Unusually well-organized 92L disturbance may become a tropical depression

By: Dr. Jeff Masters , 14. kesäkuuta 2010 klo 14:14 (GMT)

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Invest 92L, a remarkably well-developed African tropical wave for so early in the season, is midway between Africa and the Lesser Antilles Islands. Infrared satellite loops show a modest area of heavy thunderstorms along the north side of 92L's center of circulation, and the storm's heavy thunderstorms activity appears to be slowly increasing in intensity and areal coverage. Upper-level outflow is apparent to the west and north of 92L, and the outflow has been gradually improving this morning. Visible satellite loops do not show much in the way of low-level spiral bands, and my current take from the satellite imagery is that 92L is slowly organizing, and will not become a tropical depression any earlier than 11pm EDT tonight (Monday.) A 4:27 am EDT pass from the WINDSAT satellite saw a partially closed circulation at the surface (open on the south side), with top surface winds of 25 - 30 mph north of the center.


Figure 1. Morning satellite image of Invest 92L (left side of image) and a vigorous new tropical wave that has moved off the coast of Africa (right side.) None of models develop the new tropical wave, but it bears watching.

Sea surface temperatures
Climatology argues against development of 92L, since only one named storm has ever formed between Africa and the Lesser Antilles Islands in the month of June--Tropical Storm Ana of 1979 (Figure 2). However, sea surface temperatures (SSTs) underneath 92L are an extremely high 28°C, and will increase to 29°C by Thursday. In fact, with summer not even here, and three more months of heating remaining until we reach peak SSTs in the Atlantic, ocean temperatures across the entire Caribbean and waters between Africa and the Lesser Antilles are about the same as they were during the peak week for water temperatures in 2009 (mid-September.)

Dry air not a problem for 92L until Wednesday
The disturbance doesn't have to worry about dry air today or Tuesday--Total Precipitable Water (TPW) loops show a very moist plume of air accompanies 92L, and water vapor satellite loops show that the center of 92L is at least 200 - 300 miles from any substantial areas of dry air. As 92L continues to push northwest, though, the SHIPS model is predicting that relative humidity at middle levels of the atmosphere will fall from the current value of about 70%, to 60% on Wednesday. This dry air may begin to cause problems for 92L on Wednesday, especially since wind shear will be increasing at the same time. Tropical cyclones are more vulnerable to dry air when there is substantial wind shear, since the strong winds causing the shear are able to inject the dry air deep into the core of the storm.

Madden-Julian Oscillation
The 60-day cycle of enhanced thunderstorm activity called the Madden-Julian Oscillation is currently favoring upward motion over eastern tropical Atlantic, and this enhanced upward motion helps create stronger updrafts and higher chances of tropical cyclone development.


Figure 2. Tropical Storm Ana of 1979 was the only June named storm on record to form between Africa and the Lesser Antilles Islands.

Wind shear
A major issue for 92L, like it is for most June disturbances, is wind shear. The subtropical jet stream has a branch flowing through the Caribbean and tropical Atlantic north of 10° N that is bringing 20 - 40 knots of wind shear to the region. Our disturbance was located near 10°N, 40°W at 8am EDT this morning, a few hundred miles south of this band of high shear, and is currently only experiencing 5 - 10 knots of shear. This low amount of shear should allow for some steady development of 92L over the next two days as it tracks west-northwest or northwest at 15 mph. The latest run of the SHIPS model is predicting the shear will rise to 20 knots on Wednesday, which may start to cause problems for 92L.

The forecast for 92L
The National Hurricane Center is giving 92L a high (60% chance) of developing into a tropical depression by Wednesday morning, which is a reasonable forecast. The odds of development have increased since yesterday, as the storm has moved considerably to the northwest, away from the Equator. Now it can leverage the Earth's spin to a much greater degree to help get it get spinning. It is quite unusual for a tropical depression to form south of 8°N latitude.

I expect that 92L's best chance to become a tropical depression will come on Tuesday, and the storm could strengthen enough by Wednesday to be named Tropical Storm Alex. The farther south 92L stays, the better chance it has at survival. With the system's steady west-northwest movement this week, 92L will probably begin encountering hostile wind shear in excess of 20 knots by Wednesday, which should interfere with continued development. Several of our reliable models do develop 92L into a tropical storm with 40 - 55 mph winds, but all of the models foresee weakening by Thursday or Friday as 92L approaches the Lesser Antilles Islands and encounters high shear and dry air. I doubt 92L will be anything stronger than a 45 mph tropical storm when it moves through the northern Lesser Antilles Islands on Friday and Saturday, and it would be no surprise if wind shear has destroyed the storm by then. However, as usual, surprises can happen, and the GFS and the SHIPS model (which is based upon the GFS) do indicate that more modest levels of wind shear in the 15 - 20 mph range late this week may allow 92L to stay stronger than I'm expecting. Residents of the islands--particularly the northern Lesser Antilles--should follow the progress of 92L closely, and anticipate heavy rains and high winds moving through the islands as early as Thursday night.

Oil spill wind forecast
There is little change to the oil spill wind forecast for the coming two weeks. Light winds of 5 - 10 knots mostly out of the south or southeast will blow in the northern Gulf of Mexico all week, according to the latest marine forecast from NOAA. These winds will keep oil near the coast of Louisiana, Alabama, Mississippi, and the extreme western Florida Panhandle, according to the latest trajectory forecasts from NOAA and the State of Louisiana. The long range 8 - 16 day forecast from the GFS model indicates a typical summertime light wind regime, with winds mostly blowing out of the south or southeast. This wind regime will likely keep oil close to the coastal areas that have already seen oil impacts over the past two weeks.

Jeff Masters

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3191. markot
6. elokuuta 2011 klo 11:27 (GMT)
ex emily is not moving north,,, look at latest satt. loops moving just slightly north of due west.....
Member Since: 2.09.2009 Posts: 0 Comments: 226
3190. 92Andrew
15. kesäkuuta 2010 klo 20:08 (GMT)
The storm may have lost its opportunity to develop into something more threatening, but we already knew that would happen. The big question is: Do we have to worry about the storm when the wave passes over the bahamas or northern caribbean? Shear maps indicate a pass over the bahamas is more conducive for development than would be the case in the northern caribbean.
Member Since: 27.07.2009 Posts: 0 Comments: 96
3189. Caribbeanislands101
15. kesäkuuta 2010 klo 18:05 (GMT)
sorry about the image size earlier
Member Since: 7.04.2010 Posts: 5 Comments: 347
3188. Caribbeanislands101
15. kesäkuuta 2010 klo 16:41 (GMT)
Has any one heard of the 1916 Puerto Rico/Hispaniloa
Member Since: 7.04.2010 Posts: 5 Comments: 347
3187. K8eCane
15. kesäkuuta 2010 klo 15:48 (GMT)
Quoting MiamiHurricanes09:
Quick Update on 92L



92L continues to show signs of dissipation as convection continues to die down due to the 20 knots of shear aloft. But 92L hasn't seen anything yet, it's about to run into a pocket of 30-50 knot wind shear which should strip it of any convection and its circulation. At the moment there is just a small amount of shallow convection around the COC.

92L should dissipate within 48 hours, it's energy will have to be watched if it gets into the Caribbean due to the fact that the equatorial ridge will be strengthening and will push the weak TUTT into the GOM which would make the Caribbean an area primed for development.

92L should be stripped of it's invest status later today or tomorrow morning. I will no longer be posting updates on 92L as I find them unnecessary due to the fact that it should dissipate soon.

-MiamiHurricanes09


Thanks!
Member Since: 26.04.2006 Posts: 5 Comments: 3041
3186. Chicklit
15. kesäkuuta 2010 klo 15:03 (GMT)
GOMLoopShortWaveImagery

Member Since: 11.07.2006 Posts: 14 Comments: 11047
3185. RobbieLSU
15. kesäkuuta 2010 klo 15:01 (GMT)
Quoting Caribbeanislands101:

wow, thanks, i didn't know that


Yep here is a good article about why he chose to leave TWC : Link
Member Since: 9.06.2010 Posts: 12 Comments: 42
3184. MiamiHurricanes09
15. kesäkuuta 2010 klo 15:00 (GMT)
Quick Update on 92L



92L continues to show signs of dissipation as convection continues to die down due to the 20 knots of shear aloft. But 92L hasn't seen anything yet, it's about to run into a pocket of 30-50 knot wind shear which should strip it of any convection and its circulation. At the moment there is just a small amount of shallow convection around the COC.

92L should dissipate within 48 hours, it's energy will have to be watched if it gets into the Caribbean due to the fact that the equatorial ridge will be strengthening and will push the weak TUTT into the GOM which would make the Caribbean an area primed for development.

92L should be stripped of it's invest status later today or tomorrow morning. I will no longer be posting updates on 92L as I find them unnecessary due to the fact that it should dissipate soon.

-MiamiHurricanes09
Member Since: 2.09.2009 Posts: 130 Comments: 21032
3183. Caribbeanislands101
15. kesäkuuta 2010 klo 14:56 (GMT)
Quoting RobbieLSU:


He is now meteorologist in charge at the NWS station in San Angelo, TX.

wow, thanks, i didn't know that
Member Since: 7.04.2010 Posts: 5 Comments: 347
3182. Caribbeanislands101
15. kesäkuuta 2010 klo 14:55 (GMT)
Quoting Patrap:
12z Late Cycle NHC model tracks
Invest92


Statistical/Simple Models (CLIPER,BAMs,LBAR,other Statistical Models)




Dynamic Models (More sophisticated models)



I hate to be a pest, but where did you fine the sophisticated models?
Member Since: 7.04.2010 Posts: 5 Comments: 347
3181. RobbieLSU
15. kesäkuuta 2010 klo 14:55 (GMT)
Quoting Caribbeanislands101:

What happened to Doctor Lyons?


He is now meteorologist in charge at the NWS station in San Angelo, TX.
Member Since: 9.06.2010 Posts: 12 Comments: 42
3179. Caribbeanislands101
15. kesäkuuta 2010 klo 14:53 (GMT)
Quoting 69Viking:


I have to agree and the new guy is a putz, wish they still had Dr. Lyons or like you said one of those blonde babelicious types!

What happened to Doctor Lyons?
Member Since: 7.04.2010 Posts: 5 Comments: 347
3176. stormpetrol
15. kesäkuuta 2010 klo 14:49 (GMT)
92L down but not out as yet
Member Since: 29.04.2007 Posts: 0 Comments: 7506
3175. 7544
15. kesäkuuta 2010 klo 14:48 (GMT)
Quoting DestinJeff:
I think I can, I think I can


92l does not want to give up just yet lol
Member Since: 6.05.2007 Posts: 0 Comments: 6618
3174. Fl30258713
15. kesäkuuta 2010 klo 14:48 (GMT)
Quoting Patrap:
Dr. Masters on NOLA radio discussing the Oil and SST's and more.



Thanks for posting that.
Member Since: 24.07.2006 Posts: 1 Comments: 981
3172. 850Realtor
15. kesäkuuta 2010 klo 14:42 (GMT)
Quoting hurricanejunky:


Hi! Couldn't stand it, huh? Very nice animation! Keep up the good work :)
Member Since: 14.09.2009 Posts: 0 Comments: 283
3171. hercj
15. kesäkuuta 2010 klo 14:41 (GMT)
Quoting StormW:


Thanks! Doin' a little better.

As a pilot I have dealt with more than one of those sinus infections and they are awful.
Member Since: 5.09.2009 Posts: 0 Comments: 319
3170. Patrap
15. kesäkuuta 2010 klo 14:40 (GMT)
Dr. Masters on NOLA radio discussing the Oil and SST's and more.

Member Since: 3.07.2005 Posts: 415 Comments: 125628
3167. msphar
15. kesäkuuta 2010 klo 14:39 (GMT)
Pretty nasty lookin squall ya'll got there.
Member Since: 20.08.2006 Posts: 0 Comments: 289
3166. Patrap
15. kesäkuuta 2010 klo 14:38 (GMT)
12z Late Cycle NHC model tracks
Invest92


Statistical/Simple Models (CLIPER,BAMs,LBAR,other Statistical Models)




Dynamic Models (More sophisticated models)


Member Since: 3.07.2005 Posts: 415 Comments: 125628
3164. weathersp
15. kesäkuuta 2010 klo 14:38 (GMT)
Quoting Floodman:


Yeah, Robbie, let us know...been thinking about that reading and the others in the 90s in the general vicinity


I bet the oil got in it and is screwing with it.
Member Since: 14.01.2007 Posts: 17 Comments: 4140
3163. hercj
15. kesäkuuta 2010 klo 14:37 (GMT)
Quoting StormW:
TROPICAL DISTURBANCE INVEST 92L SYNOPSIS ISSUED 10:25 A.M. JUNE 15, 2010

thanks Senior Chief. I hope you are feeling better.
Member Since: 5.09.2009 Posts: 0 Comments: 319
3162. RobbieLSU
15. kesäkuuta 2010 klo 14:37 (GMT)
Quoting RecordSeason:
Well, the LSU earth scan product may well be the best satellite product i've ever seen. Works much better than the publicly published NOAA crap, and has better resolution and better options.


I worked there during this past school year, I'll let the good folks there know you appreciate them!
Member Since: 9.06.2010 Posts: 12 Comments: 42
3161. ElConando
15. kesäkuuta 2010 klo 14:37 (GMT)
Quoting beell:


Nice one, Storm. Thanks.


same here.
Member Since: 6.09.2009 Posts: 2 Comments: 3709
3160. ElConando
15. kesäkuuta 2010 klo 14:37 (GMT)
Looks like we will have some quiet for about a week to talk on about more pressing issues, hopefully.
Member Since: 6.09.2009 Posts: 2 Comments: 3709
3158. TampaSpin
15. kesäkuuta 2010 klo 14:35 (GMT)




YOU can see the LOw Level Steering and what the BAM models are showing.....i would have thought tho that whatever is leftover with 92L goes South into the Caribbean and i still think that will happen as models should shift much further South now.
Member Since: 2.09.2007 Posts: 177 Comments: 20430
3156. Floodman
15. kesäkuuta 2010 klo 14:31 (GMT)
Quoting RobbieLSU:
Oh by the way, when I left here yesterday we were discussing the water temperature at NDBC station 42040. (the one reporting 95 degree water temperature). Well I e-mailed a former co-worker over there at the NDBC and she said that they are investigating it further. So it may or may not be accurate.

I personally think it is a legitimate reading, because the only time water temp sensors really ever mess up is if they get frozen, like on this Alaskan and Great Lakes C-MAN stations. So I'll let yall know if I hear back from her in case you're curious about that station.


Yeah, Robbie, let us know...been thinking about that reading and the others in the 90s in the general vicinity
Member Since: 2.08.2006 Posts: 10 Comments: 9922
3155. beell
15. kesäkuuta 2010 klo 14:31 (GMT)
Quoting StormW:
TROPICAL DISTURBANCE INVEST 92L SYNOPSIS ISSUED 10:25 A.M. JUNE 15, 2010


Nice one, Storm. Thanks.
Member Since: 11.09.2007 Posts: 137 Comments: 15332
3154. Floodman
15. kesäkuuta 2010 klo 14:30 (GMT)
Quoting Gumbogator:
A bunch of oil clean-up bums were arrested on the beaches of Louisiana recently......outstanding warrants!! Also: thieves are stealing the anchors that hold down the booms and they are moving the booms as reported by KLFY-TV Lafayette LA!!


Why are they bums? I understand the having warants out, certainly; they need to address those issues, but they're helping clean up the oil...have you bagged any oil soaked sand? Placed any boom? Given a cold drink to someone wearing a tyvek suit?
Member Since: 2.08.2006 Posts: 10 Comments: 9922
3153. RobbieLSU
15. kesäkuuta 2010 klo 14:28 (GMT)
Oh by the way, when I left here yesterday we were discussing the water temperature at NDBC station 42040. (the one reporting 95 degree water temperature). Well I e-mailed a former co-worker over there at the NDBC and she said that they are investigating it further. So it may or may not be accurate.

I personally think it is a legitimate reading, because the only time water temp sensors really ever mess up is if they get frozen, like on this Alaskan and Great Lakes C-MAN stations. So I'll let yall know if I hear back from her in case you're curious about that station.
Member Since: 9.06.2010 Posts: 12 Comments: 42
3152. extreme236
15. kesäkuuta 2010 klo 14:28 (GMT)
Well 00z ECMWF still showing a tropical cyclone affecting the southern Antilles in about 240 hours...lol
Member Since: 2.08.2007 Posts: 19 Comments: 19234
3150. PolishHurrMaster
15. kesäkuuta 2010 klo 14:27 (GMT)
Quoting MiamiHurricanes09:
I am no longer expecting 92L to develop into a tropical depression due to its proximity to a band of shear to the north of the system. 92L continues movement towards the northwest and could possibly dissipate over the next 72 hours and could possibly become a naked swirl in just 48 hours. I think there is a low chance, about 10%, of 92L becoming a tropical depression.

I do have to say that 90L was a tropical depression late Saturday night and all of Sunday as an ASCAT pass proved that there was a closed low and there was exceedingly well satellite presentation.

I expect 92L to become TD #1 in post season analysis.


agree in 100%
Member Since: 19.05.2010 Posts: 0 Comments: 351
3149. bjdsrq
15. kesäkuuta 2010 klo 14:25 (GMT)
Quoting Floodman:


I could be wrong, of course; I'm no chemist...my understanding was the the sludge would be good fro plastics production ect, but for fuels, not so much...anyone here know about petro-chemistry?


I know BP is refining the *captured* oil and announced they are donating all proceeds to the clean up and relief efforts w/o waiting for a mandate or judgement to do so. This is more than can be said for Mexican owned Pemex during the Ixtoc incident. They screwed the US 100%.

Member Since: 26.07.2003 Posts: 3 Comments: 428
3148. 69Viking
15. kesäkuuta 2010 klo 14:25 (GMT)
Quoting RecordSeason:
I'm gonna miss Dr. Lyons. This Dr. Knabb talks with his hands too much, and looks too much like "PC" from Apple's Mac vs PC commercials.

What's the other Mets excuse for being there for 20 years and not being a "hurricane expert"?

We need one of those blonde, babelicious type hurricane experts.


I have to agree and the new guy is a putz, wish they still had Dr. Lyons or like you said one of those blonde babelicious types!
Member Since: 25.08.2006 Posts: 1 Comments: 2996
3146. Gumbogator
15. kesäkuuta 2010 klo 14:25 (GMT)
A bunch of oil clean-up bums were arrested on the beaches of Louisiana recently......outstanding warrants!! Also: thieves are stealing the anchors that hold down the booms and they are moving the booms as reported by KLFY-TV Lafayette LA!!
Member Since: 21.08.2008 Posts: 0 Comments: 106
3145. FLWeatherFreak91
15. kesäkuuta 2010 klo 14:25 (GMT)
Quoting Gustavike:
It does not weary all the time anticyclone over the southeastern United States
Florida has a shield for the time being.
Member Since: 1.12.2006 Posts: 2 Comments: 3616
3144. CaicosRetiredSailor
15. kesäkuuta 2010 klo 14:24 (GMT)


Take it off!
Member Since: 12.07.2007 Posts: 0 Comments: 5984
3143. MahFL
15. kesäkuuta 2010 klo 14:23 (GMT)
Convection fireing at the center !!!!!cat 5 alert !!!!....lol lol.
Member Since: 9.06.2004 Posts: 0 Comments: 2906
3142. Floodman
15. kesäkuuta 2010 klo 14:23 (GMT)
Quoting bjdsrq:


There was no govt regulation, mandate, or incentives, to develop better oil clean-up tech, so the oil industry did nothing for 50 years. There is some interesting video on bio-remediation trials used in texas coastal spills. I wonder why they are not using microbes for this. Seems very promising, and can't be as bad as the dispersants.


My understanding is that in a spill this size the micorobes could be nearly as bad as the oil...

Sent in the cat to kill the rat, sent in the dog to kill the cat...etc.

Member Since: 2.08.2006 Posts: 10 Comments: 9922
3141. Patrap
15. kesäkuuta 2010 klo 14:22 (GMT)
Patrap amid da well heads in the GOM

"I love the smell of Hydrocarbons in da morn'..
Member Since: 3.07.2005 Posts: 415 Comments: 125628

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About JeffMasters

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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