000
AXNT20 KNHC 220522
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST MON DEC 22 2008

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.

...THE ITCZ...
ITCZ IS CENTERED ALONG 8N10W 7N16W 5N28W 7N39W 5N53W. A SURFACE 
TROUGH IS EMBEDDED WITHIN THE ITCZ ALONG 35W/36W S OF 15N. 
CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE 
FROM 6N TO ACROSS THE EQUATOR BETWEEN 9W-23W. SCATTERED 
MODERATE/STRONG CONVECTION IS WITHIN 45 NM OF 11N FROM 41W-43W. 
  
...DISCUSSION...

GULF OF MEXICO...
A COLD FRONT EXTENDS FROM THE W ATLC ACROSS CENTRAL FLORIDA INTO 
THE GULF OF MEXICO NEAR TAMPA CONTINUING W ALONG 26N90W TO 
INLAND OVER NE MEXICO NEAR 24N97W. OVERCAST STRATOCUMULUS LOW 
CLOUDS WITH ISOLATED SHOWERS ARE N OF THE FRONT TO INLAND OVER 
THE N GULF COAST STATES. IN THE WAKE OF THE FRONT...COOLER AND 
DRIER CONDITIONS ARE OBSERVED WITH DEW POINTS IN THE TEENS FROM 
THE W FLORIDA PANHANDLE TO TEXAS WITH SINGLE DIGITS FURTHER TO 
THE N. THE UPPER TROUGH ASSOCIATED WITH THE FRONT IS MAINLY N OF 
OF THE REGION WITH A MID LEVEL SHORTWAVE TROUGH EXTENDING FROM 
THE CENTRAL GULF INTO THE BAY OF CAMPECHE. BROAD UPPER RIDGE 
DOMINATES THE GULF...THE CARIBBEAN...AND THE W ATLC SUPPORTING 
STRONG SUBSIDENCE AND DRY STABLE AIR S OF THE FRONTAL BOUNDARY. 
THE FRONT IS EXPECTED TO CLEAR THE GULF MON AS A STRONG SURFACE 
RIDGE BUILDS OVER THE GULF ANCHORED CURRENTLY BY A 1038 MB HIGH 
OVER THE CENTRAL PLAIN STATES. 

CARIBBEAN SEA...
THE CARIBBEAN IS DOMINATED BY A BROAD UPPER RIDGE ANCHORED OVER 
SOUTH AMERICA EXTENDING OVER THE GULF AND W ATLC PRODUCING 
STRONG SUBSIDENCE IN DRY AIR ACROSS THE ENTIRE BASIN. THUS ONLY 
AREAS OF LOW LEVEL CLOUDS WITH EMBEDDED LIGHT SHOWERS ARE NOTED 
ACROSS THE REGION USHERED IN ON NE TO E WINDS. MOST NOTABLY 
ISOLATED SHOWERS ARE WITHIN 120 NM OF A LINE FROM OVER THE 
LESSER ANTILLES NEAR 15N61W ALONG 17N72W TO CENTRAL AMERICA NEAR 
13N84W. THE FRONT IN THE GULF OF MEXICO IS EXPECTED TO ENTER THE 
CARIBBEAN MON THEN BEGIN TO WEAKEN INTO TUE
 
ATLANTIC OCEAN...
A COLD FRONT ENTERS THE W ATLC NEAR 32N75W EXTENDING ACROSS 
FLORIDA NEAR DAYTONA BEACH TO TAMPA THEN INTO THE GULF OF 
MEXICO. OVERCAST STRATOCUMULUS LOW CLOUDS WITH ISOLATED SHOWERS 
ARE N OF THE FRONT TO INLAND OVER FLORIDA AND TO THE COAST OF 
GEORGIA AND SOUTH CAROLINA. TO THE SE ACROSS THE REMAINDER OF 
THE W ATLC...A WEAK 1020 MB SURFACE HIGH IS CENTERED NEAR 
28N58W. A BROAD UPPER LEVEL RIDGE EXTENDS FROM THE CARIBBEAN 
WITH AXIS ACROSS HISPANIOLA TO BEYOND 32N60W AND ENCOMPASSES THE 
AREA W OF 50W. A SURFACE TROUGH IS ACROSS THE CENTRAL ATLC 
ANALYZED FROM 28N42W TO 18N45W. THIS TROUGH IS SUPPORTED BY AN 
UPPER LEVEL TROUGH ACROSS THE E/CENTRAL ATLC WITH AXIS ENTERING 
THE AREA NEAR 32N35W TO 20N38W AND SW INTO THE TROPICS TO NEAR 
11N53W. UPPER DIFFLUENCE E OF THIS UPPER TROUGH ALONG WITH AN 
UPPER RIDGE AMPLIFIED OVER THE E ATLC SE OF THE UPPER TROUGH TO 
THE CANARY ISLANDS IS ENHANCING CLOUD COVER WITH ISOLATED 
SHOWERS COVERING THE AREA S OF 26N BETWEEN 24W-38W. SURFACE 
RIDGE IS OVER THE E ATLC WITH THE AXIS EXTENDING JUST E OF THE 
AZORES THROUGH 32N27W TO 25N40W. HIGH PRESSURE ANCHORED N OF THE 
REGION IS EXPECTED TO BUILD SOUTHWARD OVER THE W ATLC ON MON 
NIGHT INTO TUE TIGHTENING THE PRESSURE GRADIENT INCREASING NE TO 
E WINDS ACROSS THE CARIBBEAN THEN SPREADING E THROUGH FRI OVER 
THE TROPICAL ATLC THROUGH FRI. 

$$
WALLACE