000 AXNT20 KNHC 170553 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON MAR 17 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... A COLD FRONT EXTENDS FROM 30N90W S-SW TO 23N96W THEN S TO 20N97W. NORTHERLY GALE-FORCE WINDS ARE OCCURRING ACROSS PORTIONS OF THE WESTERN GULF OF MEXICO FROM 21N TO 26N WEST OF 95W. 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 07N11W TO 03N15W TO 03N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N19W TO 03N24W TO 01N30W TO THE EQUATOR NEAR 49W. SCATTERED MODERATE CONVECTION IS S OF 07N BETWEEN 01W-07W...AND WITHIN 45 NM EITHER SIDE OF A LINE FROM 08N13W TO 03N18W. ISOLATED MODERATE CONVECTION IS S OF 02N BETWEEN 32W-43W. ...DISCUSSION... GULF OF MEXICO... A POSITIVELY-TILTED MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM OVER THE MID-MISSISSIPPI RIVER VALLEY SW TO OVER TEXAS AND THEN TO A BASE OVER THE SOUTHERN GULF OF CALIFORNIA NEAR 23N108W. THIS TROUGHING SUPPORTS A 1002 MB LOW CENTERED OVER NORTHWESTERN ALABAMA WITH THE ASSOCIATED COLD FRONT EXTENDS S-SW TO THE GULF COAST NEAR 29N91W TO 23N96W THEN S TO 20N97W. MOSAIC DOPPLER RADAR AND LIGHTNING DATA INDICATE SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING WITHIN 120 NM EITHER SIDE OF THE FRONT N OF 22N. A PRE-FRONTAL SURFACE TROUGH IS ANALYZED FROM NORTHERN FLORIDA NEAR 30N82W TO 27N89W WITH WIDESPREAD SHOWERS AND SCATTERED TSTMS OCCURRING OVER THE NE GULF N OF 26N BETWEEN 82W-90W. THE LOW ACROSS ALABAMA IS FORECAST TO DRIFT EASTWARD AND STALL ACROSS GEORGIA MONDAY WHILE CYCLOGENESIS TAKES PLACE ALONG THE FRONTAL BOUNDARY IN THE EASTERN GULF...THEN RAPIDLY MOVES NORTHEAST IN THE SW NORTH ATLC BY EARLY TUESDAY. THE FRONTAL BOUNDARY ASSOCIATED WITH DEVELOPMENT IS EXPECTED TO CLEAR EAST OF THE BASIN BY TUESDAY MORNING INTO THE AFTERNOON HOURS. THEREAFTER...HIGH PRESSURE WILL BE ANCHORED ACROSS THE SOUTH- CENTRAL GULF WATERS AND GRADUALLY SHIFT NORTHEASTWARD THROUGH THE DAY ON TUESDAY INTO WEDNESDAY. CARIBBEAN SEA... GENERALLY DRY AND STABLE NORTHWEST TO WESTERLY FLOW ALOFT IS NOTED ON WATER VAPOR IMAGERY THIS EVENING OVER THE CARIBBEAN BASIN. THIS OVERALL PATTERN IS RESULTING IN VERY TRANQUIL CONDITIONS AT THE SURFACE WITH ONLY A COUPLE AREAS OF LOW-LEVEL MOISTURE AND POSSIBLE ISOLATED SHOWER ACTIVITY OCCURRING. ONE SUCH AREA IS ACROSS THE SE CARIBBEAN AND WINDWARD ISLANDS S OF 14N BETWEEN 58W-66W. THE OTHER AREA IS LOCATED IN THE VICINITY OF THE WINDWARD PASSAGE AND ACROSS PORTIONS OF WESTERN HISPANIOLA FROM 18N-21N BETWEEN 70W-75W. OTHERWISE...CLEAR SKIES AND FAVORABLE CONDITIONS PREVAIL ON EAST TO SOUTHEASTERLY TRADES RANGING FROM 15 TO 25 KT. THE AREAS OF 20 TO 25 KT WINDS ARE NOTED IN CLOSE PROXIMITY TO THE COAST OF COLOMBIA AND IN THE VICINITY OF THE GULF OF HONDURAS AHEAD OF A COLD FRONT MOVING ACROSS THE GULF OF MEXICO THIS EVENING. LOOKING AHEAD...THE AFOREMENTIONED COLD FRONT WILL ENTER THE NW CARIBBEAN BY LATE MONDAY VIA THE YUCATAN CHANNEL AND STALL FROM CENTRAL CUBA TO THE GULF OF HONDURAS BY TUESDAY. HISPANIOLA... LINGERING MOISTURE ASSOCIATED WITH A FORMER FRONTAL BOUNDARY CONTINUES TO SUPPORT BROKEN SKIES AND POSSIBLE ISOLATED SHOWERS ACROSS THE ISLAND THIS EVENING. HOWEVER...A MIDDLE TO UPPER LEVEL RIDGE WITH ASSOCIATED DRY AIR AND SUBSIDENCE HINDERS THE DEVELOPMENT OF ANY SIGNIFICANT DEEP CONVECTION AND WILL CONTINUE TO SUPPORT MOSTLY FAIR WEATHER ACROSS THE ISLAND FOR THE NEXT FEW DAYS. ATLANTIC OCEAN... WEST-NORTHWESTERLY UPPER LEVEL FLOW COUPLED WITH MID-LEVEL RIDGING IS PROVIDING FOR OVERALL STABLE CONDITIONS ACROSS THE SW NORTH ATLC S OF 30N THIS EVENING AHEAD OF AN UPPER LEVEL TROUGH NOTED ON WATER VAPOR IMAGERY OVER THE SOUTHERN U.S. PLAINS. MIDDLE TO UPPER LEVEL DIFFLUENCE AHEAD OF THE APPROACHING TROUGH IS GENERATING CLOUDINESS AND ISOLATED SHOWERS AND TSTMS FOCUSED ALONG A FRONTAL BOUNDARY TO THE NORTH ALONG 33N BETWEEN 76W TO THE SOUTH CAROLINA COAST NEAR 80W. THIS AREA OF CONVECTION FALLS WITHIN THE NORTHWESTERN PERIPHERY OF A SURFACE RIDGE WHERE MAXIMUM SOUTHERLY RETURN FLOW IS NOTED ACROSS THE SW NORTH ATLC. OTHERWISE...THE REMAINDER OF THE SW NORTH ATLC IS UNDER FAIR SKIES W OF 60W AS A SURFACE RIDGE AXIS EXTENDS FROM 32N57W SW TO THE BAHAMAS NEAR 25N78W. OVER THE CENTRAL ATLC...A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR IMAGERY IN THE VICINITY OF 30N53W THAT SUPPORTS A STATIONARY FRONT EXTENDING FROM 32N41W SW INTO A 1017 MB LOW CENTERED NEAR 28N48W TO 23N60W. LOW-LEVEL MOISTURE CONVERGENCE ALONG WITH MID-LEVEL LIFT DUE TO THE SHORTWAVE ARE GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS FROM 24N-31N BETWEEN 37W-55W...EMBEDDED WITHIN THE SURFACE RIDGING TO THE NORTHWEST AND TO THE EAST. FINALLY...THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE AXIS EXTENDING FROM NE OF THE AZORES NEAR 40N21W TO 20N40W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN