000 AXNT20 KNHC 211804 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST FRI NOV 21 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 55W/56W S OF 13N MOVING W NEAR 10 KT. SATELLITE IMAGERY INDICATES THAT THIS WAVE COINCIDES WITH A WELL-DEFINED INVERTED-V PATTERN IN CLOUD COVERAGE...WHERE CIMSS 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. SCATTERED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE WAVE AXIS N OF 9N. TRENDS IN SATELLITE IMAGERY INDICATE THAT THIS TROPICAL WAVE IS NOW DETACHED FROM A NEARLY STATIONARY AREA OF LOW LEVEL CYCLONIC CIRCULATION FARTHER NORTH...WHICH IS BEING ANALYZED AS A SURFACE TROUGH EXTENDING FROM 20N52W TO 17N52W TO 15N51W. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 12N16W 6N30W 4N51W. SCATTERED MODERATE CONVECTION IS FROM 3N-4N BETWEEN 32W-36W. ...DISCUSSION... GULF OF MEXICO... AS OF 1500 UTC A COLD FRONT EXTENDS FROM CENTRAL FLORIDA TO THE CENTRAL GULF OF MEXICO TO NE MEXICO NEAR TAMPICO ALONG 29N80W 27N84W 26N90W 26N96W 23N98W. OVERCAST LOW CLOUDS WITH SCATTERED SHOWERS ARE OVER S TEXAS AND NE MEXICO FROM 20N-28N BETWEEN 95W-100W. 20-25 KT NORTHERLY WINDS ARE N OF THE FRONT. 10-15 KT NORTHERLY WINDS ARE S OF THE FRONT. THIS MODIFIED CONTINENTAL POLAR FRONT WILL REQUIRE FREEZE WARNINGS FOR N FLORIDA FOR TONIGHT AND SATURDAY MORNING. ADDITIONALLY...STRONG N TO NE SURFACE WINDS ARE FUNNELING THROUGH THE ISTHMUS OF TEHUANTEPEC RESULTING IN GALE FORCE WINDS IN THE E PACIFIC. IN THE UPPER LEVELS...THE BASE OF AN UPPER LEVEL TROUGH IS SUPPORTING THE COLD FRONT. UPPER LEVEL WINDS ARE PREDOMINATELY FROM THE WNW AT 90-110 KT. STRONG SUBSIDENCE COVERS THE ENTIRE GULF OF MEXICO. EXPECT...THE FRONT TO EXTEND FROM THE STRAITS OF FLORIDA TO THE BAY OF CAMPECHE IN 24 HOURS WITH SHOWERS OVER THE W GULF W OF 90W. CARIBBEAN SEA... IN THE SW CARIBBEAN...A 1009 MB SURFACE LOW IS LOCATED N OF PANAMA NEAR 10N81W. ADDITIONALLY...A SURFACE STATIONARY FRONT EXTENDS NE FROM THIS SURFACE LOW TO 15N77W TO 20N64W. LOW LEVEL CONVERGENCE NEAR THE SURFACE LOW AND SURFACE FRONT IS INTERACTING WITH DEEP LAYER MOISTURE OVER THE S CARIBBEAN TO GENERATE SCATTERED SHOWERS AND THUNDERSTORMS OVER THE S CARIBBEAN S OF 15N W OF 77W. SCATTERED SHOWERS ARE ALSO OVER THE E CARIBBEAN E OF 70W. ISOLATED MODERATE CONVECTION IS OVER THE SE CARIBBEAN FROM 11N-14N BETWEEN 60W-68W. IN THE UPPER LEVELS ...A RIDGE COVERS THE ENTIRE CARIBBEAN SEA WITH AXIS FROM TRINIDAD TO THE YUCATAN PENINSULA. SIGNIFICANT UPPER LEVEL MOISTURE IS S OF 16N. EXPECT... LITTLE CHANGE WITH THE STATIONARY FRONT FOR THE NEXT 24 HOURS. ATLANTIC OCEAN... A 1020 MB HIGH IS OVER THE W ATLANTIC NEAR 27N69W. A STATIONARY FRONT EXTENDS FROM 32N49W TO N OF PUERTO RICO ALONG 32N49W 22N60W 20N65W. SCATTERED SHOWERS ARE WITHIN 60 NM OF THE FRONT.A 1015 MB LOW IS OVER THE CENTRAL ATLANTIC NEAR 27N45W. ANOTHER 1013 MB LOW IS OVER THE E ATLANTIC NEAR 24N30W. A TROUGH EXTENDS S FROM THIS LOW TO 20N32W 18N35W. SCATTERED SHOWERS ARE WITHIN 60 NM OF THE TROUGH. IN THE UPPER LEVELS...ZONAL FLOW IS N OF 20N AND W OF 40W. AN UPPER LEVEL LOW IS CENTERED OVER THE E ATLANTIC NEAR 33N22W. A TROUGH IS N OF 20N AND E OF 40W. ZONAL FLOW IS OVER THE TROPICS S OF 20N AND E OF 50W. $$ FORMOSA