[Tropical] Tropical Weather Discussion

EMWIN Server emwin at nashvilleweather.net
Sun Oct 11 05:58:38 CDT 2009


AXNT20 KNHC 111057
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN OCT 11 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1015 UTC.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 38W/39W TO THE SOUTH OF
16N. IT HAS BEEN DRIFTING WESTWARD DURING THE LAST 24 HOURS.
IT APPEARS THAT ITS WESTWARD PROGRESSION IS BEING BLOCKED
BY A MIDDLE LEVEL TROUGH THAT IS ALONG 19N33W 14N45W 10N57W.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 73W/74W TO THE SOUTH
OF 16N MOVING WESTWARD 10 TO 15 KT. SHOWERS AND POSSIBLE
THUNDERSTORMS FROM 12N TO 15N BETWEEN 75W AND 78W.

A TROPICAL WAVE IS ALONG 92W/93W TO THE SOUTH OF 19N MOVING
TOWARD THE ISTHMUS OF TEHUANTEPEC 10 TO 15 KT. IT IS NOT EASY
TO RELATE ANY PRECIPITATION DIRECTLY JUST TO THIS WAVE.
AN UPPER LEVEL TROUGH IS ON TOP OF THIS AREA AT THE SAME TIME.

...THE ITCZ...

FROM 9N13W TO 8N20W TO 12N37W TO 12N42W TO NORTHERN GUYANA
AND EASTERN VENEZUELA NEAR 7N61W. NUMEROUS STRONG SHOWERS
AND THUNDERSTORMS ARE FROM 9N TO 10N BETWEEN 45W AND 48W.
ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS ARE
WITHIN 300 NM TO 400 NM TO THE NORTH OF 4N9W 5N20W 6N30W
10N39W...AND ELSEWHERE FROM 4N TO 13N BETWEEN 40W AND 57W.

...DISCUSSION...

THE GULF OF MEXICO...
THE UPPER LEVEL ATMOSPHERIC SUPPORT FOR THE CURRENT STATIONARY
FRONT IS PRETTY MUCH NON-EXISTENT. MUCH OF THE UPPER LEVEL
FLOW APPEARS TO BE ANTICYCLONIC RIGHT ON TOP OF THE FRONT.
A COMPLETELY SEPARATE UPPER LEVEL TROUGH RUNS FROM ONE CYCLONIC
CIRCULATION CENTER THAT IS ALONG THE NORTHERN COAST OF THE
ISTHMUS OF TEHUANTEPEC OF MEXICO AND A SECOND CYCLONIC CENTER
THAT IS NEAR 12N97W...THAT IS ABOUT 280 NM TO THE
SOUTH-SOUTHWEST OF THE GULF OF TEHUANTEPEC. WARMING CLOUD TOP
TEMPERATURES AND DISSIPATING CONVECTIVE PRECIPITATION ARE
OCCURRING ALONG THE MEXICO COAST FROM 17N TO 21N BETWEEN 95W
AND 97W. THE STATIONARY FRONT RUNS FROM THE FLORIDA BIG BEND
TO THE NORTH CENTRAL GULF WATERS TO COASTAL MEXICO NEAR
20N97W...AND CURVING NORTHWESTWARD BEYOND THE TEXAS BIG BEND.
SHOWERS AND POSSIBLE THUNDERSTORMS ARE WITHIN 180 NM TO THE
NORTHWEST OF 28N87W 25N93W 22N97W.

THE CARIBBEAN SEA...
THE LINE OF UPPER LEVEL DIFFLUENT FLOW THAT SEPARATES THE GULF
OF MEXICO CYCLONIC FLOW AND THE UPPER LEVEL ANTICYCLONIC FLOW
THAT COVERS THE WESTERN CARIBBEAN SEA IS MORE OR LESS ALONG
86W/87W. ANTICYCLONIC FLOW GOES FROM CENTRAL AMERICA TO 80W.
A MASS OF DRY AIR IN SUBSIDENCE IS ROLLING ACROSS THE CARIBBEAN
SEA FROM EAST-TO-WEST BETWEEN 60W AND 80W...PRESSING UP AGAINST
THE ANTICYCLONIC FLOW FROM CENTRAL AMERICA. THE ONLY SIGNIFICANT
DEEP CONVECTIVE PRECIPITATION THAT IS SURVIVING THE DRY AIR IS
THE SHOWER/THUNDERSTORM ACTIVITY FROM THE 73W/74W TROPICAL WAVE.

THE ATLANTIC OCEAN...
THE REMNANT OF HENRI IS A 1013 MB LOW PRESSURE CENTER THAT IS
NEAR 20N71W. SHOWERS AND THUNDERSTORMS ARE ALONG THE NORTHERN
COAST OF HAITI WITH THE REMNANT OF HENRI. UPPER LEVEL
ANTICYCLONIC FLOW AND DRY AIR IN SUBSIDENCE COVER THE AREA
TO THE NORTH OF 20N TO THE WEST OF 50W. EVEN MORE UPPER LEVEL
ANTICYCLONIC FLOW CONTINUES TO THE NORTH OF 20N BETWEEN 40W AND
50W...AS SOME OF THIS FLOW HEADS TOWARD THE TROUGH THAT PASSES
THROUGH 32N36W 24N37W TO 20N39W. THIS TROUGH SUPPORTS THE
STATIONARY FRONT THAT PASSES THROUGH 32N38W TO 25N41W.
A SURFACE TROUGH CONTINUES FROM 25N41W TO 20N50W AND 21N62W.
ISOLATED MODERATE SHOWERS ARE STAYING ALIVE IN THE DRY AIR FROM
19N TO 20N BETWEEN 57W AND 65W. SHOWERS AND ISOLATED STRONG
THUNDERSTORMS COVER THE AREA FROM 23N TO 32N BETWEEN 28W AND
35W...NEAR A SURFACE TROUGH THAT IS WITHIN 300 NM TO 360 NM
TO THE EAST OF THE TROUGH TO THE NORTH OF 20N.

$$
MT





This weather bulletin was brought to you by:
www.nashvilleweather.net




More information about the Tropical mailing list