000 AXNT20 KNHC 230604 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST SAT NOV 23 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... GALE FORCE WINDS ARE FORECAST TO INITIATE BY 24/0600 UTC IN ASSOCIATION WITH A COLD FRONT PROGRESSING SOUTHEASTWARD CURRENTLY OFF THE TEXAS AND LOUISIANA COASTS INTO THE NW GULF OF MEXICO. NW TO N WINDS OF 30 TO 35 KT ARE EXPECTED IN WAKE OF THE COLD FRONT S OF 25N W OF THE FRONT. SEE LATEST NHC HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 09N13W TO 03N22W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N22W TO 02N35W TO 04N47W. A CLUSTER OF MODERATE/ISOLATED STRONG CONVECTION IS FROM 03N-07N E OF 12W. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 01N- 08N BETWEEN 16W-26W. JUST WEST OF THE ITCZ AXIS...A SURFACE TROUGH IS ANALYZED FROM 11N52W TO 05N51W WITH ISOLATED SHOWERS WITHIN 240 NM EITHER SIDE OF THE AXIS. ...DISCUSSION... GULF OF MEXICO... SOUTHWEST TO WESTERLY UPPER-LEVEL FLOW DOMINATES OVER THE GULF THIS EVENING BETWEEN A MIDDLE TO UPPER LEVEL RIDGE ANCHORED OVER NICARAGUA NEAR 11N85W AND A MIDDLE TO UPPER LEVEL LOW CENTERED OFF THE COAST OF BAJA CALIFORNIA NEAR 33N118W. A BROAD MIDDLE TO UPPER LEVEL TROUGH WITH BASE ALONG THE MIDDLE MISSISSIPPI AND OHIO VALLEY EXTENDS A WEAK AXIS SW TO GENERATE A WEAKNESS ON THE RIDGE ANCHORED OVER NICARAGUA. THIS TROUGHINESS ALOFT IS SUPPORTING A FRONTAL SYSTEM ANALYZED AS A COLD FRONT FROM SOUTHERN LOUISIANA NEAR 29N92W SW TO EASTERN MEXICO NEAR 23N97W. LOW-LEVEL MOISTURE CONVERGENCE ALONG THE FRONTAL BOUNDARY AS WELL AS UPPER-LEVEL DIVERGENCE ARE SUPPORTING HEAVY SHOWERS AND TSTMS IN THE NW GULF W OF A LINE FROM 28N91W TO 22N97W. ISOLATED SHOWERS AND TSTMS ARE ALSO NOTED FROM 22N-23N BETWEEN 92W-96W AND IN THE BAY OF CAMPECHE S OF 20N E OF 92W. THE REMAINDER BASIN IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1024 MB HIGH CENTERED OVER THE WESTERN ATLC NEAR 33N67W. EASTERLY FLOW GENERALLY IN THE RANGE OF 10 TO 15 KT PRECEDES THE COLD FRONT WHICH IS EXPECTED TO SWEEP ACROSS THE GULF THROUGH THE WEEKEND WITH STRONG N-NE WINDS PERSISTING THROUGH LATE SUNDAY. A GALE IS EXPECTED TO DEVELOP ASSOCIATED WITH THIS FRONT. SEE SPECIAL FEATURE SECTION FOR MORE DETAILS. CARIBBEAN SEA... AN UPPER-LEVEL RIDGE ANCHORED OVER NICARAGUA NEAR 11N85W IS PROVIDING THE BASIN WITH NORTHWESTERLY FLOW ALOFT. WATER VAPOR IMAGERY INDICATE THAT EXCEPT FOR THE NW CARIBBEAN...THIS FLOW REMAINS DRY AND STABLE WHICH IS RESULTING IN MOSTLY FAIR CONDITIONS AT THE SURFACE TONIGHT. AT THE SURFACE IN THE NW BASIN...E-NE FLOW IN THE RANGE OF 10-15 KT IS BANKING LOW-LEVEL MOISTURE TO THE COASTLINES OF THE YUCATAN PENINSULA...BELIZE AND HONDURAS TO GENERATE SHOWERS AND ISOLATED TSTMS S OF 21N W OF 83W. FARTHER EAST...JUST SOUTH OF HISPANIOLA...LOW-LEVEL MOISTURE CONVERGENCE ALONG WITH MIDDLE-LEVEL DIFFLUENCE IS GENERATING AN AREA OF ISOLATED SHOWERS AND TSTMS OCCURRING N OF 16N BETWEEN 67W-75W. A FEW AREAS OF ISOLATED LOW-TOPPED SHOWERS ARE OCCURRING ACROSS THE VIRGIN AND LEEWARD ISLANDS. TRADES ARE FORECAST TO REMAIN 20 KT OR LESS THROUGH THE WEEKEND. ...HISPANIOLA... FAIR WEATHER CONTINUE TO DOMINATE TONIGHT WITH POSSIBLE ISOLATED SHOWERS NEAR THE SOUTHERN COASTLINE DUE TO A REGION OF LOW-LEVEL MOISTURE CONVERGENCE AND MIDDLE-LEVEL DIFFLUENCE JUST S OF THE ISLAND. WATER VAPOR IMAGERY DEPICT DRY AND STABLE NORTHWESTERLY FLOW ALOFT WHICH IS EXPECTED TO PERSIST THROUGHOUT THE REST OF THE WEEKEND. ATLANTIC OCEAN... A DEEP LAYERED LOW IS CENTERED OVER THE CENTRAL NORTH ATLC WELL NORTH OF THE DISCUSSION AREA NEAR 47N47W WHICH EXTENDS A TROUGH AXIS SW TO NE OF THE LEEWARD ISLANDS TO SUPPORT A SURFACE TROUGH BOUNDARY ANALYZED FROM 26N46W SW TO 24N54W WHERE IT BECOMES A SHEAR LINE TO 22N66W TO THE UPPER FLORIDA KEYS NEAR 24N80W. ISOLATED SHOWERS AND TSTMS ARE OCCURRING FROM 23N-31N BETWEEN 45W-53W. ISOLATED SHOWERS ARE ALSO NOTED FROM 23N-26N BETWEEN 72W-76W. THE UPPER-LEVEL TROUGH ALSO SUPPORTS A STATIONARY FRONT ANALYZED FROM 31N37W SW TO 22N46W. SCATTERED SHOWERS ASSOCIATED WITH THIS FRONTAL BOUNDARY ARE N OF 23N BETWEEN 37W-42W. THE REMAINDER OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1024 MB HIGH CENTERED NEAR 33N67W PROVIDING THE BRISK NORTHEASTERLY WINDS BETWEEN THE RIDGE AXIS AND THE SHEAR LINE AS NOTED ON EARLIER SCATTEROMETER PASSES. THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1018 MB HIGH CENTERED WEST OF THE CANARY ISLANDS NEAR 28N24W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS