[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 172357
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST TUE NOV 17 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
2315 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 11N15W 8N20W 6N30W 8N51W 5N55W.
SCATTERED MODERATE CONVECTION IS ALONG THE COAST OF WEST AFRICA
FROM 6N-8N BETWEEN 10W-13W. SCATTERED MODERATE CONVECTION IS
ALSO FROM 5N-7N BETWEEN 17W-20W. WIDELY SCATTERED MODERATE
CONVECTION IS FROM 9N-12N BETWEEN 40W-44W.

...DISCUSSION...

GULF OF MEXICO...
AS OF 2100 UTC...A COLD FRONT EXTENDS FROM THE FLORIDA PANHANDLE
TO THE THE BAY OF CAMPECHE ALONG 30N85W 26N86W 23N90W 18N93W.
SCATTERED SHOWERS ARE WITHIN 120 NM W OF THE FRONT. A STATIONARY
FRONT IS INLAND OVER MEXICO E OF THE SIERRA MADRE ORIENTAL
MOUNTAINS ALONG 17N86W 20N98W 23N99W. SCATTERED SHOWERS ARE
WITHIN 120 NM E OF THE FRONT TO THE GULF COAST. A 1021 MB HIGH
IS CENTERED OVER SOUTH TEXAS NEAR 27N98W. A TIGHT SURFACE
PRESSURE GRADIENT IS OVER THE SW GULF OF MEXICO BEHIND THE COLD
FRONT PRODUCING 20-25 KT NE WINDS. IN THE UPPER LEVELS...A
TROUGH IS OVER THE W GULF W OF 85W. AN UPPER LEVEL RIDGE IS OVER
THE E GULF E OF 85W TO INCLUDE FLORIDA. A 240 NM SWATH OF UPPER
LEVEL MOISTURE AND BROKEN TO OVERCAST HIGH CLOUDS EXTENDS FROM
THE FLORIDA PANHANDLE TO THE BAY OF CAMPECHE. STRONG SUBSIDENCE
COVERS THE REMAINDER OF THE GULF. EXPECT...THE COLD FRONT TO
EXTEND FROM CENTRAL FLORIDA TO THE YUCATAN PENINSULA IN 24 HOURS
WITH SHOWERS.

CARIBBEAN SEA...
MUCH OF THE CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER
UNDER THE INFLUENCE OF DRY AIR AND SUBSIDENCE ASSOCIATED WITH AN
UPPER LEVEL RIDGE COVERING THE WRN CARIBBEAN EXTENDING FROM THE
YUCATAN PENINSULA AND WRN CARIBBEAN ACROSS S FLORIDA TO THE WRN
ATLC. ISOLATED SHOWERS/THUNDERSTORMS ARE HOWEVER IN THE SW
CARIBBEAN AFFECTING PORTIONS OF COSTA RICA/PANAMA S OF 11N
BETWEEN 76W-84W DUE TO SURFACE CONVERGENCE NEAR THE E PACIFIC
ITCZ. WIDELY SCATTERED MODERATE CONVECTION IS OVER THE LEEWARD
ISLANDS FROM 17N-21N BETWEEN 59W-62W DUE TO A SURFACE TROUGH. AN
UPPER LEVEL TROUGH ALSO EXTENDS FROM THE W ATLANTIC SWD ACROSS
THE LESSER ANTILLES SUPPORTING THE SURFACE TROUGH N OF THE
LEEWARD ISLANDS AND PROVIDING AN UPPER DIFFLUENT ZONE ENHANCING
CONVECTION. MODERATE TO FRESH TRADE WINDS ARE ACROSS MUCH OF THE
BASIN. EXPECT... SHOWERS/THUNDERSTORMS TO CONTINUE OVER THE FAR
NE CARIBBEAN FOR THE NEXT 24 HOURS AS THE SURFACE TROUGH REMAINS
MAINLY STATIONARY. ALSO EXPECT MORE SHOWERS/THUNDERSTORMS OVER
THE SW CARIBBEAN OVER THE NEXT 24 HOURS.

ATLANTIC OCEAN...
A 1009 MB DEEP LAYERED LOW IS OVER THE W ATLANTIC CENTERED NEAR
28N65W. A SURFACE TROUGH EXTENDS S FROM THE LOW TO N OF
HISPANIOLA NEAT 20N70W. A SECOND SURFACE TROUGH EXTENDS TO THE E
ALONG 28N60W 21N62W. WIDELY SCATTERED MODERATE CONVECTION
EXTENDS 240 NM E OF THIS TROUGH. THIS CONVECTIVE ACTIVITY IS
ALSO ENHANCED BY DIFFLUENT FLOW ALOFT FROM AN UPPER LEVEL LOW
CENTERED NEAR 27N63W. A 1025 MB HIGH IS CENTERED OVER THE E
ATLANTIC NEAR 32N31W. A RIDGE AXIS EXTENDS SW FROM THE HIGH TO
20N55W. A DISSIPATING COLD FRONT IS JUST INLAND OVER WEST AFRICA
FROM 31N9W TO 21N16W. SCATTERED SHOWERS ARE FROM 32N-34N BETWEEN
10W-12W.

$$
FORMOSA




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