000 AXNT20 KNHC 131751 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST TUE NOV 13 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 74W/75W S OF 17N MOVING W NEAR 20 KT. LATEST MIMIC TPW ANIMATION FROM CIMSS SHOWS THAT THE TROPICAL WAVE IS MOVING QUICKLY WWD AND COULD BE MERGING WITH THE CLOUDINESS OVER THE SW CARIBBEAN. SCATTERED SHOWERS ARE NOTED ON THE NORTHERN END OF THE WAVE...BUT THEY APPEAR TO BE ASSOCIATED WITH THE REMNANTS OF AN OLD FRONTAL BOUNDARY LINGERING OVER THE CENTRAL CARIBBEAN ALONG 16N. ISOLATED WEAKENING SHOWERS ARE OVER NORTHERN COLOMBIA. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 8N13W 6N25W 7N40W 4N54W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 200-2440 NM N OF AXIS BETWEEN 24W-30W. SCATTERED MODERATE CONVECTION IS ALSO 220 NM N OF AXIS BETWEEN 38W-43W. DISCUSSION... GULF OF MEXICO... MORE OF THE SAME...A 1024 MB HIGH PRES SYSTEM LOCATED OVER SOUTHERN GEORGIA EXTENDS A RIDGE OVER THE MAJORITY OF THE GULF. UNDER THE INFLUENCE OF THIS FEATURE...MOSTLY FAIR WEATHER AND LIGHT TO MODERATE WINDS PREVAIL. PATCHES OF LOW/MID CLOUDS WITH EMBEDDED LIGHT SHOWERS ARE OVER THE BAY OF CAMPECHE AND THE NW PORTION OF THE GULF. THE LAST ONES ARE ASSOCIATED WITH THE SE RETURN FLOW AROUND THE HIGH. ALOFT...BROAD UPPER RIDGE EXTENDS FROM THE W CARIBBEAN ACROSS THE YUCATAN PENINSULA/CHANNEL INTO THE GULF WHERE UPPER LEVEL WINDS ARE NEARLY ZONAL. ABUNDANT MID/UPPER DRY AIR DOMINATES THE REGION S OF 26N WHILE MOISTURE IS ON INCREASE ACROSS THE N GULF WATERS MAINLY DUE TO A SHORT WAVE TROUGH MOVING ACROSS THE LOWER MISSISSIPPI VALLEY. HIGH PRES WILL REMAIN IN CONTROL OF THE WEATHER PATTERN ACROSS THE GULF DURING THE NEXT 24 HOURS. THE NEXT COLD FRONT IS FORECAST TO MOVE ACROSS THE AREA ON THURSDAY WITH AN INCREASE IN WINDS AND SEAS. CARIBBEAN SEA... THE AREA OF LOW PRES THAT WAS YESTERDAY NEAR THE EAST COAST OF SOUTHERN NICARAGUA MOVED INLAND AND DISSIPATED. PART OF THE ENERGY ASSOCIATED WITH THIS SYSTEM APPEARS TO BE MOVING ACROSS THE EPAC NEAR 10N92W WHERE SAT IMAGERY SHOWS ISOLATED SHOWERS AND TSTMS. CLUSTERS OF MODERATE/ISOLATED STRONG CONVECTION PERSIST OVER PARTS OF THE SW AND WESTERN CARIBBEAN. A DIFFLUENT PATTERN ALOFT...AND PROBABLY A TROPICAL WAVE ARE ENHANCING THIS CONVECTIVE ACTIVITY. A SFC TROUGH IS ANALYZED FROM 20N86W THROUGH HONDURAS INTO THE EPAC. THE TROUGH ITSELF IS GENERATING SCATTERED SHOWERS/ISOLATED TSTMS OVER THE NW CARIBBEAN. THE TROUGH...REMNANTS OF AN OLD FRONTAL BOUNDARY THAT WAS NORTH OF HISPANIOLA DURING THE PREVIOUS DAYS IS NOW AFFECTING THE EASTERN TIP OF DOMINICAN REPUBLIC...PUERTO RICO AND THE UK/US VIRGIN ISLANDS. THE SAN JUAN DOPPLER RADAR DEPICTS A BAND OF SHOWERS WITH EMBEDDED TSTMS APPROACHING THOSE ISLANDS. THE BASE OF AN UPPER-LEVEL TROUGH OVER THE W-CENTRAL ATLC IS SUPPORTING THIS ACTIVITY. ATLANTIC OCEAN... BROAD UPPER TROUGH COVERS THE W-CENTRAL ATLC WITH THE BASE OF THE TROUGH CURRENTLY N OF PUERTO RICO. THE ASSOCIATED COLD FRONT CLIPS THE FORECAST AREA NEAR 31N46W...THEN CONTINUES AS A SURFACE TROUGH TO JUST N OF PUERTO RICO AND THE EASTERN TIP OF DOMINICAN REPUBLIC. COMPUTER MODELS SUGGEST THE DEVELOPMENT OF A SFC LOW ALONG THIS TROUGH/OLD FRONTAL BOUNDARY OVER THE CENTRAL ATLC WHICH IS FORECAST TO MOVE QUICKLY NE. SHOWERS AND TSTMS ARE WITHIN 50 NM EITHER SIDE OF THE TROUGH PARTICULARLY E OF 55 W. PATCHES OF LOW/MID CLOUDS WITH ISOLATED SHOWERS ARE APPROACHING THE BAHAMAS. PART OF THIS ACTIVITY IS ALSO MOVING ONSHORE ACROSS E-CENTRAL FLORIDA REACHING THE LAKE OCKEECHOBEE. A SFC RIDGE ANCHORED BY A 1024 MB HIGH NEAR 34N65W COVERS THE WEST-CENTRAL ATLC...JUST BEHIND THE ABOVE MENTIONED SFC TROUGH. ANOTHER SFC RIDGE DOMINATES THE E ATLC WITH A 1020 MB HIGH NEAR 27N29W. IN THE UPPER LEVELS...A TROUGH/RIDGE/TROUGH PATTERN DOMINATES THE FORECAST AREA. $$ GR