000 AXNT20 KNHC 071750 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN SEP 07 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. ...SPECIAL FEATURES... HURRICANE IKE IS CENTERED NEAR 20.9N 74.0W AT 07/1800 UTC OR JUST W OF GREAT INAGUA ISLAND AND ABOUT 78 NM EAST-NORTHEAST OF GUANTANAMO CUBA MOVING W AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 949 MB. MAXIMUM SUSTAINED WIND SPEED IS 115 KT WITH GUSTS TO 140 KT. PLEASE SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. IKE IS AN EXTREMELY DANGEROUS CATEGORY FOUR HURRICANE ON THE SAFFIR-SIMPSON SCALE. FLUCTUATIONS IN STRENGTH ARE POSSIBLE TODAY AND TONIGHT BUT IKE IS EXPECTED TO REMAIN A MAJOR HURRICANE AS IT APPROACHES E CUBA THEN WEAKEN AS IT MOVES OVER E AND CENTRAL CUBA ON MON. THE INTENSITY FORECAST AS IT MOVES INTO THE GULF OF MEXICO IS DEPENDANT ON THE LENGTH OF TIME IKE REMAINS INLAND OVER CUBA. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM OF THE CENTER IN THE W SEMICIRCLE AND WITHIN 90 NM OF THE CENTER IN THE E SEMICIRCLE. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS COVER THE REMAINDER OF THE AREA FROM 18N-23N BETWEEN 72W-75W WITH CLUSTERS OF SIMILAR ACTIVITY IN THE OUTER RAINS FROM 17N-24N BETWEEN 65W-76W INCLUDING THE ISLANDS BETWEEN PUERTO RICO AND CUBA. ...TROPICAL WAVES... TROPICAL WAVE IS W OF THE CAPE VERDE ISLANDS ALONG 36W S OF 13N MOVING W NEAR 15 KT. WAVE IS AT THE LEADING EDGE OF A SURGE OF AFRICAN DUST AND IS NOW LOW AMPLITUDE DUE TO THE REMNANTS OF JOSEPHINE. ANY ACTIVITY IS ASSOCIATED WITH THE ITCZ. TROPICAL WAVE WAS REPOSITIONED ALONG 65W S OF 15N MOVING W NEAR 15 KT BASED ON UPPER AIR DATA FROM THE WINDWARD ISLANDS OVER THE PAST FEW DAYS AND IS EMBEDDED WITHIN AN AREA OF DEEP LAYERED MOISTURE AS INDICATED BY MIMIC-TPW. MOST OF THIS WAVES ENERGY WAS DISPLACED SEVERAL DAYS IN THE DEVELOPMENT OF WHAT IS NOW HURRICANE IKE. SCATTERED SHOWERS/AND POSSIBLE ISOLATED THUNDERSTORMS ARE S OF 14N E OF 66W AND IS COMBINED WITH CONVECTION ASSOCIATED WITH THE ITCZ. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 13N16W 6N29W 10N38W 10N46W 13N55W 11N62W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 10N-14N BETWEEN 58W-64W INCLUDING THE WINDWARD ISLANDS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 90 NM OF A LINE FROM 8N27W TO 5N34W AND WITHIN 90 NM N OF THE ITCZ FROM 53W-56W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER LONGWAVE TROUGH IS OVER THE E US TO THE N GULF COAST WITH THE ASSOCIATED FRONTAL BOUNDARY ENTERING THE GULF NEAR PENSACOLA FLORIDA SW TO 27N91W THEN RETURNING N AS A WARM TO NEAR CORPUS CHRISTI TEXAS. SCATTERED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN 75 NM N OF THE WARM FRONT. AN UPPER LEVEL RIDE IS DEVELOPING OVER THE SW GULF AND THE BAY OF CAMPECHE EXTENDING E N OF THE YUCATAN PENINSULA TO N OF W CUBA TO NEAR 24N83W. A SURFACE TROUGH EXTENDS FROM S MEXICO IN THE BAY OF CAMPECHE NEAR 17N93W TO 23N94W. UPPER LEVEL DIFFLUENCE IS GENERATING SCATTERED SHOWERS/THUNDERSTORMS S OF A LINE 25N83W TO 24N95W INCLUDING W CUBA AND THE YUCATAN CHANNEL TO THE COAST OF THE YUCATAN PENINSULA WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 24N W OF 92W TO INLAND OVER MEXICO. THE REMAINDER OF THE GULF IS CLEAR THIS AFTERNOON. CARIBBEAN SEA... HURRICANE IKE CONTINUES TO GENERATE SHOWERS/THUNDERSTORMS OVER THE N CENTRAL CARIBBEAN AS IT TRACKS ACROSS THE TURKS AND CAICOS EXPECTING TO MAKE LANDFALL OVER CUBA LATE TONIGHT/MON MORNING...SEE SPECIAL FEATURES ABOVE. NE TO E UPPER LEVEL FLOW DOMINATES THE CARIBBEAN. THE UPPER RIDGE ASSOCIATED WITH HURRICANE IKE IS DRAWING A SWATH OF DRY AIR E OF THE SYSTEM ACROSS CENTRAL CUBA AND JAMAICA. UPPER DIFFLUENCE IS GENERATING A NARROW BAND IF SCATTERED SHOWERS/THUNDERSTORMS WITHIN 30/45 NM OF LINE FROM 21N80W ACROSS CUBA INTO THE FLORIDA STRAITS NEAR 25N79.5W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 10N W OF 80W TO INLAND OVER PANAMA AND TO THE COAST OF COSTA RICA. THE ACTIVITY OVER THE E CARIBBEAN IS ASSOCIATED WITH THE ITCZ AND THE TROPICAL WAVE. STRONG SUBSIDENCE/DRY AIR ARE ACROSS THE REMAINDER OF THE CARIBBEAN RESULTING IN TRANQUIL WEATHER THIS AFTERNOON. ATLANTIC OCEAN... HURRICANE IKE CONTINUES TO BE THE MAIN CONCERN THIS AFTERNOON AS WELL AS FOR THE NEXT FEW DAYS AS IT TRACKS TOWARD CUBA AND EVENTUALLY INTO THE GULF OF MEXICO...SEE SPECIAL FEATURES ABOVE. A BROAD UPPER RIDGE ASSOCIATED WITH HURRICANE IKE COVERS THE W ATLC RESULTING IN OUTFLOW WITHIN 200 NM W OF THE CENTER AND 600 NM TO THE E. AN UPPER TROUGH THAT HAS BEEN CUTOFF FROM THE SHEAR AXIS THAT DID EXTEND FROM THE E ATLC IS CONFINED TO THE CENTRAL ATLC EXTENDING AN AXIS FROM 30N41W THROUGH A WEAK UPPER LOW NEAR 26N46W TO A LARGER UPPER LOW NEAR 21N54W CONTINUING W TO THE LEEWARD ISLANDS NEAR 18N62W. THIS UPPER TROUGH IS ENHANCING THE ACTIVITY ASSOCIATED WITH THE ITCZ THAT IS OVER THE WINDWARD ISLANDS. THE REMNANT OF JOSEPHINE...A 1010 MB LOW IS CENTERED NEAR 17N41W WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION NW OF THE CENTER FROM 17N-21N BETWEEN 40W-44W. AN E/W UPPER RIDGE EXTENDS FROM W AFRICA ALONG 21N/22N TO 40W AND S OF 28N. ALSO AT THE SURFACE IS A BROAD RIDGE THAT COVERS THE AREA N OF 25N BETWEEN 30W-65W ANCHORED N OF THE REGION BY A 1025 MB HIGH. SURGE OF AFRICAN DUST COVERS THE E TROPICAL ATLC S OF 24N E OF THE TROPICAL WAVE. $$ WALLACE