000 AXNT20 KNHC 270547 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT JUL 27 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURE... TROPICAL STORM DORIAN IS CENTERED NEAR 17.9N 48.1W AT 27/0300 UTC OR ABOUT 855 NM E OF THE NORTHERN LEEWARD ISLANDS MOVING W AT 19 KT. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. MINIMUM CENTRAL PRESSURE IS 1010 MB. PLEASE SEE THE LATEST FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC AND THE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT4/WTNT34 KNHC FOR MORE DETAILS. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 17N-19N BETWEEN 45W-50W. ...TROPICAL WAVES... A TROPICAL WAVE WAS INTRODUCED AT 27/0000 UTC EXTENDING FROM 19N20W TO 6N24W MOVING W 10-15 KT. THE SURGE OF DEEP MOISTURE USUALLY ASSOCIATED WITH A TROPICAL WAVE IS WEAK AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY WITH NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IS CURRENTLY INLAND OVER S MEXICO INTO THE E PACIFIC REGION. NO ASSOCIATED SHOWERS/CONVECTION IN THE GULF OF MEXICO. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 17N16W AND CONTINUES ALONG 11N24W TO 7N31W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 7N41W TO SOUTH AMERICA NEAR 5N52W. SCATTERED STRONG CONVECTION IS WITHIN 75 NM OF LINE FROM 13N17W TO 10N19W. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 6N-10N BETWEEN 13W-30W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE EXTENDS ACROSS TEXAS INTO THE GULF TO FLORIDA GIVING THE GULF MOSTLY NORTHERLY FLOW ALOFT. AN UPPER LOW IS OVER S MEXICO AND THE BAY OF CAMPECHE GENERATING SCATTERED SHOWERS INLAND OVER S MEXICO. A SURFACE RIDGE DOMINATES THE GULF EXTENDING FROM THE W ATLC ACROSS S FLORIDA TO THE COAST OF MEXICO WITH A 1019 MB HIGH NEAR 25N88W LEAVING THE GULF WITH MOSTLY CLEAR SKIES TONIGHT. SURFACE RIDGE WILL PREVAIL ACROSS THE GULF THROUGH WED. CARIBBEAN SEA... AN UPPER RIDGE COVERS THE W CARIBBEAN W OF 74W ANCHORED OFF THE COAST OF W PANAMA. THE UPPER TROUGH OVER THE W ATLC DIPS S OVER MOST OF THE E CARIBBEAN INCLUDING THE GREATER ANTILLES FROM E CUBA TO PUERTO RICO GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 18N BETWEEN THE MONA PASSAGE AND THE WINDWARD PASSAGE. THE MONSOON TROUGH EXTENDS ALONG 8N/9N FROM COLOMBIA ACROSS PANAMA AND COSTA RICA INTO THE E PACIFIC REGION GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 12N W OF 79W. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN UNDER MOSTLY CLEAR SKIES TONIGHT. TROPICAL STORM DORIAN IN THE CENTRAL ATLC WILL MOVE W-NW WHILE WEAKENING. DORIAN IS FORECAST TO WEAKEN TO A TROPICAL DEPRESSION E-NE OF THE LEEWARD ISLANDS SAT MORNING CONTINUING N OF PUERTO RICO MON AND N OF HISPANIOLA TUE THEN DISSIPATE WED. HISPANIOLA... CURRENTLY SKIES ARE CLEAR ACROSS MOST OF HISPANIOLA WITH THE EXCEPTION OF THE EASTERN TIP OF THE DOMINICAN REPUBLIC AND THE GULF OF GONAVE AND THE S PENINSULA OF HAITI WHERE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE CONTINUING. THIS ACTIVITY IS DUE TO THE UPPER TROUGH THAT EXTENDS FROM THE W ATLC OVER THE E CARIBBEAN. AFTERNOON SHOWERS AND THUNDERSTORMS ARE POSSIBLE WITH DAYTIME HEATING AND WILL BE ENHANCED BY THE UPPER TROUGH THAT WILL PERSIST THROUGH WED. TROPICAL STORM DORIAN WILL PASS N OF HISPANIOLA TUE BEFORE DISSIPATING. ATLANTIC OCEAN... AN UPPER TROUGH DIPS S OVER THE FAR W ATLC N OF 27N W OF 74W TO OVER NE FLORIDA SUPPORTING A STATIONARY FRONT THAT AT 27/0300 UTC EXTENDS FROM A WEAK 1014 MB LOW NEAR 32N75W ALONG 29N76W TO A 1015 MB LOW NEAR 28N79W CONTINUING TO OVER S FLORIDA NEAR WEST PALM BEACH. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 90 NM E AND SE OF THE FRONT/LOWS. AN UPPER LOW IS OVER THE W/CENTRAL ATLC CENTERED NEAR 25N65W COVERING THE AREA BETWEEN 55W-72W AND DIPPING S OVER THE E CARIBBEAN GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 27N BETWEEN 62W-69W AND FROM 26N-31N BETWEEN 50W-58W. A SURFACE RIDGE DOMINATES THE CENTRAL ATLC N OF 20N BETWEEN 30W-70W WITH A WEAK RIDGE AXIS EXTENDING W OVER THE GULF OF MEXICO AND ANCHORED BY A 1033 MB HIGH W OF THE AZORES. AN UPPER TROUGH IS OVER THE NE ATLC N OF THE DISCUSSION AREA SUPPORTING A WEAK SURFACE TROUGH THAT EXTENDS FROM 31N24W TO 27N28W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 45 NM EITHER SIDE OF THE TROUGH. SURFACE RIDGE WILL PREVAIL THROUGH WED. TROPICAL STORM DORIAN IN THE CENTRAL ATLC WILL MOVE W-NW WHILE WEAKENING. DORIAN IS FORECAST TO WEAKEN TO A TROPICAL DEPRESSION E-NE OF THE LEEWARD ISLANDS SAT MORNING CONTINUING N OF PUERTO RICO MON AND N OF HISPANIOLA TUE THEN DISSIPATE WED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW