000 AXNT20 KNHC 130603 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST FRI DEC 13 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. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS ACROSS AFRICA INTO THE EAST TROPICAL ATLC NEAR 09N13W TO 07N17W. THE ITCZ AXIS EXTENDS FROM 07N17W TO 03N30W TO 0N46W. ISOLATED SHOWERS ARE WITHIN 100 NM EITHER SIDE OF THE AXES. ...DISCUSSION... GULF OF MEXICO... A BROAD MIDDLE TO UPPER LEVEL TROUGH WITH AXIS EXTENDING ALONG THE NORTHWESTERN ATLC SUPPORTS A FRONTAL SYSTEM ANALYZED AS A STATIONARY FRONT FROM THE FLORIDA STRAITS NEAR 23N81W TO THE YUCATAN CHANNEL NEAR 21N86W...REGION OF THE SE GULF WHERE RADAR IMAGERY SHOW ISOLATED SHOWERS. A 1033 MB HIGH CENTERED OVER WESTERN TENNESSEE NEAR 35N88W EXTENDS A RIDGE INTO THE GULF AND PROVIDES NORTHEASTERLY WIND FLOW UP TO 25 KT ACROSS THE BASIN. SSMI TPW IMAGERY DEPICT AN ARCTIC AIR MASS PUSHING INTO THE NE GULF AND ALSO VERY DRY AIR ACROSS THE REMAINDER BASIN WHICH IS SUPPORTING FAIR WEATHER. IN THE UPPER-LEVEL...SOUTHWESTERLY WIND FLOW ADVECTS MOISTURE FROM THE EPAC ITCZ REGION TO SUPPORT BROKEN TO OVERCAST SKIES ACROSS THE NORTHERN GULF N OF 26N W OF 87W. HIGH PRESSURE AND NORTHEASTERLY WIND FLOW ARE EXPECTED TO CONTINUE ACROSS THE GULF THROUGHOUT FRI MORNING. RETURN FLOW STARTS TO BUILD ACROSS THE GULF FRI AFTERNOON AS THE HIGH PRESSURE CENTER MOVES TO NW ATLC WATERS NEAR THE COAST OF NORTH CAROLINA. THE PORTION OF THE FRONTAL BOUNDARY ACROSS THE SE GULF IS FORECAST TO DISSIPATE EARLY FRI. A NEW COLD FRONT IS FORECAST TO EMERGE ACROSS THE NW GULF SAT AFTERNOON. CARIBBEAN SEA... LOW-LEVEL MOISTURE CONVERGENCE IS ALONG THE COASTLINE FROM THE YUCATAN PENINSULA TO CENTRAL PANAMA TO SUPPORT SCATTERED MODERATE CONVECTION WITHIN 120 NM FROM THE COAST. OVER THE CENTRAL BASIN...A MIDDLE-LEVEL INVERTED TROUGH SUPPORTS A SURFACE TROUGH FROM THE WINDWARD PASSAGE NEAR 20N73W TO NORTHERN COLOMBIA NEAR 11N73W. ISOLATED SHOWERS ASSOCIATED WITH THE TROUGH ARE N OF 14N BETWEEN 71W-77W. ANOTHER SURFACE TROUGH APPEARS TO BE S OF PUERTO RICO WHICH IS GENERATING SHOWERS S OF 17N BETWEEN 61W-68W. ACROSS THE REMAINDER BASIN DRY AIR SUBSIDENCE FROM THE MIDDLE LEVELS DOMINATE TO SUPPORT FAIR WEATHER. OTHERWISE...A RELATIVELY TIGHT PRESSURE GRADIENT OVER THE CENTRAL-EASTERN BASIN SUPPORTS 20-25 KT WINDS EXPECTED TO PERSIST THROUGHOUT SAT MORNING. HISPANIOLA... AN INVERTED TROUGH AT THE MIDDLE-LEVEL OVER THE CENTRAL CARIBBEAN SUPPORTS A SURFACE TROUGH EXTENDING ACROSS THE WINDWARD PASSAGE NEAR 20N73W TO NORTHERN COLOMBIA NEAR 11N73W. ISOLATED SHOWERS ASSOCIATED WITH THE TROUGH ARE N OF 14N BETWEEN 71W-77W. ISOLATED SHOWERS COULD BE EXTENDING TO HAITI AS THE TROUGH SLOWLY DRIFTS WESTWARD TONIGHT. OTHERWISE...FAIR WEATHER IS FORECAST THROUGHOUT SAT AFTERNOON. ATLANTIC OCEAN... A BROAD MIDDLE TO UPPER LEVEL TROUGH WITH AXIS EXTENDING ALONG THE NORTHWESTERN ATLC SUPPORTS A FRONTAL SYSTEM ANALYZED AS A COLD FRONT FROM 30N64W SW TO 25N73W TO 23N81W. VERY DRY AIR ACROSS THE SW NORTH ATLC AND CENTRAL ATLC HINDERS CONVECTION AT THE TIME. FARTHER EAST OVER THE CENTRAL ATLC...A 1028 MB HIGH IS NEAR 29N40W WHICH IS EXPECTED TO DRIFT NE OVER THE NEXT 24 HOURS MAINTAINING FAIR WEATHER CONDITIONS ACROSS MOST OF THE ATLC. A WEAK SURFACE TROUGH IS FARTHER EAST ACROSS THE CANARY ISLANDS FROM 33N17W SE TO INLAND AFRICA NEAR 23N15W WITH NO CONVECTION ASSOCIATED WITH IT AT THE TIME. OTHERWISE...AN AREA OF SCATTERED SHOWERS IS LOCATED FROM 12N-18N E OF 37W...INCLUDING THE CAPE VERDE ISLANDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR