ATL: ARTHUR - Post-Tropical - Discussion

[cycloneye]

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 PM EDT MON JUN 30 2014

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Satellite and radar images indicate that showers and thunderstorms
associated with the low pressure area located about 90 miles east of
Vero Beach, Florida, have changed little in organization during the
last few hours. Environmental conditions continue to be favorable
for development, and only a slight increase in the organization and
persistence of the thunderstorm activity would result in the
formation of a tropical depression. The low is moving
southwestward at about 5 mph, but is expected to turn westward
tonight and northward by Wednesday when it will be near the east
coast of Florida. If this system becomes a tropical cyclone, a
tropical storm watch could be required for portions of the central
or northern Atlantic coast of Florida. A turn toward the northeast
near the southeastern U.S. coast is expected by Thursday.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 5 days...high...80 percent.

$$
Forecaster Brown

[supercane4867]

Its possible that the COC is relocating under the CDO.

There is no CDO right now

[Alyono]

structure continues to become better defined. probably have a TS this time tomorrow

[Bocadude85]

structure continues to become better defined. probably have a TS this time tomorrow

Would you mind pointing out the LLC for me? I can not see to find it any longer

[Alyono]

its under the clouds

[Aric Dunn]

convection definitely increasing in association with that second vort.. the original appears to have elongated.. also another little eddy developed well to the north..


http://www.ssd.noaa.gov/goes/east/wfo/m ... h-rgb.html

[Alyono]

based upon the latest models, this may not become a cane until it clears NC. Cristobal for the Carolinas may yet be a good analog

[ronjon]

91L seems to be fighting for its life now. Struggling with that surge of hot dry continental air from the north. The models were on to something in that they really never developed it until it was much further north where RH and PW values are progged to be higher under the influence of the trough and Bermuda high - plus aided by a baroclinic kick. As last season told us, mid-level dry air can really hamper these developing systems.

[Hammy]

structure continues to become better defined. probably have a TS this time tomorrow

Could the center be reforming just north of Grand Bahama? There seems to be some slight curvature to the convection on the last few frames of the visible.

[Aric Dunn]

structure continues to become better defined. probably have a TS this time tomorrow

Could the center be reforming just north of Grand Bahama? There seems to be some slight curvature to the convection on the last few frames of the visible.

there are multiple vort rotating around.. looking at radar your can see the convection on the east side of one of them. and then on satellite you can see the other vort rotating around..

[robbielyn]

structure continues to become better defined. probably have a TS this time tomorrow

Could the center be reforming just north of Grand Bahama? There seems to be some slight curvature to the convection on the last few frames of the visible.

it sure looks like it.

[TheStormExpert]

Its possible that the COC is relocating under the CDO.

There is no CDO right now

Looking at that satellite image I think the afternoon blowup of shws/stems over the Florida peninsula makes it look a lot more disorganized and elongated (West to East) than it really is.

[artist]

Current Weather Conditions:Freeport, Grand Bahama, Bahamas, The
24 Hour Summary

TimeEDT (UTC)TemperatureF (C)Dew PointF (C)PressureInches (hPa)WindMPHWeatherLatest
8 PM (0) Jun 3077 (25)77 (25)29.89 (1012)S 3light rain with thunder
7 PM (23) Jun 3077 (25)75 (24)29.89 (1012)WNW 5rain with thunder
6 PM (22) Jun 3080 (27)75 (24)29.87 (1011)WNW 8rain with thunder
5 PM (21) Jun 3082 (28)77 (25)29.88 (1011)W 9light rain showers
4 PM (20) Jun 3082 (28)77 (25)29.9 (1012)W 2showers in the vicinity
3 PM (19) Jun 3082 (28)77 (25)29.9 (1012)W 10showers in the vicinity
2 PM (18) Jun 3082 (28)77 (25)29.92 (1013)W 12showers in the vicinity1 PM (17) Jun 3082 (28)75 (24)29.96 (1014)W 7

[cycloneye]

00z Best Track:

AL, 91, 2014070100, , BEST, 0, 276N, 790W, 30, 1008, LO

[TheStormExpert]

Pressure continues to drop. Now down to 1008mb, two mb's lower than previous Best Track update.

[Frank2]

Pardon the hot link but the last WV frane shows what almost looks like a frontal trough more than anything (my opinion):

http://www.ssd.noaa.gov/PS/TROP/floater ... imated.gif

[SFLcane]

Only LLC i can make out is heading right for the lake heading SW. Believe this will come into fl briefly.

[robbielyn]

I think it's 78.5w and 28.2n. The llc has moved a little SE

[Alyono]

91L seems to be fighting for its life now. Struggling with that surge of hot dry continental air from the north. The models were on to something in that they really never developed it until it was much further north where RH and PW values are progged to be higher under the influence of the trough and Bermuda high - plus aided by a baroclinic kick. As last season told us, mid-level dry air can really hamper these developing systems.

not fighting for its life at all. It continues to intensify based upon the surface data. Pressure down to 1008mb

[NDG]

:uarrow: Pressure continues to drop. Now down to 1008mb, two mb's lower than previous Best Track update.

Recon's last pass through 91L before heading back reported a pressure of 1009mb, so I guess they are estimating that it dropped another mb.

Product: Air Force Vortex Message (URNT12 KNHC)
Transmitted: 30th day of the month at 21:15Z
Aircraft: Air Force Aircraft (Last 3 digits of the tail number are 304)
Mission Purpose: Investigate second suspect area (flight in the North Atlantic basin)
Mission Number: 1
Observation Number: 11
A. Time of Center Fix: 30th day of the month at 20:36:10Z
B. Center Fix Coordinates: 27°41'N 78°55'W (27.6833N 78.9167W) (View map)
B. Center Fix Location: 98 miles (157 km) to the NE (46°) from West Palm Beach, FL, USA.
C. Minimum Height at Standard Level: Not Available
D. Estimated (by SFMR or visually) Maximum Surface Wind: 30kts (~ 34.5mph)
E. Location of the Estimated Maximum Surface Wind: 3 nautical miles (3 statute miles) to the NNE (21°) of center fix
F. Maximum Flight Level Wind Inbound: From 340° at 29kts (From the NNW at ~ 33.4mph)
G. Location of Maximum Flight Level Wind Inbound: 40 nautical miles (46 statute miles) to the SW (231°) of center fix
H. Minimum Sea Level Pressure: 1009mb (29.80 inHg) - Extrapolated
I. Maximum Flight Level Temp & Pressure Altitude Outside Eye: 22°C (72°F) at a pressure alt. of 400m (1,312ft)
J. Maximum Flight Level Temp & Pressure Altitude Inside Eye: 23°C (73°F) at a pressure alt. of 386m (1,266ft)
K. Dewpoint Temp (collected at same location as temp inside eye): 22°C (72°F)
K. Sea Surface Temp (collected at same location as temp inside eye): Not Available
L. Eye Character: Not Available
M. Eye Shape: Not Available
N. Fix Determined By: Penetration, Wind, Pressure and Temperature
N. Fix Level: 1,500 feet
O. Navigational Fix Accuracy: 0.02 nautical miles
O. Meteorological Accuracy: 1.5 nautical miles
Remarks Section - Remarks That Were Decoded...
Maximum Flight Level Wind: 29kts (~ 33.4mph) at 2:31
Sea Level Pressure Extrapolation From: Below 1,500 feet
Remarks Section - Additional Remarks...
/ 40 NM 20:12:00Z