000 AXNT20 KNHC 241117 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST WED DEC 24 2014 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...SPECIAL FEATURES... A STRONG COLD FRONT IS MOVING ACROSS THE GULF WATERS FOLLOWED BY GALE FORCE WINDS. AS OF 0900 UTC...THE FRONT EXTENDS FROM MOBILE ALABAMA TO VERACRUZ MEXICO. A RECENT ASCAT PASS SHOWED NORTHERLY WINDS OF 30-35 KT W OF THE FRONT ALONG THE COAST OF MEXICO FROM MATAMOROS TO TAMPICO...WITH FRESH TO NEAR GALE FORCE WINDS ELSEWHERE W OF THE FRONT. SCATTEROMETER DATA ALSO PROVIDED OBSERVATIONS OF FRESH TO STRONG SOUTHERLY WINDS AHEAD OF THE FRONT DUE TO THE TIGHT PRES GRADIENT BETWEEN THE ATLANTIC RIDGE AND LOWER PRES ACROSS THE EAST AND CENTRAL GULF. THE FRONT WILL CONTINUE EAST AND REACH FROM THE WESTERN FLORIDA PANHANDLE TO THE CENTRAL BAY OF CAMPECHE THIS MORNING...FROM NEAR TAMPA BAY TO THE YUCATAN CHANNEL THIS EVENING...THEN SHIFT SE OF THE GULF BY THU MORNING WHEN IT IS EXPECTED TO MOVE ACROSS SOUTH FLORIDA. GALE FORCE NORTHERLY WINDS BEHIND THE FRONT IN THE WESTERN GULF WILL DIMINISH BY THIS EVENING. HIGH PRES WILL BUILD IN THE WAKE OF THE FRONT. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH CROSSES THE COAST OF AFRICA NEAR 09N13W AND CONTINUES OVER THE E ATLC WATERS TO NEAR 06N20W. THE ITCZ BEGINS NEAR 06N20W AND CONTINUES ALONG 04N30W TO 05N40W TO THE COAST OF SOUTH AMERICA AT 04N51W. ISOLATED MODERATE CONVECTION IS WITHIN 60 NM N OF THE ITCZ AXIS BETWEEN 21W AND 24W. ...DISCUSSION... GULF OF MEXICO... A STRONG COLD FRONT IS MOVING ACROSS THE GULF REGION PRODUCING GALE FORCE WINDS AND ROUGH SEAS. SEE SPECIAL FEATURES FOR DETAILS. MOSAIC DOPPLER RADAR FROM THE SE U.S. SHOWS BANDS OF SHOWERS AND STRONG TSTMS AHEAD OF THE FRONT AFFECTING THE FLORIDA PANHANDLE AND NORTHERN FLORIDA. SEVERE WEATHER CONDITIONS AS DAMAGING WINDS AND FLASH FLOODING ARE POSSIBLE IN ASSOCIATION WITH THIS BANDS OF STRONG TSTMS OVER THE FLORIDA PANHANDLE...NORTHERN FLORIDA AND SOUTHERN GEORGIA. IN THE UPPER LEVELS...WATER VAPOR IMAGERY SHOWED PLENTY OF MOISTURE STREAMING NORTHEAST ACROSS THE GULF REGION FROM SE MEXICO TO THE SE CONUS. THIS MID TO UPPER LEVEL MOISTURE IS ASSOCIATED WITH A SOUTHWESTERLY FLOW AHEAD OF A LONG-WAVE TROUGH THAT CROSSES CENTRAL TEXAS AND NORTHERN MEXICO. THIS TROUGH SUPPORTS THE COLD FRONT THAT IS CURRENTLY MOVING ACROSS THE GULF. BY FRI...EXPECT INCREASING SOUTHERLY WINDS ACROSS THE WESTERN GULF AHEAD OF THE NEXT COLD FRONT FORECAST TO ENTER THE NW GULF BY SAT NIGHT. CARIBBEAN SEA... FRESH TO STRONG TRADEWINDS PREVAIL ACROSS THE EAST AND CENTRAL CARIBBEAN WITH THE STRONGEST WINDS OF 25-30 KT NEAR THE COAST OF COLOMBIA...AND IN THE GULF OF VENEZUELA. SCATTEROMETER PASSES CONFIRMED THE PRESENCE OF THESE WINDS. FRESH TO STRONG SE WINDS ARE BLOWING ACROSS THE NW CARIBBEAN...INCLUDING THE YUCATAN CHANNEL. SHALLOW MOISTURE EMBEDDED IN THE TRADE WIND FLOW CONTINUES TO MOVE ACROSS THE REGION PRODUCING ISOLATED TO SCATTERED PASSING SHOWERS. PATCHES OF LOW LEVEL MOISTURE ARE CURRENTLY MOVING ACROSS THE LESSER ANTILLES FROM THE ATLANTIC... MORE CONCENTRATED ACROSS THE LEEWARD ISLANDS AND THE NE CARIBBEAN. PASSING SHOWERS ARE ALSO NOTED ACROSS EASTERN PUERTO RICO. FRESH TO STRONG TRADE WINDS WILL PREVAIL OVER THE CENTRAL CARIBBEAN THROUGH SUN NIGHT...AND WILL OCCASIONALLY INCREASE TO NEAR GALE FORCE NEAR THE COAST OF COLOMBIA...MAINLY BETWEEN 0600- 1200 UTC. A COLD FRONT WILL MOVE ACROSS THE YUCATAN CHANNEL INTO THE FAR NW CARIBBEAN THIS EVENING AND TONIGHT. THE FRONT IS FORECAST TO STALL AND GRADUALLY DISSIPATE FROM WESTERN CUBA TO CENTRAL HONDURAS THROUGH FRI MORNING. FRESH NORTHERLY WINDS ARE EXPECTED IN THE WAKE OF THE FRONT. IN THE UPPER LEVELS...A RIDGE WITH AXIS ACROSS HISPANIOLA COVERS MOST OF THE BASIN PRODUCING STRONG SUBSIDENCE ACROSS THE CARIBBEAN SEA...MOST OF CENTRAL AMERICA AND NORTHERN COLOMBIA AND VENEZUELA. MID TO UPPER LEVEL MOISTURE IS ON INCREASE ACROSS GUATEMALA AND THE YUCATAN PENINSULA AND OVER THE FAR NW CARIBBEAN AND WESTERN CUBA WHERE A SWLY FLOW ALOFT PREVAILS. HISPANIOLA... A VERY STABLE ENVIRONMENT ALOFT CONTINUES TO SUPPORT MOSTLY FAIR WEATHER ACROSS THE ISLAND. SIMILAR CONDITIONS ARE EXPECTED OVER THE NEXT 24 HOURS WITH LOW-TOPPED TRADE WIND SHOWERS MOVING MAINLY ACROSS THE CARIBBEAN WATERS. ATLANTIC OCEAN... A 1021 MB SURFACE HIGH PRESSURE LOCATED NEAR 28N64W EXTENDS A RIDGE ACROSS THE CENTRAL AND WESTERN ATLC...MAINLY N OF 20N W OF 50W. THE PRESSURE GRADIENT WILL INCREASE BETWEEN THE HIGH PRES AND LOWER PRESSURE OVER THE GULF OF MEXICO. AS A RESULT...EXPECT INCREASING SOUTHERLY WINDS E OF NORTHERN FLORIDA AS A COLD FRONT APPROACHES FROM THE W. CURRENTLY...MODERATE TO LOCALLY FRESH EASTERLY WINDS ARE NOTED ACROSS THE SOUTHERN PERIPHERY OF THE RIDGE...WITH MAINLY FRESH WINDS BETWEEN HISPANIOLA AND THE TURKS AND CAICOS ISLANDS. PATCHES OF LOW LEVEL MOISTURE ARE ALSO NOTED UNDER THE INFLUENCE OF THE RIDGE. FARTHER EAST...A COLD FRONT IS ANALYZED AND EXTENDS FROM 31N31W TO 26N35W TO 25N41W. THIS FRONT IS GENERATING SCATTERED MODERATE CONVECTION MAINLY N OF 25N BETWEEN 30W AND 36W. PRES GRADIENT BETWEEN THE FRONT AND THE RIDGE TO THE WEST IS RESULTING IN AN AREA OF FRESH NORTHERLY WINDS OVER THE CENTRAL ATLANTIC...ESPECIALLY N OF 29N BETWEEN 44W AND 50W. A RIDGE DOMINATES THE REMAINDER OF ATLANTIC FORECAST AREA. THE CURRENT MID TO UPPER-LEVEL MOISTURE STREAMING NE ACROSS THE GULF OF MEXICO AND FLORIDA REACHES THE SW N ATLC...AND IS RIDING ON THE NORTHERN PERIPHERY OF THE RIDGE THAT DOMINATES THE CARIBBEAN SEA AND THE BAHAMAS. ALOFT...A RIDGE/ TROUGH/RIDGE PATTERN IS NOTED ACROSS THE ATLANTIC FORECAST REGION. LOOKING AHEAD...THE STRONG COLD FRONT THAT IS MOVING ACROSS THE GULF OF MEXICO WILL ENTER THE SW N ATLC TONIGHT. THE FRONT WILL WEAKEN AS IT QUICKLY REACHES FROM 31N70W TO CENTRAL CUBA BY LATE THU. FRESH TO LOCALLY STRONG NW WINDS AND BUILDING SEAS ARE EXPECTED BEHIND THE FRONT WED NIGHT AND THU. HIGH PRESSURE WILL BUILD IN THE WAKE OF THE FRONT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR