000 AXNT20 KNHC 080546 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST THU DEC 08 2011 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 A PORTION OF AFRICA WITH THE ITCZ AXIS ENTERING THE E TROPICAL ATLC NEAR 9N14W CONTINUING ALONG 10N18W 6N33W TO 6N48W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 3N-6N BETWEEN 33W-38W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 2N-6N BETWEEN 27W-33W AND FROM 3N-6N BETWEEN 38W-41W. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH COVERS THE E CONUS E OF THE MISSISSIPPI VALLEY WITH NEAR ZONAL SW FLOW ALOFT DOMINATING THE GULF. THE UPPER TROUGH IS SUPPORTING A COLD FRONT THAT ENTERS THE GULF AT 08/0300 UTC ACROSS S FLORIDA NEAR 26N81W TO 23N85W WHERE IT BECOMES A DISSIPATING STATIONARY FRONT TO OVER THE W YUCATAN PENINSULA NEAR MERIDA. BROKEN/OVERCAST LOW/MID CLOUDS WITH SCATTERED SHOWERS ARE WITHIN 120 NM W OF THE COLD FRONT AND OVER THE S GULF S OF 23N W OF 89W. CLEAR SKIES COVER THE NW GULF N OF 27N W OF 91W WITH COLD AIR STRATOCUMULUS CLOUDS DOTING THE REMAINDER OF THE GULF WATERS. A SURFACE RIDGE IS W OF THE FRONT WITH A 1027 MB HIGH OVER N MEXICO AND A 1028 MB HIGH ALONG THE COAST OF MEXICO BETWEEN TAMPICO AND TUXPAN. COLD FRONT WILL MOVE OUT OF THE GULF OVERNIGHT. HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE SE US THROUGH SUN ALLOWING SOME INCREASE IN WINDS AND SEAS ACROSS THE GULF REGION. CARIBBEAN SEA... A NARROW UPPER TROUGH AXIS EXTENDS FROM AN UPPER LOW NE OF PUERTO RICO INTO THE CARIBBEAN OVER HISPANIOLA TO THE TIP OF NICARAGUA/HONDURAS. STRONG SUBSIDENCE AND DRY STABLE AIR COVERS MOST OF THE CARIBBEAN EXCEPT SE OF A LINE FROM THE LEEWARD ISLANDS NEAR 17N62W TO PANAMA/COSTA RICA BORDER WHERE THERE IS MOIST TROPICAL AIR. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE IN THE MOIST SECTOR ACROSS THE SE CARIBBEAN WHILE THE REMAINDER OF THE CARIBBEAN IS UNDER MOSTLY FAIR CONDITIONS AGAIN TONIGHT. COLD FRONT WILL MOVE INTO THE YUCATAN CHANNEL OVERNIGHT THEN WILL STALL AND DISSIPATE OVER THE W CARIBBEAN THROUGH THU FROM W CUBA TO BELIZE. ATLANTIC OCEAN... THE UPPER TROUGH OVER THE E CONUS IS MOVING INTO THE W ATLC SUPPORTING A COLD FRONT THAT AT 08/0300 UTC ENTERS THE W ATLC NEAR 32N77W TO ACROSS S FLORIDA BETWEEN WEST PALM BEACH AND FORT LAUDERDALE INTO THE GULF OF MEXICO. BROKEN/OVERCAST LOW/MID CLOUDS WITH SCATTERED SHOWERS ARE WITHIN 120 NM W OF THE COLD FRONT. A SURFACE RIDGE CONTINUES TO RETREAT EASTWARD AHEAD OF THE ABOVE FRONT COVERING THE W INTO THE CENTRAL ATLC BETWEEN 50W-75W AND ANCHORED BY A 1023 MB HIGH ABOUT 230 NM E-NE OF BERMUDA. A NARROWING UPPER RIDGE EXTENDS FROM W CUBA NEAR 23N80W ACROSS THE BAHAMAS AND THE W ATLC TO BEYOND 32N68W COVERING THE W ATLC NW OF AN UPPER TROUGH THAT EXTENDS FROM 27N55W THROUGH AN UPPER LOW NE OF PUERTO RICO NEAR 22N63W INTO THE CARIBBEAN OVER HISPANIOLA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 60 NM OF LINE FROM 23N57W 21N63W TO 22N68W. MODERATE/STRONG SUBSIDENCE AND DRY STABLE AIR COVERS THE REMAINDER OF THE W ATLC W OF 60W TO THE W ATLC COLD FRONT GIVING THE AREA FAIR WEATHER AGAIN TONIGHT. A SURFACE TROUGH IS ANALYZED ALONG THE W EDGE OF AN UPPER RIDGE EXTENDING THROUGH 32N42W ALONG 25N49W TO A 1009 MB LOW NEAR 21N53W CONTINUING SW TO 14N61W IN THE LESSER ANTILLES. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 18N-23N BETWEEN 45W-53W. A BROAD LOW AMPLITUDE UPPER RIDGE IS ALONG 48W FROM 10N-24N BETWEEN 35W-58W ENHANCING THE ACTIVITY ASSOCIATED WITH THE ABOVE SURFACE TROUGH/LOW. A SURFACE RIDGE DOMINATES THE E ATLC ANCHORED BY A 1033 MB HIGH E OF THE AZORES OFF THE COAST OF PORTUGAL. W ATLC COLD FRONT WILL SHIFT SE AND STALL FROM NEAR BERMUDA TO CENTRAL CUBA BY THU NIGHT THEN WILL DRIFT WESTWARD SLOWLY FRI STALLING AGAIN FROM 31N75W TO S FLORIDA BY LATE FRI BEFORE SETTLING FROM NEAR BERMUDA TO CENTRAL FLORIDA BY LATE SUN AGAIN. THE 1009 MB LOW AND SURFACE TROUGH WILL DISSIPATE THROUGH THU AS THE LOW WEAKENS AND SHIFTS W ACROSS THE LEEWARDS THROUGH LATE FRI. A SECOND TROUGH WILL MOVE W THROUGH THE LEEWARDS SAT AND SUN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW