92L very disorganized, but a long-range threat to develop
Invest 92L, which yesterday became severely disrupted by wind shear and dry air, is generating a large area of rain showers over the northern Lesser Antilles Islands today. Infrared satellite loops show that the tops of the thunderstorms associated with 92L have warmed in recent hours, and these thunderstorms are weak and disorganized. Water vapor satellite loops show that there is a large amount of dry air in the storm's environment, and this dry air is getting sucked into 92L's thunderstorms, where the dry air is sinking to the surface and creating surface "arc clouds"--arc-shaped clouds that spread out away from 92L's thunderstorms. With wind shear at 20 - 30 knots today, no signs of a surface circulation, and plenty of dry air around, 92L is not a threat to develop into a tropical depression today or Saturday. The National Hurricane Center is giving 92L a low (20% chance) of developing into a tropical depression by Sunday morning. I put the chances at 1%. You can track the progress of 92L today by looking at our wundermap for the region, with weather stations turned on. Antigua recorded sustaiined winds of 20 mph this morning from 92L.
A slight chance 92L could develop next week
Today and Saturday, 92L will encounter 20 - 40 knots of wind shear as it plows though a region of strong upper-level winds associated with the subtropical jet stream. The disturbance will also encounter the mountainous terrain of Hispaniola. These factors should significantly disrupt the disturbance. If there's anything left of 92L by Sunday, when it will be over eastern Cuba, the storm may have the opportunity to develop. At that time, 92L will have passed through the core of the subtropical jet stream and entered a region of lower shear (15 - 20 knots.) For the latest round of 00Z and 06Z model runs, the HWRF is the only reliable model calling for 92L to develop; that model predicts that 92L will organize into a tropical depression on Wednesday over the Lower Florida Keys, and head into the Gulf of Mexico. The obstacles that 92L must overcome to do this are great, and I give 92L just a 10% chance of eventually developing into a tropical depression by Wednesday next week.
Figure 1. Morning satellite image of Invest 92L. Dry air is getting sucked into 92L's thunderstorms, where the more dense dry air creates downdrafts. When these downdrafts hit the surface, the air spreads out creating surface "arc clouds"--arc-shaped clouds that spread out away from 92L's thunderstorms. This puts stable air into the storm's low level environment and blocks inflow of moist air into the core of the storm, weakening it. These arc clouds are a telltale sign that dry air is significantly disrupting the disturbance.
Elsewhere in the tropics
The NOGAPS model is calling for a tropical disturbance to form off the coast of Nicaragua on Monday and push ashore over that country on Tuesday, bringing heavy rains.
Wind and ocean current forecast for the BP oil disaster
Light and variable winds less than 10 knots will blow in the northern Gulf of Mexico for the next five days, according to the latest marine forecast from NOAA. The winds will tend to have a westerly component through Saturday, which will maintain a threat of oil hitting beaches as far east as Panama City, Florida, according to the latest trajectory forecasts from NOAA and the State of Louisiana. Ocean current forecasts for early next week show a weakening of the eastward-flowing currents along the Florida Panhandle, which would limit the eastward movement of oil so that it would not move past Panama City. 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.
Resources for the BP oil disaster
My post, What a hurricane would do the Deepwater Horizon oil spill
My post on the Southwest Florida "Forbidden Zone" where surface oil will rarely go
My post on what oil might do to a hurricane
NOAA's new interactive mapping tool allows one to overlay wind and ocean current forecasts, oil locations, etc.
Gulf Oil Blog from the UGA Department of Marine Sciences
Oil Spill Academic Task Force
University of South Florida Ocean Circulation Group oil spill forecasts
ROFFS Deepwater Horizon page
Synthetic Aperture Radar (SAR) imagery from the University of Miami
I'll have an update on Saturday.
Jeff Masters
Reader Comments
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Yep. Him too. And he might've called this one just right.
I don't know how to link that one.
Somebody will.
NHC needs to move the floater on 92L...west.
For some reason, they took off the model tracks for 92L.Link
92L not up anymore, but here it is.
Link
TIA
Invest 92
Wind: 30 MPH — Location: 16.9 65.4W — Movement: WNW
where's the plots
where's the plots
where's the plots
need more coffee
where's the plots
If they start those up again, it'll be there.
Link
I see that 92L is doing just what I was concerned it might do, use the high TCHP to fight off the shear. It looks like conditions may finally be starting to swing in its favour.
Shear is now lifting as the TUTT axis has retrograded and a big ridge of high pressure is building from the South. Last night the windflow with the shear was SW to NE but this morning it is more West to East ( zonal ) lifting to the North and falling in the Eastern and Western Caribbean at the same time.
If you look at the TCHP map below which I posted yesterday evening you will see why 92L is doing what it is doing this morning.
It may not fizzle out today as it has done for the past several days and it is also closing in on 70 West which typically marks the threshold for systems to start ramping up.
I am not saying it has won the fight with the shear but it looks like it may do so by late tonight IF it stays South of Hispaniola.
I meant the one that goes out to 384 hours....
where's the plots
and CrownWeather hasn't updated yet either
Hi. Note I just corrected the direction of windflow for shear as being West to East, not the other way around. I will look at steering in a moment
Isn't that the area the Euro wants to spin up into a major system?
Here's the link to load it.
Yesterday NOGAPS had what looked like a TD going ashore in Nicaragua from that area tomorrow !. Something else to watch for but so far not organized.
Rain and some fancy lightening around here late last night.
Good call (again) last night on 92, Kman.
can someone give me lat/lon on the center?
and yeah that floater needs to scoot to the left a little
this is the 00z run
Kudos to Kman...
Seems like it is moving at least due west if not just south of due west at the moment so it *should* or at least *could* miss hispaniola.
Headed for the GOM.
Good morning. We were talking about this around 6 or 7 yesterday evening.
The steering flow is still due West but the weakness remains to the North of Cuba and over Fla. Given 92L's improved condition this morning I would expect to see it start easing up to the N some but not dramatically so. A track between the Western tip of Haiti and Jamaica is sort of what I had in mind.
I agree with your track.
Hi Pottery and thanks.
It will be an interesting 18 hours ahead.
Tropical Wave Crossing Leeward Islands
Jun 19, 2010 7:15 AM
We are focusing our attention on two areas of disturbed weather. The first is the strong tropical wave now nearing 65 west and moving over the Leeward Islands and northeast Caribbean. This system is encountering very strong shear up to near 50 knots at times. The system will reach Puerto Rico late tonight and affect Puerto Rico and the Virgin Islands tonight and tomorrow with areas of heavy rain and gusty winds. The strong wave will move over Hispaniola causing more heavy rain and strong gusty winds. The heavier rainfall over mountainous areas of Puerto Rico and Hispaniola could lead to flooding and mudslides. The heavy rain and potential for mudslides could affect Haiti during Sunday and Monday. This tropical wave will bring active weather over much of Cuba on Monday into Tuesday and could bring a northward surge of tropical moisture over the southern half of Florida on Tuesday night through Wednesday and Thursday of next week. The strong shear will remain over the system through early next week. But the shear will slowly weaken. The shear will prevent further development of this system through the weekend and probably early next week. Beyond that, if the low-level circulation survives passage over the Greater Antilles, conditions could improve for development over the central Gulf of Mexico late next week.
A second area of concern is with a tropical wave along 48 west mostly south of 12 north. This system has a large area of clouds, showers and thunderstorms that will impact the Windward Islands this weekend with gusty winds and heavy rainfall. This system should interact with land and this will hinder development through the weekend and early next week. Some computer forecast information does show the feature becoming somewhat organized over the central Caribbean later next week.
Other tropical waves near 32 west, south of 10 north and near 76 west, south of 15 north, remain very weak and disorganized.
By AccuWeather Expert Senior Meteorologist Dan Kottlowski
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT SAT JUN 19 2010
FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...
A STRONG TROPICAL WAVE LOCATED NEAR PUERTO RICO AND THE VIRGIN
ISLANDS IS PRODUCING A LARGE AREA OF DISORGANIZED SHOWERS AND
THUNDERSTORMS. LOCALLY HEAVY RAINS...WHICH COULD CAUSE FLASH
FLOODS AND MUDSLIDES...AND GUSTY WINDS ARE POSSIBLE DURING THE NEXT
DAY OR TWO OVER PORTIONS OF THE LEEWARD ISLANDS...THE VIRGIN
ISLANDS...PUERTO RICO...THE DOMINICAN REPUBLIC...AND HAITI AS THE
WAVE MOVES WESTWARD OR WEST-NORTHWESTWARD AT 10 TO 15 MPH.
UPPER-LEVEL WINDS ARE EXPECTED TO REMAIN UNFAVORABLE FOR TROPICAL
CYCLONE DEVELOPMENT...AND THERE IS A LOW CHANCE...10 PERCENT...
OF THIS SYSTEM BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.
FOR ADDITIONAL INFORMATION ON THIS SYSTEM...PLEASE REFER TO
PRODUCTS ISSUED BY YOUR NATIONAL METEOROLOGICAL SERVICE.
ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
$$
FORECASTER STEWART/BRENNAN
that was at 1am...seems almost more S, more W, than that...unless my eyes are training in on the heavy convection.
rgb helps me see under that usually but it is too heavy this morning
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