[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 122348
TWDAT

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
705 PM EST THU JAN 12 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...ITCZ/MONSOON TROUGH...

THE MONSOON TROUGH IS ANALYZED ACROSS AFRICA ENTERING THE E
TROPICAL ATLC NEAR 7N11W TO 6N18W. THE ITCZ CONTINUES FROM 6N18W
ALONG 3N34W 1N39W ACROSS THE EQUATOR NEAR 45W INTO SOUTH AMERICA
NEAR 48W. CLUSTERS OF ISOLATED MODERATE CONVECTION ARE FROM
1N-5N BETWEEN 30W-37W.

...DISCUSSION...

GULF OF MEXICO...
A LARGE UPPER LOW IS OVER ILLINOIS DRAPING A BROAD UPPER TROUGH
OVER THE GULF SUPPORTING A STRONG RE-ENFORCING COLD FRONT THAT
AT 12/2100 UTC EXTENDS ACROSS THE FLORIDA PANHANDLE NEAR
TALLAHASSEE INTO THE GULF ALONG 25N90W TO 23N96W WHERE IT TURNS
S TO INLAND OVER MEXICO JUST S OF TUXPAN TO ALONG THE E SLOPES
OF THE SIERRA MADRE MOUNTAINS. THIS FRONT IS WELL DEFINE BY A
ROPE CLOUD ACROSS THE GULF AND DUE TO THE RECENT FRONTAL PASSAGE
IS ONLY PRODUCING ISOLATED SHOWERS WITHIN 30 NM OF THE FRONT AND
DENSE LOW/MID CLOUDS WITH POSSIBLE ISOLATED SHOWERS WITHIN 120
NM W OF THE FRONT. THE COLD FRONT THAT MOVED THROUGH THE GULF
YESTERDAY HAS STALLED OVER S FLORIDA AT 12/1800 UTC AND IS
MEANDERING OVER THE SE GULF. AT 12/2100 UTC THE FRONT EXTENDS
FROM WEST PALM BEACH TO NAPLES...JUST W OF KEY WEST FLORIA TO
NEAR MERIDA ON THE YUCATAN PENINSULA WITH SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS WITHIN 90 NM E OF THE FRONT FROM THE
FLORIDA KEYS TO MERIDA. THE STATIONARY FRONT OVER THE SE GULF
WILL GRADUALLY DISSIPATE THROUGH FRI. THE STRONG COLD FRONT WILL
RACE SE TO THE SE GULF BY EARLY FRI AND EXIT THE GULF FRI
AFTERNOON. STRONG HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT
TONIGHT THROUGH SAT BRINGING GALE FORCE WINDS TO THE SW GULF
BEHIND THE FRONT TONIGHT. THE HIGH WILL THEN SHIFT EASTWARD AND
STRENGTHEN SUN AND MON ALLOWING FOR YET ANOTHER COLD FRONT TO
MOVE INTO THE NW GULF TUE.

CARIBBEAN SEA...
THE BROAD UPPER TROUGH OVER THE GULF OF MEXICO EXTENDS OVER THE
NW CARIBBEAN WITH A BROAD UPPER RIDGE COVERING THE REMAINDER OF
THE CARIBBEAN WITH THE AXIS ALONG 64W INTO THE W ATLC. WATER
VAPOR IMAGERY INDICATES MOSTLY DRY STABLE AIR ACROSS THE REGION.
HOWEVER...LOW LEVEL MOISTURE CONTINUES TO GENERATE ISOLATED
SHOWERS WITHIN 60 NM OF LINE FROM CENTRAL CUBA NEAR CIEGO DE
AVILA TO THE GULF OF HONDURAS NEAR 16N88W INCLUDING THE CAYMAN
ISLANDS. THE REMAINDER OF THE CARIBBEAN IS EXPERIENCING FAIR
WEATHER CONDITIONS AGAIN THIS EVENING. A STRONG COLD FRONT WITH
STRONG HIGH PRESSURE BEHIND IT WILL ENTER THE NW CARIBBEAN SAT.

ATLANTIC OCEAN...
THE BROAD UPPER TROUGH OVER THE GULF OF MEXICO EXTENDS INTO THE
W ATLC N OF 24N W OF 70W SUPPORTING A COLD FRONT THAT AT 12/2100
UTC ENTERS THE ATLC OVER BERMUDA TO 27N74W WHERE IT PULLS UP
STATIONARY MEANDERING INTO THE GULF OF MEXICO ACROSS FLORIDA
NEAR WEST PALM BEACH. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS
ARE E OF THE FRONT WITHIN 75 NM OF LINE FROM 24N73W TO BEYOND
32N66W WITH ISOLATED SHOWERS WITHIN 60 NM OF LINE FROM 24N73W
ACROSS CENTRAL CUBA INTO THE CARIBBEAN NEAR CIEGO DE AVILA. THE
BROAD UPPER RIDGE THAT COVERS THE CARIBBEAN COVERS THE W ATLC
INTO THE CENTRAL ATLC WITH THE AXIS ALONG 64W/65W. A BROAD UPPER
TROUGH COVERS THE E ATLC TO 17N BETWEEN 20W-50W SUPPORTING A
DISSIPATING COLD FRONT THAT ENTERS THE REGION NEAR 32N41W
EXTENDING ALONG 27N52W TO 27N59W. A WEAK SURFACE TROUGH IS
ANALYZED ALONG 34W FROM 21N-35N. THE COLD FRONT OVER THE W ATLC
WILL WEAKEN THROUGH FRI. A STRONGER COLD FRONT WILL MOVE OFF THE
SE U.S. COAST LATE TONIGHT AND REACH FROM 31N72W TO W CUBA FRI
MERGING WITH THE REMNANTS OF THE STATIONARY FRONT BY FRI
AFTERNOON. FRONT WILL THEN EXTEND FROM NEAR BERMUDA TO E CUBA
SAT WEAKENING AND STALL ON SUN.

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

$$
PAW




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