000 AXNT20 KNHC 091802 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT TUE JUL 09 2013 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... TROPICAL STORM CHANTAL IS CENTERED NEAR 14.8N 62.7W AT 1800 UTC OR ABOUT 291 NM SE OF SAN JUAN PUERTO RICO MOVING W-NW NEAR 25 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 65 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. CHANTAL IS MOVING THROUGH THE LESSER ANTILLES AND IS EXPECTED TO PRODUCE RAIN ACCUMULATIONS OF 2 TO 4 INCHES OVER THE LEEWARD AND WINDWARD ISLANDS WITH 3 TO 6 INCHES OVER PUERTO RICO...THE U.S. VIRGIN ISLANDS...AND PORTIONS OF THE DOMINICAN REPUBLIC AND HAITI...WITH MAXIMUM AMOUNTS OF 8 INCHES POSSIBLE. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 13N-16N BETWEEN 60W-63W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS COVER THE REMAINDER OF THE AREA FROM 11N-17N BETWEEN 57W-64W. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED ALONG 18W FROM 8N-18N DRIFTING W. WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. A MID LEVEL CYCLONIC ROTATION IS NEAR THE BASE OF THE TROPICAL WAVE. NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IS ALONG 10N33W TO 4N37W MOVING W 15-20 KT. WAVE IS ALONG THE LEADING EDGE OF A LOW AMPLITUDE SURGE OF DEEP MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IS ALONG 22N85W TO OVER CENTRAL AMERICA TO 13N86W MOVING W NEAR 20 KT. WAVE IS BENEATH AN UPPER RIDGE WITH NO ASSOCIATED DEEP CONVECTION. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 13N16W CONTINUING TO 10N23W WHERE THE ITCZ BEGINS AND CONTINUES TO 7N33W THEN RESUMES W OF THE TROPICAL WAVE 4N39W TO 1N45W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 10N- 13N BETWEEN 16W-20W INCLUDING THE COAST OF GUINEA BISSAU. SCATTERED MODERATE CONVECTION IS FROM 8N-12N BETWEEN 20W-25W AND FROM 4N-8N BETWEEN 25W-30W. ISOLATED MODERATE CONVECTION IS FROM 9N-11N BETWEEN 24W-31W AND FROM 4N-6N BETWEEN 36W-42W. ...DISCUSSION... GULF OF MEXICO... A BROAD E/W UPPER RIDGE EXTENDS ACROSS THE S CONUS ANCHORED OVER THE DESERT SW TO NORTH CAROLINA GIVING THE GULF OF MEXICO NORTHERLY FLOW ALOFT. AN UPPER LOW IS OVER THE BAHAMAS REINFORCING THE NORTHERLY UPPER FLOW AND GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 25N E OF 83W TO OVER S FLORIDA AND W CUBA. A MID LEVEL SHORTWAVE TROUGH IS OVER THE W GULF FROM NEAR 28N92W TO 24N94W GENERATING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS WITHIN 60/75 NM OF LINE FROM 28N91W TO 24N95W. A WEAK SURFACE RIDGE EXTENDS FROM THE W ATLC ALONG THE N GULF COAST TO TEXAS WITH A 1023 MB HIGH OVER THE MISSISSIPPI COAST. THE EASTERLY SURFACE FLOW IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 60 NM ALONG THE COAST OF MEXICO BETWEEN 21N-25W. SURFACE RIDGE WILL REMAIN THROUGH THU BEFORE RETREATING EASTWARD. A WEAK FRONTAL SYSTEM WILL SINK INTO THE N CENTRAL GULF LATE FRI THEN STALL AND DISSIPATE BY LATE SAT. CARIBBEAN SEA... THE PRIMARY CONCERN THIS AFTERNOON IS T.S. CHANTAL THAT IS MOVING ACROSS THE LESSER ANTILLES. SEE SPECIAL FEATURES ABOVE. CHANTAL IS MOVING RAPIDLY WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OUT AHEAD OF THE SYSTEM CENTER OVER THE E CARIBBEAN. ELSEWHERE...AN UPPER RIDGE COVERS THE CARIBBEAN E OF 67W AND IS ANCHORED OVER CENTRAL AMERICA. THE EASTERLY SURFACE FLOW IS BANKING LOW CLOUDS WITH SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND OVER NICARAGUA AND HONDURAS AND IN THE GULF OF HONDURAS S OF 17N W OF 86W. THE EASTERLY TRADE WINDS ARE ALSO GENERATING ISOLATED SHOWERS/THUNDERSTORMS WITHIN 90 NM ALONG THE S COAST OF CUBA. THE MONSOON TROUGH EXTENDS ACROSS THE SW CARIBBEAN FROM COLOMBIA NEAR 10N75W ALONG 11N82W TO ACROSS S NICARAGUA/COSTA RICA NEAR 11N84W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 60 NM ALONG THE COAST OF PANAMA TO NICARAGUA S OF 12N W OF 81W. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN UNDER MOSTLY CLEAR SKIES THIS AFTERNOON. CHANTAL IS EXPECTED TO CONTINUE ON FAST W-NW TRACK AND SLOWLY INTENSIFY AS IT MOVES ACROSS THE E CARIBBEAN. CHANTAL IS EXPECTED TO WEAKEN CROSSING HISPANIOLA THEN CONTINUING MORE N-NW ACROSS THE BAHAMAS THROUGH SUN. HISPANIOLA... ISOLATED SHOWERS ARE OVER THE DOMINICAN REPUBLIC E OF 70.5W LEAVING THE REMAINDER OF THE ISLAND UNDER MOSTLY CLEAR SKIES THIS AFTERNOON. CHANTAL IS EXPECTED TO APPROACH THE S SIDE OF HISPANIOLA WED MORNING CROSSING THE ISLAND WED EVENING. HEAVY RAINFALL WILL BE POSSIBLE AND THE PROGRESS OF CHANTAL SHOULD BE WATCHED CLOSELY. TROPICAL STORM WATCHES AND WARNINGS ARE UP FOR ALL OF HISPANIOLA. ATLANTIC OCEAN... T.S. CHANTAL IS MOVING ACROSS THE CARIBBEAN THIS AFTERNOON. SEE SPECIAL FEATURES ABOVE. AN UPPER LOW COVERS THE W ATLC TO OVER THE BAHAMAS AND IS CENTERED NEAR 24N79W SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 30N75W ALONG 28N77W TO 24N79W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 150 NM E OF THE SURFACE TROUGH S OF 28N WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 200 NM W OF THE SURFACE TROUGH INCLUDING THE S PORTION FLORIDA. AN UPPER TROUGH WELL N OF THE DISCUSSION AREA EXTENDS A SURFACE TROUGH INTO THE CENTRAL ATLC NEAR 32N1W ALONG 30N55W TO 30N60W WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 60 NM NW OF THE TROUGH. A WEAK 1022 MB LOW IS TO THE E NEAR 31N41W WITH A SURFACE TROUGH EXTENDING SE TO 27N45W AND SCATTERED SHOWERS WITHIN 90 NM E OF THE LOW/TROUGH. THE REMAINDER OF THE ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1023 MB HIGH NEAR THE AZORES AND A 1026 MB HIGH NEAR BERMUDA. GOES R SATELLITE IMAGERY INDICATES A SWATH OF SAHARAN AIR LAYER COVERS THE ATLC WITHIN 450 NM OF LINE FROM BEYOND 32N21W ALONG 19N34W TO 14N51W. SURFACE RIDGE WILL SHIFT S THROUGH THU BEFORE RETREATING EASTWARD. THE SURFACE TROUGH WILL MOVE OVER FLORIDA WED AND DISSIPATE. TROPICAL STORM CHANTAL IN THE E CARIBBEAN IS EXPECTED TO MOVE ACROSS HISPANIOLA WED THEN INTO THE FAR S BAHAMAS EARLY THU THROUGH SUN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALTON