000 AXNT20 KNHC 231801 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST WED DEC 23 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... THE SURFACE PRESSURE GRADIENT THAT IS BETWEEN AN ATLANTIC OCEAN HIGH PRESSURE CENTER AND A NORTHERN COLOMBIA LOW PRESSURE CENTER IS HELPING TO SUPPORT GALE-FORCE WINDS THAT ARE ALONG THE COAST OF COLOMBIA...FROM 11N TO 14N BETWEEN 73W AND 78W. EXPECT ALSO SEA HEIGHTS TO RANGE FROM 11 FEET TO 16 FEET. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC...AND THE OFFSHORE FORECAST...MIAOFFNT3/FZNT23 KNHC...FOR MORE DETAILS. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH IS ALONG 04N BETWEEN THE PRIME MERIDIAN AND 07W. THE ITCZ CONTINUES FROM 04N07W TO 04N20W 03N23W 04N26W AND 02N39W. CONVECTIVE PRECIPITATION...ISOLATED MODERATE FROM 02N TO 08N BETWEEN 22W AND 31W. RAINSHOWERS ARE POSSIBLE ELSEWHERE FROM 10N SOUTHWARD FROM 60W EASTWARD. ...DISCUSSION... ...THE GULF OF MEXICO... BROAD UPPER LEVEL SOUTHWESTERLY WIND FLOW AND BROKEN TO OVERCAST MULTILAYERED CLOUDS COVER THE GULF OF MEXICO. AN UPPER LEVEL TROUGH PASSES THROUGH EAST TEXAS...TO THE COASTAL PLAINS OF THE DEEP SOUTH OF TEXAS. A COLD FRONT PASSES THROUGH NORTH CENTRAL TEXAS TO SOUTH CENTRAL TEXAS. A BROAD SURFACE TROUGH EXTENDS FROM THE DEEP SOUTH OF TEXAS... TO THE MEXICO COAST NEAR 21N97W TO THE ISTHMUS OF TEHUANTEPEC OF SOUTHERN MEXICO NEAR 17N95W. ...FROM THE WESTERN SECTIONS OF THE ATLANTIC OCEAN...ACROSS THE BAHAMAS AND CUBA...INTO THE WESTERN SECTIONS OF THE CARIBBEAN SEA...INCLUDING CROSSING HISPANIOLA...AND THE REST OF THE CARIBBEAN SEA... AN UPPER LEVEL TROUGH EXTENDS FROM A CARIBBEAN SEA 17N70W CYCLONIC CIRCULATION CENTER TO 12N74W TO THE NICARAGUA/COSTA RICA BORDER. THE TROUGH ALSO EXTENDS FROM THE 17N70W CYCLONIC CENTER TO 22N70W JUST OFF THE SOUTHEASTERN BAHAMAS. UPPER LEVEL CYCLONIC WIND FLOW COVERS THE CARIBBEAN SEA BETWEEN A RIDGE THAT IS ON TOP OF THE EASTERN CARIBBEAN SEA ISLANDS AND THE LINE THAT RUNS FROM SOUTHEASTERN CUBA TO 18N83W TO NORTHWESTERN COASTAL HONDURAS. CONVECTIVE PRECIPITATION...RAINSHOWERS ARE POSSIBLE FROM 16N TO 18N BETWEEN 68W AND 71W. PRECIPITATION HAS BEEN DISSIPATING/WEAKENING FROM 10N TO 11N BETWEEN NORTHWESTERN COLOMBIA AND SOUTHEASTERN COASTAL NICARAGUA. THE 24-HOUR RAINFALL TOTAL IN INCHES FOR THE PERIOD ENDING AT 23/1200 UTC...ACCORDING TO THE PAN AMERICAN TEMPERATURE AND PRECIPITATION TABLES...MIATPTPAN/SXCA01 KNHC...IS 0.20 IN TRINIDAD...0.08 IN ST. THOMAS IN THE VIRGIN ISLANDS...AND 0.05 IN SAN JUAN IN PUERTO RICO. CURRENT OBSERVATIONS...FOR PORT-AU-PRINCE IN HAITI...FEW LOW LEVEL CLOUDS. FOR THE DOMINICAN REPUBLIC...FEW CUMULONIMBUS CLOUDS ARE IN BARAHONA. SCATTERED LOW LEVEL CLOUDS ARE IN SANTO DOMINGO...LA ROMANA...AND IN PUNTA CANA. SCATTERED LOW LEVEL CLOUDS ARE IN SANTIAGO AND IN PUERTO PLATA. THE GFS MODEL FORECAST FOR 250 MB SHOWS THAT THE CURRENT TROUGH WILL MOVE SOUTHEASTWARD DURING DAY ONE...BRINGING FIRST CYCLONIC WIND FLOW AND THEN NORTHERLY WIND FLOW TO HISPANIOLA DURING DAY ONE. THE TROUGH WILL TAKE ON AN EAST-TO-WEST ORIENTATION DURING DAY ONE INTO DAY TWO. EXPECT NORTHEASTERLY WIND FLOW DURING DAY TWO. THE GFS MODEL FORECAST FOR 500 MB SHOWS THAT AN ATLANTIC OCEAN ANTICYCLONIC CIRCULATION CENTER WILL BE FROM 600 NM TO 900 NM TO THE NORTHEAST OF HISPANIOLA. EASTERLY WIND FLOW WILL MOVE ACROSS HISPANIOLA DURING THE NEXT 48 HOURS. THE GFS MODEL FORECAST FOR 700 MB SHOWS THAT AN ATLANTIC OCEAN ANTICYCLONIC CIRCULATION CENTER WILL BE FROM 800 NM TO 1000 NM TO THE NORTHEAST OF HISPANIOLA. SOUTHEASTERLY WIND FLOW WILL MOVE ACROSS HISPANIOLA DURING THE NEXT 48 HOURS. ...THE REST OF THE ATLANTIC OCEAN... AN UPPER LEVEL TROUGH PASSES THROUGH THE MADEIRA ARCHIPELAGO TO 29N29W AND 26N41W. A STATIONARY FRONT PASSES THROUGH 32N23W TO 31N26W. CONVECTIVE PRECIPITATION...RAINSHOWERS ARE POSSIBLE WITHIN 120 NM TO THE NORTHWEST OF THE LINE THAT PASSES THROUGH 32N23W TO 30N27W. MIDDLE LEVEL TO UPPER LEVEL CYCLONIC WIND FLOW COVERS THE ATLANTIC OCEAN FROM TO 32N BETWEEN 24W AND 55W. THIS FEATURE IS SURROUNDED BY COMPARATIVELY DRIER AIR IN SUBSIDENCE THAT IS APPARENT IN WATER VAPOR IMAGERY. NO SIGNIFICANT DEEP LAYER CONVECTIVE PRECIPITATION IS APPARENT. A RIDGE IS ALONG 35N23W TO A 1036 MB HIGH PRESSURE CENTER THAT IS NEAR 34N43W...TO BERMUDA...26N75W...ACROSS THE WESTERN HALF OF CUBA...TO 19N84W IN THE NORTHWESTERN CORNER OF THE CARIBBEAN SEA. FOR ADDITIONAL INFORMATION PLEASE VISIT WWW.HURRICANES.GOV/MARINE $$ MT