000
AXNT20 KNHC 280539
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST FRI DEC 28 2012

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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL 
ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0515 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL 
ATLC NEAR 9N13W TO 8N17W WHERE THE ITCZ CONTINUES ALONG 4N25W 
3N39W CROSSING THE EQUATOR INTO SOUTH AMERICA NEAR 50W. CLUSTERS 
OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 3N-6N 
BETWEEN 16W-20W...FROM 1N-6N BETWEEN 22W-35W...AND WITHIN 75 NM 
OF LINE FROM 3N37W TO 7N45W.  
 
...DISCUSSION...

GULF OF MEXICO...
AN UPPER TROUGH IS BEGINNING TO DIG S OVER THE CENTRAL PLAIN 
STATES TO THE DESERT SW AMPLIFYING AN UPPER RIDGE OVER THE GULF 
OF MEXICO TO OVER THE E CONUS. AT THE SURFACE IS A WEAK 1009 MB 
LOW ALONG THE COAST OF TEXAS JUST S OF CORPUS CHRISTI WITH A 
STATIONARY FRONT CONTINUING ALONG THE COAST OF TEXAS THE SW 
LOUISIANA NEAR LAKE CHARLES. SCATTERED SHOWERS COVER THE NW GULF 
N OF 23N W OF 90W. COLD AIR STRATOCUMULUS CLOUDS REMAIN OVER 
PORTIONS OF THE E GULF WITH A WEAK SURFACE RIDGE OVER THE AREA E 
OF 90W ANCHORED BY A 1024 MB HIGH OVER INDIANA. THE STATIONARY 
FRONT WILL DISSIPATE LATER THIS MORNING AS A COLD FRONT MOVES 
ACROSS TEXAS AND OFF THE TEXAS COAST LATER FRI MORNING AND WILL 
EXTEND FROM SE LOUISIANA TO TAMPICO MEXICO FRI EVENING THEN FROM 
THE FLORIDA BIG BEND TO THE W BAY OF CAMPECHE SAT MORNING AND 
FROM SW FLORIDA TO THE E BAY OF CAMPECHE SAT EVENING BEFORE 
MOVING OUT OF THE GULF ON SUN.

CARIBBEAN SEA...
A BROAD LOW AMPLITUDE UPPER RIDGE ANCHORED OVER SOUTH AMERICA IS 
COVERING THE CARIBBEAN WITH THE AXIS ALONG 70W. A DISSIPATING 
STATIONARY FRONT EXTENDS FROM THE W ATLC ACROSS CUBA NEAR SANTA 
CLARA OVER THE NW CARIBBEAN ALONG 22N83W TO THE YUCATAN NEAR 
19N87W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 
20N W OF 83W TO OVER CUBA AND THROUGH THE YUCATAN CHANNEL. FRESH 
TO STRONG EASTERLY TRADE WINDS ARE BANKING SCATTERED SHOWERS AND 
POSSIBLE ISOLATED THUNDERSTORMS OVER THE SW CARIBBEAN S OF 10N W 
OF 80W LEAVING THE REMAINDER OF THE CARIBBEAN UNDER CLEAR SKIES 
TONIGHT. STATIONARY FRONT WILL DISSIPATE THROUGH FRI. TRADE 
WINDS WILL PREVAIL ACROSS THE S/CENTRAL CARIBBEAN THROUGH TUE. 

ATLANTIC OCEAN...
AN UPPER TROUGH EXTENDS FROM THE CANADIAN MARITIMES OVER THE W 
ATLC N OF 30N W OF 60W SUPPORTING A COLD FRONT THAT ENTERS THE 
REGION NEAR 32N64W ALONG 27N70W TO S OF ANDROS ISLAND NEAR 
24N78W WHERE IT PULLS UP STATIONARY AND BEGINS TO DISSIPATE AS 
IT CONTINUES INTO THE CARIBBEAN ACROSS CUBA NEAR SANTA CLARA. 
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 90 NM E OF 
THE FRONT N OF 29N. A SURFACE RIDGE COVERS THE W ATLC W OF THE 
FRONT ANCHORED BY A 1024 MB HIGH OVER INDIANA. AN UPPER LOW IS 
IN THE CENTRAL ATLC NEAR 28N40W EXTENDING AN UPPER TROUGH S INTO 
THE TROPICS TO 18N47W AND SUPPORTING A SURFACE TROUGH THAT 
EXTENDS FROM 30N39W THROUGH A 1016 MB LOW NEAR 27N41W TO 23N45W. 
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 120 NM E OF 
THE TROUGH N OF 25N. A SECOND SURFACE TROUGH IS TO THE SE 
EXTENDING FROM 25N37W TO 20N43W. A BROAD UPPER RIDGE COVERS THE 
REMAINDER OF THE ATLC E OF 35W PROVIDING DIFFLUENCE ALOFT TO 
GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS N 
OF 23N BETWEEN 30W AND THE SECOND SURFACE TROUGH. A SURFACE 
RIDGE COVERS THE REMAINDER OF THE E ATLC N OF 15N W OF 30W. W 
ATLC COLD FRONT WILL WEAKEN AS IT MOVES INTO THE CENTRAL ATLC. 
ANOTHER STRONG COLD FRONT WILL MOVE OFF FLORIDA SAT AND WILL 
EXTEND FROM 32N67W TO W CUBA SUN MORNING AND FROM 32N58W TO 
CENTRAL CUBA SUN EVENING CONTINUING INTO THE CENTRAL ATLC MON.

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

$$
PAW