000
AXNT20 KNHC 142355
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT TUE APR 14 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.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 5N8W 3N12W...CROSSING THE 
EQUATOR ALONG 19W TO 1S30W AND INTO NE BRAZIL NEAR 3N44W. A 
TROPICAL WAVE-LIKE FEATURE...ANALYZED AS A SFC TROUGH IS ALONG 
13W FROM 6N TO THE EQUATOR. CONVECTION ASSOCIATED WITH THE 
TROUGH HAS PROPAGATED WESTWARD ACROSS W AFRICA AND OFF THE COAST 
ACCORDING TO THE HOVMOLLER DIAGRAM. SCATTERED MODERATE TO 
ISOLATED STRONG CONVECTION REMAINS AROUND THE SFC TROUGH FROM 
5N-3S BETWEEN 11W-18W. ELSEWHERE...SCATTERED MODERATE CONVECTION 
IS FROM THE EQUATOR TO 7S BETWEEN 18W-25W. SCATTERED MODERATE TO 
ISOLATED STRONG CONVECTION IS FROM THE EQUATOR TO 4S BETWEEN 
41W-45W. 

...DISCUSSION...

THE GULF OF MEXICO...
AS OF 2100 UTC...A COLD FRONT STRETCHES ACROSS THE GULF OF 
MEXICO FROM NEAR TALLAHASSEE IN THE FLORIDA PANHANDLE ACROSS THE 
CENTRAL GULF TO 22N92W. A LARGE AREA OF SHOWERS AND TSTMS IS 
AHEAD OF THE FRONT AFFECTING NORTH AND CENTRAL FLORIDA. THE 
FRONT WILL CONTINUE TO MOVE ACROSS FLORIDA AND THE SE GULF OF 
MEXICO AND WILL LIKELY DISSIPATE THURS. A 1018 MB SURFACE HIGH 
IS OVER THE N COAST OF TEXAS NEAR 30N95W AND WILL CONTINUE TO 
BUILD HIGH PRESSURE ACROSS THE GULF REGION IN THE WAKE OF THE 
COLD FRONT. IN THE UPPER LEVELS...A DEEP LAYERED TROUGH EXTENDS 
ACROSS THE EASTERN U.S. AND INTO THE CENTRAL AND EASTERN GULF 
SUPPORTING THE AFOREMENTIONED COLD FRONT. AN UPPER LEVEL RIDGE 
IS ACROSS THE SOUTHWEST U.S. AND INTO THE WESTERN GULF OF 
MEXICO.  

THE CARIBBEAN SEA...
MODERATE TO FRESH TRADEWINDS ARE BLOWING ACROSS THE EAST AND 
CENTRAL CARIBBEAN. WINDS VEER TO THE SE OVER THE WESTERN 
CARIBBEAN DUE TO THE PRESENCE OF THE COLD FRONT ACROSS THE GULF 
OF MEXICO. MOSTLY FAIR WEATHER PREVAILS ACROSS THE ENTIRE BASIN 
WITH A FEW SCATTERED SHOWERS OVER THE E CARIBBEAN AND OFF THE 
COAST OF COSTA RICA AND PANAMA. IN THE UPPER LEVELS...A BROAD 
RIDGE WITH STRONG SUBSIDENCE COVERS MUCH OF THE AREA. EXPECT 
LITTLE CHANGE OVER THE NEXT 24 HOURS. 
 
THE ATLANTIC OCEAN...
A COLD FRONT ENTERS THE CENTRAL ATLANTIC NEAR 32N45W THEN 
CONTINUES SW TO NEAR 26N56W. THE REMAINDER OF THE REGION IS 
UNDER THE INFLUENCE OF TWO HIGH PRESSURE SYSTEMS...A 1027 MB 
HIGH TO THE WEST OF THE FRONT CENTERED NEAR 32N61W AND A 1029 MB 
HIGH TO THE NORTHEAST OF THE FRONT CENTERED NEAR 38N31W. A COLD 
FRONT PRESENTLY OVER THE SE U.S. AND THE GULF OF MEXICO WILL 
MOVE OFF THE GEORGIA COAST T0NIGHT AND EXTEND FROM 31N74W TO 
STRAITS OF FLORIDA MIDDAY WEDNESDAY. IT CURRENTLY IS PRODUCING 
SHOWERS AND THUNDERSTORMS ACROSS CENTRAL FLORIDA AND OVER THE 
FAR WEST ATLANTIC N OF 26N AND W OF 74W. S TO SW WINDS 20 TO 30 
KT ARE EXPECTED AHEAD OF THE FRONT OVER THE NW PORTION OF THE 
DISCUSSION AREA JUST N OF THE NW BAHAMAS EARLY WED. WINDS WILL 
SHIFT TO THE W AND THEN NW AFTER THE FRONTAL PASSAGE. IN THE 
UPPER LEVELS...A RIDGE/TROUGH/RIDGE PATTERN IS PRESENT WITH THE 
FIRST RIDGE OVER THE W ATLANTIC W OF 60W. AN UPPER LEVEL TROUGH 
IS OVER THE CENTRAL ATLANTIC EXTENDING FROM 30N40W TO NEAR 
BARBADOS IN THE WINDWARD ISLANDS. ANOTHER LARGE UPPER LEVEL 
RIDGE IS OVER THE E ATLANTIC ANCHORED ON A HIGH LOCATED SOUTH OF 
THE CAPE VERDE ISLANDS NEAR 8N26W. 

$$
CW/MH