Forecast for 92L: dissipation by Friday

By: Dr. Jeff Masters , 2:17 PM GMT on June 16, 2010

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A low pressure system about 700 miles east of the Lesser Antilles Islands, Invest 92L, was near tropical depression status early this morning, but is currently weakening. Infrared satellite loops show the disturbance's heavy thunderstorm activity has decreased markedly in the past few hours, with the cloud top temperatures warming noticeably, indicating that 92L's thunderstorms are no longer pushing as high into the atmosphere. Water vapor satellite loops show that the storm is surrounded on all sides by dry air, though there is a region of moister air in front of it that 92L will encounter on Thursday. Wind shear as diagnosed by the University of Wisconsin is near 20 knots, though the SHIPS model is diagnosing the shear at a higher 25 - 30 knots. This high shear is pushing 92L's heavy thunderstorm activity to the east side of the center of circulation, and the center will probably become exposed to view late this morning. Had 92L been able to maintain the heavy thunderstorm activity it had early this morning for 12 or so hours, it could have been classified as a tropical depression. However, classification as a TD requires persistent heavy thunderstorm activity, typically interpreted to mean 12 hours of consistent heavy thunderstorm activity, and 92L did not meet that criterion.


Figure 1. Morning satellite image of Invest 92L. Image credit: NOAA.

The forecast for 92L: dissipation
Wind shear is the main story in the forecast for 92L, as a band of very high wind shear of 20 - 50 knots lies to the northwest of the storm. The current expected track of 92L carries it into this band of high wind shear, and the SHIPS model (based on the GFS model) is predicting that the shear will remain in the 25 - 30 knot range through Friday. Other models predict higher shear levels. It is likely that the high shear, combined with the dry air surrounding the storm, will destroy 92L by Friday. The National Hurricane Center is giving 92L a low (10% chance) of developing into a tropical depression by Friday morning, and this is a reasonable forecast. It is likely that 92L will bring heavy rain showers and wind gusts up to 35 mph on Friday to the Lesser Antilles Islands. I don't expect 92L to be organized enough to cause flooding problems to any of the islands in its path. None of our reliable global computer models develop 92L into a tropical depression. The rest of the tropical Atlantic is quiet, and none of the reliable computer models is calling for tropical cyclone development in the Atlantic over the next seven days.

Is the formation of 92L a harbinger of an active hurricane season?
According to the Hurricane FAQ, Goldenberg (2000) found that during the period 1944 - 1999, formation of a named storm in the tropical Atlantic south of 22°N and east of 77°W during June and July was a harbinger of at least an average season, and in many cases an above average season. The formation of a storm in this region during June or July is one factor the NOAA and Colorado State University seasonal hurricane forecast teams have used in the past as a predictor for an active season in their early August forecasts. Now, 92L didn't make it to named storm status, though it was pretty close to being a tropical depression. However, the near-formation of 92L into a tropical depression, is, in my mind, a clear harbinger that we can expect a severe hurricane season this year. It's very rare to have a development like 92L in that portion of the tropical Atlantic this early in the season. The lower than average wind shear and higher than average SSTs that helped 92L get organized are more likely than not to carry over into the main portion of hurricane season, giving us a much more active hurricane season than normal.


Figure 2. Synthetic Aperture Radar (SAR) image of the oil spill taken at 7:51 am EDT Tuesday June 15, 2010, by the Canadian Radarsat-1 satellite, operated by MDA GeospatialServices of Richmond, Canada. A large amount of oil was present on the Florida Panhandle coast near Pensacola, and was headed east towards Panama City. Image credit: Center for Southeastern Tropical Advanced Remote Sensing, University of Miami Rosenstiel School of Marine and Atmospheric Science. SAR images have a resolution of 8 - 50 meters, and can be taken through clouds and precipitation.

Oil spill wind and ocean current forecast
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 for the most part, which will maintain a slow (1/4 mph) eastward-moving surface ocean current that will transport oil eastwards along the Florida Panhandle coast, according to the latest ocean current forecast from NOAA's HYCOM model. These winds and currents may be capable of transporting oil east past Panama City, Florida to Cape San Blas by Monday. Oil will continue to threaten the coasts of Louisiana, Alabama, and Mississippi for the remainder of the week as well, 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.

NOAA has lauched a great new interactive mapping tool that allows one to overlay wind forecasts, ocean current forecasts, oil location, etc.

Oil spill resources
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 has lauched a great new interactive mapping tool that allows one to overlay forecasts and oil location observations
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 Thursday.

Jeff Masters

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Quoting kanc2001:


You gotta back those opinions up with science, recent numbers have shown El nino is gone and we are neutral/heading into weak La Nina. you are young, so you got plenty of time to learn. Heck I Lurk and I'm alot older than you, just sit back and watch the pros on here and you'll absorb a ton
I'm 13 too and I have to credit must of what I've learned about tropical meteorology to StormW, Drakoen, Levi32, and Kman. They really really helped be excel in the tropics.
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Quoting kmanhurricaneman:
this i doubt...Prove it!
How would you like me to prove it? I was born November 7, 1996.
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Dvorak continues to degrade rapidly as the Sw Winds aloft cut her down..

2km Storm Relative IR Imagery with BD Enhancement Curve
1425 UTC



2km Storm Relative IR Imagery with BD Enhancement Curve

The same infrared imagery shown in the earth relative framework is displayed in a storm relative framework, with a 2km resolution and enhanced with the "BD Curve" which is useful for directly inferring intensity via the Dvorak Enhanced IR (EIR) technique. Scaling is provided by two lightly hatched circles around the center. The two circles have radii of 1 and 2 degrees latitude, respectively.
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Quoting Baltimorebirds:
You can never have your own opinion without someone bashing you.


You gotta back those opinions up with science, recent numbers have shown El nino is gone and we are neutral/heading into weak La Nina. you are young, so you got plenty of time to learn. Heck I Lurk and I'm alot older than you, just sit back and watch the pros on here and you'll absorb a ton
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Quoting extreme236:


I really don't see much evidence of shear decreasing in a couple days. That TUTT hasn't lifted out yet.
Here is the 200 millibar GFS forecast, it's at 96 hours and you can see the TUTT over the extreme western Caribbean and over the sub-tropical Atlantic. The TUTT eventually lifts later in the run.

*Notice the very strong equatorial ridge across the basin.

GFS 06z 96 Hours 200 millibar forecast

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Quoting MiamiHurricanes09:
I'm only 13 too.
this i doubt...Prove it!
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92L not dead by a long shot.Like other people have said,if it can survive the next 48 hours we could have something to deal with.Storms forming again near the center
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Sw shear is blowing 92L's skirt up a tad.




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Quoting WINDSMURF:

Give the kid a break he is only 13. At least he is not wasting his time on other things and is trying to learn something here at this blog.
I'm only 13 too.
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Quoting Baltimorebirds:
You can never have your own opinion without someone bashing you.


An opinion should be backed up with some sort of observations or fact of some sort.
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Quoting btwntx08:
all im saying is this that the shear will weaken n the next couple of weeks and it will open the door for systems to develop
Not even, shear in the Atlantic should begin to weaken in the next 5 days as the equatorial rigde strengthens and pushed the TUTT away to the west and north. After a couple of weeks the TUTT should be gone.

Check out the GFS 200 millibar forecast.

Link

I'll help you figure out what it displays in a bit, I've got to do some stuff.
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Quoting MiamiHurricanes09:
Sometimes you just have to do your research before you kill a season.

Give the kid a break he is only 13. At least he is not wasting his time on other things and is trying to learn something here at this blog.
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92L Floater - RGB Color Infrared Loop
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Quoting btwntx08:
all im saying is this that the shear will weaken n the next couple of weeks and it will open the door for systems to develop


I really don't see much evidence of shear decreasing in a couple days. That TUTT hasn't lifted out yet.
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A small note about the high temps in the Gulf:
My sister who lives near Clearwater Beach, was swimming in the Gulf a few days ago. She swam a little further out and said she felt these hot currents flowing around her feet the like of which she's never felt in her life. She said it was like someone turned the hot faucet on in the bathtub it was so hot. Has anyone else ever experienced this? She said it was really freaky.
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Quoting extreme236:


It's not a matter of bashing. People are entitled to their opinions, but opinions not based on any evidence are hard to take very seriously.
Exactly. I see we have TD 2-E. I'm going to be conducting some analysis now.
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Quoting extreme236:


Nice catch! Wasn't paying much attention for a renumber. TD 2E:

EP, 02, 2010061612, , BEST, 0, 146N, 953W, 25, 1007


I went there to see the coordinates for the invests, and I just found it.
Member Since: April 3, 2009 Posts: 107 Comments: 382
Quoting Baltimorebirds:
You can never have your own opinion without someone bashing you.
Yes you can, it's just when your opinion isn't backed up by analysis or facts it can be extremely incorrect and could mislead people.
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Quoting extreme236:


Nice catch! Wasn't paying much attention for a renumber. TD 2E:

EP, 02, 2010061612, , BEST, 0, 146N, 953W, 25, 1007


They must be calling it at 2 pm.
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I guess the NHC will be issuing a special advisory to initiate advisories shortly.
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Thanks Dr.; However, classification as a TD requires persistent heavy thunderstorm activity, typically interpreted to mean 12 hours of consistent heavy thunderstorm activity, and 92L did not meet that criterion.

That persistency factor is key on the blobs that wax and wane over a few days and 92L has been the king of wax and wane; unfortunate exception to the general persistency rule are those storms that spin up quickly around the Gulf and Florida from frontal or wave remnants that often catch folks by surprise around the beginning and end of the seasons (Humberto comes to mind).....We will probably have a few of those this season.
Member Since: August 8, 2006 Posts: 0 Comments: 9122
85. IKE
Taking it's clothes off. Must be rather warm out there....

Member Since: June 9, 2005 Posts: 23 Comments: 37858
Latest TCFA track suggests that Mexico has to watch 93E. SHIPS takes it to hurricane strength before hitting Mexico.

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Quoting Baltimorebirds:
You can never have your own opinion without someone bashing you.


It's not a matter of bashing. People are entitled to their opinions, but opinions not based on any evidence are hard to take very seriously.
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Quoting Magicchaos:
invest_RENUMBER_ep932010_ep022010.ren
Link

We have Blas in the Eastern Pacific


Nice catch! Wasn't paying much attention for a renumber. TD 2E:

EP, 02, 2010061612, , BEST, 0, 146N, 953W, 25, 1007
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80. IKE
12Z non-tropical NAM
Member Since: June 9, 2005 Posts: 23 Comments: 37858
invest_RENUMBER_ep932010_ep022010.ren
Link

We have TD2 in the Eastern Pacific
Member Since: April 3, 2009 Posts: 107 Comments: 382
Quoting btwntx08:
baltimorebird's doesnt really know whats going on lol looks like becoming a downcast
Sometimes you just have to do your research before you kill a season.
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The real player out in the Pacific now is 93E. 92E appears to only be in a marginally favorable environment.
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Quoting Baltimorebirds:
Exactly.
Please practice patience, wait until the system completed dissipated before you just give up on it. I'm telling you from now, that if 92L has a circulation in the Caribbean it should have no problems developing, I can tell you that.
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Quoting MiamiHurricanes09:
Ok let me correct all your errors.

1. Just because you don't get a system in June doesn't mean the season is a bust. To give you an example 2004 had 15 named storms (I think) and the first named storm developed on July 31st. And the reason that this system never really took off is the location of where it developed, c'mon how many African waves do you see develop in June?

2. July will probably be when the systems begin to roll as the GFS forecasts shear to drop considerably throughout the basin, plus you have warm SSTs and lots of upward motion in the basin, as forecasted by the GFS.

3. Shear will not let up until August? That's pretty funny, how about you look at the GFS 200 mb forecast and then tell me if shear isn't going to let up until August. By the way the TUTT is a semi-permanent feature in the Atlantic, it just happened to be there when 92L passed by.

4. And it's pretty funny that you said that 14-16 named storms is an average hurricane season. An average season is 9-10 named storms. 14-16 can be considered as "above average".


I'll second this. Miami, I'm glad you got to 'em before I did.
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I think 93E is very close to being a tropical depression if it is no longer
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Quoting Baltimorebirds:
I think the pacific will be more active.
There is a La Nina in the Pacific, there is no way that the Pacific season will be more active than the Atlantic hurricane season, and you can take that to the bank. You're just saying that because the EPAC season has been more active so far. Anyways their season starts 15 days earlier than ours, there's a reason for that.
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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.