000 AXNT20 KNHC 162340 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST WED NOV 16 2011 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... A TROPICAL WAVE EXTENDS FROM 15N43W TO 4N45W MOVING WNW AT 10-15 KT. THE WAVE LIES JUST W OF A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. AN UPPER LEVEL TROUGH EXTENDING FROM THE CENTRAL ATLC TO THE LESSER ANTILLES IS PLACING DIFFLUENCE ALOFT OVER THE AREA BETWEEN 37W-60W...INCLUDING THE WAVE. THIS MAKES IT DIFFICULT TO DISCERN WHETHER CONVECTION NEAR THE WAVE IS ASSOCIATED DIRECTLY WITH THE WAVE OR THE UPPER LEVEL PATTERN. REGARDLESS OF THE INFLUENCE...SCATTERED MODERATE/STRONG CONVECTION IS FROM 7N-13N BETWEEN 40W-48W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA ENTERING OVER ATLC WATERS NEAR 12N16W TO 9N19W. THE ITCZ CONTINUES FROM 9N19W ALONG 5N28W 7N40W PICKING UP ON THE OTHER SIDE OF THE TROPICAL WAVE ALONG 6N46W TO 9N57W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 5N-9N BETWEEN 19W-32W. SIMILAR ACTIVITY IS FROM 5N-8N BETWEEN 34W-39W. ...DISCUSSION... THE GULF OF MEXICO... A FAST MOVING SQUALL LINE IS CONTINUING TO IMPACT THE SE CONUS AND NE GULF OF MEXICO THIS EVENING EXTENDING FROM THE FLORIDA PANHANDLE NEAR PANAMA CITY TO 28N88W. THE REMAINDER OF THE BASIN IS STILL UNDER THE INFLUENCE OF WEAK SURFACE RIDGING EXTENDING FROM THE W ATLC AND DRY AIR ALOFT WHICH ARE MAINTAINING FAIR CONDITIONS. SURFACE SE-S WINDS OF 10-15 KTS ARE AROUND THE RIDGE WITH STRONGER WINDS LIKELY NEAR THE SQUALL LINE. ALOFT...MAINLY SWLY FLOW DOMINATES AROUND AN UPPER LEVEL RIDGE OVER THE WRN ATLC AND WRN CARIBBEAN. AN UPPER LEVEL TROUGH MOVING INTO THE CENTRAL CONUS WILL SUPPORT A COLD FRONT THAT IS EXPECTED TO ENTER THE GULF WITHIN THE NEXT 24 HOURS AND MOVE QUICKLY EWD BEFORE ANOTHER SURFACE RIDGE BUILDS LATE IN THE WEEK AND INTO THE WEEKEND. THE CARIBBEAN SEA... DRY AIR AND SUBSIDENCE COVER MUCH OF THE CARIBBEAN THIS EVENING AROUND AN UPPER LEVEL RIDGE CENTERED OVER THE BAHAMAS HELPING MAINTAIN FAIR CONDITIONS BASIN-WIDE. A FEW ISOLATED SHOWERS ARE NOTED OVER PORTIONS OF HISPANIOLA...JAMAICA...AND ERN CUBA. SCATTERED SHOWERS/THUNDERSTORMS ARE ALSO OVER PANAMA...COSTA RICA...NICARAGUA AND HONDURAS. SOME OF THIS ACTIVITY IS ASSOCIATED WITH THE MONSOON TROUGH THAT EXTENDS ACROSS NRN COSTA RICA TO NRN COLOMBIA. AT THE SURFACE...TRADEWIND FLOW OF 15-20 KTS COVERS MUCH OF THE BASIN. EXPECT SHOWER ACTIVITY TO REMAIN NEAR THE MONSOON TROUGH AND ACROSS CENTRAL AMERICA WITH POSSIBLE SHOWERS ALSO OVER THE WINDWARD ISLANDS ASSOCIATED WITH AN AREA OF MOISTURE CURRENTLY TO THE E OF THE ISLANDS. THE ATLANTIC OCEAN... THE WRN ATLC IS EXPERIENCING MOSTLY FAIR WEATHER AROUND A SURFACE RIDGE EXTENDING FROM A 1025 MB HIGH NEAR 35N42W WITH AXIS EXTENDING TOWARD S FLORIDA. ALOFT...AN UPPER LEVEL RIDGE IS CENTERED OVER THE BAHAMAS ACCOMPANIED BY DRY AIR WHICH IS HELPING MAINTAIN THE FAIR CONDITIONS. FARTHER E...A SHARP UPPER TROUGH EXTENDS FROM NEAR 32N46W TO THE LESSER ANTILLES. UPPER LEVEL DIFFLUENCE AROUND THE E SIDE OF THE TROUGH IS HELPING SUPPORT A BROAD AREA OF SHOWERS/THUNDERSTORMS FROM N OF THE ITCZ TO 20N BETWEEN 40W-60W...AND N OF 20N BETWEEN 40W-50W. SOME OF THE ACTIVITY IS ALSO ENHANCED BY A SURFACE TROUGH EXTENDING FROM 27N47W TO 18N49W...A SECOND SURFACE TROUGH E OF THE WINDWARD ISLANDS ALONG 14N58W TO 8N59W...AND A TROPICAL WAVE ALONG 15N43W TO 4N45W. THE ERN ATLC IS COVERED BY AN UPPER LEVEL RIDGE CENTERED NEAR 8N25W MAINTAINING MOSTLY FAIR WEATHER. A SHORTWAVE UPPER TROUGH N OF THE DISCUSSION AREA BETWEEN THE AZORES ISLANDS AND THE CANARY ISLANDS IS SUPPORTING A COLD FRONT ALONG 32N16W TO 28N23W WITH ISOLATED SHOWERS ALONG THE AXIS. EXPECT SHOWERS/POSSIBLE THUNDERSTORMS TO REMAIN ACROSS THE CENTRAL ATLC FOR THE NEXT SEVERAL DAYS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON