TD 2 nearly dead; African disturbance 90L gathering strength

By: Dr. Jeff Masters , 2:38 PM GMT on August 13, 2009

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Tropical Depression Two is near death, but is still worth watching. The dry, Saharan air to the north and west of the depression, combined with moderately high levels of wind shear of 15 - 20 knots, have almost completely destroyed all of TD 2's heavy thunderstorms. Satellite loops of the storm show a well-formed circulation, but almost no heavy thunderstorm activity.

Wind shear over TD 2 is expected to remain in the modereate range, 10 - 20 knots, over the next five days. Sea Surface Temperatures (SSTs) are 27°C, but will warm to 28°C three days from now. There is plenty of dry, stable air from the Saharan Air Layer (SAL) to to TD 2's north and west that will continue to cause the storm problems. The relatively cool SSTs and dry air mean that TD 2 will not be able to intensify quickly, and some of the models indicate the TD 2 may get destroyed in the next day or two. However, several models still predict TD 2 will become a tropical storm. The HWRF model predicts TD 2 will become a hurricane five days from now, but this seems unlikely given the dry air and relatively high wind shear affecting the storm.


Figure 1. Tropical Depression Two (left side of image) and tropical wave 90L (right side of image).

African tropical wave 90L
A strong tropical wave with a large circulation and plenty of heavy thunderstorm activity is a few hundred miles south of the Cape Verdes Islands, off the coast of Africa. NHC dubbed this disturbance 90L this morning. This morning's QuikSCAT pass shows that 90L has a very large circulation, and top winds of about 30 mph. Satellite imagery from the European METEOSAT satellite show that the heavy thunderstorms associated with 90L are in two major bands, to the north and to the south of the center. There is no heavy thunderstorm activity near the center yet, and this would have to happen before 90L can be named Tropical Depression Three. Water vapor imagery shows that since 90L is forming several hundred miles south of the dry air of the Saharan Air Layer (SAL), the storm should not be affected by dry air and dust as much as Tropical Depression Two has been. Wind shear is about 20 knots over 90L, and is forecast to remain in the moderate range, 10 - 20 knots, over the next five days. Sea Surface Temperatures are about 28°C, and will remain in the 27 - 28°C range the next five days, which are high enough above the 26°C threshold for tropical cyclone formation to allow some slow development to occur. The GFS and ECMWF models continue to predict the development of this wave, though they are now less aggressive about intensifying it than they were in earlier runs. The consensus among the reliable HWRF, GFDL, GFS, and ECMWF models is to bring 90L to point near or just north of the northernmost Lesser Antilles Islands 6 - 8 days from now. The storm could be at hurricane strength by then, as forecast by the SHIPS intensity model.

I'll have an update Friday morning.

Jeff Masters

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Personally I think the wave near the Bahamas looks better than 90L IMO
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1386. KEEPEROFTHEGATE (Mod)
Quoting Patrap:
.."I gotta Tell ya Folks,Patrap and Ike and Drak and all them wunderbloggers are right about one thing,..trouble is Brewing and now's the time to prepare for what may come along downstream in time..

Back to you Guys in the Studio"..

only a matter of time now and time feels like it moves real fast sometimes
Member Since: July 15, 2006 Posts: 169 Comments: 53296
Looks like a SEX change will be in order for 90L......Call the nurses and Surgeons in please before he/she changes thems mind again
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Quoting Vortex95:
Thats one of the more optimistic Last advisories i've seen. In the chance it does regenerate will it be recalled TD2 or TD 3,4


Would still be TD 2 unless it merges with another entity and the remnants can no longer be identified.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
Quoting Drakoen:
I'll be watching TD2 for regeneration.

regeneration of (ex) TD2 would likely happen when?
Member Since: June 13, 2009 Posts: 2 Comments: 11004
Quoting Drakoen:


Regardless


We'll see...
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1380. HadesGodWyvern (Mod)
At 18:00 PM UTC, Tropical Storm Guillermo (992 hPa) located at 17.2N 123.1W or 815 NM west-southwest of the southern tip of Baja California Peninsula has sustained winds of 60 knots with gusts of 75 knots. The cyclone is reported as moving west at 13 knots.

Gale/Storm-force Winds
================
90 NM from the center

Forecast and Intensity
======================
12 HRS: 17.6N 125.1W - 65 knots (SSHS-1 Cyclone)
24 HRS: 18.2N 127.9W - 70 knots (SSHS-1 Cyclone)
48 HRS: 19.4N 133.6W - 60 knots (Tropical Storm)
72 HRS: 20.5N 139.0W - 50 knots (Tropical Storm)
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1379. cg2916
Quoting Seflhurricane:
lets do a poll on 90L

A) 90L becomes TD3 at 11PM

B)90L becomes TD3 at 5Am

C)90L Becomes TD 3 at 11Am

D) 90L does not become a TD At all

E. Takes until 5 PM Friday or sometime Saturday.
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Quoting Seflhurricane:
lets do a poll on 90L

A) 90L becomes TD3 at 11PM

B)90L becomes TD3 at 5Am

C)90L Becomes TD 3 at 11Am

D) 90L does not become a TD At all


C.
Member Since: Posts: Comments:
Quoting Seflhurricane:
lets do a poll on 90L

A) 90L becomes TD3 at 11PM

B)90L becomes TD3 at 5Am

C)90L Becomes TD 3 at 11Am

D) 90L does not become a TD At all


That seems the most reasonable. Just to give it time.
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Quoting Vortex95:
Thats one of the more optimistic Last advisories i've seen. In the chance it does regenerate will it be recalled TD2 or TD 3,4


Assuming that it's the same circulation...then yes, I believe so. Could be wrong. I remember Katrina was given a new number after regeneration.
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Quoting Seflhurricane:
lets do a poll on 90L

A) 90L becomes TD3 at 11PM

B)90L becomes TD3 at 5Am

C)90L Becomes TD 3 at 11Am

D) 90L does not become a TD At all

I guessing B.
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The NHC needs to find a cloud, any old cloud will do, and name her Ana so we can get this over with. 90L will probably die in the next 24 minutes also.
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1373. Patrap
Quoting NOLABean:
Pat, you are on fire today. I have laughed all day.


Speaking of Fire,..I just Lit da pit here Uptown,gonna Burn some Cluckers this evening
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What will be interesting to see if Complex Genesis occurs on ex-TD2 with that Tropical Wave north of Haiti that's interacting with an ULL. Its a thought, but this set up does remind me of ex-TD10.
Member Since: August 10, 2009 Posts: 3 Comments: 672
Latest from NWS San Juan...

THE MAIN STORY REMAINS THE LONGER TERM TROPICAL SITUATION WHICH
REMAINS VERY UNCLEAR AT THE CURRENT MOMENT. LATEST NHC ADVISORIES
AND DISCUSSION HAVE DOWNPLAYED TD 2 INTO A WEAK SYSTEM...AND
KEEPING IT AS SUCH THROUGHOUT THE FORECAST PERIOD. WHILE THIS IS
SEEMINGLY GOOD NEWS...IT WOULD LIKELY RESULT IN A MUCH MORE
SOUTHERLY TRACK...PERHAPS EVEN SOUTH OF PUERTO RICO. THE GOOD NEWS
REMAINS THAT A DEEP SAL LAYER AND MODERATE EASTERLY SHEAR ARE
IMPEDING DEVELOPMENT OF THE SYSTEM...BUT THE SOUTHERLY TRACK COULD
MEAN A MUCH CLOSER TRACK TO THE LOCAL AREA SHOULD THE SYSTEM
SURVIVE THE DRY AND SHEARED ENVIRONMENT TO ENTER A MORE FAVORABLE
ENVIRONMENT IN THE EASTERN CARIBBEAN. WITH LARGE VARIABILITY IN
THIS SYSTEMS FUTURE...WILL TREND TOWARD ONLY AROUND 50 PERCENT FOR
MONDAY.

THE MAIN STORY STILL REMAINS THE TROPICAL WAVE OFF OF
AFRICA...WHICH HAS A HIGH PROBABILITY OF BECOMING A DEPRESSION
OVER THE NEXT DAY OR SO. MODEL CONSENSUS SEEMS TO POINT TO A TRACK
JUST NORTH OF THE LEEWARDS...TAKING THE SYSTEM NE OF THE VI AND
PUERTO RICO. HOWEVER...GFS STILL TRACKING THE SYSTEM OVER THE
ISLAND AND HAS REMAINED VERY CONSISTENT IN ITS SOLUTIONS.
DEFINITELY CONTINUING TO MONITOR THIS SITUATION AS SATELLITE
IMAGERY HAS BECOME MORE IMPRESSIVE THIS AFTERNOON.
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Quoting cg2916:
It's dead.

I would not make such a hasty conclusion about the ex td2. i believe that there is a 50/50 (at least) that it will rejuvenate, once it encounters a more favorable conditions ahead of the system. We have seen this happen on numerous occasions...it's not dead...
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1368. java162
Quoting Seflhurricane:
lets do a poll on 90L

A) 90L becomes TD3 at 11PM

B)90L becomes TD3 at 5Am

C)90L Becomes TD 3 at 11Am

D) 90L does not become a TD At all


the answer is c
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1367. cg2916
Let me be the first to say it...

The focus of this blog shall now change over to Invest 90L.
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No comment.

Currently higher than 2005.
2009


Anomaly to 2005.

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1353. hurricanehanna 8:48 PM GMT on August 13, 2009
Quoting Patrap:
.."I gotta Tell ya Folks,Patrap and Ike and Drak and all them wunderbloggers are right about one thing,..trouble is Brewing and now's the time to prepare for what may come along downstream in time..

Back to you Guys in the Studio"..



Keep him away from the GOM!



lol....yes keep Mr. Doom & Gloom away!!!
Member Since: Posts: Comments:
...SEVERAL OF THE INTENSITY FORECAST
MODELS CONTINUE TO FORECAST STRENGTHENING...SO IF THE SYSTEM FINDS
A MORE FAVORABLE ENVIRONMENT IT COULD REGENERATE...

...THE NEW FORECAST TRACK IS
BASICALLY AN UPDATE OF THE PREVIOUS ADVISORY. IT SHOULD BE NOTED
THAT SEVERAL GLOBAL MODELS SHOW THE REMNANT LOW WEAKENING TO A
TROPICAL WAVE...AND IF THIS OCCURS THE SYSTEM COULD MOVE FARTHER
SOUTH THAN CURRENTLY FORECAST...

Member Since: Posts: Comments:
Pat, you are on fire today. I have laughed all day.
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Quoting StormChaser81:
WTNT32 KNHC 132041
TCPAT2
BULLETIN
TROPICAL DEPRESSION TWO ADVISORY NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022009
500 PM AST THU AUG 13 2009

...DEPRESSION HAS DECAYED INTO A REMNANT LOW PRESSURE AREA...

AT 500 PM AST...2100 UTC...THE CENTER OF THE REMNANTS OF TROPICAL
DEPRESSION TWO WAS LOCATED NEAR LATITUDE 14.2 NORTH...LONGITUDE
38.3 WEST OR ABOUT 930 MILES...1500 KM...WEST OF THE SOUTHERNMOST
CAPE VERDE ISLANDS.

THE LOW IS MOVING TOWARD THE WEST NEAR 8 MPH...13 KM/HR. THE
REMNANTS OF THE DEPRESSION ARE EXPECTED TO CONTINUE A GENERAL
WESTWARD MOTION FOR THE NEXT COUPLE OF DAYS.

MAXIMUM SUSTAINED WINDS ARE NEAR 30 MPH...45 KM/HR...WITH HIGHER
GUSTS. THE REMNANTS ARE EXPECTED TO CHANGE LITTLE IN STRENGTH OVER
THE NEXT COUPLE OF DAYS.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB...29.77 INCHES.

...SUMMARY OF 500 PM AST INFORMATION...
LOCATION...14.2N 38.3W
MAXIMUM SUSTAINED WINDS...30 MPH
PRESENT MOVEMENT...WEST OR 275 DEGREES AT 8 MPH
MINIMUM CENTRAL PRESSURE...1008 MB

THIS IS THE LAST PUBLIC ADVISORY ISSUED BY THE NATIONAL HURRICANE
CENTER ON THIS SYSTEM. THE SYSTEM WILL BE CLOSELY MONITORED FOR
SIGNS OF REGENERATION. ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE
FOUND IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER
SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

$$
FORECASTER BEVEN


:'( RIP. That is not a shock considering its very poor satellite presentation with the center fully exposed, and almost nill in the way of heavy convection. We'll see what happens over teh next few days.
Member Since: Posts: Comments:
Quoting NOLABean:
Weatherboykris, some people are just more concerned with the GOM because they live on it, have family or property on it, or have had a bad hit. Some people in my area, for example, can still get pretty understandably jumpy.


I understand. It jsut seems like every thunderstorm that pops up in the Carib. or GOM is "potential trouble for the Gulf"....IDK, doesn't really matter.
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1359. Drakoen
Quoting weatherboykris:


Same forecast models...


Regardless
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1358. sfla82
Althought things have picked up alot here the last day or two for the tropics, I am glad to see that TD2 has fizzled and 90L is most likely going to take the usual turn out to see! Looks like the only thing to watch out for in S Florida is that weak tropical wave moving through Saturday which might give us a liitle rain! We need it. It hasnt rained in weeks here in Pompano Beach!
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Um dry air?
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lets do a poll on 90L

A) 90L becomes TD3 at 11PM

B)90L becomes TD3 at 5Am

C)90L Becomes TD 3 at 11Am

D) 90L does not become a TD At all
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Bye, bye TD2.
Hello 90L.
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1354. IKE
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS, MD
300 PM EDT THU AUGUST 13 2009



8-14 DAY OUTLOOK FOR AUG 21 - 27 2009

TODAYS GFS-BASED ENSEMBLE MEANS ARE IN GOOD AGREEMENT IN DEPICTING A DEEP
TROUGH NEAR THE EASTERN CONUS AND A RIDGE NEAR THE WESTERN CONUS.
Member Since: Posts: Comments:
Quoting Patrap:
.."I gotta Tell ya Folks,Patrap and Ike and Drak and all them wunderbloggers are right about one thing,..trouble is Brewing and now's the time to prepare for what may come along downstream in time..

Back to you Guys in the Studio"..


Keep him away from the GOM!
Member Since: Posts: Comments:
Quoting Stormchaser2007:
All too familiar.
TD10
Later formed into Katrina in the Bahamas.


Yup
Member Since: Posts: Comments:
Weatherboykris, some people are just more concerned with the GOM because they live on it, have family or property on it, or have had a bad hit. Some people in my area, for example, can still get pretty understandably jumpy.
Member Since: Posts: Comments:
1350. KEEPEROFTHEGATE (Mod)
Quoting CaneWarning:
RIP TD2. (Not saying it won't reform.)
not rip its just sleeping shhhh dont wake it up
Member Since: July 15, 2006 Posts: 169 Comments: 53296
1318. CaneWarning 8:42 PM GMT on August 13, 2009
Quoting weatherboykris:


Can I ask why some people seem to have this obsession with the GOM since 2005? That's a serious question, not tryin to be rude...


Probably because if it gets into the gulf its almost 100% likely to hit land. Also, the gulf has been hit hard so I think some are paranoid.


no not really paranoid just expecting it...each year it seems something gets into the GOM...so it's not anxiety it's just mother nature sparking the anxiety...lol
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Quoting Drakoen:


Different system different conditions.


Same forecast models...
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Rest in peace, Tropical Depression 2, we (luckily) hardly knew ye...and hopefully it'll stay that way.
Member Since: Posts: Comments:
000
WTNT32 KNHC 132041
TCPAT2
BULLETIN
TROPICAL DEPRESSION TWO ADVISORY NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022009
500 PM AST THU AUG 13 2009

...DEPRESSION HAS DECAYED INTO A REMNANT LOW PRESSURE AREA...

