000 AXNT20 KNHC 081756 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU AUG 08 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE E TROPICAL ATLC EXTENDS FROM 22N29W TO 11N28W MOVING W 10-15 KT. A SURGE OF DEEP MOISTURE IS TRAILING THE WAVE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY WITH DRY SAHARAN AIR PRECEDING THE WAVE AS SEEN ON GOES R IMAGERY. NO ASSOCIATED CONVECTION. TROPICAL WAVE IN THE CARIBBEAN EXTENDS FROM 21N75W ACROSS CUBA TO THE COAST OF COLOMBIA NEAR 10N76W MOVING W NEAR 20 KT. WAVE IS IN AN AREA OF LIGHT MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY WITH NO ASSOCIATED CONVECTION. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 12N16W ALONG 12N28W TO 9N40W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 8N51W TO SOUTH AMERICA NEAR 8N60W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 6N-11N E OF 30W TO THE COAST OF W AFRICA AND FROM THE ITCZ TO 10N BETWEEN 56W-60W. A SURFACE TROUGH IS IN THE W TROPICAL ATLC FROM 13N55W TO 9N54W. ...DISCUSSION... GULF OF MEXICO... A LARGE UPPER RIDGE COVERS THE GULF INTO THE NW ATLC AND NW CARIBBEAN ANCHORED OVER THE LOWER MISSISSIPPI VALLEY. A SURFACE TROUGH IS OVER THE CENTRAL GULF EXTENDING FROM 29N88W TO THE N COAST OF THE YUCATAN PENINSULA NEAR 21N88W. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS COVER THE E GULF E OF 92W. A WEAK 1014 MB HIGH IS OVER THE NW GULF NEAR 27N91W WITH CLEAR SKIES COVERING THE REMAINDER OF THE GULF THIS AFTERNOON. SURFACE TROUGH WILL MOVE W ACROSS THE GULF THROUGH SAT THEN INLAND OVER TEXAS AND MEXICO SUN. CARIBBEAN SEA... THE LARGE UPPER RIDGE OVER THE GULF OF MEXICO EXTENDS OVER THE NW CARIBBEAN W OF 82W. THE UPPER LOW IN THE W ATLC EXTENDS S OVER THE N/CENTRAL CARIBBEAN TO 16N BETWEEN 70W-82W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 75 NM OF LINE FROM JAMAICA NEAR 18N77W TO 21N84W INCLUDING THE COAST OF SW CUBA AND THE CAYMAN ISLANDS. SCATTERED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS ARE N OF 17N BETWEEN THE LEEWARD ISLANDS AND E CUBA. AN UPPER RIDGE COVERS THE E CARIBBEAN ANCHORED OVER N VENEZUELA. A SURFACE TROUGH IS IN THE E CARIBBEAN EXTENDING FROM 15N66W THROUGH A 1010 MB LOW NEAR 13N66W TO OFF THE COAST OF VENEZUELA NEAR 11N66W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE FROM 12N-15N BETWEEN THE WINDWARD ISLANDS AND 68W. THE MONSOON TROUGH EXTENDS FROM A 1009 MB LOW INLAND OVER COLOMBIA TO ACROSS PANAMA AND COSTA RICA INTO THE E PACIFIC REGION GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 12N BETWEEN 74W-79W. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN WITH FAIR WEATHER THIS AFTERNOON. TROPICAL WAVE WILL MOVE INTO THE W CARIBBEAN FRI NIGHT. THE SURFACE TROUGH WILL DISSIPATE IN THE CENTRAL CARIBBEAN FRI. HISPANIOLA... CURRENTLY SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE OVER THE DOMINICAN REPUBLIC WITH POSSIBLE SHOWERS MOVING OVER HAITI. THE UPPER TROUGH THAT COVERS THE N/CENTRAL CARIBBEAN IS MOVING W AWAY FROM HISPANIOLA AS THE UPPER RIDGE TO THE E MOVING TOWARD THE ISLAND. THE TROPICAL WAVE HAS CLEARED THE ISLAND. THERE IS A CHANCE OF AFTERNOON SHOWERS/ THUNDERSTORMS OVER THE NEXT SEVERAL DAYS. ATLANTIC OCEAN... THE UPPER RIDGE OVER THE GULF OF MEXICO EXTENDS OVER THE NW ATLC N OF 32N W OF 80W. AN UPPER TROUGH IS N OF 32N EXTENDING FROM E OF THE CANADIAN MARITIMES TO BERMUDA SUPPORTING A SURFACE TROUGH THAT EXTENDS THROUGH 32N58W ALONG 28N69W TO THE BAHAMAS NEAR 25N76W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN 90/120 NM N OF THE TROUGH. AN UPPER LOW IS OVER THE BAHAMAS NEAR 24N76W WITH THE UPPER TROUGH EXTENDING S OVER THE N/CENTRAL CARIBBEAN AND COVERING THE W ATLC S OF 30N BETWEEN 67W-80W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE S OF 25N TO OVER THE GREATER ANTILLES BETWEEN 68W-80W. THE REMAINDER OF THE ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1029 MB HIGH NE OF THE AZORES. GOES R SATELLITE IMAGERY SHOWS DRY SAHARAN AIR N OF 20N E OF 35W AND FROM 10N-20N BETWEEN 27W-55W. W ATLC SURFACE TROUGH WILL LIFT N AND WEAKEN THROUGH TONIGHT. THE N OF A TROPICAL WAVE IN THE CARIBBEAN WILL MOVE ACROSS THE SW ATLC THROUGH FRI. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW