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

By: Dr. Jeff Masters , 2:14 PM GMT on June 14, 2010

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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
11:27 AM GMT on August 06, 2011
ex emily is not moving north,,, look at latest satt. loops moving just slightly north of due west.....
Member Since: September 2, 2009 Posts: 0 Comments: 226
3190. 92Andrew
8:08 PM GMT on June 15, 2010
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: July 27, 2009 Posts: 0 Comments: 96
3189. Caribbeanislands101
6:05 PM GMT on June 15, 2010
sorry about the image size earlier
Member Since: April 7, 2010 Posts: 5 Comments: 347
3188. Caribbeanislands101
4:41 PM GMT on June 15, 2010
Has any one heard of the 1916 Puerto Rico/Hispaniloa
Member Since: April 7, 2010 Posts: 5 Comments: 347
3187. K8eCane
3:48 PM GMT on June 15, 2010
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: April 26, 2006 Posts: 5 Comments: 3222
3186. Chicklit
3:03 PM GMT on June 15, 2010
GOMLoopShortWaveImagery

Member Since: July 11, 2006 Posts: 14 Comments: 11405
3185. RobbieLSU
3:01 PM GMT on June 15, 2010
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: June 9, 2010 Posts: 12 Comments: 42
3184. MiamiHurricanes09
3:00 PM GMT on June 15, 2010
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: September 2, 2009 Posts: 130 Comments: 21194
3183. Caribbeanislands101
2:56 PM GMT on June 15, 2010
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: April 7, 2010 Posts: 5 Comments: 347
3182. Caribbeanislands101
2:55 PM GMT on June 15, 2010
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: April 7, 2010 Posts: 5 Comments: 347
3181. RobbieLSU
2:55 PM GMT on June 15, 2010
Quoting Caribbeanislands101:

What happened to Doctor Lyons?


He is now meteorologist in charge at the NWS station in San Angelo, TX.
Member Since: June 9, 2010 Posts: 12 Comments: 42
3179. Caribbeanislands101
2:53 PM GMT on June 15, 2010
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: April 7, 2010 Posts: 5 Comments: 347
3178. btwntx08
2:53 PM GMT on June 15, 2010
new blog
Member Since: July 13, 2008 Posts: 6 Comments: 10796
3177. WindDamage
2:52 PM GMT on June 15, 2010
Gotta love reporting scumbags, anyhow, good morning to all.
3176. stormpetrol
2:49 PM GMT on June 15, 2010
92L down but not out as yet
Member Since: April 29, 2007 Posts: 0 Comments: 8134
3175. 7544
2:48 PM GMT on June 15, 2010
Quoting DestinJeff:
I think I can, I think I can


92l does not want to give up just yet lol
Member Since: May 6, 2007 Posts: 0 Comments: 6874
3174. Fl30258713
2:48 PM GMT on June 15, 2010
Quoting Patrap:
Dr. Masters on NOLA radio discussing the Oil and SST's and more.



Thanks for posting that.
Member Since: July 24, 2006 Posts: 1 Comments: 987
3172. 850Realtor
2:42 PM GMT on June 15, 2010
Quoting hurricanejunky:


Hi! Couldn't stand it, huh? Very nice animation! Keep up the good work :)
Member Since: September 14, 2009 Posts: 0 Comments: 283
3171. hercj
2:41 PM GMT on June 15, 2010
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: September 5, 2009 Posts: 0 Comments: 319
3170. Patrap
2:40 PM GMT on June 15, 2010
Dr. Masters on NOLA radio discussing the Oil and SST's and more.

Member Since: July 3, 2005 Posts: 427 Comments: 129334
3167. msphar
2:39 PM GMT on June 15, 2010
Pretty nasty lookin squall ya'll got there.
Member Since: August 20, 2006 Posts: 0 Comments: 289
3166. Patrap
2:38 PM GMT on June 15, 2010
12z Late Cycle NHC model tracks
Invest92


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




Dynamic Models (More sophisticated models)


Member Since: July 3, 2005 Posts: 427 Comments: 129334
3165. btwntx08
2:38 PM GMT on June 15, 2010
probably not lol
Member Since: July 13, 2008 Posts: 6 Comments: 10796
3164. weathersp
2:38 PM GMT on June 15, 2010
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: January 14, 2007 Posts: 17 Comments: 4140
3163. hercj
2:37 PM GMT on June 15, 2010
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: September 5, 2009 Posts: 0 Comments: 319
3162. RobbieLSU
2:37 PM GMT on June 15, 2010
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: June 9, 2010 Posts: 12 Comments: 42
3161. ElConando
2:37 PM GMT on June 15, 2010
Quoting beell:


Nice one, Storm. Thanks.


same here.
Member Since: September 6, 2009 Posts: 2 Comments: 3784
3160. ElConando
2:37 PM GMT on June 15, 2010
Looks like we will have some quiet for about a week to talk on about more pressing issues, hopefully.
Member Since: September 6, 2009 Posts: 2 Comments: 3784
3159. RecordSeason
2:35 PM GMT on June 15, 2010
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.
Member Since: June 13, 2010 Posts: 0 Comments: 2336
3158. TampaSpin
2:35 PM GMT on June 15, 2010




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: September 2, 2007 Posts: 179 Comments: 20448
3157. btwntx08
2:32 PM GMT on June 15, 2010
this is funny the gom blob is way better than 92L lol its trying to rub it in his face
Member Since: July 13, 2008 Posts: 6 Comments: 10796
3156. Floodman
2:31 PM GMT on June 15, 2010
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: August 2, 2006 Posts: 10 Comments: 9922
3155. beell
2:31 PM GMT on June 15, 2010
Quoting StormW:
TROPICAL DISTURBANCE INVEST 92L SYNOPSIS ISSUED 10:25 A.M. JUNE 15, 2010


Nice one, Storm. Thanks.
Member Since: September 11, 2007 Posts: 145 Comments: 16916
3154. Floodman
2:30 PM GMT on June 15, 2010
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: August 2, 2006 Posts: 10 Comments: 9922
3153. RobbieLSU
2:28 PM GMT on June 15, 2010
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: June 9, 2010 Posts: 12 Comments: 42
3152. extreme236
2:28 PM GMT on June 15, 2010
Well 00z ECMWF still showing a tropical cyclone affecting the southern Antilles in about 240 hours...lol
Member Since: August 2, 2007 Posts: 19 Comments: 19234
3150. PolishHurrMaster
2:27 PM GMT on June 15, 2010
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: May 19, 2010 Posts: 0 Comments: 358
3149. bjdsrq
2:25 PM GMT on June 15, 2010
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: July 26, 2003 Posts: 3 Comments: 428
3148. 69Viking
2:25 PM GMT on June 15, 2010
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: August 25, 2006 Posts: 1 Comments: 3094
3147. btwntx08
2:25 PM GMT on June 15, 2010
gom system looking way better than that lol
Member Since: July 13, 2008 Posts: 6 Comments: 10796
3146. Gumbogator
2:25 PM GMT on June 15, 2010
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: August 21, 2008 Posts: 0 Comments: 106
3145. FLWeatherFreak91
2:25 PM GMT on June 15, 2010
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: December 1, 2006 Posts: 2 Comments: 3634
3144. CaicosRetiredSailor
2:24 PM GMT on June 15, 2010


Take it off!
Member Since: July 12, 2007 Posts: 0 Comments: 6069
3143. MahFL
2:23 PM GMT on June 15, 2010
Convection fireing at the center !!!!!cat 5 alert !!!!....lol lol.
Member Since: June 9, 2004 Posts: 0 Comments: 3804
3142. Floodman
2:23 PM GMT on June 15, 2010
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: August 2, 2006 Posts: 10 Comments: 9922
3141. Patrap
2:22 PM GMT on June 15, 2010
Patrap amid da well heads in the GOM

"I love the smell of Hydrocarbons in da morn'..
Member Since: July 3, 2005 Posts: 427 Comments: 129334

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About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.