AT 500 PM AST...2100 UTC...THE CENTER OF THE REMNANTS OF TROPICAL
DEPRESSION TWO WAS LOCATED NEAR LATITUDE 14.2 NORTH...LONGITUDE
38.3 WEST OR ABOUT 930 MILES...1500 KM...WEST OF THE SOUTHERNMOST
CAPE VERDE ISLANDS.

THE LOW IS MOVING TOWARD THE WEST NEAR 8 MPH...13 KM/HR. THE
REMNANTS OF THE DEPRESSION ARE EXPECTED TO CONTINUE A GENERAL
WESTWARD MOTION FOR THE NEXT COUPLE OF DAYS.

MAXIMUM SUSTAINED WINDS ARE NEAR 30 MPH...45 KM/HR...WITH HIGHER
GUSTS. THE REMNANTS ARE EXPECTED TO CHANGE LITTLE IN STRENGTH OVER
THE NEXT COUPLE OF DAYS.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB...29.77 INCHES.

...SUMMARY OF 500 PM AST INFORMATION...
LOCATION...14.2N 38.3W
MAXIMUM SUSTAINED WINDS...30 MPH
PRESENT MOVEMENT...WEST OR 275 DEGREES AT 8 MPH
MINIMUM CENTRAL PRESSURE...1008 MB

THIS IS THE LAST PUBLIC ADVISORY ISSUED BY THE NATIONAL HURRICANE
CENTER ON THIS SYSTEM. THE SYSTEM WILL BE CLOSELY MONITORED FOR
SIGNS OF REGENERATION.
ADDITIONAL INFORMATION ON THIS SYSTEM CAN BE
FOUND IN HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER
SERVICE...UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

$$
FORECASTER BEVEN


There is still hope for TD 2
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1345. hahaguy
Quoting Drakoen:
I'll be watching TD2 for regeneration.


same here.
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R.I.P. TD#2

*sound of Taps in the background"
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Ivan, Jeane, Frances,Dean, Felix were supposed to recurve. Its the same ole story.
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2 depressions have formed and no ana huuuuuum
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1341. Patrap
.."I gotta Tell ya Folks,Patrap and Ike and Drak and all them wunderbloggers are right about one thing,..trouble is Brewing and now's the time to prepare for what may come along downstream in time..

Back to you Guys in the Studio"..

Member Since: Posts: Comments:
ya, i hate to say it, but the weather channel has changed it's programming and it's just not the same.........even so, i still keep that channel on 85 percent of the time........'you might need to get a life if....'
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1339. Drakoen
I'll be watching TD2 for regeneration.
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WHILE PERSISTING OVER THE PAST SEVERAL HOURS...THE AREA OF
CONVECTION JUST WEST OF THE CENTER OF TROPICAL DEPRESSION TWO IS
TOO SMALL TO BE CLASSIFIED USING THE DVORAK TECHNIQUE. INDEED...IT
HAS BEEN ALMOST 24 HR SINCE ENOUGH ORGANIZED CONVECTION EXISTED TO
GET A DATA-T NUMBER. BASED ON THIS...THE DEPRESSION HAS DECAYED
INTO A REMNANT LOW PRESSURE AREA. IT IS LIKELY THAT THE SYSTEM
WILL CONTINUE TO PRODUCE BURSTS OF CONVECTION FOR THE NEXT SEVERAL
DAYS...AND A FASTER FORWARD MOTION IS EXPECTED BY THE END OF THE
FORECAST PERIOD. THIS IS THE BASIS FOR KEEPING A 25 KT INTENSITY
FOR THE REMNANTS THROUGH 120 HR. SEVERAL OF THE INTENSITY FORECAST
MODELS CONTINUE TO FORECAST STRENGTHENING...SO IF THE SYSTEM FINDS
A MORE FAVORABLE ENVIRONMENT IT COULD REGENERATE.


Watch ex-TD2, it could very well pull a Katrina in terms of formation (not strength of course) There are favorable conditions ahead.
Member Since: August 10, 2009 Posts: 3 Comments: 672
LOL and alot of people were calling it Ana right before this morn's 5am advis.

Ana is gonna be 90L by the way it looks
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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