000 AXNT20 KNHC 100545 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST TUE NOV 10 2009 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... TROPICAL STORM IDA IS CENTERED NEAR 29.5N 88.8W AT 10/0600 UTC OR ABOUT 80 MILES SSW OF MOBILE ALABAMA MOVING N AT 9 KT. LATEST MINIMUM CENTRAL PRESSURE REPORTED BY RECONNAISSANCE AIRCRAFT WAS 998 MB. MAXIMUM SUSTAINED WIND SPEED IS 50 KT WITH GUSTS TO 60 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC OR THE PUBLIC ADVISORY UNDER AWIPS/WMO HEADER MIATCPAT1/WTNT31 KNHC FOR MORE DETAILS. IDA HAS ENCOUNTERED A SHEAR ENVIRONMENT RESULTING IN MOST OF THE HEAVIER RAINFALL ALREADY SPREAD ONSHORE FROM MISSISSIPPI ACROSS ALABAMA BECOMING LIGHTER OVER GEORGIA AS WELL AS PORTIONS OF THE FLORIDA. TROPICAL STORM FORCE WINDS COVER A LARGE AREA UP TO 175 NM OF THE CENTER. SCATTERED SHOWERS REMAIN OVER THE NE GULF N OF 26N E OF 86W AND N OF 28N E OF 90W WITH SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS WITHIN 120 NM OF LINE FROM THE NW CARIBBEAN NEAR 20N85W ACROSS CUBA E OF THE FLORIDA KEYS NEAR 25N84W TO OVER FLORIDA NEAR 26N82W. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 10N13W 5N31W 7N48W 8N61W. SCATTERED MODERATE/STRONG CONVECTION IS WITHIN 150 NM N OF THE ITCZ FROM 18W-24W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 150 NM N OF THE ITCZ FROM 24W-34W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 250 NM S OF THE ITCZ BETWEEN 10W-30W. ...DISCUSSION... GULF OF MEXICO... TROPICAL STORM IDA REMAINS THE DOMINANT FEATURE IN THE GULF TONIGHT BUT IS EXPECTED TO MAKE LANDFALL DURING THE NEXT SEVERAL HOURS...SEE SPECIAL FEATURES ABOVE. AN UPPER TROUGH THAT COVERS THE CENTRAL US AND MEXICO EXTENDS OVER MUCH OF THE GULF W OF 85W ADVECTING DRY CONTINENTAL AIR OVER THE GULF W OF 86W. THUS ONLY LOW CLOUDS WITH POSSIBLE ISOLATED SHOWERS COVER THE N GULF N OF 25N. A NARROW UPPER RIDGE EXTENDS FROM THE NW CARIBBEAN ACROSS CUBA NEAR HAVANA TO OVER THE FLORIDA PENINSULA FROM THE MIDDLE FLORIDA KEYS TO NEAR MELBOURNE AND INTO THE W ATLC PROVIDING DIFFLUENCE ALOFT TO ENHANCE THE ACTIVITY ASSOCIATED WITH TROPICAL STORM IDA. A COLD FRONT IS EXPECTED TO MOVE INTO THE GULF LATER TODAY TRAILING THE REMNANTS OF IDA. CARIBBEAN SEA... AN UPPER RIDGE EXTENDS FROM THE NW CARIBBEAN NEAR 18N85W ACROSS CUBA AND INTO THE GULF OF MEXICO NEAR HAVANA PROVIDING DIFFLUENCE ALOFT TO ENHANCE THE ACTIVITY IN THE NW CARIBBEAN ASSOCIATED WITH TROPICAL STORM IDA. AN UPPER LOW IN THE W/CENTRAL ATLC NNE OF PUERTO RICO DIPS S OVER THE CARIBBEAN N OF 13N E OF 77W PROVIDING STRONG SUBSIDENCE OVER THE GREATER ANTILLES FROM THE VIRGIN ISLANDS TO E CUBA. THE REMNANTS OF A STATIONARY FRONT EXTENDS ACROSS THE LEEWARD ISLANDS NEAR 17N62W TO THE COAST OF VENEZUELA NEAR 11N64W. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE OVER THE NE CARIBBEAN FROM 14N-18N E OF 67W TO OVER THE LEEWARD AND VIRGIN ISLANDS. SIMILAR ACTIVITY IS IN THE SW CARIBBEAN DUE TO THE CLOSE PROXIMITY OF THE ITCZ JUST S OF PANAMA/COSTA RICA S OF 12N W OF 80W TO INLAND OVER CENTRAL AMERICA. ATLANTIC OCEAN... THE W ATLC CONTINUES TO BE DOMINATED BY A BROAD SURFACE RIDGE ANCHORED BY A 1031 MB HIGH N OF BERMUDA. THE UPPER RIDGE OVER THE E GULF OF MEXICO AND NW CARIBBEAN ENTERS THE W ATLC NEAR MELBOURNE FLORIDA NE TO BEYOND 32N77W. A LARGE UPPER LOW DOMINATES THE REMAINDER OF THE W ATLC AND THE CENTRAL ATLC CENTERED NNE OF PUERTO RICO NEAR 24N64W COVERING THE AREA BETWEEN 55W-77W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 120 NM OF LINE FROM THE UPPER LOW NEAR 23N65W TO 30N54W. A REMNANT STATIONARY BOUNDARY ENTERS THE CENTRAL ATLC NEAR 32N43W EXTENDING SW ALONG 25N53W INTO THE CARIBBEAN NEAR 17N62W. THE UPPER SUPPORT FOR THIS BOUNDARY HAS SHIFTED N OF THE REGION. AN E/W UPPER RIDGE EXTENDS FROM W AFRICA ALONG 11W TO 55W AND IS PROVIDING DIFFLUENCE ALOFT TO ENHANCE CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 175 NM OF LINE FROM 16N58W TO NEAR 26N52W. A SURFACE RIDGE COVERS THE REMAINDER OF THE E ATLC ANCHORED BY A 1029 MB HIGH BETWEEN THE AZORES AND MADEIRA ISLANDS. $$ WALLACE