000 AXNT20 KNHC 061039 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST WED NOV 06 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 1015 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 12N16W TO 8N17W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 6N28W 7N35W 5N41W TO 5N50W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 6N-13N BETWEEN 30W- 36W AND WITHIN 180/200 NM S OF THE ITCZ BETWEEN 25W-43W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LOW IS MOVING ACROSS THE SE GULF JUST N OF THE YUCATAN PENINSULA NEAR 23N88W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 22N-26N BETWEEN 84W-89W. ISOLATED SHOWERS DOT THE REMAINDER OF THE AREA S OF 27N E OF 90W. A BROAD UPPER RIDGE EXTENDS FROM NE FLORIDA ACROSS THE MISSISSIPPI VALLEY TO OVER THE W GULF TO MEXICO NEAR TAMPICO. A SURFACE RIDGE DOMINATES THE N GULF ANCHORED OFF THE CANADIAN MARITIMES AND VIRGINIA. THIS IS GIVING THE REMINDER OF THE GULF TRANQUIL WEATHER THIS MORNING. A STRONG PRESSURE GRADIENT EXISTS BETWEEN THE LOWER PRESSURE ACROSS THE CARIBBEAN AND THIS SURFACE RIDGE GENERATING NE WINDS 20 TO 25 KT ACROSS MOST OF THE E GULF. THE STRONG PRESSURE GRADIENT WILL RELAX TODAY AHEAD OF A COLD FRONT EXPECTED TO MOVE INTO THE NW GULF EARLY TONIGHT REACHING FROM THE FLORIDA PANHANDLE TO W BAY OF CAMPECHE THU AND FROM CENTRAL FLORIDA TO CENTRAL BAY OF CAMPECHE FRI. GALES ARE EXPECTED TO SPREAD S ACROSS OFFSHORE MEXICAN WATERS IN THE W AND SW GULF BEHIND FRONT BY THU AFTERNOON AND SPREAD S INTO THE W BAY OF CAMPECHE THROUGH FRI BEFORE BECOMING DIFFUSE SAT. CARIBBEAN SEA... A BROAD UPPER RIDGE COVERS THE CARIBBEAN ANCHORED NEAR 19N81W GIVING THE W CARIBBEAN S FLOW ALOFT. A SURFACE TROUGH IS BENEATH THIS UPPER RIDGE EXTENDING FROM 21N84W ALONG 19N85W TO THE COAST OF HONDURAS NEAR 16N85W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 90 NM OF LINE FROM THE GULF OF HONDURAS NEAR 16N87W TO THE COAST OF W CUBA NEAR 22N84W. AN UPPER TROUGH OVER THE CENTRAL CARIBBEAN EXTENDS TO A WEAK UPPER LOW N OF THE MONA PASSAGE CONTINUING TO HISPANIOLA NEAR 19N73W. SATELLITE WATER VAPOR IMAGERY SHOWS DRY STABLE AIR N OF THIS UPPER TROUGH. THE PERSISTENT BROAD 1008 MB LOW IS NOW A SURFACE TROUGH THAT EXTENDS FROM THE CAYMAN ISLANDS SE TO 16N77W WITH CLUSTERS OF ISOLATED SHOWERS/THUNDERSTORMS N OF 15N E OF THE SURFACE TROUGH TO THE LESSER ANTILLES INCLUDING THE VIRGIN ISLANDS...PUERTO RICO...SW HAITI...AND W CUBA. THIS ACTIVITY IS BEING ENHANCED BY THE UPPER RIDGE AND AN UPPER TROUGH THAT EXTENDS FROM THE CENTRAL ATLC TO OVER HISPANIOLA. THE SURFACE TROUGH EXTENDING FROM THE CAYMAN ISLANDS TO S OF JAMAICA WILL LINGER ACROSS THE W CARIBBEAN THROUGH FRI. HISPANIOLA... CURRENTLY ISOLATED SHOWERS/THUNDERSTORMS DOT SW HAITI WHILE THE REMAINDER OF THE ISLAND IS UNDER CLEAR SKIES THIS MORNING SUE TO THE DRY AIR N OF THE UPPER TROUGH AXIS THAT EXTENDS FROM THE CENTRAL ATLC TO OVER HISPANIOLA. ABUNDANCE OF LOW LEVEL MOISTURE WILL REMAIN OVER THE S PORTION OF THE ISLAND THROUGH TODAY CONTINUING SHOWERS/THUNDERSTORMS. THU THROUGH SUN THESE SHOWERS/THUNDERSTORMS WILL BECOMING LESS SEVERE. AS USUAL AFTERNOON SHOWERS REMAIN A POSSIBILITY THROUGH THE WEEKEND. ATLANTIC OCEAN... THE UPPER RIDGE OVER THE W GULF OF MEXICO COVERS THE W ATLC WITH AN UPPER AXIS EXTENDING FROM NE FLORIDA TO BERMUDA. A SURFACE RIDGE COVERS THE AREA ANCHORED BY A 1036 MB LOW OVER THE CANADIAN MARITIMES AND A 1032 MB HIGH OVER VIRGINIA. THIS IS PRODUCING A STRONG PRESSURE GRADIENT BETWEEN THIS RIDGE AND THE LOWER PRESSURE OVER THE CARIBBEAN GENERATING NE WINDS 20 TO 25 KT W OF 70W. A NARROW UPPER TROUGH EXTENDS INTO THE CENTRAL ATLC NEAR 32N56W ALONG 25N62W TO A WEAK UPPER LOW N OF THE MONA PASSAGE CONTINUING TO HISPANIOLA NEAR 19N73W SUPPORTING A STATIONARY FRONT THAT IS ANALYZED THROUGH 32N46W ALONG 30N56W TO 28N60W TO 25N67W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 175 NM OF LINE FROM 20N60W TO BEYOND 32N49W. A SURFACE TROUGH EXTENDS FROM 27N69W TO 22N69W. THE E ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1023 MB HIGH NE OF THE MADEIRA ISLANDS. AN UPPER TROUGH IS IN THE TROPICAL ATLC EXTENDING FROM AN UPPER LOW NEAR 23N47W TO 10N52W SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 19N52W TO 14N55W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 120 NM OF LINE FROM 13N39W 20N38W TO 23N45W WITH ISOLATED SHOWERS WITHIN 75 NM W OF THE SURFACE TROUGH. STRONG WINDS OVER THE W ATLC WILL BEGIN TO DIMINISH AND VEER MORE EASTERLY LATE TONIGHT THROUGH THU AS THE SURFACE RIDGE SHIFTS E TO N/CENTRAL ATLC. A COLD FRONT WILL MOVE SE OFF THE SE CONUS COAST ON THU AND REACH FROM BERMUDA TO CENTRAL FLORIDA LATE FRI. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW