000
AXNT20 KNHC 152332
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED APR 15 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 IS CENTERED ALONG 5N9W...CROSSING THE EQUATOR ALONG 18W 
CONTINUING TO 3S30W AND INTO NE BRAZIL NEAR 4S40W. SCATTERED 
MODERATE CONVECTION IS FROM 4S-4N BETWEEN 5W-13W. SCATTERED 
MODERATE TO ISOLATE STRONG CONVECTION IS FROM 2S-EQ BETWEEN 
15W-19W. SCATTERED MODERATE CONVECTION IS ALSO NOTED WHERE THE 
ITCZ AXIS MEETS THE COAST OF BRAZIL.

...DISCUSSION...

THE GULF OF MEXICO...
AS OF 2100 UTC...A COLD FRONT EXTENDS OVER S FLORIDA AND BECOMES 
STATIONARY OVER THE SE GULF OF MEXICO EXTENDING ALONG 26N82W 
25N86W 22N91W. ISOLATED SHOWERS AND TSTMS CONTINUE ALONG THE 
FRONTAL BOUNDARY...HOWEVER THE UPPER LEVEL SUPPORT THAT HELPED 
PRODUCE STRONG CONVECTION YESTERDAY HAS OUTRUN THE FRONT. A 
SURFACE TROUGH PERSISTS OVER THE BAY OF CAMPECHE AND EXTENDS 
FROM 21N92W TO 18N93W. ISOLATED SHOWERS ARE ASSOCIATED WITH THE 
TROUGH. A 1021 MB HIGH IS JUST OFF THE SE COAST OF LOUISIANA AND 
HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE SE U.S. 
ALOFT...A RIDGE WITH AXIS ALONG 92W DOMINATES THE GULF REGION. 
EXPECT THE AFOREMENTIONED COLD FRONT TO CONTINUE TO DRIFT 
SOUTHWARD AND TO WEAKEN AND DISSIPATE BY THURSDAY AFTERNOON. THE 
NEXT COLD FRONT IS FORECAST TO MOVE OFF THE SE TEXAS COAST SAT 
NIGHT.

THE CARIBBEAN SEA...
TRADEWINDS OF 10-20 KTS ARE BLOWING ACROSS THE EAST AND CENTRAL 
CARIBBEAN. WINDS BECOME SOUTHEASTERLY OVER THE WESTERN CARIBBEAN 
DUE TO THE AFOREMENTIONED FRONT OVER THE SE GULF OF MEXICO. LOW 
LEVEL MOISTURE MOVES ACROSS THE REGION PRODUCING ISOLATED TO 
SCATTERED SHOWERS MAINLY IN THE CENTRAL GULF AND OVER THE 
GREATER ANTILLES. IN THE UPPER LEVELS...THE BASE OF AN 
UPPER-LEVEL TROUGH OVER THE W ATLC REACHES CUBA. THE REMAINDER 
OF THE CARIBBEAN IS DOMINATED BY BROAD RIDGING WITH MODERATE TO 
STRONG SUBSIDENCE. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS.
 
THE ATLANTIC OCEAN...
A COLD FRONT ENTERS THE AREA NEAR 32N75W AND CONTINUES SW AND 
CROSSES SOUTH FLORIDA NEAR WEST PALM BEACH AND CONTINUES TO THE 
GULF OF MEXICO WHERE IT BECOMES STATIONARY. ISOLATED SHOWERS AND 
POSSIBLE TSTMS ARE ALONG THE FRONTAL BOUNDARY. A SECOND COLD 
FRONT ENTERS THE AREA NEAR 32N37W AND EXTENDS SW TO 25N50W. 
ISOLATED SHOWERS ARE ASSOCIATED WITH THIS FRONTAL BOUNDARY. THIS 
SECOND COLD FRONT IS EMBEDDED BETWEEN TWO HIGH PRESSURE SYSTEMS 
WHICH DOMINATE THE REMAINDER OF THE REGION. A 1026 MB HIGH IS TO 
THE W NEAR 32N49W AND THE SECOND HIGH IS TO THE E NEAR 30N30W. 
IN THE UPPER LEVELS...A TROUGH/RIDGE/TROUGH PATTERN PERSISTS 
ACROSS THE ATLC WITH THE FIRST TROUGH LOCATED W OF 65W. THE 
SECOND TROUGH AXIS IS TILTED EXTENDING FROM 32N24W TO 13N46W.

$$
WALTON/HUFFMAN