000 AXNT20 KNHC 280543 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN JUL 28 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. ...TROPICAL WAVES... TROPICAL WAVE IS W OF THE CAPE VERDE ISLANDS EXTENDING FROM 18N32W TO 9N28W MOVING W-SW NEAR 20 KT. WAVE APPEARS TO BE ROTATING W-SW ALONG THE MONSOON TROUGH. NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE E OF THE LESSER ANTILLES...PREVIOUSLY TROPICAL STORM DORIAN THAT WAS DOWNGRADED AT 27/2100 UTC...EXTENDS FROM 21N55W TO 13N56W MOVING W NEAR 20 KT. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE WITHIN 75/90 NM OF LINE FROM 21N54W TO 19N59W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 17N16W AND CONTINUES ALONG 12N25W 7N31W TO 6N38W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 6N45W TO SOUTH AMERICA NEAR 5N53W. SCATTERED CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 120 NM S OF THE MONSOON TROUGH/ITCZ BETWEEN 25W-48W AND WITHIN 60/75 NM OF LINE FROM 6N47W TO 9N57W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE EXTENDS ACROSS TEXAS INTO THE GULF TO 84W WITH AN UPPER LOW OVER S MEXICO COVERING THE BAY OF CAMPECHE. AN UPPER TROUGH OVER THE E CONUS EXTENDS TO OVER THE NE GULF N OF 28N E OF 84W SUPPORTING A FRONTAL SYSTEM THAT REMAINS INLAND OVER THE N GULF COAST FROM THE FLORIDA PANHANDLE TO TEXAS. THE FRONT IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND AND WITHIN 60/75 NM ALONG THE COAST BETWEEN THE APALACHICOLA BAY FLORIDA AND GALVESTON TEXAS. ISOLATED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE ALONG THE FLORIDA KEYS. A WEAK SURFACE RIDGE DOMINATES THE GULF EXTENDING FROM THE W ATLC ACROSS S FLORIDA TO THE COAST OF MEXICO WITH A 1016 MB HIGH NEAR 24N88W LEAVING THE REMAINDER OF THE GULF WITH MOSTLY CLEAR SKIES TONIGHT. SURFACE RIDGE WILL PREVAIL ACROSS THE GULF THROUGH THU. CARIBBEAN SEA... AN UPPER RIDGE COVERS THE W CARIBBEAN S OF 20N W OF 78W ANCHORED OVER NICARAGUA. A WEAK UPPER TROUGH IS N OF THIS UPPER RIDGE EXTENDING FROM THE YUCATAN CHANNEL OVER THE CAYMAN ISLANDS AND JAMAICA TO 15N73W. THE UPPER LOW OVER THE W ATLC EXTENDS S OVER THE N/CENTRAL CARIBBEAN N OF 14N BETWEEN THE VIRGIN ISLANDS AND THE WINDWARD PASSAGE GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND AND ALONG THE IMMEDIATE COAST OF HAITI. THE MONSOON TROUGH EXTENDS ALONG 9N/10N FROM COLOMBIA ACROSS PANAMA/COSTA RICA INTO THE E PACIFIC REGION GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 13N W OF 78W. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN UNDER MOSTLY CLEAR SKIES TONIGHT. THE TROPICAL WAVE...PREVIOUSLY DORIAN...WILL CONTINUE TO MOVE W ENTERING THE E CARIBBEAN BY SUN INTO THE CENTRAL CARIBBEAN MON NIGHT AND THE W CARIBBEAN TUE NIGHT THEN SHIFTING W OF THE AREA LATE THU. HISPANIOLA... CURRENTLY SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE OVER PORTIONS OF HAITI AND ALONG THE IMMEDIATE COAST WITH ISOLATED SHOWERS ARE ACROSS THE DOMINICAN REPUBLIC. THE UPPER TROUGH CURRENTLY OVER HISPANIOLA WILL PULL AWAY TO THE NW ON TUE. HOWEVER...AFTERNOON SHOWERS AND THUNDERSTORMS ARE POSSIBLE WITH DAYTIME HEATING AND WILL BE ENHANCED BY THE TROPICAL WAVE THAT WILL MOVE ACROSS THE ISLAND MON AND TUE. ATLANTIC OCEAN... A WEAK UPPER RIDGE EXTENDS FROM CENTRAL CUBA TO 30N74W PROVIDING DIFFLUNCE ALOFT TO GENERATE CLUSTERS OF SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS DOTTING THE AREA FROM 22N-27N BETWEEN 76W- 81W INCLUDING PORTIONS OF S FLORIDA. AN ELONGATED UPPER LOW IS OVER THE W/CENTRAL ATLC CENTERED NEAR 23N69W COVERING THE AREA BETWEEN 65W-73W GENERATING CLUSTERS OF SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS DOTTING THE AREA FROM 22N-32N BETWEEN 65W- 72W. A SURFACE RIDGE DOMINATES THE W AND CENTRAL ATLC N OF 20N BETWEEN 35W-78W WITH A WEAK RIDGE AXIS EXTENDING W OVER THE GULF OF MEXICO AND ANCHORED BY A 1027 MB HIGH BETWEEN BERMUDA AND THE AZORES. AN UPPER TROUGH EXTENDS OVER THE E ATLC THROUGH 32N16W TO 21N32W SUPPORTING A WEAK SURFACE TROUGH THAT EXTENDS FROM A 1013 MB LOW OVER MADEIRA ISLANDS ALONG 30N24W TO 25N35W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 45 NM EITHER SIDE OF THE TROUGH. SURFACE RIDGE WILL PERSIST THROUGH THU. THE TROPICAL WAVE...PREVIOUSLY DORIAN...WILL MOVE RAPIDLY W-NW S OF THE SURFACE RIDGE THROUGH WED BEFORE MOVING W OF THE AREA BY THU. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW