000 AXNT20 KNHC 282347 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE SEP 28 2010 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... TROPICAL DEPRESSION SIXTEEN IS CENTERED NEAR 21.4N 82.0W AT 29/0000 UTC OR ABOUT 95 NM SSE OF HAVANA CUBA AND ABOUT 280 NM SSW OF MIAMI FLORIDA MOVING NNE AT 7 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. THE SYSTEM IS EXPECTED TO BRING LARGE AMOUNTS OF RAIN TO THE CAYMAN ISLANDS...CUBA...JAMAICA...AND SOUTHERN FLORIDA OVER THE NEXT 24-48 HOURS. THESE AREAS SHOULD MONITOR THE SYSTEM FOR THREAT OF FLOODING AND MUDSLIDES IN MOUNTAINOUS TERRAIN. WHILE THE SYSTEM REMAINS A BROAD AREA OF LOWER PRESSURE ENCOMPASSING THE NW CARIBBEAN SEA...EASTERN GULF OF MEXICO...AND FAR WESTERN ATLC...MOST OF THE SCATTERED MODERATE TO STRONG CONVECTION IS OCCURRING WITHIN THE SOUTHERN SEMICIRCLE OF THE LOW FROM 15N-20N BETWEEN 77W-89W. SCATTERED MODERATE CONVECTION SPREADS NORTHWARD OVER THE EASTERN SEMICIRCLE FROM 15N-25N BETWEEN 74W-83W AND OVER PORTIONS OF THE NW BAHAMAS AND SOUTHERN FLORIDA DUE TO A FRONTAL BOUNDARY FROM 25N-32N BETWEEN 76W-84W. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 08N28W TO 18N30W MOVING W AT 10-15 KT. BROAD LOW-LEVEL CYCLONIC FLOW IS NOTED ON SATELLITE IMAGERY IN THE VICINITY OF THE WAVE AXIS S OF 16N. THE WAVE ALSO COINCIDES WITH AN AREA OF MAXIMUM DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY FROM 06N-13N BETWEEN 22W-32W. LARGELY EMBEDDED WITHIN THE ITCZ...SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 04N-11N BETWEEN 24W-34W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 12N16W 10N28W 08N39W 09N51W 08N59W. A COMPLEX OF SCATTERED MODERATE TO STRONG CONVECTION IS ALONG THE W AFRICA COAST FROM 11N-16N BETWEEN 14W-19W. ASIDE FROM CONVECTION ASSOCIATED WITH THE TROPICAL WAVE...A PAIR OF SURFACE TROUGHS ARE ANALYZED OVER THE CENTRAL TROPICAL ATLC. ONE IS FROM 11N42W TO 16N41W WITH SCATTERED MODERATE CONVECTION FROM 10N-18N BETWEEN 38W-46W. THE OTHER SURFACE TROUGH EXTENDS FROM 08N51W TO 15N48W WITH SCATTERED MODERATE CONVECTION FROM 09N-15N BETWEEN 46W-53W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL TROUGH IS LOCATED OVER THE GULF OF MEXICO AND REMAINS N OF 21N. THIS UPPER LEVEL TROUGH SUPPORTS A COLD FRONT THAT EXTENDS ACROSS FLORIDA FROM FLAGLER BEACH TO TAMPA BAY AND INTO THE GULF ALONG 28N83W 25N88W 21N90W. WHILE MOST OF THE ENERGY ASSOCIATED WITH THE MIDDLE TO UPPER LEVEL TROUGH IS NORTH OF 24N...NUMEROUS SHOWERS AND SCATTERED TSTMS COVER A LARGE AREA FROM 24N-30N E OF 85W...INCLUDING MUCH OF THE FLORIDA PENINSULA THIS EVENING. WEST OF THE COLD FRONT AND S OF 21N...UPPER LEVEL DIFFLUENCE ASSOCIATED WITH AN UPPER