say if 99L will recurve north of the Lesser Antilles Islands or not, since it will be at least 6 days before the storm makes it that far.

The GFS model predicts development of a new tropical wave coming off the coast of Africa about 6 - 7 days from now.

[Andrew92]

I have a personal wish about this particular system......

I actually hope this one develops into Ana and stays far away from any land. But I do also hope conditions are just favorable enough over those open waters to where this can become a hurricane. Ana has come and gone every year since 1979 without becoming a hurricane, I think she's due. Just stay out in the middle of nowhere though, OK?

Looking at this wave and the models, I think it's got a reasonable chance. Remember, intensity forecasts are difficult to pin down.

-Andrew92

[Ptarmigan]

Looks like we could have TD or even Ana by later today.

[KWT]

Looks like they've decided to wait for another 6hrs before pushing it upto a red alert. IMO though this probably should be code red, its looking very impressive right now.

Models do seem to be suggesting this weakening in about 72hrs, nearly all of them weaken it just as the next wave rolls off Africa. We shall see I suppose!

[vacanechaser]

The loop of the 12z GFDL has a 70kt cane at one point of the loop.

http://moe.met.fsu.edu/cgi-bin/gfdltc2. ... =Animation

12z HWRF has a moderate tropical storm.

http://moe.met.fsu.edu/cgi-bin/hwrftc2. ... =Animation

seems like the hwrf takes less of a northern track... looks a little south of the gfdl... at least at this point...



Jesse V. Bass III
http://www.vastormphoto.com
Hurricane Intercept Research Team

[Aric Dunn]

latest RGB loop..... also the latest amsre microwave image which is quite a good pass and shows some very interesting features. the image shows banding setting up in all quads but much more limited on west side also its pretty near the surface.