000 AXNT20 KNHC 171737 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST WED NOV 17 2010 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 10N14W 9N20W 8N30W 6N38W 5N50W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE WITHIN 60 NM OF THE ITCZ BETWEEN 34W-37W. CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION ARE WITHIN 120/150 NM EITHER SIDE OF THE ITCZ BETWEEN 26W-39W AND WITHIN 120 NM N OF THE ITCZ BETWEEN 44W-49W. SMALL CLUSTERS OF SIMILAR CONVECTION ARE FROM 3N-6N BETWEEN 10W-16W. ...DISCUSSION... GULF OF MEXICO... THE BROAD UPPER TROUGH CONTINUES TO MOVE NE WHILE THE UPPER RIDGE ANCHORED IN THE CARIBBEAN IS LEAVING THE GULF WATERS WITH UPPER LEVEL WSW FLOW. THE TAIL END OF THE COLD FRONT IS MOVING ACROSS THE GULF FROM TAMPA BAY NEAR 27N83W EXTENDING TO 24N88W BECOMING STATIONARY AND DISSIPATING FROM 22N92W TO THE COAST OF MEXICO NEAR VERA CRUZ. NOT MUCH SHOWER ACTIVITY IS ASSOCIATED WITH THIS FRONT. A SURFACE RIDGE IS BUILDING BEHIND THE FRONT ANCHORED BY WEAK SURFACE HIGHS OVER ALABAMA CAUSING MAINLY RETURN FLOW OVER THE NORTHERN GULF BEHIND THE FRONT. MODERATE/ STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT COVERS THE GULF GIVING THE ENTIRE AREA FAIR WEATHER THIS AFTERNOON. THIS FRONT WILL MOVE SE OF THE AREA BY EARLY THURSDAY AS A SECOND FRONT IS EXPECTED TO MOVE INTO THE NW GULF LATER TONIGHT. CARIBBEAN SEA... A SURFACE TROUGH EXTENDS FROM 19N83W THROUGH AN 1012 MB LOW NEAR 15N81W TO 13N79W GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 120 NM NE OF THE SURFACE TROUGH N OF THE LOW CENTER. A BROAD UPPER RIDGE COVERS THE ENTIRE CARIBBEAN ANCHORED BETWEEN HISPANIOLA AND JAMAICA NEAR 17N75W AND EXTENDS INTO THE W ATLC PROVIDING DIFFLUENCE ALOFT TO ENHANCE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 120/150 NM OF A LINE FROM 19N78W TO THE COAST OF COLOMBIA NEAR 11N74W. E CARIBBEAN IS UNDER STRONG SUBSIDENCE AND DRY STABLE AIR E OF 72W GIVING THE AREA MOSTLY CLEAR SKIES. A SURFACE TROUGH E OF THE LESSER ANTILLES IS GENERATING LOW LEVEL SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS OVER THE SE CARIBBEAN SE OF A LINE FROM GUADALUPE TO THE ABC ISLANDS. EXPECT SHOWERS/ THUNDERSTORMS ASSOCIATED WITH THE LOW/TROUGH TO CONTINUE OVER THE CENTRAL CARIBBEAN FOR THE NEXT DAY OR SO AND AN INCREASE IN SHOWERS/THUNDERSTORMS OVER THE E CARIBBEAN AS THE SURFACE TROUGH MOVES ACROSS THE LESSER ANTILLES. ATLANTIC OCEAN... AN UPPER TROUGH HAS MOVED INTO THE NW ATLANTIC SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N78W ACROSS FLORIDA INTO THE GULF OF MEXICO NEAR DAYTONA BEACH. THE UPPER RIDGE ANCHORED IN THE CARIBBEAN COVERS THE W ATLC BETWEEN 60W-70W WITH A SURFACE RIDGE N OF 30N BETWEEN 55W-70W. STRONG SUBSIDENCE AND DRY STABLE AIR ALOFT COVER THE W ATLC W OF 50W GIVING THE AREA FAIR WEATHER THIS AFTERNOON. AN ELONGATED DEEP LAYERED LOW IS OVER THE CENTRAL ATLC WITH THE UPPER LOW CENTERED N OF THE REGION AND THE UPPER TROUGH EXTENDING S TO 16N BETWEEN 40W-55W. THIS UPPER SYSTEM IS SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM A 1011 MB SURFACE LOW NEAR 29N50W ALONG 25N52W TO 24N57W WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 150/200 NM OF LINE FROM 21N47W TO BEYOND 32N41W. A BROAD UPPER RIDGE COVERS THE E ATLC ENHANCING THE ACTIVITY DESCRIBED ABOVE. A SURFACE RIDGE COVERS THE E ATLC N OF 18N E OF 40W ANCHORED BY A WEAK 1022 MB HIGH W OF THE CANARY ISLANDS NEAR 29N23W. A SURFACE TROUGH IS IN THE W TROPICAL ATLC EXTENDING FROM 17N56W TO INLAND OVER SOUTH AMERICA NEAR 7N59W GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 13N W OF 53W ACROSS THE LESSER ANTILLES INTO THE SE CARIBBEAN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ SMM/PAW