000
AXNT20 KNHC 051032
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT SUN APR 05 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 0945 UTC.

...THE ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 6N11W 2N20W CROSSING THE EQUATOR 
NEAR 23W THEN ALONG 3S30W 1S38W AND INTO NE BRAZIL NEAR 3S43W. 
SCATTERED MODERATE CONVECTION IS WITHIN 60 NM EITHER SIDE OF THE 
AXIS BETWEEN 24W-36W. SCATTERED MODERATE/ISOLATED STRONG 
CONVECTION IS WITHIN 160 NM OF THE COAST OF BRAZIL BETWEEN 
41W-44W.

...DISCUSSION...

THE GULF OF MEXICO...
THE WARM FRONT THAT HAD BEEN MOVING NORTH THROUGH THE EASTERN 
GULF HAS BECOME DIFFUSE THROUGHOUT THE MORNING. SCATTERED CLOUDS 
AND ISOLATED SHOWERS REMAIN IN THE NE GULF. THESE SHOWERS WILL 
DIMINISH TODAY AS MID-UPPER LEVEL DRY AIR ASSOCIATED WITH A 
RIDGE OVER THE GULF OF TEHUANTEPEC SHIFTS EASTWARD. STRONG 
WESTERLY FLOW AROUND THIS RIDGE IS ADVECTING HIGH CLOUDS/UPPER 
LEVEL MOISTURE ACROSS THE GULF N OF 26N. AT THE SFC...SLY FLOW 
15-20 KT COVERS THE REGION ON THE LEADING EDGE OF A TROUGH THAT 
EXTENDS FROM THE CENTRAL US TO THE BAY OF CAMPECHE. THIS TROUGH 
WILL DEEPEN AND BRING A STRONG COLD FRONT TO THE NW GULF 
TONIGHT. EXPECT THIS FRONT TO MOVE RATHER QUICKLY...EXITING THE 
GULF MON NIGHT. HIGH PRESSURE FROM CANADA IS EXPECTED TO SURGE 
INTO THE AREA IN THE WAKE OF THE FRONT...GENERATING GALE 
CONDITIONS IN THE SW GULF MON.
 
THE CARIBBEAN SEA...
SATELLITE IMAGERY AND SAN JUAN DOPPLER RADAR REVEAL SCATTERED 
SHOWERS ASSOCIATED WITH A SFC TROUGH ALONG 65W ARE STARTING TO 
MOVE OVER PUERTO RICO. CONVECTION ASSOCIATED WITH THIS TROUGH 
EXTENDS FROM 60W-67W N OF 13N. THIS IS THE ONLY NOTABLE AREA OF 
MOISTURE IN THE CARIBBEAN. UPPER LEVEL CONFLUENCE BETWEEN A 
RIDGE OVER THE GULF OF TEHUANTEPEC/WESTERN CARIBBEAN AND A 
TROUGH OVER THE EASTERN CARIBBEAN IS RESULTING IN STRONG 
SUBSIDENCE ACROSS THE BASIN. MODERATE TRADE WINDS OF 15-20 KT 
ARE OBSERVED ACROSS THE CARIBBEAN...EXCEPT UP TO 25 KT ALONG THE 
COAST OF COLOMBIA.

THE ATLANTIC OCEAN...
A DRIER AIRMASS HAS SETTLED INTO THE W ATLC IN THE WAKE OF A 
COLD FRONT. AS OF 0900 UTC...THE COLD FRONT ENTERS THE 
DISCUSSION AREA NEAR 31N61W AND STRETCHES ALONG 27N68W TO THE 
BAHAMAS NEAR 25N77W. SCATTERED SHOWERS AND ISOLATED 
THUNDERSTORMS ARE WITHIN 90 NM AHEAD OF THE FRONT. TO THE 
EAST...A WEAK...BUT PERSISTENT...SFC LOW IS CENTERED NEAR 
30N40W. AN ASSOCIATED SFC TROUGH IS ALONG 31N36W 28N34W 23N38W. 
SCATTERED SHOWERS EXTEND UP TO 140 NM AHEAD OF THE TROUGH. 
A NARROW SFC RIDGE MAINTAINS TRANQUIL CONDITIONS E OF 31W. IN 
THE TROPICS...A DIFFLUENT PATTERN ALOFT IS GENERATING MODERATE 
CONVECTION OVER NE SOUTH AMERICA AND THE TROPICAL ATLC S OF 12N 
BETWEEN 39W-54W.


$$
WADDINGTON