Forecast for 92L: dissipation by Friday

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

Share this Blog
3
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 517 - 467

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30Blog Index

Quoting Patrap:


Microburst or a straight line td..?

Bet that was Hairy,..eh



I believe it was just straight line winds, as it was form the gust front at the leading edge of the storms.

but yeah, it got chilly and windy in hurry
Member Since: Posts: Comments:
Digital Dvorak



Digital Dvorak Intensity Estimates

Using the infrared (IR) images collected as part of the CIRA tropical cyclone IR image archive, which are displayed in an earth relative format as a product on this web page. Center positions are extrapolated using the current position and the past 12-h mean motion vector. Tropical cyclone intensity estimates can be made using two temperatures derived from the IR imagery. The first is the warmest pixel in the eye, and second is the warmest pixel on the coldest circle between 24 and 111 km from the cyclone center. Using these values a Raw T-number can be created by using the locally developed Table That expands upon the table published in Dvorak (1984). Each T-number has an intensity, in terms of maximum 1-minute sustained winds, associated with it and can be converted to an intensity.

While Raw T-numbers give an estimate of how strong a given storm is, the quantity is noisy, and because it is an instantaneous measure does not properly account for the relatively slow decay process of tropical cyclone winds. To remove the noisy nature of the Raw T-numbers time averaging is employed to produce a 6-h running mean of the raw T-numbers. This 6-h running mean is considered the T-number associated with the current intensity if the 6-h running mean is not decreasing at more than 1.5 T-numbers per day. If the 6-h running mean is decreasing very rapidly, a maximum of 1.5 T-number per day decay rate is prescribed. This final value of the 6-h running mean with a decay rule applied is considered the current intensity number or CI. The CI, as with any T-number estimate, can be converted into a intensity. However, it is important to note that THIS TECHNIQUE IS ONLY VALID FOR STORMS OF HURRICANE INTENSITY (65 kt) OR GREATER.

Member Since: July 3, 2005 Posts: 428 Comments: 129767
Quoting tornadodude:


yesterday we had a squall line move through and it had winds around 80 mph, saw a semi get completely flipped over in front of me, and the temperature dropped from 90 to 72 in 4 minutes!


Microburst or a straight line td..?

Bet that was Hairy,..eh

Member Since: July 3, 2005 Posts: 428 Comments: 129767
Hay Pat look at a close-up on that visible I think I see the Tidy Bowel Man, an he looks like he is not going down for the count this time.
Member Since: Posts: Comments:
Some CV Like Vortexes are seemingly defiant seems sometimes.

1995 is a good example of fighting CV that mange to develop downstream.

They all bear watching till they dissolve or wisp away.

2005 and Cindy,early July is what Im looking to trend early as we swing into the 2nd half of June proper.

Close to the Yucatan is a Climo favored spot .
Member Since: July 3, 2005 Posts: 428 Comments: 129767
Quoting clwstmchasr:


I saw on radar the storm over downtown.


yesterday we had a squall line move through and it had winds around 80 mph, saw a semi get completely flipped over in front of me, and the temperature dropped from 90 to 72 in 4 minutes!
Member Since: Posts: Comments:
Quoting clwstmchasr:


I saw on radar the storm over downtown.


It popped up out of nowhere. It's still cloudy here but it looks like the rain has stopped.
Member Since: Posts: Comments:
Quoting Patrap:


Dvorak is ragged at best as well.



its gone and what it was
is gone with it
and its not even on paper
Member Since: July 15, 2006 Posts: 178 Comments: 55970
Quoting Levi32:


For Joe Bastardi....it is to me, though I liked it better when he was free. Not his fault though Accuweather wanted to make a profit off of him. The rest of the site isn't really worth it, though it is really good for diverse world-wide model maps.
Oh ok, thanks.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting clwstmchasr:


Is Joe really that good? I saw him a couple of days ago and he that that there was nothing to stop 92L from becoming Alex. That is just one scenario but to me he seems like a lot of hype.


Of course he does....that's how a lot of people view him, but he's a long-range forecaster. He's going to tell you when there is a possibility for trouble way down the road. And I personally have not seen him say there is nothing stopping 92L from becoming Alex. He has been iffy on it this entire time.

Let's put it this way....I wouldn't know 90% of what I know about Meteorology if I hadn't been following Bastardi since I was 9 years old.
Member Since: Posts: Comments:
Let's do some comparisons...

Homer, Alaska (Airport)
Updated: 51 min 51 sec ago
Overcast
47 °F
Overcast
Windchill: 46 °F
Humidity: 90%
Dew Point: 44 °F
Wind: Calm
Pressure: 29.99 in (Steady)
Visibility: 10.0 miles
UV: 1 out of 16
Clouds:
Mostly Cloudy 4500 ft
Overcast 6000 ft
(Above Ground Level)
Elevation: 82 ft

VS.

Twig's Digs - Coconut Grove, Coconut Grove, Florida (PWS)
Updated: 17 min 12 sec ago
Scattered Clouds
95.3 °F
Scattered Clouds
Humidity: 64%
Dew Point: 76 °F
Wind: 9.0 mph from the SE
Wind Gust: 10.0 mph
Pressure: 29.96 in (Falling)
Heat Index: 112 °F
Visibility: 10.0 miles
UV: 12 out of 16
Pollen: 3.50 out of 12
Pollen Forecast new!
Clouds:
Scattered Clouds 3500 ft
Scattered Clouds 25000 ft
(Above Ground Level)
Elevation: 14 ft

Oh did you know that the distance between Homer, Alaska and Miami, Florida is 5238 miles. Sorry Levi, I'm not going to visit you by car, lol.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
"Never seen a Caribbean red pool this big in June. In fact it's rare to get them this big in any month."


What do you think its going to look like come round september? I still can't even fathom the possibility.

Dr. Masters stated in the his previous blog that water temps currently throughout the tropical Atlantic, GOM, and Carribean are already at the max temperatures that was achieved last year during september.

Whether we see 10 or 20 storms this season, I still believe whatever manages to form will blossom eventually. The shear might keep the total down, i don't believe however that its going to effect number of big hurricanes that would have developed vs. total named storms. With the ridiculous amount of fuel out there storms that are about to truely tap that energy will be able to generate a strong anticyclonic flow above them to help protect them more from shear. The heat content in the Carribean and GOM is just unreal, especially the Carribean.



Member Since: Posts: Comments:
Oh my God maybe Obama will finally get some credit for something positive. Maybe the right and left will get of his buns for 1 day.
Member Since: Posts: Comments:
And the low level Swirlie Vortex is Naki


Storm Relative 1km Geostationary Visible Imagery
1745 UTC

Member Since: July 3, 2005 Posts: 428 Comments: 129767
Quoting MiamiHurricanes09:
Damn it. LOL, is it worth it for $25?


There's a free site video out today though. Link
Member Since: Posts: Comments:


Dvorak is ragged at best as well.

Member Since: July 3, 2005 Posts: 428 Comments: 129767
Quoting clwstmchasr:


I live in Oldsmar - thunder is booming right now but no rain. The storm is just to my east. The same thing happened yesterday. All noise but no rain.


We had a nice little storm in downtown Tampa. Lots of rain and strong winds and lightning!
Member Since: Posts: Comments:
Quoting Patrap:
Oooofh..

as it Hits da Wall-O-Shear




Looks like a line of shaving cream ahead of the razor...
Member Since: Posts: Comments:
Oooofh..

as it Hits da Wall-O-Shear


Member Since: July 3, 2005 Posts: 428 Comments: 129767
This thing looks like a depression over land but it is an extratropical vortex
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
Damn it. LOL, is it worth it for $25?


For Joe Bastardi....it is to me, though I liked it better when he was free. Not his fault though Accuweather wanted to make a profit off of him. The rest of the site isn't really worth it, though it is really good for diverse world-wide model maps.
Member Since: Posts: Comments:
493. xcool
MiamiHurricanes09 yeah
Member Since: Posts: Comments:
Quoting Levi32:


Accuweather Pro site :P
Damn it. LOL, is it worth it for $25?
Member Since: September 2, 2009 Posts: 130 Comments: 21194
12z NAEFS week 2 temperatures period from June 24th through July 1st.

This is just awful....really. The gulf is cooking, more than I've ever seen it in my short time observing.

Wish I could find out how close we are to record GOM SST anomalies.

Member Since: Posts: Comments:
BP is suspending their dividend in addition to establishing a $20 billion escrow account.
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:
Link please.


Accuweather Pro site :P
Member Since: Posts: Comments:
486. xcool
24.95$ MiamiHur
Member Since: Posts: Comments:
Quoting Levi32:
Never seen a Caribbean red pool this big in June. In fact it's rare to get them this big in any month.



..impressive but pretty unuseful with strong winds shear. 92L is pitiful
Member Since: Posts: Comments:
484. xcool
. Levi32
i think going to up,
Member Since: Posts: Comments:
Quoting StSimonsIslandGAGuy:
Closed isobar.

So I have a question, doesn't a closed isobar define a tropical depression? Or is it also subjective, such as if the NHC doesn't think it has much of a chance, they will not call it a tropical depression even if it meets the requirements (unless it strengthened and organized in defiance of predictions)



A closed isobar is seen in the synoptic map of the 12z
Member Since: Posts: Comments:
482. MTWX
Quoting Floodman:


No worries at all... **poof!** and no more problem

LOL!! How have you been Flood??
Member Since: Posts: Comments:
Quoting Levi32:


Interesting as usual. Wonder if he's actually going to up his numbers like his joking hint at the end of the video.
Link please.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting LongGlassTube:
My brother was one year old when Betsy hit and I was one year old when Camile hit. I really don't remember a lot of storms from my childhood. It was a pretty calm period for Louisiana after Camile. I can remember Cat 1 Juan in 85 because of the floods. The first storm that I remember that did a lot of wind damage here was Andrew in 1992. Pretty much went from 1969 to 1992 with little to talk about here in south Louisiana. Tropical Storm Allison in 2001 put 4 feet of water in my house with barely a breeze blowing. Having Katrina, Rita and Gustav all do damage to my home in such a short period was certainly a remarkable period for me personally. Gustav did so much damage that I'm still making repairs. I just came down from making repaifs to the roof of my boathouse. The Heat Index is about 110 and rising. Time to cool off and eat lunch.





Itsa scorcher outside today for sure.

Best of luck in your continued recovery as well.
Member Since: July 3, 2005 Posts: 428 Comments: 129767
Quoting xcool:
Levi32 .how about joe b new
videos >?


Interesting as usual. Wonder if he's actually going to up his numbers like his joking hint at the end of the video.
Member Since: Posts: Comments:
So true Keeper when the maestro waves his wand to start the CV season this year, I got a gut feeling were all going to want to walk out before the concert is finished.
Member Since: Posts: Comments:
Quoting jasoniscoolman09:
three lows in the p.ocean wow
LOL. Look at the low train.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Quoting CaneWarning:


That can't be good for the blog.


No worries at all... **poof!** and no more problem
Member Since: Posts: Comments:
Quoting IKE:


WOOHOO!
That would suck. We wouldn't have a blog to blog on when we need to blog because there is a hurricane out there that needs blogging from us bloggers. If that made any sense. lol.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
My brother was one year old when Betsy hit and I was one year old when Camile hit. I really don't remember a lot of storms from my childhood. It was a pretty calm period for Louisiana after Camile. I can remember Cat 1 Juan in 85 because of the floods. The first storm that I remember that did a lot of wind damage here was Andrew in 1992. Pretty much went from 1969 to 1992 with little to talk about here in south Louisiana. Tropical Storm Allison in 2001 put 4 feet of water in my house with barely a breeze blowing. Having Katrina, Rita and Gustav all do damage to my home in such a short period was certainly a remarkable period for me personally. Gustav did so much damage that I'm still making repairs. I just came down from making repaifs to the roof of my boathouse. The Heat Index is about 110 and rising. Time to cool off and eat lunch.



Quoting Patrap:
A lot of folks here older than 45 or so remember when all Canes were named after ladies.

My first Cat-3 was Betsy,,then Camille hit the coast 4 years later when I was 9.
Member Since: Posts: Comments:
468. MTWX
Quoting FLWeatherFreak91:
Sea breeze very evident around Tampa Bay. I'm watching the line blow up from Odessa, north of tpa.

Link here you go...
Member Since: Posts: Comments:
Quoting YourCommonSense:
I don't expect any tropical development in the Atlantic for the next 2 years. Have a great day!


YourCommonSense
maybe a screen name change
to NoCommonSense
would be better
Member Since: July 15, 2006 Posts: 178 Comments: 55970

Viewing: 517 - 467

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30Blog Index

Top of Page

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.

Local Weather

Light Snow
29 °F
Light Snow

JeffMasters's Recent Photos

Lake Effort Snow Shower Over Windsor, Ontario
Sunset on Dunham Lake
Pictured Rocks Sunset
Sunset on Lake Huron