ATL : INVEST 92L - DISCUSSION

[Hurricane Andrew]

what are the realistic chances that this can stay organized and make it to the islands?

Belive it or not, this is my forcast.

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Dissipating-20%
island/east Carribean-50%
East coast-20%
OTS-10%

[cycloneye]

From 8 PM EDT discussion:

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC...

...SPECIAL FEATURES...

A BROAD AREA OF CYCLONIC CIRCULATION IS IN THE CENTRAL TROPICAL
ATLANTIC ABOUT 975 NM WSW OF THE CAPE VERDE ISLANDS...FOCUSED ON
A 1010 MB SURFACE LOW CENTERED NEAR 7N37W. THE SYSTEM IS
EMBEDDED IN A LARGE AREA OF DEEP LAYER MOISTURE EVIDENT IN TOTAL
PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/STRONG CONVECTION
IS N AND NE OF THE LOW CENTER FROM 8N-10N BETWEEN 34W-38W...AND
FROM 10N-12N BETWEEN 30W-34W. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS FROM 2N-8N BETWEEN 35W-39W...AND FROM 8N-12N
BETWEEN 38W-42W. THE SYSTEM CONTINUES TO HAVE GOOD ENVIRONMENTAL
CONDITIONS CONDUCIVE FOR FURTHER DEVELOPMENT. THERE IS CURRENTLY
A HIGH CHANCE...60 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL
CYCLONE DURING THE NEXT 48 HRS.

[Hurricane Andrew]

Note-You 98 guests out there, come and join the fun!

[Gustywind]

Red Code

[Duddy]

Wow look at the wave behind it!

[jaxfladude]

Bad Omen Alert for the Rest of the Season?!

[Gustywind]

Wow look at the wave behind it!

[Cdeck81]

Note-You 98 guests out there, come and join the fun!

I'm only 13 and I'm having tons of fun!

[Hurricane Andrew]

Note-You 98 guests out there, come and join the fun!

I'm only 13 and I'm having tons of fun!

???

Anyway..i think wave#2 sould be Invest 93, and code yellow. agreed?

[Explorer93]

I have no knowledge in sheer, but does models show sheer breaking up, and allowing systems to develop any time soon?

[Cdeck81]

Note-You 98 guests out there, come and join the fun!

I'm only 13 and I'm having tons of fun!

???

Anyway..i think wave#2 sould be Invest 93, and code yellow. agreed?

I agree, just wait until all of it emerges off the west coast of Africa.

[Hurricane Andrew]

We are up to 102 guests.

Anyway...I think Ale and Bonnie are both on the near horzon.

[KWT]

System is now reminding me a little of Bertha in 2008 before it got upgraded...with a cracking structure to it but a waning convective look...of course it eventually got over that and I'd have thought this system will do so over the next 12-24hrs.

[WmE]

Wow, shouldn't the Cape Verde season start a little later. I'd like to see that second wave emerge from the coast as it could fizzle out. Any info on the SAL this year?

[Gustywind]

Looks like the train is roughly (already?) in route from Africa to the Atlantic...

[Gustywind]

First tropical depression of the season may form from 92L
http://www.wunderground.com/blog/JeffMa ... ticle.html

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.


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.


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.

[Time_Zone]

Note-You 98 guests out there, come and join the fun!

I'm only 13 and I'm having tons of fun!

???

Anyway..i think wave#2 sould be Invest 93, and code yellow. agreed?

Wait until it emerges off of Africa...I wouldn't be surprised at all to see it poof.

[ROCK]

that wave after 92L should fizzle as its too soon for CV season right.... I thought that about 92L after it exited also....

[rd261]

Hello fellow storm chasers

I have been lurking in this forums since 2004 but never commented. I decided to do so now because I have been obsessed with this storm since it came out of the African continent. Anyways, I have really enjoyed the forums for the past couple of years and hope to continue doing so for many more seasons to come.

By the way wxman57, Im a fan I have learned lots from your discussions.

[Cdeck81]

Hello fellow storm chasers

I have been lurking in this forums since 2004 but never commented. I decided to do so now because I have been obsessed with this storm since it came out of the African continent. Anyways, I have really enjoyed the forums for the past couple of years and hope to continue doing so for many more seasons to come.

By the way wxman57, Im a fan I have learned lots from your discussions.

Welcome to Storm2k! I'm glad we have another person in the convo!