000 AXNT20 KNHC 210532 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST WED NOV 21 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 0445 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 82W S OF 19N MOVING W 10-15 KT. WAVE CONTINUES TO WEAKEN AS IT MOVES OVER THE W CARIBBEAN. ANY ACTIVITY IS ASSOCIATED WITH UPPER LEVEL DIFFLUENT PATTERN. TROPICAL WAVE IS ALONG 95W S OF 21N MOVING W 10 KT. WAVE IS MOSTLY IN THE E PACIFIC REGION WITH ONLY SOME ISOLATED LOW LEVEL SHOWERS OVER THE W BAY OF CAMPECHE. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 6N9W 4N22W 7N38W 3N53W. SMALL CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 45 NM ALONG THE ITCZ AXIS FROM 9W-24W. A BROAD AREA OF SCATTERED MODERATE CONVECTION IS N OF THE ITCZ FROM 7N-13N BETWEEN 26W AND A SURFACE TROUGH LOCATED FROM 13N39W TO 5N41W AND IS PRODUCED BY UPPER LEVEL DIFFLUENCE. DISCUSSION... GULF OF MEXICO... UPPER LEVEL LOW IS CENTERED OVER NW MEXICO COVERING MOST OF MEXICO INTO TEXAS. BROAD UPPER RIDGE COVERS THE GULF EXTENDING FROM THE CARIBBEAN OVER THE NE YUCATAN PENINSULA GAINING AMPLITUDE TO OVER THE E US ALONG THE MISSISSIPPI VALLEY. A SURFACE RIDGE REMAINS OVER THE GULF ANCHORED BY A 1022 MB HIGH OVER GEORGIA AND A 1024 MB HIGH INT HE W ATLC. PATCHES OF LOW LEVEL CLOUDS WITH WIDELY ISOLATED SHOWERS DOTS THE SE GULF AND THE N GULF N OF 28N FROM ALABAMA TO CENTRAL LOUISIANA. THE NEXT COLD FRONT IS STILL 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 ACROSS THE NE YUCATAN PENINSULA COVERING THE ENTIRE CARIBBEAN. THE UPPER DIFFLUENCE CONTINUES TO GENERATE NUMEROUS SHOWERS/ISOLATED THUNDERSTORMS OVER THE W CARIBBEAN S OF 17N BETWEEN 80W-88W INCLUDING CENTRAL AMERICA. THE ITCZ AXIS EXTENDS ACROSS SOUTH AMERICA AND PANAMA INTO THE E PACIFIC REGION ENHANCING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 10N E OF 80W TO INLAND OVER PANAMA AND COLOMBIA. A FAST MOVING COLD FRONT EXTENDS FROM THE CENTRAL ATLC JUST N OF PUERTO RICO ALONG THE N COAST OF HISPANIOLA TO E CUBA GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 15N TO OVER THE GREATER ANTILLES AND THE VIRGIN/LEEWARD ISLANDS E OF 78W WHILE THE CENTRAL CARIBBEAN IS UNDER MOSTLY HIGH CLOUDS. THE FAR E CARIBBEAN REMAINS RATHER CLEAR AGAIN TONIGHT. ATLANTIC OCEAN... AN UPPER TROUGH EXTENDS FROM THE CENTRAL ATLC ACROSS THE W ATLC N OF 20N W OF 50W OVER THE FLORIDA PENINSULA WITH THE ASSOCIATED FAST MOVING COLD FRONT EXTENDING THROUGH 32N53W ALONG 27N54W N OF PUERTO RICO NEAR 20N67W TO E CUBA MOVING E AT 20 TO 25 KT. A JET STREAM WITH WINDS ESTIMATED TO BE 80 TO 120 KT EXTENDING FROM THE TURKS AND CAICOS TO 25N58W COMBINING WITH A NORTHERN JET EXTENDING THROUGH 32N65W CONTINUING TO 31N48W. NARROW UPPER RIDGE AXIS EXTENDS FROM THE TROPICS NEAR 20N43W N TO BEYOND 32N47W PROVIDING UPPER LEVEL DIFFLUENCE AND COUPLED WITH THE FAST MOVING COLD FRONT ARE GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 180 NM E OF THE FRONT N OF 23N AND FROM 23N-28N BETWEEN 42W-48W. SIMILAR ACTIVITY IS BETWEEN THE COLD FRONT AND A SECONDARY BOUNDARY TO THE W THAT EXTENDS THROUGH 32N58W TO 28N60W. A SURFACE RIDGE COVERS THE W ATLC INTO THE GULF OF MEXICO W OF 65W ANCHORED BY A 1022 MB HIGH OVER GEORGIA AND A 1024 MB HIGH INT HE W ATLC. BROAD UPPER TROUGH COVERS THE REMAINDER OF THE NE ATLC N OF 27N E OF 37W WITH A REMNANT STATIONARY FRONT N OF THE REGION. A WEAK 1019 MB HIGH IS LOCATED NW OF THE CAPE VERDE ISLANDS NEAR 21N32W. WESTERLY NEAR ZONAL UPPER LEVEL FLOW DOMINATES THE TROPICS ENHANCING THE ACTIVITY IN THE ITCZ SECTION ABOVE. $$ WALLACE