000
AXNT20 KNHC 082358
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST TUE DEC 08 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.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 6N10W 3N27W 4N39W 2N50W. CLUSTERS OF 
ISOLATED MODERATE CONVECTION ARE FROM 7N TO THE EQUATOR BETWEEN 23W 
TO 40W.

...DISCUSSION...

GULF OF MEXICO...
AT 2100 UTC...THE GULF WATERS ARE BEGINNING TO CLEAR THIS EVENING 
AS A COLD FRONT MOVES THROUGH TEXAS TO OVER THE MID MISSISSIPPI 
VALLEY WHILE THE STATIONARY FRONT FROM THE W ATLC EXTENDS OVER THE 
FLORIDA PANHANDLE DISSIPATING OVER S ALABAMA/MISSISSIPPI. A LARGE 
UPPER LOW IS MOVING THROUGH THE CENTRAL PLAIN STATES PROVIDING 
SUPPORT FOR THE COLD FRONT OVER TEXAS. NEAR ZONAL WESTERLY UPPER 
FLOW DOMINATES THE ENTIRE GULF WITH A WEAK SURFACE RIDGE FROM THE W 
ATLC EXTENDING ACROSS THE FLORIDA PENINSULA GIVING THE GULF 
SOUTHERLY SURFACE FLOW. ISOLATED SHOWERS ARE NOTED N OF 29N ACROSS 
THE N GULF. 

CARIBBEAN SEA...
A BROAD UPPER RIDGE EXTENDS FROM OVER THE YUCATAN PENINSULA ACROSS 
CENTRAL CUBA INTO THE ATLC GIVING THE ENTIRE CARIBBEAN STRONG 
SUBSIDENCE AND EASTERLY FLOW AT ALL LEVELS SW OF THE UPPER RIDGE 
AXIS. SURFACE RIDGE N OF THE CARIBBEAN IS MAINTAINING MODERATE TO 
FRESH EASTERLY TRADE WINDS ACROSS THE REGION AND IS EXPECTED TO 
INCREASE OVER THE E CARIBBEAN BEGINNING THU. IN SPITE OF THE STRONG 
SUBSIDENCE SCATTERED SHOWERS ARE OVER THE N/CENTRAL CARIBBEAN N OF 
15N TO OVER HISPANIOLA BETWEEN 68W-75W. ISOLATED SHOWERS CAN BE 
ACROSS THE REMAINDER OF THE N CARIBBEAN BETWEEN 15N-20N. 

ATLANTIC OCEAN...
A COLD FRONT ENTERS THE E/CENTRAL ATLC NEAR 32N35W EXTENDING W 
ACROSS THE ATLC TO 28N49W WHERE IT BECOMES STATIONARY ALONG 27N57W 
29N68W 28N73W TO OVER THE FLORIDA PANHANDLE NEAR JACKSONVILLE WITH 
SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF THE FRONTAL BOUNDARY. 
THE UPPER SUPPORT FOR THIS FRONT IS WELL N OF THE REGION. THE BROAD 
UPPER RIDGE THAT CROSSES THE NW CARIBBEAN EXTENDS FROM OVER CENTRAL 
CUBA E TO 26N28W. THIS IS GIVING THE S ATLC AND MOST OF THE TROPICAL 
ATLC STRONG SUBSIDENCE. AN UPPER TROUGH IS OVER THE FAR E ATLC OVER 
THE CANARY ISLANDS S TO THE CAPE VERDE ISLANDS. AT THE SURFACE...A 
RIDGE EXTENDS FROM A 1025 MB HIGH OVER S SPAIN AND A WEAK 1020 MB 
HIGH NEAR 27N37W. 

$$
WALLACE