000 AXNT20 KNHC 042359 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE OCT 04 2011 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...SPECIAL FEATURES... THE CENTER OF TROPICAL STORM PHILIPPE AT 04/2100 UTC IS NEAR 24.1N 60.0W OR ABOUT 550 NM SSE OF BERMUDA. PHILIPPE IS MOVING WESTWARD AT 9 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 55 KT WITH GUSTS TO 65 KT. SOME ADDITIONAL STRENGTHENING IS POSSIBLE OVER THE NEXT COUPLE OF DAYS. PLEASE READ THE LATEST NHC FORECAST/ ADVISORY UNDER THE AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. A CLUSTER OF NUMEROUS STRONG CONVECTION IS NEAR THE STORM CENTER FROM 23N-24N BETWEEN 59W-60W. NUMEROUS MODERATE CONVECTION IS ELSEWHERE FROM 22N-25N BETWEEN 57W-61W. ...TROPICAL WAVES... TROPICAL WAVE IS MOVING ACROSS THE CENTRAL TROPICAL ATLC ALONG 16N36W TO 5N44W MOVING W AT 15-20 KT. THE WAVE LIES ON THE WRN EDGE OF A SURGE OF DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY. THE WAVE IS ALSO ON THE ERN SIDE OF AN UPPER LEVEL TROUGH THAT EXTENDS FROM THE AZORES ISLANDS TO NEAR 17N45W. THIS IS PROVIDING SWLY SHEAR ACROSS THE WAVE WHICH IS DRAWING MOISTURE TO THE NE OF THE WAVE. CURRENTLY SCATTERED MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE WAVE AXIS. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS NE OF THE WAVE FROM 14N-19N BETWEEN 27W-33W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 7N23W. THE ITCZ AXIS CONTINUES W OF THE CENTRAL ATLC TROPICAL WAVE ALONG 9N45W 8N61W. A CLUSTER OF STRONG CONVECTION IS MOVING OFF THE AFRICAN COAST OVER GUINEA-BISSAU FROM 10N-13N BETWEEN 14W-17W. SIMILAR ACTIVITY IS ALSO MOVING ACROSS SIERRA LEONE. SCATTERED MODERATE/STRONG CONVECTION IS N OF THE MONSOON AXIS FROM 9N-13N BETWEEN 22W-26W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS N OF THE ITCZ AXIS FROM 7N-9N BETWEEN 45W-52W. SIMILAR ACTIVITY IS FROM 8N-10N BETWEEN 54W-58W. CLUSTERS OF STRONG CONVECTION ARE ALSO ALONG THE SOUTH AMERICAN COASTLINE BETWEEN 54W-62W. ISOLATED MODERATE CONVECTION IS E OF THE WINDWARD ISLANDS FROM 10N-13N BETWEEN 55W-62W. ...DISCUSSION... THE GULF OF MEXICO... MAIN FEATURE IN THE GULF IS A STATIONARY FRONT THAT EXTENDS FROM 24N81W TO THE YUCATAN PENINSULA AT 22N87W. SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS ARE SOUTH OF THE FRONT WITHIN 70 NM BETWEEN 80W-85W. THE REMAINDER OF THE GULF IS UNDER SURFACE RIDGING FROM A HIGH PRESSURE CENTER LOCATED NEAR 36N90W. IN THE UPPER LEVELS A WEAK TROUGH IS CURRENTLY CENTERED OVER THE BASIN AND DRY AIR SUBSIDENCE IS OCCURRING WHICH IS FAVORING FAIR WEATHER CONDITIONS TO THE ENTIRE GULF EXCEPT E OF THE FRONTAL BOUNDARY. MOSTLY LIGHT NELY-ELY WINDS OF 10-15 KT ARE OVER THE ENTIRE BASIN EXCEPT N OF THE STATIONARY FRONT WHERE WINDS OF 20-25 KT ARE OBSERVED FROM 24N-26N BETWEEN 81W-84W. SIMILAR WIND MAGNITUDE IS FROM 23N-24N BETWEEN 85W-87W. EXPECT LITTLE CHANGE OVER THE NEXT 24 HOURS. THE CARIBBEAN SEA... A STATIONARY FRONT IS JUST NW THE WESTERN CARIBBEAN EXTENDING FROM 24N81W TO THE YUCATAN PENINSULA AT 22N87W. COMBINATION OF THE MOISTURE ASSOCIATED TO THE FRONT ALONG WITH DAYTIME HEATING IS PRODUCING SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS OVER WESTERN CUBA. OTHER REGIONS BEING AFFECTED BY THESE FACTORS ARE EASTERN CUBA...THE CAYMAN ISLANDS AND JAMAICA. MODERATE CONVECTION AND THUNDERSTORMS ARE OBSERVED FROM 19N-20N BETWEEN 81W-82W. SCATTERED SHOWERS WITH ISOLATED MODERATE CONVECTION IS SEEN FROM 16N-21N BETWEEN 82W-85W. A SURFACE TROUGH IS APPROACHING THE YUCATAN PENINSULA FROM 15N88W TO 20N87W. THIS INSTABILITY IN THE ATMOSPHERE MIGHT BE ASSOCIATED TO BOTH THE HIGH MOISTURE OVER THE REGION ASSOCIATED TO THE FRONT AS WELL AS UPPER LEVEL DIFFLUENCE FROM THE GULF UPPER TROUGH AND AN UPPER RIDGE CENTERED NEAR 17N86W. OVER HONDURAS...NICARAGUA AND 150 NM E OF NICARAGUA COAST SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS OCCURRING MOSTLY ASSOCIATED TO THE MONSOON TROUGH PROXIMITY AS WELL AS DAYTIME HEATING. SIMILAR CONVECTION IS OBSERVED OVER NORTHERN PANAMA. OVER NORTHERN COLOMBIA AND NORTHERN VENEZUELA CLOSE TO THEIR COASTLINES NUMEROUS MODERATE TO STRONG CONVECTION WITH THUNDERSTORMS ARE OCCURRING DUE TO PROXIMITY TO THE EASTERN REAR OF THE MONSOON TROUGH...DAYTIME HEATING...AND AN UPPER LEVEL LOW CENTERED NEAR 10N73W. SCATTERED SHOWERS ASSOCIATED TO A REGION OF DEEP LAYER MOISTURE ARE OBSERVED W OF THE WINDWARD ISLAND FROM 13N-15N BETWEEN 61W-65W. ELSEWHERE IN THE CARIBBEAN DRY AIR SUBSIDENCE FROM THE UPPER LEVELS IS AFFECTING THE REGION WHICH IS FAVORING FAIR WEATHER. EXPECT SIMILAR WEATHER CONDITIONS IN THE NEXT 24 HOURS. THE ATLANTIC OCEAN... A COLD FRONT ENTERS THE WESTERN ATLC AND EXTENDS FROM 30N66W SW TO 27N71W. FROM THERE A QUASI-STATIONARY FRONT EXTENDS SW CROSSING THE BAHAMAS AND THEN ENTERS THE GULF OF MEXICO NEAR 24N81W. SCATTERED MODERATE TO ISOLATED STRONG SHOWERS ARE OBSERVED WITHIN 135 NM EITHER SIDE OF THE FRONT N OF 25N. PRECIPITATION IN THIS REGION IS DUE TO THE PLUM OF MOISTURE ASSOCIATED TO THE FRONTAL BOUNDARY AND UPPER LEVEL DIFFLUENCE FROM AN UPPER LEVEL TROUGH WITH AXIS NEAR 73W AND AN UPPER LEVEL RIDGE THAT CROSSES CUBA AND EXTENDS TO THE NE UP TO 60W. TROPICAL STORM PHILIPPE IS IN THE CENTRAL ATLANTIC LYING BETWEEN AN UPPER LEVEL RIDGE TO THE W AND A BROAD UPPER LEVEL HIGH CENTERED NEAR 35N46W. SEE THE SPECIAL FEATURES SECTION ABOVE FOR MORE DETAILS ON PHILIPPE. OVER THE EASTERN ATLANTIC A SURFACE TROUGH EXTENDS FROM 23N33W TO 30N29W. SHOWERS AND THUNDERSTORMS ARE OBSERVED WITHIN 75 NM E OF THE TROUGH. A TROPICAL WAVE IS ALSO ANALYZED...SEE THE TROPICAL WAVES SECTION ABOVE. IN THE UPPER LEVELS AN ELONGATED TROUGH THAT EXTENDS S TO 15 N IS SHEARING THE TROPICAL WAVE CONVECTION NE OF ITS AXIS. THIS UPPER LEVEL TROUGH IS ALSO SUPPORTING THE SURFACE TROUGH SHOWERS AND THUNDERSTORMS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS/WALTON