000 AXNT20 KNHC 190002 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST THU NOV 18 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N15W 5N24W 6N37W 5N48W 6N56W. AN EMBEDDED SURFACE TROUGH IS ALONG 11N36W TO 3N37W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 3N-11N BETWEEN 25W-34W. SCATTERED MODERATE/STRONG CONVECTION IS FROM 6N-11N BETWEEN 37W-48W. NUMEROUS STRONG CONVECTION IS INLAND OVER NE SOUTH AMERICA FROM 2N-6N BETWEEN 51W-59W. ...DISCUSSION... THE GULF OF MEXICO... A DEEP LAYER TROUGH SITUATED OVER THE FAR ERN CONUS CONTINUES TO SUPPORT A PAIR OF COLD FRONTS ACROSS THE GULF OF MEXICO. THE PRIMARY FRONTAL BOUNDARY EXTENDS FROM THE SE COAST OF FLORIDA NEAR 25N80W THROUGH THE STRAITS OF FLORIDA AND INTO THE NRN YUCATAN PENINSULA NEAR 20N90W. SCATTERED SHOWERS ARE WITHIN 60 NM BEHIND THE FRONT AND WITHIN 150 NM AHEAD OF THE FRONT. A SECOND AND WEAKER FRONTAL BOUNDARY EXTENDS FROM A WEAK 1020 MB LOW OVER MOBILE ALABAMA ALONG 27N91W 24N96W 20N97W FOLLOWING A WELL DEFINED ROPE CLOUD EVIDENT IN VISIBLE SATELLITE IMAGERY. ISOLATED SHOWERS ARE AHEAD OF THE FRONT IN THE BAY OF CAMPECHE FROM 19N-24N BETWEEN 93W-97W. THE REMAINDER OF THE BASIN IS EXPERIENCING FAIR CONDITIONS UNDER THE INFLUENCE OF DRY AIR AROUND AN UPPER LEVEL RIDGE COVERING THE CARIBBEAN AND W ATLC...ALONG WITH A SHORTWAVE UPPER RIDGE BUILDING ACROSS TEXAS. EXPECT THE PRIMARY FRONT TO MOVE OUT OF THE AREA OVER THE NEXT SEVERAL HOURS...WHILE THE SECONDARY BOUNDARY BEGINS TO WEAKEN AS THE UPPER TROUGH SUPPORTING IT MOVES AHEAD OF IT TO THE E. THE CARIBBEAN SEA... A BROAD AREA OF LOW PRESSURE COVERS THE NW CARIBBEAN CENTERED AROUND A 1014 MB LOW N OF HONDURAS NEAR 17N87W. A SURFACE TROUGH EXTENDS THROUGH THE LOW CENTER FROM S OF WRN CUBA NEAR 21N85W TO 14N85W. SURFACE CONVERGENCE NEAR THE LOW AND TROUGH ALONG WITH THE APPROACHING FRONTAL BOUNDARY TO THE N IS ENHANCING STRONG SHOWERS/THUNDERSTORMS NEAR THE CENTER FROM 17N-19N BETWEEN 85W-86W...AND SCATTERED SHOWERS/THUNDERSTORMS FROM 15N-22N BETWEEN 80W-90W. AN UPPER LEVEL RIDGE CENTERED N OF HISPANIOLA IS ADVECTING DRY AIR ACROSS THE CENTRAL CARIBBEAN MAINTAINING FAIR CONDITIONS ACROSS THIS PORTION OF THE BASIN. ANOTHER SURFACE TROUGH IS IMPACTING THE ERN CARIBBEAN FROM NEAR DOMINICA AT 16N61W TO NRN VENEZUELA NEAR 9N65W. SCATTERED SHOWERS/THUNDERSTORMS ARE S OF 14N BETWEEN 64W-72W...WITH ISOLATED SHOWERS S OF 15N BETWEEN 60W-64W. EXPECT SHOWER ACTIVITY TO CONTINUE IN THE NW CARIBBEAN AS THE LOW PRESSURE SYSTEM MOVES WWD. SHOWER ACTIVITY IS ALSO LIKELY IN THE SE AND S CENTRAL CARIBBEAN AS MOISTURE ASSOCIATED WITH THE SURFACE TROUGH DRIFTS W. THE ATLANTIC OCEAN... AN UPPER LEVEL TROUGH ACROSS THE FAR ERN CONUS SUPPORTS A COLD FRONT ENTERING THE DISCUSSION AREA NEAR 32N64W CONTINUING ALONG 29N71W 28N77W TO S FLORIDA NEAR 25N80W. SCATTERED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE FRONT...AND WITHIN 150 NM AHEAD OF THE FRONT W OF 78W. AN UPPER LEVEL RIDGE EXTENDING FROM THE CENTRAL CARIBBEAN IS MAINTAINING FAIR CONDITIONS ELSEWHERE ACROSS THE W ATLC. FARTHER E...A NARROW UPPER LEVEL TROUGH ALONG 44W IS SUPPORTING A SURFACE LOW NEAR 25N48W WITH A SURFACE TROUGH EXTENDING FROM THE CENTER TO NEAR 17N50W. SCATTERED SHOWERS ARE E OF THE LOW CENTER FROM 23N-28N BETWEEN 43W-46W. UPPER LEVEL DIFFLUENCE TO THE E SIDE OF THE UPPER TROUGH IS SUPPORTING AN AREA OF CLOUDS WITH POSSIBLE SHOWERS BETWEEN 35W-45W...AND IS ALSO ENHANCING CONVECTION ALONG THE ITCZ. AN UPPER LEVEL RIDGE COVERS THE ERN ATLC SUPPORTING A SURFACE RIDGE ANCHORED BY A 1019 MB HIGH W OF THE CANARY ISLANDS NEAR 29N26W WHICH IS PROVIDING FAIR WEATHER ACROSS THE FAR E ATLC. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON