ATL: ISAAC - Post-Tropical - Discussion

[cycloneye]

For the folks that live in the Eastern Caribbean islands,there is a thread up as sticky where you can post about preparations,observations of the weather as system approaches,you can post weather alerts/discussions from the weather offices and by crownweather,weather channel etc.

viewtopic.php?f=59&t=113410&p=2252883#p2252883

[CalmBeforeStorm]

http://www.ssd.noaa.gov/PS/TROP/floater ... -long.html
A nice rotation this morning but still no convection around the center. This is a tropical storm the minute you see the deep convection develop IMO.

[OuterBanker]

Believe it or not, local mets are hoping that Issac to be comes this way this week (offshore of course.)

Why? Because the east coast surfing championship is this week, the largest and oldest on the east coast held in Virginia Beach.

Todays current surf forecast, one foot

As you can see we need a little help.

[cycloneye]

Remains at 80%

A TROPICAL WAVE AND A LOW PRESSURE AREA LOCATED ABOUT 1100 MILES
EAST OF THE LESSER ANTILLES CONTINUES TO PRODUCE SHOWER AND
THUNDERSTORM ACTIVITY. ENVIRONMENTAL CONDITIONS ARE CONDUCIVE FOR A
TROPICAL DEPRESSION TO FORM DURING THE NEXT DAY OR SO AS THIS LARGE
DISTURBANCE MOVES WESTWARD AT 20 TO 25 MPH. THIS SYSTEM HAS A HIGH
CHANCE...80 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS. INTERESTS IN THE LESSER ANTILLES SHOULD MONITOR THE
PROGRESS OF THIS SYSTEM.

[CalmBeforeStorm]

Remains at 80%

A TROPICAL WAVE AND A LOW PRESSURE AREA LOCATED ABOUT 1100 MILES
EAST OF THE LESSER ANTILLES CONTINUES TO PRODUCE SHOWER AND
THUNDERSTORM ACTIVITY. ENVIRONMENTAL CONDITIONS ARE CONDUCIVE FOR A
TROPICAL DEPRESSION TO FORM DURING THE NEXT DAY OR SO AS THIS LARGE
DISTURBANCE MOVES WESTWARD AT 20 TO 25 MPH. THIS SYSTEM HAS A HIGH
CHANCE...80 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS. INTERESTS IN THE LESSER ANTILLES SHOULD MONITOR THE
PROGRESS OF THIS SYSTEM.

Do you have the new BAM's CycloneEye?

[cycloneye]

Do you have the new BAM's CycloneEye?

They should be up between 8 AM and 9 AM.Check the models thread.

[NDG]

94L may not look to good on vis sat this morning with organized deep convection, but on microwave it clearly shows what a large circulation it has established, it just needs to get away from the SAL so that it can blow up with convection.

[tolakram]

Closeup

[cycloneye]

Let's see if bouy 41041 that 94L will move thru soon provides some valuable information later today.

http://www.ndbc.noaa.gov/station_page.php?station=41041

[Blown Away]

Closeup

http://img585.imageshack.us/img585/784/zztemp.jpg

Is that the exposed LLC?? That is an awesome view!

[Blown Away]

94L gaining a little latitude, I see the LLC near 15.6N/44.6W? Small convection blowup around LLC, let's see if it can maintain and grow??
http://www.ssd.noaa.gov/PS/TROP/floater ... short.html

[wxman57]

94L gaining a little latitude, I see the LLC near 15.6N/44.6W? Small convection blowup around LLC, let's see if it can maintain and grow??
http://www.ssd.noaa.gov/PS/TROP/floater ... short.html

That little swirl on the visible shot above is the center. At 1145Z it was near 15.7N/44.8W. Currently (1215Z) near 15.7N/45W. One small thunderstorm just developed east of the center.

[Aric Dunn]

well all we need and have needed for the pasy 24 hours is convection. its rather strange there is none. plenty of moisture sal is not bad. May just need to slow down some.

[Gustywind]

805 TWD



AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 40W/41W FROM
A 1010 MB LOW PRESSURE CENTER THAT IS NEAR 15N ALONG THE WAVE.
THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS AS IT MOVES WESTWARD 17 TO 22 KNOTS.
CONVECTIVE PRECIPITATION...SCATTERED MODERATE TO ISOLATED STRONG
FROM 10N TO 18N BETWEEN 39W AND 50W. BROKEN TO OVERCAST
MULTILAYERED CLOUDS AND OTHER POSSIBLE RAINSHOWERS COVER THE
ATLANTIC OCEAN ELSEWHERE FROM 10N TO 21N BETWEEN 35W AND 50W.
INTERESTS IN THE LESSER ANTILLES SHOULD MONITOR THE PROGRESS OF
THIS SYSTEM.

[NDG]

Close up of the convection firing up near the apparent LLC

[HURRICANELONNY]

Don't know if anyone posted this from NWS miami today 8/20/12. Pretty much just says to watch. I'm sure it will change many times.
Long term...[wednesday-weekend]
quite a bit of uncertainty becomes introduced as we approach the
weekend due to a considerable amount of variance within the latest
model package. This amount of uncertainty will keep the forecast
confidence low as a result through this time. The main interest
through this period will remain on what is currently an area of
interest well east of the Lesser Antilles that could become a
tropical cyclone over the upcoming 24-48 hours. While some of the
individual models take this area of interest due west across the
Caribbean Sea...the GFS and its ensemble mean solutions indicate a
north and northwest turn across Cuba over the weekend. Due to the
amount of low confidence through this time...will continue to
indicate mainly more of a seasonal rainfall forecast with
scattered afternoon rain showers/thunderstorms each day and continue to monitor
the latest model guidance over the upcoming days as confidence
should gradually begin to increase.

[cycloneye]

12z Best Track

AL, 94, 2012082012, , BEST, 0, 156N, 448W, 25, 1010, DB

ftp://ftp.nhc.noaa.gov/atcf/tcweb/inves ... 012.invest

[blp]

Wow, the above pic does at least confirm a closed LLC. If the convection picks up around the LLC. I don't see why this can't be a TD.

[canes04]

Finally! Here we go.
It will need to slow down to consolidate.

[RL3AO]

Looks like its hit a window of lower shear (10kt or so) as 300mb winds have become easterly around 20kts. Still appears to have some convergence issues probably related to its rapid movement.