000
AXNT20 KNHC 140516
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EST SUN DEC 13 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0445 UTC.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 9N12W 5N19W 3N32W 2S48W. 
ISOLATED MODERATE CONVECTION IS FROM 4N-6N BETWEEN 12W-18W...AND 
FROM 2N-4N BETWEEN 22W-25W.

...DISCUSSION...

GULF OF MEXICO...
AS OF 0300 UTC...A STATIONARY FRONT EXTENDS ACROSS THE FLORIDA 
PANHANDLE FROM NEAR TALLAHASSEE TO SE LOUISIANA NEAR 29N92W 
LIFTING AS A WARM FROM TO S OF CORPUS CHRISTI TEXAS NEAR 27N97W. 
RADAR IMAGERY ALONG WITH RECENT LIGHTNING DATA INDICATE ISOLATED 
SHOWERS/THUNDERSTORMS WITHIN 60 NM OF THE FRONT AXIS W OF THE 
LOUISIANA/MISSISSIPPI STATE BORDER. MOIST SWLY FLOW ALOFT IS 
DRAWING MOISTURE NE SUPPORTING THE SHOWER ACTIVITY NEAR THE 
FRONT. SURFACE RIDGING EXTENDS S OF THE FRONT FROM THE E WITH 
AXIS ALONG 27N SUPPORTING GENERALLY FAIR WEATHER ACROSS THE 
REMAINDER OF THE AREA. EXPECT THE FRONT TO BECOME DIFFUSE WITHIN 
THE NEXT 24 HRS AS HIGH PRESSURE CONTINUES TO BUILD ACROSS THE E 
AND CENTRAL GULF.

CARIBBEAN SEA...
MODERATE TO STRONG TRADEWINDS CONTINUE ACROSS THE CARIBBEAN DUE 
TO A RELATIVITY STRONG PRESSURE GRADIENT BETWEEN HIGH PRESSURE 
OVER THE W ATLC AND LOW PRESSURE OVER NRN S AMERICA. GALE FORCE 
WINDS ARE NOTED OFF THE COAST OF COLOMBIA. WATER VAPOR IMAGERY 
INDICATES STRONG SUBSIDENCE ACROSS THE BASIN AROUND AN UPPER 
LEVEL RIDGE CENTERED S OF CUBA. HOWEVER...ISOLATED SHOWERS ARE 
ACROSS PORTIONS OF THE BASIN INCLUDING PUERTO RICO AND 
HISPANIOLA. EXPECT THE GALE FORCE WINDS TO CONTINUE THROUGH MON 
NIGHT WITH CONTINUING STRONG TRADEWINDS ELSEWHERE. 

ATLANTIC OCEAN...
A SHORTWAVE UPPER LEVEL TROUGH OFF THE NE UNITED STATES COAST 
SUPPORTS A FRONTAL BOUNDARY EXTENDING DOWN THE ERN SEABOARD. 
DIFFLUENT FLOW ALOFT E OF THE UPPER TROUGH IS SUPPORTING 
SCATTERED SHOWERS/THUNDERSTORMS N OF 26N BETWEEN 65W-74W. 
ELSEWHERE ACROSS THE W ATLC...HIGH PRESSURE DOMINATES ANCHORED 
BY A 1028 MB HIGH NEAR 34N61W BRINGING GENERALLY FAIR WEATHER 
ACROSS THE AREA. THE SURFACE HIGH IS SUPPORTED BY AN UPPER LEVEL 
RIDGE EXTENDING FROM THE W CARIBBEAN INTO THE W ATLC. FARTHER 
E...A COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N30W 
CONTINUING ALONG 27N38W 23N48W BECOMING STATIONARY TO 22N60W. 
SCATTERED SHOWERS ARE WITHIN 200 NM BEHIND...90 NM AHEAD OF THE 
FRONT N OF 28N WITH ISOLATED SHOWERS POSSIBLE ALONG THE 
REMAINDER OF THE FRONT. THE BOUNDARY IS SUPPORTED BY AN UPPER 
LEVEL TROUGH WITH AXIS ALONG 40W. A WEAK SURFACE RIDGE IS SE OF 
THE FRONT ANCHORED BY A 1015 MB HIGH NEAR 25N25W.

$$
WALTON