ATL: RAFAEL - Post-Tropical - Discussion

[TropicalAnalystwx13]

Should be enough for classification at 11pm EDT or early tomorrow morning.

Hurricane Hunters found about a 10-mile wide band of westerly winds near 13.5°N 63°W, but the circulation is pretty broad, and may not qualify as a TD yet. No TS force winds at flight level yet.

If you're going to quote Dr. Masters, give him credit...

[cycloneye]

Should be enough for classification at 11pm EDT or early tomorrow morning.

http://i47.tinypic.com/16gg4lx.jpg

Hurricane Hunters found about a 10-mile wide band of westerly winds near 13.5°N 63°W, but the circulation is pretty broad, and may not qualify as a TD yet. No TS force winds at flight level yet.

If you're going to quote Dr. Masters, give him credit...

I forgot to put his name but is there now.

[wxman57]

Nothing on the recon reports indicates any well-defined center. They're hunting around about 120 miles south of where the center of the broad circulation might be right now. All evidence points to no upgrade today. Maybe not tomorrow, either.

Note that the plane has yet to fly into any squalls across the Lesser Antilles where stronger SE-S winds are located. I'm sure they'll find some 30-35 kt winds over there.

[HurricaneAndrew92]

Nothing on the recon reports indicates any well-defined center. They're hunting around about 120 miles south of where the center of the broad circulation might be right now. All evidence points to no upgrade today. Maybe not tomorrow, either.

Note that the plane has yet to fly into any squalls across the Lesser Antilles where stronger SE-S winds are located. I'm sure they'll find some 30-35 kt winds over there.

Oh, come on. Probably not 5, but at 11 I'd give a 60% chance. But tomorrow it is almost guaranteed that it will form.

[wxman57]

Nothing on the recon reports indicates any well-defined center. They're hunting around about 120 miles south of where the center of the broad circulation might be right now. All evidence points to no upgrade today. Maybe not tomorrow, either.

Note that the plane has yet to fly into any squalls across the Lesser Antilles where stronger SE-S winds are located. I'm sure they'll find some 30-35 kt winds over there.

Oh, come on. Probably not 5, but at 11 I'd give a 60% chance. But tomorrow it is almost guaranteed that it will form.

Guaranteed? Nope. And there won't be anything new in the observations by this evening, unless there's a big burst of convection around 62-63W north of 15N - which probably won't occur due to continued strong SW wind shear. Given that the NHC can often be quite lenient with its upgrades, it's possible it could become a TD/TS on Saturday. But it needs to have a much better-defined LLC and not a broad low pressure area several hundred miles across. I'm not so sure wind shear will drop off enough tomorrow for that to happen.

Side-note: Plane is flying SE of ST Lucia now finding SSE wind 40kts at FL, just as expected. But just a strong disturbance and not a TS yet.

[TropicalAnalystwx13]

Winds on the north side of the circulation are from the west when they should be from the east, and winds on the west side of the circulation are more from the south when they should be from the north. It is probably closed, but just barely. Satellite imagery shows a continued consolidation of this center, and with relaxing shear and its proximity to land, I wouldn't be surprised if this was declared later tonight. As I said in my last post, 11pm EDT isn't too bad of a guess.

[cycloneye]

A bunch of TS force winds on last set.

201600 1321N 06042W 9596 00421 0072 +214 +177 166040 040 026 001 00
201630 1322N 06041W 9595 00423 0070 +221 +177 166039 041 026 001 00
201700 1323N 06039W 9592 00426 0070 +222 +177 165037 038 024 003 00
201730 1324N 06038W 9597 00420 0069 +225 +178 164037 038 029 001 00
201800 1325N 06037W 9596 00423 0069 +227 +180 164037 038 032 002 00
201830 1326N 06035W 9598 00420 0070 +227 +183 163037 038 033 001 00
201900 1327N 06034W 9590 00430 0072 +223 +186 165038 039 033 002 00
201930 1328N 06033W 9593 00424 0071 +228 +187 166040 043 035 001 00

[wxman57]

Winds on the north side of the circulation are from the west when they should be from the east, and winds on the west side of the circulation are more from the south when they should be from the north. It is probably closed, but just barely. Satellite imagery shows a continued consolidation of this center, and with relaxing shear and its proximity to land, I wouldn't be surprised if this was declared later tonight. As I said in my last post, 11pm EDT isn't too bad of a guess.

The plane hasn't flown north of the "center" yet. The center a bit north of 15N and the plane is around 13-14N. Those westerly winds are south of the broad center.

[wxman57]

A bunch of TS force winds on last set.

201600 1321N 06042W 9596 00421 0072 +214 +177 166040 040 026 001 00
201630 1322N 06041W 9595 00423 0070 +221 +177 166039 041 026 001 00
201700 1323N 06039W 9592 00426 0070 +222 +177 165037 038 024 003 00
201730 1324N 06038W 9597 00420 0069 +225 +178 164037 038 029 001 00
201800 1325N 06037W 9596 00423 0069 +227 +180 164037 038 032 002 00
201830 1326N 06035W 9598 00420 0070 +227 +183 163037 038 033 001 00
201900 1327N 06034W 9590 00430 0072 +223 +186 165038 039 033 002 00
201930 1328N 06033W 9593 00424 0071 +228 +187 166040 043 035 001 00

No surprise there, that's where the stronger winds should be - in the heavy squalls to the east.

[Sanibel]

This thing is starting to shoot some depth on AVN. Pretty IR colors.

[HurricaneAndrew92]

This thing is starting to shoot some depth on AVN. Pretty IR colors.

I know. I'll wait until 11. Look at the clouds. Starting to wrap around.

[Gustywind]

000
ABNT20 KNHC 122100
TWOAT

SPECIAL TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
500 PM EDT FRI OCT 12 2012

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

SPECIAL OUTLOOK ISSUED TO UPDATE DISCUSSION OF SYSTEM AFFECTING THE
LESSER ANTILLES.

UPDATED...AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT IS
CURRENTLY INVESTIGATING THE AREA OF LOW PRESSURE LOCATED OVER THE
EASTERN CARIBBEAN SEA ABOUT 100 MILES WEST-SOUTHWEST OF DOMINICA.
PRELIMINARY DATA FROM THE AIRCRAFT INDICATE THAT THE LOW COULD BE
DEVELOPING A WELL-DEFINED CENTER...AND THAT IT IS PRODUCING WINDS
OF TROPICAL-STORM FORCE NEAR PORTIONS OF THE WINDWARD ISLANDS. IF
ADDITIONAL AIRCRAFT DATA CONFIRM THE EXISTENCE OF A CENTER...
ADVISORIES WOULD BE INITIATED ON TROPICAL STORM RAFAEL EARLY THIS
EVENING. THIS SYSTEM HAS A HIGH CHANCE...90 PERCENT...OF BECOMING
A TROPICAL CYCLONE DURING THE NEXT 48 HOURS.

IF A TROPICAL STORM FORMS...TROPICAL STORM WARNINGS WOULD BE NEEDED
FOR PORTIONS OF THE LESSER ANTILLES AND THE VIRGIN ISLANDS.
REGARDLESS OF DEVELOPMENT...STRONG GUSTY WINDS AND LOCALLY HEAVY
RAINFALL ARE POSSIBLE ACROSS PORTIONS OF THE LESSER ANTILLES AND
THE VIRGIN ISLANDS DURING THE NEXT COUPLE OF DAYS AS THE SYSTEM
MOVES NORTHWESTWARD TO NORTH-NORTHWESTWARD AT 10 TO 15 MPH. FOR
ADDITIONAL INFORMATION ON THIS SYSTEM...PLEASE MONITOR PRODUCTS
FROM YOUR LOCAL WEATHER OFFICE AND HIGH SEAS FORECASTS ISSUED BY
THE NATIONAL WEATHER SERVICE.

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

&&

HIGH SEAS FORECASTS ISSUED BY THE NATIONAL WEATHER SERVICE CAN BE
FOUND UNDER AWIPS HEADER NFDHSFAT1 AND WMO HEADER FZNT01 KWBC.

$$
FORECASTER BRENNAN

[TropicalAnalystwx13]

Nothing unexpected there...it appears it will be classified at 11pm EDT.

[HurricaneAndrew92]

Nothing unexpected there...it appears it will be classified at 11pm EDT.

Interesting...sounds like it will. Notice NHC said TS...

[HURRICANELONNY]

Looking at PR radar. Looks like there going to get some heavy rain tonight from soon to be raphael.

http://radar.weather.gov/ridge/radar.ph ... 1&loop=yes

Heads up cycloneye

[weatherwindow]

Nothing unexpected there...it appears it will be classified at 11pm EDT.

It would appear that "IF additional aircraft data confirm the existence of the center, advisories will be initiated on Tropical Storm Rafael EARLY this evening"...may well be much earlier than 11pm, likely shortly after the last VDM(Vortex Data Message) is transmitted

[MGC]

ULL to 98L NW is causing a good bit of shear over the disturbance....I don't see any rapid intensification or organization happening with 98L because of this. Disturbance should start interacting with land soon too and if it crosses Hispanolia it will likely be toast or severly impacted. Circulation has tightened up some today and some convection is starting to fire near the circulation center....but, most if not all of the strong convection is displaced a good distance from the circulation center. This will be another flip a coin type upgrade if the NHC decides to pull the trigger and name 98L as there is already TS force winds associated with the disturbance in the heavy convection to the east of the center. IMO 98L does not yet qualify as a TC.......MGC

The above is the opinion of MGC and not an official forecast.

[TropicalAnalystwx13]

ULL to 98L NW is causing a good bit of shear over the disturbance....I don't see any rapid intensification or organization happening with 98L because of this. Disturbance should start interacting with land soon too and if it crosses Hispanolia it will likely be toast or severly impacted. Circulation has tightened up some today and some convection is starting to fire near the circulation center....but, most if not all of the strong convection is displaced a good distance from the circulation center. This will be another flip a coin type upgrade if the NHC decides to pull the trigger and name 98L as there is already TS force winds associated with the disturbance in the heavy convection to the east of the center. IMO 98L does not yet qualify as a TC.......MGC

The above is the opinion of MGC and not an official forecast.

Shear is going to relax as it moves towards the northwest and its heading already has it missing Hispaniola.

[weatherwindow]

[quote="Driftin"]Are those hot towers i see near the center?
Speaking of "hot towers"...G CANE is missing in action, I was looking, in vain, for his his terse power point style contributions. They are always a highlight for me

[TropicalAnalystwx13]

Recon found a much better defined circulation (southern side at least) on the latest pass. Expect Rafael shortly.