First tropical depression of the season may form from 92L

By: Dr. Jeff Masters , 3:38 PM GMT on June 13, 2010

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An unusually large and well-developed African tropical wave for so early in the season has developed midway between the coast of Africa and South America. The storm was designated Invest 92L by the National Hurricane Center yesterday, and has a good chance of becoming the first tropical depression of the Atlantic hurricane season. Surface winds measured by the 8:23am EDT pass of the European ASCAT satellite revealed that 92L already has a closed surface circulation, though the circulation is large and elongated. Top winds seen by ASCAT were about 25 mph. METEOSAT visible satellite loops show a large and impressive circulation that is steadily consolidating, with spiral bands building inward towards center, and upper-level outflow beginning to be established to the northwest and north.


Figure 1. Morning satellite image of Invest 92L.

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 - 30°C, which is warmer than the temperatures reached during the peak of hurricane season last year, in August - September. 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.) While 92L will cross over a 1°C cooler patch of water on Monday, the storm will encounter very warm SSTs of 28-29°C again by Tuesday.

The disturbance doesn't have to worry about dry air--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 300 - 400 miles from any substantial areas of dry air. The 60-day cycle of enhanced thunderstorm activity called the Madden-Jullian 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.

The forecast for 92L
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 is currently located at 7°N, well south of this band of high shear, and is only experiencing 5 - 15 knots of shear. This moderate amount of shear should allow for some steady development of 92L over the next few days as it tracks west-northwest at 10 - 15 mph. The National Hurricane Center is giving 92L a medium (30% chance) of developing into a tropical depression by Tuesday morning. Based on visible satellite imagery over the past few hours, I believe this forecast is not aggressive enough, and that 92L has a 50% chance of developing into a tropical depression by Tuesday morning. Another factor holding 92L back is its proximity to the Equator. I would give 92L higher chances of developing if it were not so close to the Equator. The system is organizing at about 7°N latitude, which is so close to the Equator that it cannot leverage the Earth's spin much to help it get spinning. It is quite unusual for a tropical depression to form south of 8°N latitude.

The farther south 92L stays, the better chance it has at survival. With the system's steady west-northwest movement this week, 92L should begin encountering hostile wind shear in excess of 30 knots by Thursday, which should be able to greatly weaken or entirely destroy the storm before it gets to the Lesser Antilles Islands. However, 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 by Saturday or Sunday next weekend. The GFDL and HWRF models are predicting that 92L will develop into a moderate strength tropical storm that will then be weakened or destroyed by the end of the week, before it reaches the islands. This looks like a reasonable forecast.


Figure 3. The departure of sea surface temperature (SST) from average for June 10, 2010. Image credit: NOAA/NESDIS.

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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ok well time for bed night everyone
Member Since: March 10, 2010 Posts: 1 Comments: 7874
Quoting xcool:
scottsvb NOPE .CMC A ON 92L


CMC= FAIL

if we went by the CMC we would of had a TS 24hrs ago..and 4 already this year
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The little flare up near 9.2N and 39.2W is close to where the LLC is (best bet not 100%) this would have to sustain and develop more over the next 6-12hrs
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3194. xcool
scottsvb NOPE .CMC A+ ON 92L
Member Since: September 26, 2009 Posts: 2 Comments: 15684
3193. EricSFL
I always feel that data posted on the NHC is a little outdated. I mean, it takes a while for the model runs and analysis so by the time they post the TWO, the storm / hurricane has already changed ( in intensity or direction) Like what happened with Agatha : it made landfall much earlier than predicted so the stretched the "cone" to fit the new center location, making it look weird and improbable...
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Quoting JLPR2:
Cat 1?
All I see is a TS or a TD





Never go by the CMC... its a farmers alnamac model

Models to use are

GFS,GFDL,ECMWF (in no real order cause 1 of the other is usually correct) each 1 has its flaw. GFS is pretty accurate on development..GFDL is pretty good on path...and ECMWF is good for days 4-5 ..after 5 days I wouldnt use any model for accuracy.
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3190. xcool


Member Since: September 26, 2009 Posts: 2 Comments: 15684
3188. JLPR2
Quoting xcool:
TO FAR OUT JLPR2




now?
guys, dont look at the 850mb for intensity, that one is tricky, look at the SLP for that
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Quoting hurricane23:


I concur after viewing that ASCAT pass. Structure wise this thing has looked great with some beautiful poleward and equatorial outflow channels typical of what you would see with canes. But till now this thing has yet to maintain any deep convection near the coc. Morning visibles should be interesting.


Your 100% correct hurricane23
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3184. EricSFL
Convection is definitely becoming more confined around the coc.
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3183. xcool
TO FAR OUT JLPR2
Member Since: September 26, 2009 Posts: 2 Comments: 15684
Quoting thunderman16:
92L looks really good with the banding but no convection present around the coc..I think some dry air has invaded the coc and i look for the NHC in the next TWO to drop the color back down to orange..It needs to get its act together it looks really ragged now..I say a 35% chance of it reaching tropical depression stage and that wont be tomorrow..It will be more likely on tuesday morning..


there is ZERO dry air anywhere near this system and it does not look ragged, they also will not drop this back down to orange unless 92L really unravels and that is not happening at the moment

I think you are taking way too much stock in the convection and not looking enough at the overall structure of the system and the definition of the circulation; structure is very impressive and the circulation continues to get better defined

The convection waning earlier is just part of the process that most systems go through as they develop. Thousands of systems before this one have done it and this one is too, this is nothing new.
Member Since: March 10, 2010 Posts: 1 Comments: 7874
3180. JLPR2
Cat 1?
All I see is a TS or a TD



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LOOKS like the multiple swirls is now ONE...cyclogensis might start coming together now.
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ok time for bed, will be up early tomorrow

night
Member Since: March 10, 2010 Posts: 1 Comments: 7874
3176. xcool
YEAH CAT 1
Member Since: September 26, 2009 Posts: 2 Comments: 15684
3174. xcool
WELCOME
Member Since: September 26, 2009 Posts: 2 Comments: 15684
3172. EricSFL
AFTER Hurricane Andrew 1992 the Dade County Building Code was established. Other south FL counties also use it (Broward for Example). All exterior walls are concrete with rebars. Roofs are attached with hooks that cane withstnd stronger windspeeds.
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3171. JLPR2
Quoting btwntx08:
btw jlpr gets a cookie...here u go :)


hurray!
*goes to corner to eat it silently* XD
eh... I think that staying up so late every night is messing with my brain LOL!
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3170. xcool
LMAO
Member Since: September 26, 2009 Posts: 2 Comments: 15684
3168. xcool


cmc A+
Member Since: September 26, 2009 Posts: 2 Comments: 15684
3166. xcool
TampaSpin w/back.
Member Since: September 26, 2009 Posts: 2 Comments: 15684
Member Since: Posts: Comments:
3163. xcool
Member Since: September 26, 2009 Posts: 2 Comments: 15684
3161. JLPR2
Quoting Bordonaro:

Homes in OK and many parts of the Midwest have basements or storm cellars.

Home in FL were NOT built for major Hurricanes. Look at what happened with Andrew, very sad situation, indeed. Lax building codes!!

Building codes in TX and the rest of "Tornado Alley" do not mandate a storm cellar, or "safe-room". Living in N TX, outside of Ft Worth, TX, that was hit by an F2 in 2000, which did $500 million in damage in downtown Ft Worth, TX in 4 minutes, I have seen the devastation, first hand. Lax building codes!!

California sits on several major fault zones, remember Loma Prieta in 1989 and Northridge in 1994. SAD!! Lax building codes!!!


could you believe I didn't know what a basement and a attic were till I was like 10-12 years old XD
I dont have either of them, so I have no place to hide my junk T_T
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000
ABNT20 KNHC 140523
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT MON JUN 14 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

A LARGE LOW PRESSURE SYSTEM LOCATED ABOUT 1025 MILES WEST-SOUTHWEST
OF THE CAPE VERDE ISLANDS HAS CHANGED LITTLE DURING THE PAST SEVERAL
HOURS. HOWEVER...ENVIRONMENTAL CONDITIONS ARE EXPECTED TO REMAIN
CONDUCIVE FOR ADDITIONAL DEVELOPMENT OF THIS DISTURBANCE AS IT
MOVES WEST-NORTHWESTWARD TO NORTHWESTWARD AT ABOUT 15 MPH. THERE
REMAINS A HIGH CHANCE...60 PERCENT...OF THIS SYSTEM BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER STEWART/BLAKE
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3159. EricSFL
Sorry, someone already posted it. lol
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Quoting 7544:


and it gets stonger right before it approches so fla hmmmm for now


Lets keep in mind thats 240 hours out and the CMC :P
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3156. 7544
Quoting Hurricanes4life:


http://meteocentre.com/animate.php?lang=en&satdir=/models/gemglb_amer_00/&satn ame=gemglbPR00&satext =gif&num=56&speed=5&src=1&title=GEM%20GLB%2000Z%20ANIMHere you go, from the 52- the final (56th) frames you'll see the storm moving through the bahamas and into south florida


and it gets stonger right before it approches so fla hmmmm for now
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3155. xcool
ZCZC MIATWOAT ALL
TTAA00 KNHC DDHHMM
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT MON JUN 14 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

1. A LARGE LOW PRESSURE SYSTEM LOCATED ABOUT 1025 MILES WEST-SOUTHWEST
OF THE CAPE VERDE ISLANDS HAS CHANGED LITTLE DURING THE PAST SEVERAL
HOURS. HOWEVER...ENVIRONMENTAL CONDITIONS ARE EXPECTED TO REMAIN
CONDUCIVE FOR ADDITIONAL DEVELOPMENT OF THIS DISTURBANCE AS IT
MOVES WEST-NORTHWESTWARD TO NORTHWESTWARD AT ABOUT 15 MPH. THERE
REMAINS A HIGH CHANCE...60 PERCENT...OF THIS SYSTEM BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

Member Since: September 26, 2009 Posts: 2 Comments: 15684
Quoting EricSFL:
A little bit off topic, BUT!
How come homes in weather-sensitive areas of the US such as hurricane prone coastal regions (except South FL) and "Tornado alley" aren't built better? I mean come'on people! Wood ai'nt gonna hold nothin'...

Homes in OK and many parts of the Midwest have basements or storm cellars.

Home in FL were NOT built for major Hurricanes. Look at what happened with Andrew, very sad situation, indeed. Lax building codes!!

Building codes in TX and the rest of "Tornado Alley" do not mandate a storm cellar, or "safe-room". Living in N TX, outside of Ft Worth, TX, that was hit by an F2 in 2000, which did $500 million in damage in downtown Ft Worth, TX in 4 minutes, I have seen the devastation, first hand. Lax building codes!!

California sits on several major fault zones, remember Loma Prieta in 1989 and Northridge in 1994. SAD!! Lax building codes!!!
Member Since: Posts: Comments:
..
Member Since: March 10, 2010 Posts: 1 Comments: 7874
3151. JLPR2
Quoting LouisianaWoman:
000
ABNT20 KNHC 140523
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT MON JUN 14 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

A LARGE LOW PRESSURE SYSTEM LOCATED ABOUT 1025 MILES WEST-SOUTHWEST
OF THE CAPE VERDE ISLANDS HAS CHANGED LITTLE DURING THE PAST SEVERAL
HOURS. HOWEVER...ENVIRONMENTAL CONDITIONS ARE EXPECTED TO REMAIN
CONDUCIVE FOR ADDITIONAL DEVELOPMENT OF THIS DISTURBANCE AS IT
MOVES WEST-NORTHWESTWARD TO NORTHWESTWARD AT ABOUT 15 MPH. THERE
REMAINS A HIGH CHANCE...60 PERCENT...OF THIS SYSTEM BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER STEWART/BLAKE




ha! where is my cookie?
It stayed the same :3
Member Since: Posts: Comments:
000
ABNT20 KNHC 140523
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
200 AM EDT MON JUN 14 2010

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

A LARGE LOW PRESSURE SYSTEM LOCATED ABOUT 1025 MILES WEST-SOUTHWEST
OF THE CAPE VERDE ISLANDS HAS CHANGED LITTLE DURING THE PAST SEVERAL
HOURS. HOWEVER...ENVIRONMENTAL CONDITIONS ARE EXPECTED TO REMAIN
CONDUCIVE FOR ADDITIONAL DEVELOPMENT OF THIS DISTURBANCE AS IT
MOVES WEST-NORTHWESTWARD TO NORTHWESTWARD AT ABOUT 15 MPH. THERE
REMAINS A HIGH CHANCE...60 PERCENT...OF THIS SYSTEM BECOMING A
TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER STEWART/BLAKE


Member Since: Posts: Comments:
3148. JLPR2
Quoting EricSFL:


That is what insulation materials are for. Everytime I look at The Weather Channel there is video of an entire town leveled... no kidding! Build better and many more lives could be saved.


exactly, insulation in a cement house is, well... a little difficult XD
so wood it is, seriously I cant imagine myself living in one of those houses, they are just so weak, like in the movies when people can actually punch a wall and make a hole O_o?
Then I think what the result would be here in my house LOL!
Lots of bandages and maybe a fractured something XD I have solid walls :3
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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.

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