000 AXNT20 KNHC 231200 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE OCT 23 2012 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... TROPICAL STORM SANDY IS CENTERED NEAR 13.4N 77.9W AT 23/1200 UTC OR ABOUT 280 NM SSW OF KINGSTON JAMAICA MOVING NNE AT 3 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT3/WTNT33 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT3/WTNT23 KNHC FOR MORE DETAILS. NUMEROUS STRONG CONVECTION IS WITHIN 45 NM OF LINE FROM 11N78W TO 13N76W WITH SCATTERED MODERATE/STRONG CONVECTION COVERING THE REMAINDER OF THE AREA FROM 10N-16N BETWEEN 74W-79W AND S OF 15N BETWEEN 69W-73W. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE S OF 14N W OF 79W TO THE COAST OF PANAMA TO NICARAGUA. SANDY IS EXPECTED TO PRODUCE TOTAL RAINFALL AMOUNTS OF 5 TO 10 INCHES ACROSS JAMAICA...HAITI...THE DOMINICAN REPUBLIC...AND EASTERN CUBA...WITH ISOLATED MAXIMUM AMOUNTS OF 16 INCHES POSSIBLE...ESPECIALLY IN AREAS OF MOUNTAINOUS TERRAIN. THESE RAINS MAY PRODUCE LIFE THREATENING FLASH FLOODS AND MUDSLIDES. TROPICAL DEPRESSION NINETEEN IS CENTERED NEAR 24.1N 51.5W AT 23/0900 OR ABOUT 715 NM NE OF THE LEEWARD ISLANDS MOVING N-NE AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. SEE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT4/ WTNT34 KNHC AND THE FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. SCATTERED MODERATE/ ISOLATED STRONG CONVECTION IS FROM 23N-26N BETWEEN 48W-52W WITH CLUSTERS OF SIMILAR CONVECTION WITHIN 45/60 NM OF LINE FROM 16N46W 25N47W TO 30N60W. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED ALONG 26W/27W BETWEEN 9N-15N MOVING W 10-15 KT. WAVE IS ALONG THE LEADING EDGE OF A SURGE OF DEEP MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. HOWEVER THERE IS NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IN THE CENTRAL TROPICAL ATLC IS ANALYZED FROM 13N39W TO 9N38W DRIFTING W. WAVE IS EMBEDDED WITHIN A NARROW SURGE OF MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. HOWEVER THERE IS NO ASSOCIATED DEEP CONVECTION. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS W AFRICA INTO THE E TROPICAL ATLC NEAR 12N16W OF THE E TROPICAL WAVE NEAR 8N26W CONTINUING ALONG 9N32W THEN S OF THE W TROPICAL WAVE TO 8N41W WITH THE ITCZ BEGINS AND CONTINUES ALONG 9N47W TO 9N53W. SCATTERED MODERATE/ STRONG CONVECTION IS FROM 4N-7N BETWEEN 28W-32W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE 90 NM ALONG THE COAST OF W AFRICA BETWEEN 10N-13N...WITHIN 120 NM OF LINE FROM 4N12W TO 7N15W...WITHIN 45 NM OF LINE FROM 7N15W TO TO 14N21W...AND FROM 6N-10N BETWEEN 28W-37W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE EXTENDS FROM SW MEXICO OVER TEXAS/LOUISIANA GIVING THE GULF NW FLOW ALOFT WITH DRY CONTINENTAL AIR REMAINING IN PLACE OVER THE GULF. A BROAD SURFACE RIDGE DOMINATES THE GULF THIS MORNING ANCHORED BY A 1024 MB HIGH OVER NORTH CAROLINA. A SHORTWAVE UPPER TROUGH EXTENDS FROM THE FLORIDA PENINSULA S ACROSS CUBA INTO THE NW CARIBBEAN GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS IN THE STRAITS OF FLORIDA S OF 24N E OF 81W. ISOLATED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 90 NM ALONG THE COAST OF MEXICO S OF 24N W OF 95W. THIS IS LEAVING THE REMAINDER OF THE GULF WITH REMARKABLY CLEAR SKIES AGAIN THIS MORNING. E WINDS WILL INCREASE ACROSS THE SE GULF TODAY AND CONTINUE THROUGH LATE WED. THESE WINDS ARE THE RESULT FROM PRESSURE GRADIENT BETWEEN SURFACE RIDGE OVER THE GULF AND W ATLC AND TROPICAL STORM SANDY IN THE CARIBBEAN. CARIBBEAN SEA... THE PRIMARY CONCERN THIS MORNING IS TROPICAL STORM SANDY IN THE S/CENTRAL CARIBBEAN...PLEASE SEE SPECIAL FEATURES ABOVE. A SHORTWAVE UPPER TROUGH EXTENDS FROM THE FLORIDA PENINSULA ACROSS CUBA OVER THE NW CARIBBEAN NEAR 15N83W GENERATING ISOLATED SHOWERS/THUNDERSTORMS FROM 15N-21N W OF 78W INCLUDING THE GULF OF HONDURAS. ABUNDANT MOISTURE REMAINS OVER THE CARIBBEAN ENHANCING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ACROSS THE REMAINDER OF THE CENTRAL CARIBBEAN BETWEEN 69W-78W. TROPICAL STORM SANDY WILL MOVE N INTENSIFYING TO HURRICANE BEFORE MOVING ACROSS JAMAICA WED EVENING AND CUBA THU BEFORE BECOMING A TROPICAL STORM ONCE AGAIN AS IT CONTINUES INTO THE W ATLC THU AFTERNOON. ATLANTIC OCEAN... BROAD UPPER TROUGH COVERS THE W ATLC N OF 28N W OF 52W SUPPORTING A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 32N54W TO 27N62W WHERE IT DISSIPATES E OF THE BAHAMAS NEAR 25N68W. ISOLATED SHOWERS ARE WITHIN 60 NM E OF THE FRONT. THE SHORTWAVE UPPER TROUGH THAT EXTENDS FROM THE FLORIDA PENINSULA INTO THE NW CARIBBEAN COUPLED WITH AN UPPER RIDGE THAT EXTENDS FROM HISPANIOLA NEAR 19N70W TO 27N68W ARE GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 26N TO ACROSS THE GREATER ANTILLES INTO THE CARIBBEAN BETWEEN 67W-80W. A SURFACE RIDGE REMAINS OVER THE W ATLC N OF 26N W OF 66W INTO THE GULF OF MEXICO. AN UPPER TROUGH IN THE NE ATLC DIPS S TO 21N E OF 28W SUPPORTING A DISSIPATING COLD FRONT THAT EXTENDS THROUGH 32N20W TO 28N29W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 60 NM E OF THE FRONT. A BROAD UPPER RIDGE EXTENDS ACROSS THE TROPICAL ATLC FROM AFRICA NEAR 11N16W ALONG 17N34W TO 23N38W AND IS DRAWING TROPICAL MOISTURE N AWAY FROM THE TROPICAL WAVES. SURFACE RIDGE WILL REMAIN ACROSS THE AREA TODAY THROUGH WED. TROPICAL STORM SANDY WILL MOVE ACROSS CUBA INTO THE W ATLC ON THU ACROSS BAHAMAS EARLY FRI THEN NE OF THE BAHAMAS ON SAT NIGHT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW