000
AXNT20 KNHC 092340
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
805 PM EDT FRI APR 09 2010

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 7N8W 3N22W 4N39W IN47W TO INLAND 
OVER BRAZIL SOUTH AMERICA NEAR 1N50W. CLUSTERS OF SCATTERED 
MODERATE/STRONG CONVECTION ARE WITHIN 120/150 NM EITHER SIDE OF 
THE ITCZ BETWEEN 19W-45W. 

...DISCUSSION...

GULF OF MEXICO...
AS OF 09/2100 UTC...A COLD FRONT ENTERS THE GULF ACROSS THE 
FLORIDA PENINSULA S OF NAPLES EXTENDING ALONG 24N84W TO 23N86W 
WHERE IT BECOMES STATIONARY ALONG 23N89W THEN S TO OVER THE 
YUCATAN PENINSULA NEAR 21N90W CONTINUING S TO JUST E OF THE 
ISTHMUS OF TEHUANTEPEC. A WEAK PRE-FRONTAL SURFACE TROUGH IS SE 
OF THE FRONT EXTENDING FROM THE W COAST OF FLORIDA NEAR 25N81W 
THROUGH THE LOWER FLORIDA KEYS TO JUST N OF THE YUCATAN CHANNEL 
NEAR 22N86W. BROKEN/OVERCAST LOW/MID CLOUDS WITH ISOLATED 
SHOWERS ARE WITHIN 60 NM OF A LINE FROM FORT MYERS FLORIDA TO 
23N91W THEN WITHIN 120 NM OF A LINE TO INLAND OVER S MEXICO NEAR 
18N93W. THE UPPER LEVEL TROUGH SUPPORTING THIS FRONT IS MOVING 
OFF THE E US INTO THE W ATLC COVERING THE NE GULF OF MEXICO N OF 
26N E OF 87W AND CONTINUES TO SHIFT EASTWARD. MODERATE TO STRONG 
SUBSIDENCE AND DRY STABLE AIR ALOFT ARE OVER THE E GULF LIMITING 
SHOWER ACTIVITY IN THE GULF WATERS ASSOCIATED WITH THE FRONT. 
WEAK UPPER RIDGE IS OVER MEXICO BRINGING UPPER LEVEL MOISTURE TO 
THE W GULF WITH SCATTERED SHOWERS N OF 25N W OF 93W TO INLAND 
OVER TEXAS. A SURFACE RIDGE IS BUILDING BEHIND THE FRONT OVER 
THE N GULF ANCHORED BY A 1022 MB HIGH OVER THE MISSISSIPPI DELTA 
OF LOUISIANA. THE COLD FRONT IS EXPECTED TO MOVE E OF THE GULF 
WATERS TONIGHT WHILE THE STATIONARY FRONT IS EXPECTED TO 
DISSIPATE LATER TONIGHT.  

CARIBBEAN SEA...
THE SURFACE RIDGE OVER THE W AND CENTRAL ATLC IS GIVING THE 
CARIBBEAN MODERATE TO STRONG EASTERLY TRADE WINDS. NEAR ZONAL 
WESTERLY FLOW ALOFT COVERS THE ENTIRE CARIBBEAN WITH MODERATE TO 
STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT. AN ABUNDANCE OF LOW 
LEVEL MOISTURE REMAINS OVER THE CARIBBEAN GENERATING BROKEN/ 
OVERCAST MULTILAYERED CLOUDS WITH SCATTERED SHOWERS S OF 15N E 
OF 66W ACROSS WINDWARD ISLANDS AND INTO THE W TROPICAL ATLC. 
BROKEN/OVERCAST LOW/MID CLOUDS WITH ISOLATED SHOWERS ARE N OF 
14N TO OVER HISPANIOLA BETWEEN 68W-73W. THE REMAINDER OF THE 
CARIBBEAN IS ENJOYING FAIR WEATHER THIS EVENING. 

ATLANTIC OCEAN...
AS OF 09/2100 UTC...A COLD FRONT ENTERS THE W ATLC THROUGH 
32N75W EXTENDING SSW TO OVER THE FLORIDA PENINSULA JUST N OF 
WEST PALM BEACH TO OVER THE GULF OF MEXICO JUST S OF NAPLES. 
SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 60 NM E OF THE FRONT. 
THE UPPER LEVEL TROUGH SUPPORTING THIS FRONT IS MOVING OFF THE E 
US INTO THE W ATLC N OF 26N W OF 72W INTO THE GULF OF MEXICO AND 
CONTINUES TO SHIFT EASTWARD. MODERATE TO STRONG SUBSIDENCE AND 
DRY STABLE AIR ALOFT ARE W OF THE FRONT CLEARING SKIES BEHIND 
THE FRONT. A SURFACE RIDGE COVERS THE REMAINDER OF THE W ATLC 
OVER THE CENTRAL ATLC AND INTO THE E ATLC BETWEEN 23W-70W 
ANCHORED BY A 1027 MB HIGH NEAR 32N56W PRODUCING STRONG 
SUBSIDENCE ALOFT AND GIVING THE AREA FAIR WEATHER AGAIN THIS 
EVENING. THE REMNANTS OF A STATIONARY FRONT REMAIN IN THE E ATLC 
EXTENDING THROUGH 32N27W TO 20N35W WITH NO ASSOCIATED SHOWER 
ACTIVITY AND THE UPPER LEVEL SUPPORT REMAINS N OF THE REGION. A 
SURFACE TROUGH REMAINS IN THE TROPICS EXTENDING FROM 16N43W 
14N52W TO BARBADOS. SCATTERED SHOWERS ARE WITHIN 120 NM OF THE 
SURFACE TROUGH AND ACROSS THE WINDWARD ISLANDS INTO THE SE 
CARIBBEAN. 

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
WALLACE