LEVEL RIDGE AXIS EXTENDING FROM WEST-CENTRAL MEXICO NEAR 20N105W TO THE EASTERN YUCATAN PENINSULA NEAR 18N88W IS SUPPORTING ISOLATED SHOWERS AND TSTMS S OF 20N OVER SOUTHERN MEXICO AND THE BAY OF CAMPECHE. ELSEWHERE...WEST OF THE FRONT...STRONG N TO NE SURFACE WINDS UP TO 25 KT ARE OCCURRING AND ALONG WITH STRONG NORTH-NORTHWESTERLY FLOW ALOFT...ARE PROVIDING FOR STRONG SUBSIDENCE AND A RELATIVELY DRY AND STABLE AIRMASS. CONDITIONS ACROSS THE SE GULF AND FLORIDA STRAITS ARE EXPECTED TO DETERIORATE OVER THE NEXT 24 HOURS AS T.D. SIXTEEN MOVES N-NE OVER WESTERN CUBA. CARIBBEAN SEA... T.D. SIXTEEN IS THE MAIN FEATURE ACROSS THE NW CARIBBEAN THIS EVENING GENERATING NUMEROUS SHOWERS AND SCATTERED TSTMS OVER MUCH OF THE BASIN N OF 12N BETWEEN 65W-89W. THIS WIDESPREAD AREA OF CONVECTION IS SUPPORTED ALOFT BY AN ANTICYCLONIC CIRCULATION CENTERED NEAR 18N75W THAT EXTENDS AN UPPER LEVEL RIDGE AXIS SE TO NE VENEZUELA NEAR 10N62W. AS T.D. SIXTEEN IS STEERED NORTH- NORTHEASTWARD OVER THE NEXT COUPLE OF DAYS BY THE MIDDLE TO UPPER LEVEL TROUGHING OVER THE GULF OF MEXICO...10-15 KT E-SE TRADEWINDS ARE EXPECTED TO RESUME OVER THE BASIN E OF 72W WITH SURFACE TROUGHING FORECAST TO DRIFT OVER THE WESTERN CARIBBEAN BETWEEN 80W-85W THROUGH EARLY SATURDAY. ATLANTIC OCEAN... A DEEP LAYER TROUGH IS LOCATED ACROSS THE EASTERN CONUS AND GULF OF MEXICO THAT SUPPORTS A COLD FRONT ENTERING THE AREA NEAR 32N78W TO THE FLORIDA COAST NEAR 29N81W ENHANCING NUMEROUS SHOWERS AND SCATTERED TSTMS N OF 25N W OF 76W. LOW TO MIDDLE LEVEL MOISTURE CONTINUES TO ADVECT NORTHWARD FROM THE CARIBBEAN SEA OVER THE GREATER ANTILLES AND SW NORTH ATLC GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS FROM 18N-25N BETWEEN 63W-73W. FARTHER EAST...TWO WEAK SURFACE LOW CIRCULATIONS ARE ACROSS THE REMAINDER OF THE W ATLC. A 1014 MB LOW IS CENTERED NEAR 32N66W ENHANCING ISOLATED SHOWERS WITHIN 210 NM OF THE CENTER IN THE NW SEMICIRCLE. ANOTHER LOW AT 1016 MB IS CENTERED NEAR 28N56W AND SUPPORTS AN AREA OF ISOLATED SHOWERS FROM 24N-29N BETWEEN 52W-57W. THESE LOWS ARE FORECAST TO GRADUALLY DISSIPATE OVER THE NEXT 24 HOURS AND BECOMING EMBEDDED WITHIN SURFACE RIDGING W OF 50W. A SURFACE TROUGH IS ANALYZED FROM 19N46W TO 28N41W WITH POSSIBLE SHALLOW LOW-LEVEL ISOLATED SHOWERS FROM 24N-30N BETWEEN 39W-45W. OVER THE EASTERN ATLC...A 1017 MB LOW IS CENTERED NEAR 30N31W WITH SURFACE TROUGHING EXTENDING NORTHWARD TO 35N33W AND SOUTHWARD TO 25N33W. ANY POSSIBLE ISOLATED SHOWERS ARE BEING SHEARED TO THE NE DUE TO A WEAK UPPER LEVEL SHORTWAVE TROUGH WITH AXIS ALONG 29W. THE ISOLATED SHOWERS ARE MAINLY N OF 29N BETWEEN 25W-32W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN