000 AXNT20 KNHC 021202 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI AUG 02 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... A SURFACE TROUGH...REMNANTS OF DORIAN...EXTENDS FROM 28N78W BETWEEN THE BAHAMA ISLANDS AND S FLORIDA TO THE COAST OF CUBA NEAR 23N80W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE WITHIN 150 NM E OF THE SURFACE TROUGH. GRADUAL DEVELOPMENT OF THIS SYSTEM IS POSSIBLE BEFORE UPPER-LEVEL WINDS BECOME UNFAVORABLE OVER THE WEEKEND. CLOUDINESS...SHOWERS...AND GUSTY WINDS ARE POSSIBLE TO PORTIONS OF THE NW BAHAMAS AND THE COASTAL WATERS OF SE FLORIDA TODAY AND SATURDAY AS THE SYSTEM MOVES NW AND N. AFTER THAT THE SYSTEM IS EXPECTED TO MOVE TOWARD THE N-NE AND BECOME ASSOCIATED WITH A FRONTAL TROUGH CURRENTLY OVER THE SE CONUS. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... TROPICAL WAVE NEAR THE CAPE VERDE ISLANDS EXTENDS FROM 22N23W THROUGH A WEAK 1010 MB LOW NEAR 18N23W TO 13N23W MOVING W NEAR 5 KT. WAVE IS EMBEDDED WITHIN AN AREA OF MODERATE MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY WITH A WELL DEFINED BUT BROAD MID LEVEL CIRCULATION. HOWEVER...THE WAVE IS ALSO EMBEDDED WITH A DENSE LAYER OF DRY SAHARAN DUST THAT COVERS THE TROPICAL ATLC LIMITING ANY SHOWER ACTIVITY. TROPICAL WAVE OVER THE S GULF OF MEXICO ALONG 89W/90W S OF 25N TO OVER THE YUCATAN PENINSULA TO NW GUATEMALA MOVING W 10-15 KT. WAVE IS EMBEDDED WITHIN AN AREA OF DEEP MOISTURE THAT COVERS MOST OF THE GULF AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. THE WAVE CONTINUES TO BE ILL-DEFINED WITH NO ASSOCIATED DEEP CONVECTION. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 17N16W AND CONTINUES ALONG 17N18W THROUGH THE 1010 MB LOW ASSOCIATED WITH THE TROPICAL WAVE NEAR 18N23W THEN ALONG 12N32W TO 9N41W WHERE THE ITCZ BEGINS AND CONTINUES TO SOUTH AMERICA NEAR 8N60W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 120 NM OF LINE FROM 13N20W TO 7N26W... WITHIN 75/90 NM OF LINE FROM 9N27W TO 8N41W...AND FROM 5N TO THE ITCZ BETWEEN 45W-48W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM THE ITCZ TO 10N W OF 53W TO INLAND OVER SOUTH AMERICA. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE ANCHORED OVER CENTRAL TEXAS EXTENDS SE ACROSS THE GULF TO W TIP OF CUBA GIVING THE GULF N TO E FLOW ALOFT. AN UPPER TROUGH EXTENDS FROM THE NEW ENGLAND TO NE FLORIDA SUPPORTING A FRONTAL BOUNDARY THAT IS INLAND OVER THE SE CONUS. REMNANT SCATTERED SHOWERS/ISOLATED THUNDERSTORMS REMAIN IN THE N/CENTRAL GULF N OF 27N BETWEEN 90W-92W INCLUDING PORTIONS OF SE LOUISIANA. WEAK SURFACE RIDGE ANCHORED IN THE ATLC EXTENDS ACROSS N FLORIDA TO OVER THE GULF. SOME ISOLATED SHOWERS REMAIN IN THE E BAY OF CAMPECHE S OF 20N BETWEEN 91W- 94W. THIS IS LEAVING THE REMAINDER OF THE GULF UNDER MOSTLY CLEAR SKIES THIS MORNING. THE N PORTION OF THE TROPICAL WAVE WILL MOVE ACROSS THE SW GULF TODAY AND TONIGHT. THE WEAK SURFACE RIDGE WILL REMAIN NEARLY STATIONARY THROUGH SAT THEN SHIFT SOUTHWARD SUN THROUGH TUE. CARIBBEAN SEA... AN UPPER LOW REMAINS CENTERED OVER THE CAYMAN ISLANDS COVERING THE NW CARIBBEAN AND EXTENDING AN UPPER TROUGH SW TO THE GULF OF HONDURAS. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 21N TO INLAND OVER CUBA BETWEEN 80W-84W AND IN THE GULF OF HONDURAS S OF S OF 17N W OF 87W. AN UPPER RIDGE COVERS THE SW CARIBBEAN S OF 18N BETWEEN 69W-82W. A BROAD UPPER TROUGH EXTENDS FROM AN UPPER LOW OVER THE CENTRAL ATLC ACROSS THE GREATER ANTILLES BETWEEN THE VIRGIN ISLANDS AND THE DOMINICAN REPUBLIC COVERING THE E CARIBBEAN. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE INLAND AND WITHIN 60 NM ALONG THE S COAST OF HISPANIOLA AND IN THE GULF OF GONAVE E OF 75W. THE MONSOON TROUGH EXTENDS ALONG 10N/11N FROM COLOMBIA TO COSTA RICA GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 13N W OF 76W TO OVER NICARAGUA. FRESH TO STRONG TRADE WINDS WILL PREVAIL ACROSS THE CENTRAL CARIBBEAN TODAY THROUGH THE WEEKEND. MODERATE TO FRESH TRADE WINDS WILL BE ACROSS THE REMAINDER OF THE BASIN. HISPANIOLA... SCATTERED SHOWERS/ISOLATED THUNDERSTORMS DOT THE ISLAND THIS MORNING WITH THE HIGHEST CONCENTRATION OF THUNDERSTORMS WITHIN 60 NM ALONG THE S COAST OF THE DOMINICAN REPUBLIC AND THE N COAST E OF 71W. THE UPPER TROUGH OVER THE E CARIBBEAN WILL CONTINUE TO DRIFT W TO OVER HISPANIOLA THROUGH THE FIRST OF NEXT WEEK. THIS WILL INCREASE AFTERNOON SHOWERS AND THUNDERSTORMS. ATLANTIC OCEAN... AN UPPER TROUGH EXTENDS FROM NEW ENGLAND TO OVER NE FLORIDA SUPPORTING A FRONTAL BOUNDARY INLAND OVER THE SE CONUS. THE UPPER LOW IN THE NW CARIBBEAN EXTENDS OVER THE W ATLC S OF 27N BETWEEN 74W-81W SUPPORTING THE SURFACE TROUGH IN THE SPECIAL FEATURES ABOVE. AN UPPER RIDGE ANCHORED N-NE OF BERMUDA EXTENDS A RIDGE AXIS S TO THE TURKS AND CAICOS. THIS UPPER RIDGE IS PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS FROM 21N-26N BETWEEN 71W-75W. A LARGE UPPER LOW IS IN THE N/CENTRAL ATLC NEAR 33N51W AND EXTENDS AN UPPER TROUGH SW TO OVER THE E CARIBBEAN. THE REMAINDER OF THE ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1027 MB W OF THE AZORES. GOES-R SATELLITE SHOWS A BROAD AREA OF SAHARAN DUST LAYER COVERING THE TROPICAL ATLC INTO THE E CARIBBEAN E OF 65W. A SURFACE LOW...POSSIBLY A TROPICAL CYCLONE...MAY DEVELOP ALONG THE SPECIAL FEATURES SURFACE TROUGH AS IT SLOWLY MOVES NW TO N THROUGH TONIGHT. THE TROUGH OR LOW WILL THEN MOVE TO THE N-NE THIS WEEKEND WHILE MERGING WITH A FRONTAL BOUNDARY OFF THE SE CONUS. THE SURFACE RIDGE WILL DOMINATE THE REMAINDER OF THE BASIN THROUGH THE TUE. ANOTHER FRONTAL BOUNDARY MAY DROP S OF 31N LATE MON INTO TUE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW