000 AXNT20 KNHC 112332 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU JUL 11 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. ...SPECIAL FEATURES... A BROAD AREA OF LOWER PRESSURE ASSOCIATED WITH THE REMNANTS OF CHANTAL COVERS THE SW ATLC AND THE BAHAMA ISLANDS. THERE IS WEAKENING SURFACE TROUGH THAT EXTENDS FORM 26N73W TO 22N76W AND A STRONGER SURFACE TROUGH THAT EXTENDS FROM NEAR GRAND BAHAMA ISLAND TO CENTRAL CUBA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 15N TO OVER CUBA BETWEEN 73W AND THE STRONG SURFACE TROUGH. ISOLATED SHOWERS/THUNDERSTORMS ARE FROM 25N-27N BETWEEN 76W-79W. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... TROPICAL WAVE IN THE E TROPICAL ATLC EXTENDS FROM 17N32W TO 11N33W MOVING W NEAR 15 KT. WAVE IS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. A MID LEVEL CYCLONIC ROTATION IS E OF THE TROPICAL WAVE NEAR 14N30W. NO ASSOCIATED DEEP CONVECTION. THE TROPICAL WAVE THAT NEAR 45W IS NO LONGER DISCERNIBLE AND WAS DROPPED FROM THE ANALYSIS. TROPICAL WAVE IN THE CARIBBEAN EXTENDS ALONG 79W FROM 12N-21N MOVING W 15 KT. WAVE IS EMBEDDED WITHIN AN AREA DEEP MOISTURE THAT COVERS THE CARIBBEAN W OF 72W AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 17N TO OVER CUBA BETWEEN 75W-80W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 14N17W AND CONTINUES TO 13N25W WHERE THE ITCZ BEGINS AND CONTINUES TO THE TROPICAL WAVE NEAR 13N32W THEN RESUMES W OF THE WAVE NEAR 11N34W AND CONTINUES ALONG 9N39W 7N48W TO SOUTH AMERICA NEAR 5N53W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 90 NM N OF THE ITCZ BETWEEN 41W-50W AND S OF 8N TO INLAND OVER SOUTH AMERICA BETWEEN 51W-57W. CLUSTERS OF ISOLATED MODERATE CONVECTION ARE WITHIN 200 NM S OF THE ITCZ AND WITHIN 120 NM N OF THE ITCZ BETWEEN 30W-38W. ...DISCUSSION... GULF OF MEXICO... A BROAD E/W UPPER RIDGE EXTENDS ALONG THE N GULF FROM TEXAS TO W FLORIDA THEN NE TO ALONG THE NORTH CAROLINA COAST GIVING THE N GULF OF MEXICO NE FLOW ALOFT. THIS UPPER RIDGE IS PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/THUNDERSTORMS INLAND OVER LOUISIANA AND IS PUSHING THEM INTO THE GULF WATERS WITHIN 45 NM ALONG THE COAST. AN UPPER TROUGH IS ACROSS THE S GULF EXTENDING FROM AN UPPER LOW IN THE STRAITS OF FLORIDA TO NEAR TAMPICO MEXICO GENERATING CLUSTERS OF ISOLATED SHOWERS/ THUNDERSTORMS S OF 25N DOTTING THE ENTIRE S GULF. A WEAK SURFACE RIDGE COVERS THE GULF AND IS ANCHORED BY A 1017 MB HIGH NEAR 26N91W. SURFACE RIDGE WILL SHIFT EASTWARD AS A WEAK FRONTAL SYSTEM MOVES INTO THE N/CENTRAL GULF FRI THEN WILL STALL AND DISSIPATE SAT. WEAK HIGH PRESSURE WILL RE-BUILD BACK ACROSS THE AREA AFTER SUN. CARIBBEAN SEA... THE TROPICAL WAVE IS THE PRIMARY FEATURE IN THE CARIBBEAN THIS EVENING. AN UPPER RIDGE COVERS THE CARIBBEAN E OF 75W AND IS ANCHORED OVER NICARAGUA. THE UPPER RIDGE IS PROVIDING DIFFLUENCE ALOFT TO GENERATE CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS DOTTING THE NW CARIBBEAN N OF 15N W OF 80W TO OVER THE YUCATAN PENINSULA AND INTO THE YUCATAN CHANNEL. THE MONSOON TROUGH EXTENDS ACROSS THE SW CARIBBEAN FROM COLOMBIA NEAR 11N75W ALONG 10N80W TO ACROSS COSTA RICA NEAR 9N84W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 12N W OF 78W TO INLAND OVER PANAMA TO S NICARAGUA. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN UNDER CLEAR SKIES THIS EVENING. CARIBBEAN TROPICAL WAVE WILL MOVE W INTO THE W CARIBBEAN FRI AND SAT THEN W OF THE AREA SAT NIGHT. THE TROPICAL ATLC TROPICAL WAVE WILL MOVE INTO THE E CARIBBEAN MON. HISPANIOLA... ISOLATED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS ARE OVER THE DOMINICAN REPUBLIC THIS EVENING. NOW THAT CHANTAL HAS CLEARED HISPANIOLA...THE THREAT OF AFTERNOON SHOWERS/ THUNDERSTORMS WILL REMAIN THROUGH SAT. A SURFACE TROUGH WILL APPROACH THE N PORTION OF THE ISLAND SUN AND COULD INCREASE THE SHOWER ACTIVITY. ATLANTIC OCEAN... AN UPPER LOW IS CENTERED IN THE STRAITS OF FLORIDA NEAR 24N80W AND COVERS THE SW ATLC ENHANCING THE ACTIVITY ASSOCIATED WITH THE REMNANTS OF CHANTAL. SEE SPECIAL FEATURES ABOVE. A STATIONARY FRONT DIPS INTO THE CENTRAL ATLC THROUGH 32N44W ALONG 31N50W TO 29N55W WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 60 NM N OF THE FRONT. A WEAK SURFACE TROUGH EXTENDS FROM 24N51W TO 21N54W AND IS NOT PRODUCING ANY SHOWER ACTIVITY. THE REMAINDER OF THE ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1020 MB HIGH NEAR 22N34W AND A 1022 MB HIGH NE NEAR BERMUDA. SURFACE RIDGE WILL SHIFT EASTWARD THROUGH FRI. A SURFACE TROUGH OVER THE BAHAMAS WILL MOVE NW THEN N AROUND THE PERIPHERY OF THE RIDGE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW