000 AXNT20 KNHC 131757 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU MAR 13 2014 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 FROM 32N71W SW TO THE SOUTHERN FLORIDA PENINSULA NEAR 27N80W AND INTO THE SE GULF OF MEXICO PRODUCING GALE FORCE SW WINDS N OF 30N EAST OF THE FRONT TO 61W. 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 06N10W TO 03N14W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N14W TO THE EQUATOR AT 20W. ISOLATED MODERATE CONVECTION IS S OF 03N BETWEEN 19W-39W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL SOUTHWESTERLY FLOW ALOFT IS NOTED ON WATER VAPOR IMAGERY OVER THE GULF THIS AFTERNOON BETWEEN AN UPPER LEVEL RIDGE OVER THE CARIBBEAN SEA AND A VIGOROUS UPPER LEVEL TROUGH MOVING EAST OFF THE EASTERN U.S. SEABOARD. THE TROUGHING SUPPORTS A COLD FRONT THAT EXTENDS ACROSS THE SW NORTH ATLC TO THE SOUTHERN FLORIDA PENINSULA AND INTO THE GULF NEAR 26N82W W- SW TO 24N90W THEN SW TO 20N94W. WHILE THE FRONT REMAINS RELATIVELY PRECIPITATION-FREE...THE MAIN IMPACT IS THE STRONGER WINDS ACROSS THE EASTERN GULF NORTH OF THE FRONT IN THE RANGE OF 15 TO 20 KT E OF 90W. AS THE FRONT CONTINUES EXITING THE BASIN TO THE SOUTH AND EAST...HIGH PRESSURE CURRENTLY ANCHORED ACROSS EASTERN TEXAS IS FORECAST TO SLIDE EASTWARD ALONG 30N/31N THROUGH EARLY FRIDAY WITH SOUTHERLY RETURN FLOW ONCE AGAIN RE- ESTABLISHING ITSELF ACROSS PORTIONS OF THE WESTERN AND CENTRAL GULF INTO THE UPCOMING WEEKEND. CARIBBEAN SEA... OVERALL CONDITIONS ACROSS THE CARIBBEAN THIS AFTERNOON REMAIN RELATIVELY TRANQUIL WITH THE EXCEPTION OF THE NW CARIBBEAN AS A PRE-FRONTAL SURFACE TROUGH EXTENDS FROM WESTERN CUBA NEAR 23N83W TO THE YUCATAN CHANNEL NEAR 21N86W TO THE GULF OF HONDURAS NEAR 17N88W. ISOLATED SHOWERS AND TSTMS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF A LINE FROM 23N81W TO CENTRAL GUATEMALA NEAR 15N90W. IN ADDITION...THE SURFACE TROUGH DENOTES THE INITIAL WIND SHIFT AND CHANGE IN AIR MASS THAT IS ANTICIPATED OVERNIGHT INTO FRIDAY. A COLD FRONT CURRENTLY ANALYZED ACROSS THE SE GULF OF MEXICO IS FORECAST TO MOVE ACROSS THE YUCATAN CHANNEL AND INTO THE NW CARIBBEAN EARLY FRIDAY. OTHERWISE...THE REMAINDER OF THE BASIN IS UNDER THE INFLUENCE OF A MIDDLE TO UPPER LEVEL RIDGE ANCHORED OVER THE SW CARIBBEAN NEAR 12N79W. WATER VAPOR IMAGERY INDICATES VERY DRY AIR WITH SUBSIDENCE PREVAILING GENERALLY S OF 20N E OF 83W. THE ONLY SIGNIFICANT AREA OF ISOLATED SHOWERS IS FOUND FROM 13N-17N BETWEEN 65W-70W IN WEAK LOW-LEVEL MOISTURE CONVERGENCE. FINALLY...TRADES ARE RELATIVELY WEAK ACROSS THE CARIBBEAN AS A FRONTAL BOUNDARY MOVES ACROSS THE SW NORTH ATLC REGION TO THE NORTH. ...HISPANIOLA... CURRENTLY MOSTLY CLEAR SKIES AND FAIR CONDITIONS ARE NOTED ON VISIBLE SATELLITE IMAGERY ACROSS THE ISLAND THIS AFTERNOON. HIGH PRESSURE REMAINS ANCHORED TO THE NORTHEAST ACROSS THE CENTRAL ATLC GENERATING LIGHT E-SE WINDS. A FRONTAL BOUNDARY IS LOCATED TO THE NORTH OF HISPANIOLA ACROSS THE SW NORTH ATLC WATERS AND IS FORECAST TO IMPACT THE ISLAND FRIDAY INTO SATURDAY WITH A HIGHER PROBABILITY OF PRECIPITATION AND STRONG NORTHEAST WINDS. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY OFF THE EASTERN U.S. SEABOARD SUPPORTING A FRONT EXTENDS FROM 32N372W SW TO THE SOUTHERN FLORIDA PENINSULA NEAR 27N80W. POSSIBLE ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE FRONT...HOWEVER MORE LIKELY PRECIPITATION IS OCCURRING IN ASSOCIATION WITH THE PRE-FRONTAL SURFACE TROUGH ANALYZED FROM 28N73W SW TO WESTERN CUBA NEAR 23N82W. ISOLATED SHOWERS AND TSTM ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE SURFACE TROUGH AXIS. FARTHER EAST...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1030 MB HIGH CENTERED NEAR 34N41W. A WEAKENING SURFACE TROUGH REMAINS EMBEDDED WITHIN THE SOUTHWESTERN PERIPHERY OF THE RIDGE ANALYZED FROM 27N47W SW TO 21N58W. POSSIBLE ISOLATED SHOWERS ARE FROM 20N-29N BETWEEN 45W-56W. FINALLY...ON THE EASTERN PERIPHERY OF THE RIDGING...A COLD FRONT EXTENDS INTO THE DISCUSSION AREA NEAR 32N30W THEN SW TO 28N34W. ISOLATED SHOWERS AND TSTMS ARE OCCURRING N OF 30N WITHIN 120 NM EAST OF THE FRONT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN