000 AXNT20 KNHC 281801 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST MON DEC 28 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 COLD FRONT IS OVER THE GULF OF MEXICO FROM 30N89W TO 24N91W TO 18.5N95W. NORTHWEST GALE-FORCE WINDS ARE NORTHWEST OF THE FRONT S OF 20N W OF 95W WITH SEAS TO 10 FT. PLEASE READ THE HIGH SEAS FORECAST...MIAHSFAT2/FZNT02 KNHC... AND THE OFFSHORE FORECAST...MIAOFFNT4/FZNT24 KNHC...FOR MORE DETAILS. A STRONG PRESSURE GRADIENT EXISTS BETWEEN LOWER PRESSURE ACROSS NORTHWESTERN SOUTH AMERICA AND HIGH PRESSURE OVER THE W ATLANTIC. GALE FORCE WINDS ARE FORECAST TO START AGAIN ALONG THE COAST OF N COLOMBIA 0N 30/0300 UTC FROM 11N-12N BETWEEN 73W-76W WITH SEAS TO 14 FT. 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 EQUATOR AND THE PRIME MERIDIAN TO 01N07W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 01N07W TO 0N14W TO 04S30W TO THE COAST OF SOUTH AMERICA AT 04S39W. SCATTERED SHOWERS ARE WITHIN 90 NM OF THE AXIS. ...DISCUSSION... GULF OF MEXICO... A COLD FRONT IS OVER THE GULF OF MEXICO FROM S MISSISSIPPI AT 30N89W TO 24N91W TO THE BAY OF CAMPECHE AT 18.5N95W. A GALE IS OVER THE BAY OF CAMPECHE. SEE ABOVE. EAST OF FRONT...15-25 KT SW RETURN FLOW REMAINS OVER THE E GULF OF MEXICO WITH MOSTLY FAIR WEATHER. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS OVER THE WESTERN GULF W OF 90W SUPPORTING THE SURFACE FRONT. AN UPPER LEVEL RIDGE IS OVER THE EASTERN GULF. THE GULF OF MEXICO HAS MOSTLY STRONG SUBSIDENCE. EXPECT IN 24 HOURS FOR THE COLD FRONT TO EXTEND FROM THE FLORIDA PANHANDLE TO THE BAY OF CAMPECHE WITH SCATTERED SHOWERS. CARIBBEAN SEA... 15-30 KT TRADEWINDS ARE OVER THE CARIBBEAN SEA WITH STRONGEST WINDS ALONG THE COAST OF N COLOMBIA. A GALE IS FORECAST TO START AGAIN ON 30/03Z. SEE ABOVE. RADAR IMAGERY SHOWS SCATTERED SHOWERS OVER PUERTO RICO. SIMILAR LOW LEVEL TRADEWIND SHOWERS ARE OVER THE WINDWARD AND LEEWARD ISLANDS...HISPANIOLA...AND CENTRAL AMERICA FROM PANAMA TO BELIZE. IN THE UPPER LEVELS...AN UPPER LEVEL RIDGE IS OVER THE WESTERN CARIBBEAN W OF 75W. AN UPPER LEVEL TROUGH IS OVER THE EASTERN CARIBBEAN. STRONG SUBSIDENCE COVERS THE ENTIRE CARIBBEAN SEA. EXPECT OVER THE NEXT 24 HOURS FOR ADDITIONAL SHOWERS TO ADVECT OVER THE SE CARIBBEAN. ...HISPANIOLA... PRESENTLY SHOWERS ARE OVER CENTRAL HISPANIOLA. STRONG SUBSIDENCE IS SUPPRESSING THUNDERSTORM FORMATION. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... HIGH PRESSURE RIDGING IS OVER THE WESTERN ATLANTIC. A COLD FRONT IS OVER THE EASTERN ATLANTIC FROM 31N24W TO 29N30W TO 31N39W. SCATTERED SHOWERS ARE WITHIN 90 NM OF THE FRONT. A 1028 MB HIGH IS OVER THE EASTERN ATLANTIC NEAR 27N29W. A SURFACE TROUGH IS OVER THE E ATLANTIC FROM 30N12W ACROSS THE CANARY ISLANDS TO 27N15W. SCATTERED SHOWERS ARE WITHIN 90 NM OF THE TROUGH. EXPECT OVER THE NEXT 24 HOURS FOR COLD FRONT TO MOVE NE OF THE AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORMOSA