000 AXNT20 KNHC 211106 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 83W S OF 19N MOVING W 10 KT. WAVE CONTINUES TO WEAKEN AS IT MOVES TOWARD CENTRAL AMERICA. ANY ACTIVITY IS ASSOCIATED WITH UPPER LEVEL DIFFLUENT PATTERN. TROPICAL WAVE IS ALONG 96W S OF 21N MOVING W 10 KT. WAVE IS MOSTLY IN THE E PACIFIC REGION WITH ONLY SOME WIDELY ISOLATED LOW LEVEL SHOWERS OVER THE W BAY OF CAMPECHE. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 6N7W 4N18W 6N32W 4N45W 5N55W. SMALL CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 120 NM ALONG THE ITCZ AXIS FROM 8W-30W WITH LARGER CLUSTERS FROM THE EQUATOR TO THE COAST OF SW AFRICA E OF 3W ACROSS THE PRIME MERIDIAN. A BROAD AREA OF SCATTERED SHOWERS IS N OF THE ITCZ FROM 10N-15N BETWEEN 25W-43W WITH A SURFACE TROUGH EXTENDING FROM 8N42W TO 15N40W BUT IS PRODUCED BY UPPER LEVEL DIFFLUENCE. DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE COVERS THE ENTIRE 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 1023 MB HIGH IN THE W ATLC. PATCHES OF LOW LEVEL CLOUDS WITH ISOLATED SHOWERS DOTS THE E GULF WITH A LINE OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 45 NM OF 25N90W TO INLAND OVER THE N GULF COAST NEAR ALABAMA/MISSISSIPPI BORDER. 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 AN UPPER RIDGE AXIS FROM COLOMBIA NW ACROSS THE NE YUCATAN PENINSULA COVERING THE ENTIRE CARIBBEAN. THE UPPER DIFFLUENCE CONTINUES TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER THE W CARIBBEAN FROM 11N-16N W OF 81W TO INLAND OVER NICARAGUA AND HONDURAS. THE ITCZ AXIS EXTENDS ACROSS SOUTH AMERICA...PANAMA...AND COSTA RICA INTO THE E PACIFIC REGION ENHANCING NUMEROUS SHOWERS/SCATTERED THUNDERSTORMS S OF 12N E OF 77W TO INLAND OVER PANAMA AND COSTA RICA. A FAST MOVING COLD FRONT EXTENDS FROM THE CENTRAL ATLC N OF PUERTO RICO TO ALONG THE N COAST OF HISPANIOLA TO THE WINDWARD PASSAGE GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS N OF 15N TO OVER THE GREATER ANTILLES AND THE VIRGIN/LEEWARD ISLANDS E OF 78W WHILE THE REMAINDER OF CARIBBEAN IS UNDER BROKEN TO OVER HIGH CLOUDS. ATLANTIC OCEAN... AN UPPER TROUGH EXTENDS FROM THE CENTRAL ATLC ACROSS THE W ATLC N OF 18N W OF 48W TO THE FLORIDA E COAST WITH THE ASSOCIATED COLD FRONT EXTENDING THROUGH 32N50W ALONG 24N54W N OF PUERTO RICO NEAR 19N67W ALONG THE N COAST OF HISPANIOLA TO THE WINDWARD PASSAGE. A WEAK JET STREAM WITH WINDS ESTIMATED TO BE 80 TO 90 KT EXTENDS FROM JUST N OF THE GREATER ANTILLES NEAR 20N70W TO 24N54W COMBINING WITH A STRONGER NORTHERN JET WITH WINDS ESTIMATED TO BE 80 TO 110 KT EXTENDING THROUGH 32N65W ALONG 26N53W TO 32N45W. A WIDENING UPPER RIDGE AXIS EXTENDS FROM THE TROPICS NEAR 20N37W N TO BEYOND 32N41W PROVIDING UPPER LEVEL DIFFLUENCE AND COUPLED WITH THE COLD FRONT ARE GENERATING NUMEROUS SHOWERS/SCATTERED THUNDERSTORMS WITHIN 180 NM E OF THE FRONT N OF 28N AND SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 120 NM OF LINE FROM 23N48W TO 30N42W. SIMILAR ACTIVITY IS W OF THE COLD FRONT N OF 30N TO 58W. A SURFACE RIDGE COVERS THE W ATLC INTO THE GULF OF MEXICO W OF 65W ANCHORED BY A 1023 MB HIGH IN THE W ATLC NEAR 31N78W. BROAD UPPER TROUGH COVERS THE REMAINDER OF THE NE ATLC N OF 27N E OF 30W WITH A REMNANT STATIONARY FRONT N OF THE REGION. A WEAK 1019 MB HIGH IS LOCATED NW OF THE CAPE VERDE ISLANDS NEAR 23N33W. WESTERLY NEAR ZONAL UPPER LEVEL FLOW DOMINATES THE TROPICS ENHANCING THE ACTIVITY IN THE ITCZ SECTION ABOVE. $$ WALLACE