000 AXNT20 KNHC 121743 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST THU FEB 12 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 EXTENDS SOUTHWARD FROM A DEEP LOW PRESSURE SYSTEM OVER THE NW ATLANTIC TO 31N50W AND SOUTHWESTWARD TO THE LEEWARD ISLANDS. STRONG WINDS AHEAD OF THE FRONT ARE REACHING GALE FORCE E OF THE FRONT N OF 29N AND W OF 48W. SEAS OF 13 TO 21 FT CAN BE EXPECTED. THIS AREA OF GALE FORCE WINDS WILL CONTINUE TO TRANSLATE EASTWARD UNTIL 00Z WHEN WINDS ARE FORECAST TO DECREASE BELOW GALE FORCE. 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 10N14W TO 03N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N19W TO 01N30W TO 04N43W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION ARE FROM 01N-08N BETWEEN 11W-16W. ISOLATED MODERATE CONVECTION IS FROM 02S-06N BETWEEN 21W-42W. ...DISCUSSION... GULF OF MEXICO... SOUTHWESTERLY FLOW ALOFT IS OCCURRING OVER THE GULF TO THE SOUTH OF AN UPPER TROUGH THAT EXTENDS FROM TX TO THE TENNESSEE VALLEY. THIS TROUGH SUPPORTS LOW PRESSURE OVER THE SOUTHERN APPALACHIANS WITH A COLD FRONT EXTENDING FROM THE LOW TO THE FL PANHANDLE NEAR 31N85W TO 28N90W TO THE TX COAST NEAR 26N97W. NORTHERLY WINDS OF 15 TO 20 KT ARE N OF THE FRONT. N TO NE WINDS OF 10 TO 15 KT ARE S OF THE FRONT. FAIR WEATHER AND SUBSIDENCE COVER THE ENTIRE GULF BASIN. THE NORTHERN HALF OF THE BASIN IS CLOUD FREE WITH PATCHES OF STRATOCUMULUS OVER THE SOUTHERN HALF OF THE BASIN. OVER THE NEXT 24 HOURS THE COLD FRONT WILL MOVE SE ACROSS THE EASTERN GULF. HIGH PRESSURE WILL BUILD SE ACROSS THE GULF BEHIND THE FRONT WITH FAIR WEATHER EXPECTED TO CONTINUE ACROSS THE BASIN INTO SATURDAY. CARIBBEAN SEA... A STORM SYSTEM OVER THE NW ATLANTIC SUPPORTS A COLD FRONT THAT EXTENDS S ACROSS THE CENTRAL ATLANTIC TO THE LEEWARD ISLANDS NEAR 17N62W AND ACROSS THE EASTERN CARIBBEAN TO 17N71W. SCATTERED SHOWERS ARE POSSIBLE WITHIN 100 NM OF EITHER SIDE OF THE COLD FRONT. SOUTHERLY FLOW OF 10 TO 15 KT ARE S OF THE FRONT OVER THE EASTERN CARIBBEAN. VARIABLE WINDS OF 5 TO 10 KT ARE OVER THE CENTRAL CARIBBEAN. N TO NE WINDS OF 10 TO 15 KT COVER THE WESTERN CARIBBEAN. OVER THE NEXT 24 HOURS THE FRONT OVER THE CARIBBEAN WILL DISSIPATE. ...HISPANIOLA... ISOLATED SHOWERS ARE POSSIBLE THIS AFTERNOON OVER THE HIGHER TERRAIN OF HISPANIOLA AS LOW LEVEL MOISTURE IN NORTHERLY FLOW PASSES OVER THE ISLAND. FAIR WEATHER IS EXPECTED TONIGHT. ATLANTIC OCEAN... A 979 MB LOW CENTERED OVER THE NW ATLANTIC NEAR 41N57W SUPPORTS A COLD FRONT THAT EXTENDS ACROSS THE CENTRAL ATLANTIC TO 32N50W TO 22N55W TO 17N62W AND THEN OVER THE EASTERN CARIBBEAN. A DISSIPATING COLD FRONT FOLLOWS THE COLD FRONT TO THE WEST AND EXTENDS FROM 31N54W TO 25N58W TO 22N66W. SCATTERED SHOWERS ARE POSSIBLE WITHIN 100 NM OF EITHER SIDE OF THE EASTERNMOST COLD FRONT. GALE FORCE WINDS ARE OCCURRING N OF 29 N AHEAD OF THE COLD FRONT. SEE THE SPECIAL FEATURES SECTION FOR MORE DETAILS. FARTHER EAST...A WEAKENING SURFACE LOW OF 1017 MB IS NEAR 26N35W WITH A SURFACE TROUGH EXTENDING S OF THIS LOW TO 22N36W. NO DEEP CONVECTION IS NOTED WITH THE LOW AND SURFACE TROUGH. THE BASE OF AN UPPER TROUGH NEAR 22N32W IS SUPPORTING ISOLATED MODERATE CONVECTION FROM 20N TO 26N BETWEEN 28W AND 32W. OVER THE NEXT 24 HOURS A COLD FRONT WILL MOVE OFF THE SE US COAST INTO THE SW NORTHERN ATLANTIC. THE COLD FRONT OVER THE CENTRAL ATLANTIC WILL BEGIN TO DISSIPATE AND TRANSITION INTO A SURFACE TROUGH. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO