000 AXNT20 KNHC 200541 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST TUE NOV 20 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND THE 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 77W S OF 20N MOVING W 10-15 KT. WAVE CONTINUES TO WEAKEN AS IT MOVES INTO THE W CARIBBEAN. ANY ACTIVITY IS ASSOCIATED WITH UPPER LEVEL FEATURES. TROPICAL WAVE IS ALONG 91W/92W S OF 21N MOVING W NEAR 15 KT. WAVE IS MOSTLY IN THE E PACIFIC REGION WITH ONLY SOME WIDELY ISOLATED LOW LEVEL SHOWERS OVER THE BAY OF CAMPECHE. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 10N13W 6N27W 5N41W 4N53W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE OVER A BROAD AREA FROM 1N-13N BETWEEN 22W-40W AND IS PRODUCED BY UPPER LEVEL DIFFLUENCE. DISCUSSION... GULF OF MEXICO... UPPER LEVEL LOW IS N MEXICO INTO THE FAR W GULF FROM 20N-26N W OF 95W. A NARROW UPPER TROUGH EXTENDS ACROSS THE SE US FROM THE W ATLC TO E TEXAS NEAR HOUSTON. VERY BROAD UPPER RIDGE COVERS THE REMAINDER OF THE GULF EXTENDING FROM THE CARIBBEAN THROUGH THE YUCATAN CHANNEL TO 26N93W. A SURFACE RIDGE REMAINS OVER THE GULF ANCHORED OVER GEORGIA BY A PAIR OF 1025 MB HIGHS. PATCHES OF LOW LEVEL CLOUDS WITH WIDELY ISOLATED SHOWERS DOTS THE ENTIRE GULF. THE NEXT COLD FRONT IS EXPECTED TO ENTER THE GULF ON THU BRINGING SHOWER ACTIVITY AND GUSTY WINDS BEHIND THE FRONT AS IT TRANSVERSES THE GULF. CARIBBEAN SEA... THE BROAD UPPER RIDGE OVER THE GULF OF MEXICO EXTENDS FROM THE CARIBBEAN ANCHORED OVER SOUTH AMERICA EXTENDING A MEAN RIDGE AXIS FROM COLOMBIA THROUGH THE YUCATAN CHANNEL COVERING THE ENTIRE CARIBBEAN. THE UPPER DIFFLUENCE IS GENERATING SHOWERS/ SCATTERED THUNDERSTORMS OVER THE W CARIBBEAN FROM 11N-19N W OF 80W TO INLAND OVER CENTRAL AMERICA. THE ITCZ AXIS EXTENDS ACROSS SOUTH AMERICA AND PANAMA/COSTA RICA INTO THE E PACIFIC REGION GENERATING SIMILAR ACTIVITY S OF 11N W OF 79W. A SURFACE TROUGH IN THE CENTRAL ATLC EXTENDS ACROSS THE LEEWARD ISLANDS NEAR 17N62W TO THE DOMINICAN REPUBLIC NEAR 19N69W GENERATING SHOWERS/ ISOLATED THUNDERSTORMS N OF 16N TO OVER THE GREATER ANTILLES BETWEEN 63W-77W WHILE THE REMAINDER OF THE CARIBBEAN IS CLEAR TONIGHT. ATLANTIC OCEAN... TE NARROW UPPER TROUGH ACROSS THE N GULF OF MEXICO EXTENDS FROM THE W ATLC THROUGH 32N76W ACROSS N FLORIDA AND THE SE US. BROAD UPPER RIDGE COVERING THE GULF OF MEXICO AND THE CARIBBEAN EXTENDS OVER THE W ATLC INTO THE CENTRAL ATLC W OF 55W WITH A JET STREAM WITH WINDS OF 80 TO 120 KT EXTENDING FROM THE E FLORIDA COAST NEAR PALM BEACH ALONG 29N73W TO BEYOND 32N66W. A SURFACE RIDGE COVERS THE W ATLC INTO THE GULF OF MEXICO W OF 50W. BROAD UPPER TROUGH COVERS THE REMAINDER OF THE ATLC N OF 20N E OF 55W WITH A DISSIPATING FRONTAL BOUNDARY EXTENDS FROM 31N41W THROUGH A WEAK 1010 MB LOW NEAR 25N47W TO 20N55W WHERE IT CONTINUES AS A SURFACE TROUGH THROUGH THE LEEWARD ISLANDS NEAR 17N62W RE-EMERGE N OF THE DOMINICAN REPUBLIC TO THE TURKS AND CAICOS NEAR 21N71W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 20N BETWEEN 63W-71W WITH HEAVY SHOWERS/SCATTERED THUNDERSTORMS BETWEEN THE TURKS AND CAICOS THROUGH THE WINDWARD PASSAGE TO OVER HAITI AND E CUBA. A WEAK 1017 MB HIGH IS LOCATED NE OF THE CAPE VERDE ISLANDS NEAR 20N22W. WESTERLY NEAR ZONAL UPPER LEVEL FLOW DOMINATES THE TROPICS ENHANCING THE ACTIVITY IN THE ITCZ SECTION ABOVE. $$ WALLACE