ATL : TROPICAL DEPRESSION ERIKA (06L)

[BensonTCwatcher]

I'm sure it (MM5) is too, but the low res version has got closed lows and TC's all over it from the Gulf to Carolinas?? My point is this system (especially this year) will not be predicted by a single model or ensemble. It will be done by forecasters looking at in-situ data, models and synoptics. I like to see the back and forth when it's based on a data set or observation. If a global model is handling most features well (like the GFS) but missing some (like ULL's) which are handled better by others (like the Euro, and even the CMC sometimes) we can still get a better solution without all the "my model is better than your model" no matter how fun it is watch

[Derek Ortt]

is this possibly it?
http://moe.met.fsu.edu/mm5/

nope. The MM5s SHOULD be publicly available soon

[Evil Jeremy]

Shear appears to have lessened this evening,look at outflow and more circular shape.

http://www.ssd.noaa.gov/goes/east/catl/loop-wv.html

First the shear is going to kill this, then it relaxes into the evening! The tropics are crazy lol. Looking at that ULL though, I think it is moving faster to the west than 94L is.

[Evil Jeremy]

WHXX04 KWBC 312316
CHGQLM
ATTENTION...NATIONAL HURRICANE CENTER

NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR

TROPICAL DEPRESSION INVEST 94L

INITIAL TIME 18Z AUG 31

DISCLAIMER ... THIS INFORMATION IS PROVIDED AS GUIDANCE. IT
REQUIRES INTERPRETATION BY HURRICANE SPECIALISTS AND SHOULD
NOT BE CONSIDERED AS A FINAL PRODUCT. PLEASE SEE THE TPC/NHC
OFFICIAL FORECAST.


FORECAST STORM POSITION

HOUR LATITUDE LONGITUDE HEADING/SPEED(KT)

0 15.3 53.7 300./13.0

STORM DISSIPATED AT 0 HRS AT THE ABOVE PSN.

[GeneratorPower]

I think I can see the shear really decreasing and a big explosion of deep convection on the western/northern side of the center. That wasn't happening before. That's a huge convective burst.

[Weatherboy1]

very deep convection firing right over the middle of the elongated circulation area. Wonder if an LLC didn't finally just come together, and this big burst is a result. Hard to tell from IR, but I wouldn't be surprised.

[cycloneye]

ABNT20 KNHC 312334
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT MON AUG 31 2009

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

SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A BROAD AREA OF LOW
PRESSURE LOCATED ABOUT 450 MILES EAST OF THE LESSER ANTILLES
CONTINUE TO SHOW SIGNS OF ORGANIZATION. CONDITIONS REMAIN SOMEWHAT
FAVORABLE FOR THIS SYSTEM TO BECOME A TROPICAL DEPRESSION DURING
THE NEXT DAY OR SO AS IT MOVES WEST-NORTHWESTWARD AT AROUND 15 MPH.
THERE IS A HIGH CHANCE...GREATER THAN 50 PERCENT...OF TROPICAL
CYCLONE FORMATION IN THIS AREA DURING THE NEXT 48 HOURS. INTERESTS
IN THE LESSER ANTILLES SHOULD MONITOR THE PROGRESS OF THIS SYSTEM.

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

$$
FORECASTER KIMBERLAIN/BRENNAN

[Derek Ortt]

GFDL is dissipating this because there is no vortex in the initial field. The model will crash with no vortex

[jlauderdal]

ABNT20 KNHC 312334
TWOAT
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT MON AUG 31 2009

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

SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A BROAD AREA OF LOW
PRESSURE LOCATED ABOUT 450 MILES EAST OF THE LESSER ANTILLES
CONTINUE TO SHOW SIGNS OF ORGANIZATION. CONDITIONS REMAIN SOMEWHAT
FAVORABLE FOR THIS SYSTEM TO BECOME A TROPICAL DEPRESSION DURING
THE NEXT DAY OR SO AS IT MOVES WEST-NORTHWESTWARD AT AROUND 15 MPH.
THERE IS A HIGH CHANCE...GREATER THAN 50 PERCENT...OF TROPICAL
CYCLONE FORMATION IN THIS AREA DURING THE NEXT 48 HOURS. INTERESTS
IN THE LESSER ANTILLES SHOULD MONITOR THE PROGRESS OF THIS SYSTEM.

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

$$
FORECASTER KIMBERLAIN/BRENNAN

i bet if they would have code oranged this thing at 2pm we would have a classified system at 11, its just the way things are working this year

[Aric Dunn]

its beginning to wrap around the area i circled earlier.. and its quite the impressive blow up .. have to say this is the largest and most concentrated convective burst so far..

[Ivanhater]

[Ivanhater]

[cycloneye]

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT MON AUG 31 2009

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...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2300 UTC.

...SPECIAL FEATURES...

A BROAD AREA OF LOW PRESSURE ASSOCIATED WITH A 1008 MB LOW IS
CENTERED NEAR 15N54W...ABOUT 500 MILES E OF THE LESSER ANTILLES.
THE AREA COINCIDES WITH BROAD DEEP LAYER MOISTURE OBSERVED IN
TOTAL PRECIPITABLE WATER IMAGERY. MAXIMUM VALUES OF LOW-LEVEL
VORTICITY ARE ALSO OBSERVED IN THE VICINITY OF THE LOW BASED ON
CIMSS WAVETRAK MODEL GUIDANCE. A LARGE CLUSTER OF NUMEROUS
STRONG CONVECTION IS FROM 14N-18N BETWEEN 50W-53W. SCATTERED
MODERATE/STRONG CONVECTION IS FROM 11N-14N BETWEEN
51W-54W...FROM 18N-20N BETWEEN 48W-53W...AND FROM 13N-15N
BETWEEN 58W-59W. THIS SYSTEM HAS A HIGH CHANCE...GREATER THAN 50
PERCENT...OF BECOMING A TROPICAL DEPRESSION DURING THE NEXT DAY
OR SO AS IT MOVES WNW NEAR 15 KT. INTERESTS IN THE LESSER
ANTILLES SHOULD MONITOR THE PROGRESS OF THIS SYSTEM.

[North Naples]

Ivanhater, where did you get that second satellite loop? That's great.

[smw1981]

Ivanhater, where did you get that second satellite loop? That's great.

I was wondering the same thing...pretty impressive loop!

[clfenwi]

31/2345 UTC 16.7N 54.5W T2.0/2.0 94L -- Atlantic

[cycloneye]

Numbers of depression.

[ddad040]

Is the tutt just north and a little west (30 or so n 57 w) helping pull 94 north or just venting?

[Aric Dunn]

hare is two of the latest microwave images, they are around 2 hours apart and the first being at 1954 UTC showing the beginnings of the circulation. then the later image at 2255 UTC shows it progressing and beginning to wrap up and banding features are becoming more noticeable.
by the 2am outlook we are probably going to be looking at a completely different system compared to earlier today. shear out of no where has come down this evening and the earlier vortex as dissipated allowing the new center to start consolidating at around 16.4N 54.3W. the present burst is probably significant enough to close of a tight closed low allowing this to become A td by morning that is if things progress as they have for the last 4 hours.

1st image 1954 UTC


2nd image 2255 UTC

[Aric Dunn]

31/2345 UTC 16.7N 54.5W T2.0/2.0 94L -- Atlantic

hmmm... maybe at 11 pm they may upgrade.. new data is starting to show it closing off..

2.0 is a depression technically interesting.. .