000 AXNT20 KNHC 021741 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST WED DEC 02 2015 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... A GALE WARNING IS IN EFFECT FOR THE WEST-CENTRAL AND SW GULF OF MEXICO. AT 1200 UTC...A COLD FRONT IS ANALYZED ACROSS THE GULF AND EXTENDS FROM PENSACOLA FLORIDA TO S OF TAMPICO MEXICO. REINFORCING COLDER AIR MOVING ACROSS EASTERN TEXAS WILL PUSH INTO THE NW GULF ALLOWING THE FRONT TO REACH A POSITION FROM THE FLORIDA BIG BEND TO VERACRUZ MEXICO THIS EVENING AND FROM SW FLORIDA TO THE BAY OF CAMPECHE THU AFTERNOON. STRONG TO GALE FORCE NORTHERLY WINDS AND BUILDING SEAS WILL FOLLOW THE FRONT ALONG THE COAST OF MEXICO LATE TONIGHT THROUGH THU NIGHT AS STRONG HIGH PRES BUILDS IN THE WAKE OF THE FRONT. IT IS FORECAST TO STALL FROM SOUTH FLORIDA AND THE FLORIDA KEYS TO THE YUCATAN CHANNEL FRI THROUGH SUN. PLEASE SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/ FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 9N13W TO 08N17W. THE INTERTROPICAL CONVERGENCE ZONE AXIS CONTINUES FROM 08N17W TO 04N30W TO 05N45W TO 04N51W. AN AREA OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS NOTED FROM 03N-07N BETWEEN 42W-53W. ...DISCUSSION... GULF OF MEXICO... A VIGOROUS MIDDLE TO UPPER LEVEL LOW IS OBSERVED ON WATER VAPOR IMAGERY OVER THE NORTH-CENTRAL CONUS WITH TROUGHING DIPPING SOUTHWEST OVER NORTHERN TEXAS AND NW MEXICO. THE TROUGH SUPPORTS THE AFOREMENTIONED COLD FRONT. PLEASE SEE SPECIAL FEATURES FOR MORE DETAILS. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING ALONG THE FRONTAL BOUNDARY. A PRE-FRONTAL TROUGH EXTENDS FROM 31N85W TO 26N92W. MOSAIC DOPPLER RADAR FROM SE U.S. INDICATES A BAND OF SHOWERS WITH EMBEDDED TSTMS IN ASSOCIATION WITH THIS TROUGH AFFECTING PARTS OF THE FLORIDA PANHANDLE. SOME SHOWER ACTIVITY IS ALSO NOTED OVER SOUTH FLORIDA UNDER THE INFLUENCE OF A MOIST LOW LEVEL ONSHORE SE FLOW. OTHERWISE...WHILE FRESH TO LOCALLY STRONG NORTHERLIES ARE OCCURRING NW OF THE FRONT...THE REMAINDER OF THE GULF REGION IS UNDER THE INFLUENCE OF WEAK RIDGING AND GENTLE TO MODERATE ANTICYCLONIC FLOW. A THERMAL TROUGH IS MOVING WWD ACROSS THE BAY OF CAMPECHE. CARIBBEAN SEA... AN UPPER-LEVEL LOW PERSISTS OVER HAITI WITH A TROUGH EXTENDING SW TO NEAR THE COSTA RICA-NICARAGUA BORDER. A RIDGE IS BEHIND THE TROUGH AXIS AND STRETCHES FROM SE MEXICO AND WESTERN CUBA INTO THE NW BAHAMAS. A DIFFLUENT PATTERN ALOFT BETWEEN THESE TWO UPPER LEVEL FEATURES IS HELPING TO INDUCE AN AREA OF SHOWERS WITH EMBEDDED TSTMS FROM 16N-20N BETWEEN 81W AND A SURFACE TROUGH ANALYZED FROM 20N83W TO 15N84W. ISOLATED SHOWERS ARE ALSO OCCURRING ACROSS THE CENTRAL CARIBBEAN WITHIN THE AREA OF MAXIMUM DIFFLUENCE EAST OF THE TROUGH AXIS PRIMARILY BETWEEN 67W- 75W...INCLUDING HISPANIOLA. FARTHER EAST...ANOTHER WEAK SURFACE TROUGH IS ANALYZED NE OF PUERTO RICO PROVIDING FOCUS FOR ISOLATED SHOWERS ACROSS THE NE CARIBBEAN...INCLUDING PARTS OF PUERTO RICO AND UK/US VIRGIN ISLANDS. HIGH PRES OVER THE CENTRAL ATLC AND THE ABOVE MENTIONED TROUGH IN THE NW CARIBBEAN WILL SUPPORT FRESH TO STRONG TRADE WINDS OVER MAINLY THE CENTRAL CARIBBEAN THROUGH THE WEEKEND. A RECENT ASCAT PASS PROVIDED OBSERVATIONS OF FRESH TO STRONG WINDS ACROSS THE CENTRAL CARIBBEAN...PARTICULARLY BETWEEN HISPANIOLA AND NW VENEZUELA. AS THE UPPER LEVEL LOW DRIFTS WESTWARD THROUGH THURSDAY...WEAK SURFACE TROUGH AND THE ASSOCIATED PRECIPITATION IS EXPECTED ACROSS WESTERN CUBA...THE NW CARIBBEAN AND PORTIONS OF NORTHERN CENTRAL AMERICA. ANOTHER FACTOR FOR INCREASING RAIN PROBABILITY WILL BE THE PRESENCE OF A STALLING COLD FRONT ACROSS SOUTH FLORIDA...THE FLORIDA KEYS AND THE YUCATAN CHANNEL FRI THROUGH SUN. LOCALLY HEAVY RAIN MAY OCCUR. ...HISPANIOLA... AN UPPER LEVEL LOW IS CENTERED OVER HAITI AND CONTINUES TO SUPPORT INCREASED CLOUDINESS AND ISOLATED SHOWERS ACROSS THE ISLAND. THE UPPER LEVEL FEATURE WILL DRIFT WESTWARD DURING THE NEXT 24 HOURS RESULTING IN DRIER WEATHER CONDITIONS LATE TODAY INTO THURSDAY. MAINLY ISOLATED SHOWERS ARE EXPECTED. ATLANTIC OCEAN... ALOFT...A RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE DISCUSSION AREA. THE UPPER LEVEL TROUGH SUPPORTS A COLD FRONT THAT ENTERS THE FORECAST REGION NEAR 31N31W AND EXTENDS TO NEAR 27N48W WHERE IT BECOMES STATIONARY TO NEAR 29N58W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE COLD FRONT. FRESH TO STRONG NORTHERLY WINDS ARE NOTED PER SCATTEROMETER DATA BEHIND THE FRONT. OTHERWISE...A SURFACE RIDGE INFLUENCES THE REMAINDER OF THE AREA. PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES IN THE VICINITY OF THE ITCZ IS PRODUCING FRESH TO LOCALLY STRONG TRADE WINDS ACROSS THE TROPICS E OF THE LESSER ANTILLES. THE FRONT WILL CONTINUE TO MOVE SE ACROSS THE ATLC WATERS FOLLOWED BY A STRONG HIGH PRES FORECAST TO REACH A CENTRAL PRES OF 1037 MB BY THU MORNING. ANOTHER COLD FRONT IS FORECAST TO MOVE OFF THE COAST OF NE FLORIDA THIS EVENING... REACHING FROM 31N77W TO CENTRAL FLORIDA EARLY THU MORNING...AND FROM 31N70W TO SOUTH FLORIDA LATE THU...THEN FROM 31N65W TO THE FLORIDA KEYS ON FRI. A BAND OF SHOWERS AND TSTMS WILL BE ASSOCIATED WITH THE FRONT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR