000 AXNT20 KNHC 020536 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 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 23N81W MOVING NORTHWARD. SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 120 NM ALONG THE N COAST OF CUBA BETWEEN 76W AND THE SURFACE TROUGH WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 150 NM W OF THE REMAINDER OF THE SURFACE TROUGH. SOME DEVELOPMENT OF THIS SYSTEM IS POSSIBLE BEFORE UPPER- LEVEL WINDS BECOME UNFAVORABLE IN A DAY OR TWO. CLOUDINESS AND SHOWERS WILL SPREAD OVER SE FLORIDA ON FRI AND SAT. 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 23N22W THROUGH A WEAK 1009 MB LOW NEAR 18N23W TO 11N23W MOVING W 5 TO 10 KT. WAVE IS EMBEDDED WITHIN AN AREA OF MODERATE MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY WITH A WELL DEFINED 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 EXTENDS FROM 25N88W TO OVER THE YUCATAN PENINSULA TO N 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 22N17W AND CONTINUES THROUGH A THE 1011 MB LOW ASSOCIATED WITH THE TROPICAL WAVE NEAR 17N21W THEN ALONG 10N30W TO 7N42W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 6N51W TO SOUTH AMERICA NEAR 6N58W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 10N-12N E OF 19W TO THE COAST OF W AFRICA... FROM 11N-15N BETWEEN 17W-20W...AND WITHIN 60 NM OF LINE FROM 10N18W TO 8N22W. CLUSTERS OF SCATTERED MODERATE CONVECTION FROM 5N-10N BETWEEN 36W-59W. ...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. THIS FRONT HAS GENERATED SCATTERED SHOWERS/ISOLATED THUNDERSTORMS THAT HAVE MOVED INTO THE N/CENTRAL GULF N OF 28N BETWEEN 87W-91W INCLUDING PORTIONS OF SE LOUISIANA. WEAK SURFACE RIDGE ANCHORED IN THE ATLC EXTENDS ACROSS N FLORIDA TO OVER THE GULF. AFTERNOON SHOWERS/THUNDERSTORMS THAT DEVELOPED INLAND OVER THE YUCATAN PENINSULA HAVE MOVED INTO THE E BAY OF CAMPECHE S OF 21N E OF 92W. THIS IS LEAVING THE REMAINDER OF THE GULF UNDER MOSTLY CLEAR SKIES TONIGHT. WEAK RIDGE WILL REMAIN NEARLY STATIONARY THROUGH FRI NIGHT THEN SHIFT S TO NEAR 26N SAT THROUGH TUE. CARIBBEAN SEA... AN UPPER LOW IS CENTERED OVER THE CAYMAN ISLANDS COVERING THE NW CARIBBEAN AND EXTENDING AN UPPER TROUGH TO THE GULF OF HONDURAS AND GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 18N BETWEEN 77W-80W AND N OF 21N BETWEEN 81W-85W. AN UPPER RIDGE COVERS THE SW CARIBBEAN S OF 17N BETWEEN 68W-85W. A BROAD UPPER TROUGH EXTENDS FROM AN UPPER LOW OVER THE CENTRAL ATLC ACROSS THE VIRGIN ISLANDS/PUERTO RICO COVERING THE E CARIBBEAN. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 18N BETWEEN PUERTO RICO AND THE GULF OF GONAVE INCLUDING A PORTION OF HAITI. THE MONSOON TROUGH EXTENDS ACROSS PANAMA FROM COLOMBIA TO COSTA RICA AND IS GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 12N BETWEEN 73W-84W. FRESH TO STRONG TRADE WINDS WILL PREVAIL ACROSS MUCH OF THE S/CENTRAL CARIBBEAN THROUGH TUE. HISPANIOLA... SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE ACROSS THE ISLAND TONIGHT WITH THE HIGHEST CONCENTRATION OF THUNDERSTORMS OVER THE E TIP OF THE DOMINICAN REPUBLIC AND IN THE GULF OF GONAVE OFF HAITI. THE UPPER TROUGH OVER THE E CARIBBEAN WILL DRIFT W TO OVER HISPANIOLA LATE FRI THROUGH THE FIRST OF NEXT WEEK. AFTERNOON SHOWERS AND THUNDERSTORMS REMAIN POSSIBLE THROUGH NEXT WEEK WITH INCREASED CHANCE OF THESE STORMS LINGERING LATER INTO THE EVENING. ATLANTIC OCEAN... AN UPPER TROUGH EXTENDS FROM NEW ENGLAND TO OVER NE FLORIDA SUPPORTING A FRONTAL BOUNDARY INLAND OVER THE SE CONUS. THIS FRONT HAS GENERATED SCATTERED SHOWERS/ISOLATED THUNDERSTORMS THAT HAVE MOVED INTO THE W ATLC NW OF LINE FROM DAYTONA BEACH FLORIDA TO BEYOND 32N75W. THE UPPER LOW IN THE NW CARIBBEAN EXTENDS OVER THE W ATLC S OF 29N BETWEEN 73W-80W SUPPORTING THE SURFACE TROUGH IN THE SPECIAL FEATURES ABOVE. A LARGE UPPER LOW IS IN THE N/CENTRAL ATLC NEAR 33N51W EXTENDS AN UPPER TROUGH SW TO OVER THE E CARIBBEAN AND GENERATING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS FROM 30N-33N BETWEEN 51W-55W. THE REMAINDER OF THE ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1029 MB W OF THE AZORES AND A WEAKER 1026 MB HIGH NEAR 32N45W. SURFACE RIDGE WILL REMAIN THROUGH SAT NIGHT THEN SHIFT S TO NEAR 26N EARLY MON AS A WEAK FRONT PASSES N OF THE AREA. THE SPECIAL FEATURES SURFACE TROUGH WILL MOVE NW TO N TO OFF THE FLORIDA COAST BY FRI EVENING WITH POSSIBLE LOW PRESSURE DEVELOPING ALONG IT. THE TROUGH IS THEN FORECAST TO MOVE IN A N TO NE DIRECTION REACHING FROM THE NEWLY DEVELOP LOW NEAR 30N70W POSSIBLY AS A TROPICAL CYCLONE TO 27N79W BY SAT MORNING. BY SAT EVENING THE TROUGH LOW...OR POSSIBLE TROPICAL CYCLONE...SHOULD BE MERGING WITH A FRONTAL TROUGH NEAR OR JUST N OF 31N. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW