000 AXNT20 KNHC 201201 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST FRI DEC 20 2013 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 1115 UTC. ...SPECIAL FEATURE... ...GALE-FORCE WIND SPEEDS IN THE CARIBBEAN SEA AT 24 HOURS... THE 24-HOUR FORECAST CONSISTS OF NORTHEAST-TO-EAST GALE-FORCE WINDS AND SEA HEIGHTS 10 TO 15 FEET FROM 11N TO 13N BETWEEN 73W AND 77W. ALSO NORTHEAST TO EAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS 8 TO 12 FEET ELSEWHERE FROM 10N TO 17N BETWEEN 72W AND 80W AND FROM 14N TO 18N BETWEEN 65W AND 74W. EXPECT ALSO WINDS 20 KNOTS OR LESS AND 8 TO 11 FOOT SEA HEIGHTS ELSEWHERE FROM 10N TO 17N BETWEEN 80W AND 82W. CURRENT CONDITIONS... NORTHEAST TO EAST WINDS 20 TO 25 KNOTS... EXCEPT TO 30 KNOTS WITHIN 90 NM OF THE COAST OF COLOMBIA...AND SEA HEIGHTS 8 TO 12 FEET FROM 10N TO 17N BETWEEN 73W AND 80W AND FROM 13N TO 18N BETWEEN 68W AND 73W. EXPECT WINDS 20 KNOTS OR LESS AND SEA HEIGHTS TO 9 FEET FROM 10N TO 16N BETWEEN 80W AND 82W AND FROM 12N TO 16N BETWEEN 64W AND 68W EXPECT ALSO NORTHEAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS LOWER THAN 8 FEET IN THE WINDWARD PASSAGE. PLEASE REFER TO THE METEO-FRANCE FORECASTS...BULLETINS MARINE EXPERTISES FOR MORE DETAILS ABOUT GALE-FORCE WINDS IN THE ATLANTIC OCEAN...IN THE AREAS OF SIERRA LEONE...CAP BLANC...CAP TIMIRIS...CAPE VERDE...AND CANARIAS. ...THE ITCZ/THE MONSOON TROUGH... THE ITCZ IS ALONG 5N8W AT THE COAST OF SOUTHERN LIBERIA...TO 5N15W 6N18W 5N25W 5N35W 2N44W. A SURFACE TROUGH IS 38W FROM 10N TO 19N. A MIDDLE LEVEL TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS NEAR 21N36W. CYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN FROM 14N TO 30N BETWEEN 25W AND 46W. BROKEN TO OVERCAST MULTILAYERED CLOUDS COVER THE AREA THAT IS FROM 10N TO 30N BETWEEN 20W AND 50W. WIDELY SCATTERED TO SCATTERED MODERATE CONVECTIVE PRECIPITATION IS FROM 20N TO 27N BETWEEN 23W AND 36W. ISOLATED MODERATE ELSEWHERE IN THE SAME AREA OF OVERALL CLOUDINESS FROM 10N TO 30N BETWEEN 20W AND 50W. CONVECTIVE PRECIPITATION FOR THE ITCZ...SCATTERED TO NUMEROUS STRONG FROM 4.5N TO 6N BETWEEN 20W AND 29W. WIDELY SCATTERED MODERATE TO ISOLATED STRONG TO THE SOUTH OF 3N TO THE EAST OF 4W...AND FROM 3N TO 4N BETWEEN 15W AND 20W. RAINSHOWERS ARE POSSIBLE ELSEWHERE TO THE SOUTH OF 10N TO THE WEST OF 30W. ...DISCUSSION... ...THE GULF OF MEXICO... A MIDDLE LEVEL TO UPPER LEVEL RIDGE IS ALONG 85W/86W. COMPARATIVELY DRIER AIR IN SUBSIDENCE...AS DEPICTED IN WATER VAPOR IMAGERY...COVERS THE GULF OF MEXICO. A SURFACE RIDGE EXTENDS FROM AN ATLANTIC OCEAN 1029 MB HIGH PRESSURE CENTER THAT IS NEAR 34N64W...TO 32N79W...CROSSING NORTHEASTERN FLORIDA...INTO THE GULF OF MEXICO NEAR 28N86W...TO THE NORTHERN PART OF THE YUCATAN PENINSULA. THE WIND SPEEDS IN THE GULF OF TEHUANTEPEC ON THE EASTERN PACIFIC OCEAN SIDE OF SOUTHERN MEXICO ARE NOW LESS THAN GALE-FORCE. FOR THE OFFSHORE OIL PLATFORM SITES THAT ARE TO THE NORTH OF 27N TO THE WEST OF 87W/88W... LOW CLOUD CEILINGS ARE AT THE FOLLOWING ICAO STATIONS...KMZG... KBBF...KBQX...KVAF HAS CLEARED UP DURING THE LAST FEW OBSERVATIONS...KEMK...KGUL...KHQI...KEHC...KMYT...AND KMDJ. KATP IS REPORTING MIDDLE LEVEL CLOUD CEILINGS. ICAO STATION KDLP HAS BEEN REPORTING LOW LEVEL AND MIDDLE LEVEL CLOUD CEILINGS FOR THE LAST FEW OBSERVATIONS. CLEAR SKIES/FAIR SKIES ARE BEING REPORTED ELSEWHERE AT OR LOWER THAN 12000 FEET. FOR THE COASTAL PLAINS OF THE U.S.A. FROM TEXAS TO FLORIDA... LOW LEVEL CLOUD CEILINGS COVER THE TEXAS COASTAL PLAINS. LOW LEVEL AND MIDDLE LEVEL CLOUD CEILINGS COVER THE LOUISIANA COASTAL PLAINS...MISSISSIPPI...ALABAMA...AND THE WESTERN PART OF THE FLORIDA PANHANDLE. LOW CLOUD CEILINGS COVER THE FLORIDA KEYS FROM MARATHON TO KEY WEST. CLEAR SKIES/FAIR SKIES ARE BEING REPORTED ELSEWHERE AT OR LOWER THAN 12000 FEET. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...AND THE OFFSHORE FORECAST...MIAOFFNT4/FZNT24 KNHC...FOR MORE DETAILS ABOUT...EAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS TO 8 FEET FROM 23N TO 25N TO THE EAST OF 85W. ...HISPANIOLA... MIDDLE LEVEL TO UPPER LEVEL NORTHWESTERLY WIND FLOW MOVES ACROSS CUBA...BECOMING NORTHWESTERLY-TO-NORTHERLY WIND FLOW ACROSS HISPANIOLA. THIS WIND REGIME IS ASSOCIATED WITH A LARGE-SCALE MIDDLE LEVEL TO UPPER LEVEL ATLANTIC OCEAN TROUGH. MIDDLE LEVEL EASTERLY WIND FLOW APPROACHES EASTERN SECTIONS HISPANIOLA FROM THE EAST. FOR THE DOMINICAN REPUBLIC...LOW LEVEL CLOUD CEILINGS WITH RAINSHOWERS ARE IN THE NORTHWESTERN SECTIONS. FEW TO SCATTERED LOW LEVEL CLOUDS COVER THE SOUTHEASTERN COASTAL SECTIONS. THE GFS FORECAST FOR 250 MB SHOWS THAT SOUTHWESTERLY...AND GRADUALLY NORTHWESTERLY WIND FLOW WILL MOVE ACROSS THE AREA WITH A RIDGE. THE RIDGE BEGINS THE 48-HOUR FORECAST PERIOD SPANNING THE CARIBBEAN SEA. THE RIDGE EVENTUALLY BUILDS WITH TIME AND IT COVERS THE AREAS FROM THE BAHAMAS INTO THE CARIBBEAN SEA. THE GFS FORECAST FOR 500 MB SHOWS THAT NORTHEASTERLY WIND FLOW WILL COVER THE AREA...RELATED TO A CARIBBEAN SEA EAST-TO-WEST ORIENTED RIDGE. THE ANTICYCLONIC CIRCULATION CENTER THAT WILL BE ASSOCIATED WITH THE RIDGE EVENTUALLY MOVES INTO THE ATLANTIC OCEAN...JUST TO THE NORTHEAST OF THE BAHAMAS. THE GFS FORECAST FOR 700 MB SHOWS THAT EASTERLY AND NORTHEASTERLY WIND FLOW WILL CROSS HISPANIOLA WITH AN ATLANTIC OCEAN RIDGE. THE REST OF THE CARIBBEAN SEA... MIDDLE LEVEL TO UPPER LEVEL NORTHWESTERLY WIND FLOW MOVES ACROSS CUBA AND HISPANIOLA WITH A LARGE-SCALE MIDDLE LEVEL TO UPPER LEVEL ATLANTIC OCEAN TROUGH. UPPER LEVEL SOUTHERLY-TO-SOUTHWESTERLY WIND FLOW MOVES FROM THE AREA OF THE CARIBBEAN SEA THAT IS TO THE WEST OF 75W...IN THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA...TOWARD THE NORTH AND NORTHEAST. THIS WIND FLOW EVENTUALLY CURVES ANTICYCLONICALLY... TO THE EAST OF 75W...TOWARD THE SOUTHEASTERN CORNER OF THE AREA. CONVECTIVE PRECIPITATION...RAINSHOWERS ARE POSSIBLE TO THE NORTH OF 12N TO THE WEST OF 80W. A MIDDLE LEVEL TO UPPER LEVEL INVERTED TROUGH IS ALONG 69W TO THE SOUTH OF 16N. RAINSHOWERS ARE POSSIBLE TO THE SOUTH OF 17N BETWEEN 67W AND 76W...IN AN AREA OF BROKEN LOW LEVEL TO MIDDLE LEVEL CLOUDS THAT IS MOVING WITH THE INVERTED TROUGH. NORTHEASTERLY-TO-EASTERLY WIND FLOW SPANS THE CARIBBEAN SEA. RAINSHOWERS ARE POSSIBLE ELSEWHERE ACROSS THE REST OF THE CARIBBEAN SEA IN AREAS OF BROKEN LOW LEVEL TO MIDDLE LEVEL CLOUDS. 24-HOUR RAINFALL TOTALS IN INCHES FOR THE PERIOD ENDING AT 20/0000 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...WERE 0.13 IN CURACAO...AND 0.05 IN GUADELOUPE. TOTALS FOR THE 24-HOUR PERIOD ENDING AT 19/1200 UTC WERE...0.34 IN SAN JUAN IN PUERTO RICO... 0.12 IN CURACAO...0.11 IN TRINIDAD...0.09 IN GUADELOUPE...AND 0.07 IN ST. THOMAS. THE MONSOON TROUGH IS ALONG 8N75W IN COLOMBIA...TO 6N80W...AND BEYOND 6N84W...INTO THE EASTERN PACIFIC OCEAN. CONVECTIVE PRECIPITATION...RAINSHOWERS ARE POSSIBLE IN THE SOUTHWESTERN CORNER OF THE CARIBBEAN SEA TO THE SOUTH OF 12N TO THE WEST OF 75W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...AND THE OFFSHORE FORECAST...MIAOFFNT3/FZNT23 KNHC...FOR MORE DETAILS ABOUT...NORTHEAST TO EAST WINDS 20 TO 30 KNOTS AND SEA HEIGHTS 8 TO 12 FEET FROM 11N TO 14N BETWEEN 73W AND 78W. EXPECT NORTHEAST TO EAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS TO 9 FEET ELSEWHERE FROM 12N TO 17N BETWEEN 68W AND 77W. EXPECT ALSO WINDS 20 KNOTS OR LESS AND SEA HEIGHTS TO 9 FEET FOR THE REMAINDER OF THE AREA FROM 10N TO 17N BETWEEN 64W AND 82W. ...THE ATLANTIC OCEAN... A CENTRAL ATLANTIC OCEAN MIDDLE LEVEL TO UPPER LEVEL TROUGH PASSES THROUGH 32N51W TO 27N54W 23N56W AND 20N63W. THE TROUGH SUPPORTS A FRONTAL BOUNDARY THAT BEGINS WITH A COLD FRONT THAT PASSES THROUGH 32N45W TO 29N52W AND 27N66W. THE FRONT BECOMES STATIONARY AND IT CONTINUES FROM 27N66W TO ABACO ISLAND IN THE BAHAMAS. A SURFACE TROUGH IS WITHIN 200 NM TO THE SOUTHEAST OF THE FRONTAL BOUNDARY...BETWEEN 52W AND 75W. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE RAINSHOWERS ARE TO THE NORTH AND NORTHWEST OF THE LINE THAT PASSES THROUGH 32N40W TO 26N50W TO 22N73W. A SURFACE RIDGE EXTENDS FROM A 1034 MB HIGH PRESSURE CENTER THAT IS NEAR 37N18W TO 34N34W AND 32N42W. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...FOR MORE DETAILS ABOUT...NORTHEAST TO EAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS 10 TO 13 FEET FROM 13N TO 17N TO THE EAST OF 36W. EXPECT NORTHEAST TO EAST WINDS 20 TO 25 KNOTS AND SEA HEIGHTS 8 TO 10 FEET TO THE SOUTH OF 21N BETWEEN 63W AND 68W AND BETWEEN 72W AND 75W...INCLUDING APPROACHES TO THE WINDWARD PASSAGE. EXPECT ALSO WINDS 20 KNOTS OR LESS AND SEA HEIGHTS 8 TO 11 FEET ELSEWHERE TO THE EAST OF THE BAHAMAS TO THE SOUTH OF THE LINE FROM 31N39W TO 23N52W TO 23N73W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ MT