000 AXNT20 KNHC 231128 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST SUN NOV 23 2008 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS OVER THE E CARIBBEAN ALONG 68W/69W S OF 18N MOVING W NEAR 10 KT. SATELLITE IMAGERY INDICATES THAT THIS WAVE COINCIDES WITH AN INVERTED-V PATTERN IN CLOUD COVERAGE...WHERE WAVETRAK PRODUCT INDICATES A MAXIMUM IN LOW LEVEL CYCLONIC CIRCULATION. ADDITIONALLY...A MAXIMUM IN DEEP LAYER MOISTURE COINCIDES WITH THIS WAVE BASED ON TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. UPPER AIR TIME-HEIGHT ANALYSIS FOR CURACAO...LOCATED IN THE NETHERLANDS ANTILLES NEAR 12N69W... DEPICTS A RECENT AND SUBTLE VEERING OF THE MEAN LOW/MID-LEVEL FLOW FROM NE TO SE...SUGGESTING THAT THIS WAVE IS LIKELY IN THE VICINITY OF CURACAO. SCATTERED MODERATE CONVECTION IS OCCURRING WITHIN 150 NM EITHER SIDE OF THE WAVE AXIS S OF 16N. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 9N12W 7N24W 9N32W 8N44W 6N57W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-11N BETWEEN 14W-21W. SCATTERED MODERATE CONVECTION IS FROM 5N-12N BETWEEN 26W-39W. SCATTERED MODERATE CONVECTION IS ALSO FROM 6N-10N BETWEEN 42W-48W. ...DISCUSSION... GULF OF MEXICO... STRONG WESTERLY UPPER LEVEL WINDS COVER THE GULF REGION. AT THE SURFACE...A SURFACE TROUGH OVER THE W GULF EXTENDS FROM 25N97W TO 23N97W TO 21N96W. LOW LEVEL CONVERGENCE IS SUPPORTING ISOLATED SHOWERS WITHIN 60 NM EITHER SIDE OF THE SURFACE TROUGH. OVER THE N AND E GULF REGION...A MODIFIED CONTINENTAL POLAR AIRMASS IS IN PLACE...WHERE TEMPERATURES REMAIN BELOW SEASONAL AVERAGES. THIS AIRMASS IS BEING SUPPORTED BY A 1033 MB SURFACE HIGH OVER SOUTH CAROLINA NEAR 33N81W...WITH AN ASSOCIATED SURFACE RIDGE EXTENDING ACROSS THE NE GULF. AS COOLER AIR IS BEING ADVECTED OVER THE RELATIVELY WARMER GULF WATERS...WEAK LOW LEVEL INSTABILITY IS SUPPORTING SCATTERED STRATOCUMULUS CLOUDS ACROSS THE GULF MAINLY N OF 24N W OF 84W. HOWEVER...SUBSIDENCE AND STABLE ATMOSPHERIC CONDITIONS HIGHER IN THE ATMOSPHERE ARE INHIBITING DEEP CONVECTION ACROSS THE GULF REGION. ADDITIONALLY...STRONG N TO NE SURFACE WINDS ARE BLOWING THROUGH THE ISTHMUS OF TEHUANTEPEC RESULTING IN GALE FORCE WINDS IN THE E PACIFIC REGION. THESE WINDS ARE FORECAST TO DIMINISH BELOW GALE FORCE AT 24/0000 UTC. CARIBBEAN SEA... IN THE SW CARIBBEAN...LOW LEVEL CONVERGENCE IN THE VICINITY OF A 1008 MB SURFACE LOW N OF PANAMA IS INTERACTING WITH DEEP LAYER MOISTURE OVER THE W CARIBBEAN TO RESULT IN SCATTERED SHOWERS AND THUNDERSTORMS OVER THE CARIBBEAN S OF 13N W OF 76W...INCLUDING PORTIONS OF COSTA RICA...PANAMA...AND S NICARAGUA. DEVELOPMENT OF THIS SYSTEM...IF ANY...SHOULD BE SLOW TO OCCUR DUE ITS INTERACTION WITH LAND. HOWEVER...HEAVY RAINFALL CAUSING LOCALIZED FLOODING WILL BE POSSIBLE OVER MUCH OF PANAMA...COSTA RICA...AND NICARAGUA DURING THE NEXT COUPLE OF DAYS. THIS SHOWER AND THUNDERSTORM ACTIVITY IS BEING ENHANCED BY UPPER LEVEL DIFFLUENCE IN THE VICINITY OF AN UPPER RIDGE PRESENT OVER THE W CARIBBEAN...WITH THE AXIS OF THIS UPPER RIDGE EXTENDING FROM N COLOMBIA NEAR 11N73W TO 16N81W TO THE NW CARIBBEAN NEAR 19N84W. ALSO...A WEAKENING SURFACE COLD FRONT IN THE NW CARIBBEAN EXTENDS FROM 21N81W TO E CUBA NEAR 21N77W...WITH SCATTERED SHOWERS WITHIN 60 NM OF THIS FRONT. OVER THE E CARIBBEAN...UPPER LEVEL DIVERGENCE IS INTERACTING WITH DEEP LAYER MOISTURE TO SUPPORT SCATTERED SHOWERS AND THUNDERSTORMS S OF 16N BETWEEN 65W-74W. THIS ACTIVITY IS BEING ENHANCED BY LOW LEVEL CONVERGENCE ASSOCIATED WITH THE TROPICAL WAVE ALONG 68W/69W DISCUSSED IN THE TROPICAL WAVES SECTION ABOVE. ALSO...FOR LOCATIONS N OF 14N BETWEEN 69W-75W IN THE E CARIBBEAN...NE TO E SURFACE WINDS OF 20 TO 30 KT ARE FORECAST TO OCCUR THROUGH MONDAY NIGHT...WITH GUSTS TO GALE FORCE ACROSS THE WINDWARD PASSAGE. ATLANTIC OCEAN... A BROAD UPPER LEVEL TROUGH OVER THE W ATLC IS SUPPORTING A SURFACE COLD FRONT THAT EXTENDS FROM E CUBA NEAR 21N77W TO 26N62W TO 32N56W TO N OF THE DISCUSSION AREA. ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THIS COLD FRONT. TO THE W OF THIS COLD FRONT...A MODIFIED CONTINENTAL POLAR AIRMASS IS IN PLACE...WITH TEMPERATURES BELOW SEASONAL AVERAGES ACROSS FLORIDA AND SCATTERED STRATOCUMULUS CLOUDS BETWEEN THIS FRONT AND THE COAST OF THE SE CONUS. THIS AIRMASS IS BEING SUPPORTED BY A 1033 MB SURFACE HIGH OVER SOUTH CAROLINA NEAR 33N81W. FARTHER TO THE E...A SURFACE TROUGH EXTENDS FROM 28N58W TO A 1017 MB SURFACE LOW NEAR 26N58W TO 22N57W...WITH ANOTHER SURFACE TROUGH EXTENDING FROM 16N59W TO A 1010 MB SURFACE LOW NEAR 15N53W TO 14N47W. ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM OF THESE SURFACE LOWS AND SURFACE TROUGHS. TO THE E...AN UPPER TROUGH IS PRESENT OVER THE E ATLC N OF 17N E OF 43W WITH AN UPPER LOW NEAR 30N35W. AN ASSOCIATED SURFACE TROUGH EXTENDS FROM A 1013 MB SURFACE LOW NEAR 23N35W TO 21N32W TO 18N36W. LOW LEVEL CONVERGENCE NEAR THE SURFACE TROUGH AND SURFACE LOW IS SUPPORTING SCATTERED SHOWERS FROM 21N-27N BETWEEN 26W-36W...WHICH ARE BEING ENHANCED BY UPPER LEVEL DIVERGENCE IN THE VICINITY OF A MID/UPPER-LEVEL WIND SPEED MAXIMUM AND ATMOSPHERIC INSTABILITY IN THE VICINITY OF THE UPPER TROUGH AND UPPER LOW. $$ COHEN