000 AXNT20 KNHC 171142 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST SUN FEB 17 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. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 03N22W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N22W TO THE EQUATOR NEAR 29W. SCATTERED MODERATE CONVECTION IS FROM THE EQUATOR TO 03N BETWEEN THE PRIME MERIDIAN AND 04W. ...DISCUSSION... GULF OF MEXICO... A BROAD MIDDLE TO UPPER LEVEL TROUGH COVERS THE EASTERN CONUS AND FAR WESTERN NORTH ATLC THAT SUPPORTS A STRONG COLD FRONT ANALYZED FROM THE FLORIDA STRAITS NEAR 23N80W TO THE NORTHERN YUCATAN PENINSULA NEAR 21N87W THEN TO 20N93W IN THE SW GULF. WHILE THE FRONT REMAINS PRECIPITATION FREE...SATELLITE IMAGERY SHOWS STRATOCUMULUS CLOUDINESS COVERS MUCH OF THE EASTERN GULF AND SOUTH-CENTRAL GULF E OF 90W AND FROM 20N-26N BETWEEN 90W-93W. LOW-LEVEL OVERCAST SKIES ARE ALSO EVIDENT SW OF A LINE FROM 25N98W TO 19N93W IN THE SW GULF. ELSEWHERE SKIES REMAIN MOSTLY CLEAR OVER NW PORTIONS OF THE BASIN AS A STRONG SURFACE RIDGE BUILDS IN ACROSS THE BASIN. A 1030 MB HIGH IS CENTERED NEAR 27N94W AND EXTENDS A RIDGE AXIS N-NE TO NORTHERN MISSISSIPPI AND S-SW ALONG THE CENTRAL AND SOUTHERN MEXICO COAST. NORTHERLY WINDS IN THE RANGE OF 10 TO 20 KT WILL PERSIST THROUGH THE MORNING HOURS SUNDAY E OF 90W AND WILL SLIDE EASTWARD INTO THE SW NORTH ATLC REGION LATE SUNDAY AS THE HIGH SHIFTS EASTWARD AS WELL. THEREAFTER...SOUTHERLY RETURN FLOW IS EXPECTED TO RE-ESTABLISH ITSELF OVER THE WESTERN GULF W OF 92W AS AN AREA OF LOW PRESSURE DEVELOPS OVER THE CENTRAL U.S. PLAINS. CARIBBEAN SEA... A STRONG MIDDLE TO UPPER LEVEL TROUGH IS OVER THE SW NORTH ATLC REGION THAT SUPPORTS THREE BOUNDARIES EXTENDING INTO THE NW CARIBBEAN. THE MAIN FEATURE OF THE THREE BOUNDARIES IS A COLD FRONT ANALYZED FROM WESTERN CUBA NEAR 23N81W TO THE NORTHERN YUCATAN PENINSULA NEAR 21N89W. WHILE THIS FRONT REMAINS RELATIVELY PRECIPITATION-FREE...STRONG NORTHERLY WINDS IN THE RANGE OF 15 TO 25 KT ARE EXPECTED TO FILTER SOUTHEASTWARD AS THE FRONT MOVES EASTWARD AND TRANSITIONS INTO A SHEAR LINES BY EARLY MONDAY ACROSS THE CENTRAL CARIBBEAN. TO THE SOUTHEAST OF THE COLD FRONT...A REMNANT FRONT...ANALYZED AS A DISSIPATING STATIONARY FRONT IS NOTED FROM CENTRAL CUBA NEAR 22N79W TO 16N85W. ISOLATED SHOWERS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE FRONT. FINALLY...A PRE-FRONTAL SURFACE TROUGH IS ANALYZED FROM EASTERN CUBA NEAR 20N76W TO 16N80W WITH LOW-LEVEL CONVERGENCE PROVIDING FOCUS FOR ISOLATED SHOWERS WITHIN 150 NM EAST OF THE SURFACE TROUGH AXIS. ELSEWHERE...THE REMAINDER OF THE CENTRAL AND EASTERN CARIBBEAN ARE UNDER THE INFLUENCE OF A MIDDLE TO UPPER LEVEL RIDGE. WATER VAPOR IMAGERY INDICATES THAT VERY DRY AIR AND STRONG SUBSIDENCE PERSISTS E OF 75W PROVIDING FOR OVERALL FAIR CONDITIONS. A FEW ISOLATED SHOWERS ARE HOWEVER ADVECTING FROM THE TROPICAL ATLC ACROSS THE EASTERN CARIBBEAN E OF 73W. ATLANTIC OCEAN... A BROAD MIDDLE TO UPPER LEVEL TROUGH OVER THE EASTERN CONUS AND FAR WESTERN NORTH ATLC IS SUPPORTING A PAIR OF BOUNDARIES ACROSS THE SW NORTH ATLC. THE PRIMARY BOUNDARY IS ANALYZED AS A COLD FRONT INTO THE DISCUSSION AREA NEAR 32N72W TO THE NW BAHAMAS NEAR 25N77W AND INTO THE NW CARIBBEAN SEA VIA WESTERN CUBA NEAR 23N81W. THE FRONT REMAINS FAIRLY PRECIPITATION-FREE...HOWEVER IS FORECAST TO SWEEP RAPIDLY ACROSS THE SW NORTH ATLC THROUGH THE DAY ON SUNDAY. THIS FRONT IS CURRENTLY USHERING IN STRONG W-NW WINDS TO GALE FORCE N OF 28N WEST OF THE FRONT. THE OTHER BOUNDARY IS A PRE-FRONTAL SURFACE TROUGH ANALYZED FROM 32N68W TO THE SE BAHAMAS NEAR 23N74W AND INTO THE WESTERN CARIBBEAN VIA EASTERN CUBA NEAR 20N76W. ISOLATED SHOWERS ARE OCCURRING WITHIN 150 NM EITHER SIDE OF THE SURFACE TROUGH AXIS. OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A BROAD SURFACE RIDGE ANCHORED BY A 1025 MB HIGH CENTERED NEAR 30N41W. THE ONLY WEAKNESS LOCATED WITHIN THE RIDGING IS A DISSIPATING COLD FRONT ANALYZED INTO THE DISCUSSION AREA NEAR 32N18W SW TO 27N33W. ISOLATED SHOWERS ARE OCCURRING WITHIN 75 NM EITHER SIDE OF THE FRONT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN