000 AXNT20 KNHC 272359 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE AUG 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE W OF THE CAPE VERDE ISLANDS EXTENDS FROM 18N34W TO A WEAK 1013 MB LOW NEAR 11N33W MOVING W NEAR 20 KT. WAVE IS EMBEDDED WITHIN AN SURGE OF DEEP MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE TO STRONG CONVECTION IS W OF THE LOW FROM 8N-12N BETWEEN 35W-40W. TROPICAL WAVE IN THE W ATLC EXTENDS FROM 23N48W TO 14N48W MOVING NW NEAR 15 KT. WAVE IS EMBEDDED WITHIN AN SURGE OF MODERATE MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. NO ASSOCIATED SHOWERS/CONVECTION. TROPICAL WAVE IN THE W CARIBBEAN EXTENDS FROM 19N84W INLAND OVER CENTRAL AMERICA TO 11N84W MOVING W NEAR 15 KT. WAVE IS EMBEDDED WITHIN AN AREA OF DEEP MOISTURE THAT COVERS MOST OF THE CARIBBEAN AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 13N-18N BETWEEN 80W-87W. THIS ACTIVITY IS BEING ENHANCED BY THE EASTERLY SURFACE FLOW AND THE SOUTHERLY FLOW ALOFT. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 12N16W AND CONTINUES ALONG 10N26W THROUGH THE LOW/TROPICAL WAVE NEAR 11N33W THEN ALONG 13N42W THROUGH A WEAK 1012 MB LOW NEAR 11N54W TO SOUTH AMERICA NEAR 9N61W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS INLAND AND WITHIN 75 NM ALONG THE COAST OF W AFRICA BETWEEN 7N-16N AND WITHIN A 75/90 NM RADIUS OF THE 11N54W LOW. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE COVERS THE GULF W OF 90W AND IS ANCHORED INLAND OVER CENTRAL MEXICO. AN UPPER LOW IS CENTERED OVER THE STRAITS OF FLORIDA NEAR 24N81W COVERING THE E GULF SUPPORTING A SURFACE TROUGH THAT AT 27/2100 UTC EXTENDS FROM THE W ATLC NEAR 26N79W TO THE N COAST OF CUBA NEAR 23N81W. A SECOND SURFACE TROUGH IS IN THE E GULF EXTENDING FROM 28N86W TO 24N84W. A SEABREEZE SURFACE TROUGH IS ALONG THE W COAST OF FLORIDA FROM 30N84W OVER TAMPA INTO THE GULF TO NEAR 26N82W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 28N E OF 84W TO OVER FLORIDA/CUBA AND INTO THE W ATLC. AFTERNOON THUNDERSTORMS THAT HAVE DEVELOPED INLAND OVER THE YUCATAN PENINSULA ARE MOVING INTO THE E BAY OF CAMPECHE WITHIN 45 NM ALONG THE COAST BETWEEN 19N-21N. A SURFACE RIDGE IS BUILDING S OVER THE N GULF ANCHORED BY A 1023 MB HIGH OVER MISSISSIPPI. THE REMAINDER OF THE GULF IS UNDER MOSTLY CLEAR SKIES THIS EVENING. THE WEAK SURFACE TROUGH ASSOCIATED WITH THE UPPER LOW WILL MOVE INTO THE S/CENTRAL GULF WED BEFORE DISSIPATING EARLY THU. SURFACE RIDGE WILL BUILD ACROSS THE GULF ALONG ROUGHLY 26N THU THROUGH SUN. CARIBBEAN SEA... THE UPPER LOW OVER THE STRAITS OF FLORIDA EXTENDS OVER THE FAR NW CARIBBEAN W OF 82W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 20N W OF 78W. THE REMAINDER OF THE CARIBBEAN IS DOMINATED BY AN UPPER RIDGE ANCHORED S OF HISPANIOLA NEAR 16N71W. THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 10N75W ALONG 11N80W TO ACROSS NICARAGUA NEAR 11N84W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 13N W OF 79W TO INLAND OVER PANAMA TO S NICARAGUA. A SURFACE TROUGH OVER THE NE CARIBBEAN EXTENDS FROM THE SW ATLC NEAR 23N69W ACROSS HISPANIOLA TO 16N70W GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS N OF 15N BETWEEN 67W-72W INCLUDING PUERTO RICO AND THE MONA PASSAGE. CARIBBEAN TROPICAL WAVE WILL MOVE ACROSS THE GULF OF HONDURAS THROUGH EARLY WED. W TROPICAL ATLC TROPICAL WAVE WILL WEAKEN AS IT APPROACHES THE LEEWARD ISLANDS THU THEN ACROSS THE NE CARIBBEAN TO HISPANIOLA FRI BEFORE LOSING DEFINITION OVER THE CARIBBEAN. HISPANIOLA... THE SURFACE TROUGH THAT EXTENDS ACROSS THE DOMINICAN REPUBLIC COUPLED WITH THE SOUTHERLY FLOW ALOFT ARE GENERATING SCATTERED TO HEAVY SHOWERS WITH EMBEDDED THUNDERSTORMS ACROSS THE ISLAND THIS EVENING. THE STRONGEST STORMS ARE CURRENTLY OVER HAITI. THE SURFACE TROUGH WILL LIFT N AND BECOME DIFFUSE OVERNIGHT. THE SOUTHERLY FLOW ALOFT WILL CONTINUE THROUGH THU BEFORE BECOMING MORE NORTHERLY THROUGH THE WEEKEND. TROPICAL WAVE WILL APPROACH THE DOMINICAN REPUBLIC LATE THU AGAIN INCREASING SHOWERS/ THUNDERSTORMS DISSIPATING SAT. ATLANTIC OCEAN... THE UPPER LOW OVER THE STRAITS OF FLORIDA COVERS THE W ATLC S OF 30N W OF 76W SUPPORTING A SURFACE TROUGH THAT AT 27/2100 UTC EXTENDS FROM 26N79W TO THE COAST OF CUBA NEAR 23N81W AND GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 28N W OF 76W TO INLAND OVER FLORIDA AND CUBA. A WEAK SURFACE TROUGH IS N OF THE BAHAMAS EXTENDING FROM 32N76W TO 28N77W. AN UPPER TROUGH IS OVER THE W/CENTRAL ATLC NARROWING AS IT EXTENDS THROUGH 32N64W TO 29N72W SUPPORTING A DISSIPATING STATIONARY FRONT THAT EXTENDS THROUGH 32N63W TO 30N73W. SCATTERED SHOWERS /ISOLATED THUNDERSTORMS ARE WITHIN 90 NM S OF THE FRONT E OF 65W. A SURFACE TROUGH PRECEDES THE FRONT EXTENDING FROM 30N60W TO 28N66W SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 45 NM SE OF THE TROUGH. ANOTHER SURFACE TROUGH EXTENDS FROM 23N69W TO ACROSS HISPANIOLA INTO THE CARIBBEAN NEAR 19N70W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND AND WITHIN 45 NM ALONG THE N COAST OF HAITI. A SURFACE RIDGE COVERS THE REMAINDER OF THE ATLC ANCHORED BY A 1030 MB HIGH N OF THE AZORES. STATIONARY FRONT WILL DISSIPATE EARLY WED. SURFACE TOUGH OVER HISPANIOLA WILL LIFT N AND BECOME DIFFUSE OVERNIGHT AS WILL THE SURFACE TROUGH N OF THE BAHAMAS. SURFACE RIDGE WILL BUILD ALONG 28N WED AND SHIFT S TO 26N BY FRI AS THE N EXTENT OF A TROPICAL WAVE PASSES OVER THE SW ATLC S OF 22N. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW