000
AXNT20 KNHC 041813
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SUN JAN 04 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1745 UTC.

...THE ITCZ...

ITCZ IS CENTERED ALONG 08N13W 03N30W 01N50W. NO SIGNIFICANT 
CONVECTION. 

...DISCUSSION...

GULF OF MEXICO...
A WEAKENING SHORT WAVE TROUGH IS EXITING THE NE GULF AND MOVING 
EAST ACROSS NORTH FLORIDA...ON THE NORTHERN EXTENT OF AN UPPER 
RIDGE CENTERED OVER THE WESTERN CARIBBEAN. ASSOCIATED 
THUNDERSTORMS SW OF PANAMA CITY FLORIDA DISSIPATED SHORTLY AFTER 
SUNRISE...LEAVING A BROAD AREA OF SHOWERS N OF 27N AND E OF 80W 
WHERE DEEP LAYER MOISTURE REMAINS ABUNDANT. ADDITIONAL SHOWERS 
ARE POSSIBLE OVER THE NE GULF AS THE LEFT FRONT EXIT REGION OF A 
120 KT JET MOVING INTO THE AREA. AREAS OF SEA FOG WITH 
VISIBILITIES BELOW 2 MILES BLANKET MUCH OF THE TEXAS COAST. 
VISIBLE IMAGERY SHOWS A COMPACT SWIRL SE OF TAMPICO MEXICO NEAR 
21N97W AT THE SOUTHERN END OF A SURFACE TROUGH EXTENDING SOUTH 
FROM S TEXAS...AGREEING WITH AREA OBSERVATIONS HINTING OF A 1009 
MB SURFACE LOW IN THE AREA. BUOYS AND QUIKSCAT SHOW LIGHT TO 
MODERATE E TO SE WINDS ACROSS THE GULF BETWEEN THE TROUGH AND 
HIGH PRES NOSING IN FROM THE WESTERN ATLC. A COLD FRONT NOW OVER 
SE TEXAS WILL MOVE INTO THE NW GULF LATER TODAY...THEN STALL 
FROM SE LOUISIANA TO S TEXAS MON. A REINFORCING FRONT PUSHES IN 
TUE...REACHING SE OF THE AREA BY MIDWEEK.

CARIBBEAN...
AN UPPER TROUGH IS DIGGING INTO THE EASTERN CARIBBEAN NEAR 70W 
AHEAD OF AN UPPER RIDGE OVER THE WESTERN CARIBBEAN NEAR 85W. A 
SURFACE TROUGH ASSOCIATED WITH THE UPPER FEATURE IS MOVING WEST 
ACROSS 74W. ASSOCIATED SCATTERED SHOWERS ARE NOTED S OF HAITI. 
QUIKSCAT SHOWS MODERATE TO FRESH TRADES MAINLY E OF THE TROUGH. 
THE TROUGH DISSIPATES LATER TODAY AS UPPER SUPPORT WEAKENS. 
SURFACE HIGH PRES N OF THE AREA MAINTAINS FRESH TRADES THROUGH 
MIDWEEK.

ATLANTIC...
UPPER TROUGH EXTENDS FROM 32N53W TO PUERTO RICO IS WEAKENING AND 
LIFTING NE AHEAD OF UPPER RIDGE BUILDING INTO THE WESTERN 
ATLC...SUPPORTING A 1021 MB SURFACE HIGH NEAR 28N70W. FURTHER 
EAST...AN UPPER RIDGE EXTENDS ALONG ROUGHLY 40W...BETWEEN THE 
TROUGH TO THE WEST AND AN UPPER TROUGH DIGGING INTO THE CANARY 
ISLANDS. THE UPPER RIDGE IS SUPPORTING A 1028 MB SURFACE HIGH 
CENTERED NEAR THE AZORES...DOMINATING THE EASTERN ATLC. BUOYS 
AND QUIKSCAT SHOWS A BROAD SWATH OF FRESH TRADE WINDS SOUTH OF 
THE SURFACE HIGH PRES. 

$$
CHRISTENSEN