ATL: ERNESTO - Post-Tropical

[northjaxpro]

99L is slowly but surely gradually getting its act together early this morning. Convection is building close to where the low level circulation is spinning. I look for NHC to bump up the probability to 30% or possibly 40% by 8 a.m. TWO. I think we will see Ernesto born by Thursday.


The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of this poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org.

[Gustywind]

Loop. 99L continues to slowly organize with a more prononced thunderstorm activity.

[Nimbus]

All I had was a very low resolution IR loop but there did appear to be a naked low level circulation spinning down near 7.5N, As this area crossed -40W convection burst just to the north of the spinning low clouds which would be consistent with the system starting to develop.

If there really was a LLC next update should be at least orange even if they feel it is going to take some time to make a clean break from the ITCZ.

[Gustywind]

000
AXNT20 KNHC 310539
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT TUE JUL 31 2012

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0515 UTC.

...TROPICAL WAVES...

MID ATLC TROPICAL WAVE EXTENDS FROM 15N36W TO A 1010 MB LOW NEAR
9N36W MOVING W 5-10 KT. THE LOW IS EMBEDDED WITHIN THE MONSOON
TROUGH AND IS MOVING WSW 5-10 KT ALONG THE MONSOON TROUGH. LOW
IS EMBEDDED WITHIN THE DEEP MOISTURE OF THE MONSOON TROUGH AS
DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. CLUSTERS OF
SCATTERED MODERATE/STRONG CONVECTION ARE FROM 6N-12N BETWEEN
34W-42W.

[Nimbus]

The models don't have a good initialization yet. If a depression forms near 8 or 9n at -43W for example the tracking will be swept left.

Looks like some of the models are expecting heavy shear in the Caribbean.

[Gustywind]

From the Weather Channel...

Stu Ostro, Senior Meteorologist, The Weather Channel

Jul 31, 2012 1:13 am ET

http://www.weather.com/newscenter/hurri ... index.html

ATLANTIC

- Farther out in the Atlantic, a portion of the "monsoon trough" continues to show rotation and organization. This system has the potential to gain sufficient structure to become a tropical cyclone during the next few days, as it traverses the Atlantic far enough south to avoid the most hostile atmospheric conditions and moves on a track far enough away from the equator for it to spin up. It is headed toward the Lesser Antilles by the end of the week or first part of the weekend.

[GCANE]

GCANE, a big hot tower.

Awesome! Sorry, I didn't keep up with it yesterday.

[GCANE]

Nice anti-cyclone over it now with UL outflow supported by the ULL at ~ 26N 44W

http://tropic.ssec.wisc.edu/real-time/w ... oom=&time=

http://tropic.ssec.wisc.edu/real-time/w ... zoom=&time

[GCANE]

Impressive:

http://tropic.ssec.wisc.edu/real-time/w ... oom=&time=

[GCANE]

Nice LL Circulation, but core hasn't warmed up yet due to limited convection.

http://rammb.cira.colostate.edu/product ... 0_SWHR.GIF

http://rammb.cira.colostate.edu/product ... 0_AMSU.GIF

http://rammb.cira.colostate.edu/product ... 6_TANO.GIF


Needs another hot tower or two.

[GCANE]

Shear should be low for the next 3 days.

http://rammb.cira.colostate.edu/product ... 310000.PNG

[tolakram]

Please don't forget the storm2k disclaimer when making predictions.

GCANE's posts above do not need a disclaimer, but predicting when it might hit the gulf or the islands, or other forecasts do need it.

The disclaimer can be found just above the post box, near the top of each page on this forum.

Personal Forecast Disclaimer:
The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[tolakram]

Some consensus at 96 hours showing a storm near or over the islands. CMC is much stronger then the Euro or GFS, which probably explains the position.

Saved images.

[Gustywind]

000
AXNT20 KNHC 311126
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE JUL 31 2012

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND
METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1115 UTC.

...TROPICAL WAVES...

MID ATLC TROPICAL WAVE EXTENDS FROM 12N36W TO A 1010 MB LOW NEAR
9N37W MOVING W 5-10 KT. THE LOW IS EMBEDDED WITHIN THE MONSOON
TROUGH AND IS MOVING WSW 5-10 KT ALONG THE MONSOON TROUGH. LOW
IS EMBEDDED WITHIN THE DEEP MOISTURE OF THE MONSOON TROUGH AS
DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED
MODERATE/STRONG CONVECTION IS FROM 7N-11N BETWEEN 37W-42W.

[Gustywind]

Discussion of 99L by Rob of Crown Weather:

The following post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org. For Official Information please refer to the NHC and NWS products.

http://www.crownweather.com/?page_id=4557


Invest 99L Slowly Becoming More Organized & May Develop Into Tropical Storm Ernesto & Affect Barbados, The Southern Leeward Islands & The Windward Islands On Saturday


Tuesday, July 31, 2012 5:55 am

by Rob Lightbown

Invest 99L, which is an area of low pressure, is located about 1200 miles or so to the west-southwest of the Cape Verde Islands this morning. The latest satellite loops indicate that this disturbance is gradually becoming more organized as deeper thunderstorm activity seems to be firing near the low pressure system. I do think that we will see 99L continue to slowly develop over the coming days and I do think that we will see it become a tropical depression on Wednesday and then strengthen into Tropical Storm Ernesto as early as late Thursday.

Looking at the forecast guidance this morning: The GFS model seems to have backed off some on how much this system will develop in the coming days. It does forecast 99L to become a low-end tropical storm before it tracks across the Leeward and Windward Islands on Friday, but then forecasts it to fall apart as the low-level center outruns the mid and upper level center due to strong trade winds in the Caribbean.

The latest European model forecasts that 99L will develop into a tropical storm before affecting the southern Leeward Islands, the Windward Islands and Barbados during the day Friday. After that, the European model forecasts that this system will fall apart due to the aforementioned strong trade winds in the Caribbean. It should be noted that the 10 day European model forecast, valid for August 9th forecasts some reorganization and development of this system once it reaches the southern Gulf of Mexico.

The Canadian model continues to be the most aggressive and forecasts 99L to become a hurricane before it affects the northern Leeward Islands by Friday and forecasts this system to approach the Bahamas by late this weekend. The longer range Canadian model forecasts this system to affect the east coast of Florida right around next Wednesday and next Thursday. At this point, the Canadian model is the odd-man out and will be disregarded for now, however, as we saw with Debby and the correct forecast by the GFS model (also the odd-man out at the time), you can never rule out any one model forecast.

At this point looking at all of the environmental factors and weighing in the latest forecast guidance and the most recent satellite imagery, I think that we will see development into a tropical depression during the day Wednesday and then intensify into a tropical storm by later Thursday afternoon or during the night Thursday night. I currently expect that this system will track very near the island of Barbados on Saturday morning as a tropical storm and then affect the southern Leeward Island and the Windward Islands during Saturday afternoon with tropical storm conditions, including strong winds with gusts to 50 mph, heavy rainfall and rough seas.

Beyond that, the future of this system becomes very murky as strong trade winds in the Caribbean may cause future Ernesto to fall apart very quickly and dissipate. So, at this point, we should concentrate on the fact that we do have a slowly organizing tropical disturbance that has a fairly good chance of becoming a tropical storm in the next few days.

I am monitoring Invest 99L closely and I will keep you all updated on the latest.

[cycloneye]

Stays at 20%.

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT TUE JUL 31 2012

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

A WEAK AREA OF LOW PRESSURE ASSOCIATED WITH A TROPICAL WAVE LOCATED
ABOUT 1150 MILES WEST-SOUTHWEST OF THE CAPE VERDE ISLANDS CONTINUES
TO PRODUCE DISORGANIZED SHOWER AND THUNDERSTORM ACTIVITY.
ENVIRONMENTAL CONDITIONS APPEAR CONDUCIVE FOR SOME GRADUAL
DEVELOPMENT OF THIS LOW OVER THE NEXT FEW DAYS. THIS SYSTEM HAS A
LOW CHANCE...20 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS AS IT MOVES WESTWARD AT 10 TO 15 MPH.

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

$$
FORECASTER KIMBERLAIN

[Blown Away]

00z Nogaps similar to Canadian, develops 99L into a stronger storm then tracks through NE Caribbean towards SE Bahamas. Seems a deeper 99L gets pulled more NW and shallow 99L goes into the central Caribbean and gets mauled by strong upper level winds. JMHO

http://raleighwx.americanwx.com/models/ ... sLoop.html

[wxman57]

Canadian seems way too far to the right. Hard to believe it'll miss/graze the eastern Caribbean as per the Canadian.

[cycloneye]

Let's see when they run GFDL and HWRF as both have not been runned since 06z on Monday morning.

[drezee]

It has the look. It looks a lot like Iris from 1995. Same elongated structure that turned into a storm very quickly once it got going.