000 AXNT20 KNHC 040545 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU JUL 04 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. ...TROPICAL WAVES... TROPICAL WAVE OVER THE CAPE VERDE ISLANDS EXTENDS FROM 21N22W TO 11N24W MOVING NW 15 KT. WAVE REMAINS WITHIN A SURGE OF MODERATE MOISTURE AS DEPICTED BY THE TOTAL PRECIPITABLE WATER IMAGERY. A SWATH OF DRIER AIR IS BEING INTRODUCED ALONG THE WAVE BY THE MID LEVEL SWIRL THAT IS CENTERED NEAR 18N23W. NO ASSOCIATED DEEP CONVECTION. TROPICAL WAVE IN THE CENTRAL TROPICAL ATLC EXTENDS FROM 17N37W TO 6N47W MOVING W-NW NEAR 15 KT. WAVE REMAINS EMBEDDED WITHIN A SURGE OF DEEP MOISTURE AS DEPICTED BY THE TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS ARE WITHIN 120 NM EITHER SIDE OF THE WAVE AXIS. TROPICAL WAVE EXTENDS FROM 23N61W TO ACROSS THE VIRGIN ISLANDS TO 14N67W IN THE NE CARIBBEAN MOVING W-NW 10-15 KT. WAVE REMAINS WITHIN AN AREA VOID OF DEEP MOISTURE AS DEPICTED BY THE TOTAL PRECIPITABLE WATER IMAGERY. NO ASSOCIATED SHOWERS/CONVECTION. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 11N15W AND CONTINUES ALONG 8N19W TO 7N25W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 8N31W TO 12N38W. CLUSTERS OF SCATTERED MODERATE TO SCATTERED STRONG CONVECTION ARE FROM 5N- 11N E OF 21W TO THE COAST OF W AFRICA AND FROM 5N-9N BETWEEN 21W- 28W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 5N TO S OF THE EQUATOR BETWEEN 41W-48W AND WITHIN 120 NM ALONG THE COAST OF SOUTH AMERICA BETWEEN 51W-57W. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH COVERS THE GULF N OF 21N W OF 88W EXTENDING FROM AN UPPER LOW OVER THE MISSOURI/KANSAS BORDER AND SUPPORTING A SURFACE TROUGH THAT AT 04/0300 UTC EXTENDS INTO THE GULF OVER MOBILE BAY ALABAMA ACROSS THE MISSISSIPPI DELTA ALONG 29N90W 24N92W TO THE BAY OF CAMPECHE 20N94W. ISOLATED SHOWERS/ THUNDERSTORMS ARE POSSIBLE WITHIN 60/75 NM EITHER SIDE OF THE TROUGH. AN UPPER RIDGE EXTENDS FROM THE YUCATAN PENINSULA ALONG 24N85W TO ACROSS NE FLORIDA INTO THE W ATLC AND IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS E OF A LINE FROM S MEXICO NEAR 20N97W ALONG 21N92W 25N88W TO THE N GULF COAST NEAR 30N87W. THE SURFACE RIDGE OVER THE ATLC BASIN IS BEGINNING TO SHIFT W INTO THE FAR E GULF. SURFACE TROUGH WILL SHIFT W THROUGH FRI TO OVER THE W GULF THEN WILL MOVE TO ALONG THE COASTAL PLAINS OF MEXICO SAT. WEAK SURFACE LOW MAY FORM ALONG THE TROUGH BEFORE IT MOVES INLAND. CARIBBEAN SEA... AN UPPER RIDGE COVERS THE CARIBBEAN W OF 70W AND IS ANCHORED OVER THE YUCATAN PENINSULA. AN ELONGATED UPPER LOW IS CENTERED OVER THE CENTRAL BAHAMAS AND EXTENDS S TO THE N COAST OF HISPANIOLA AND W CUBA. THE UPPER RIDGE IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 19N W OF 74W AND W OF 85W TO OVER CENTRAL AMERICA AND THROUGH THE YUCATAN CHANNEL. THE MONSOON TROUGH EXTENDS ACROSS PORTIONS OF PANAMA IN THE E PACIFIC REGION GENERATING ISOLATED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 12N W OF 80W. EASTERLY TRADE WINDS ARE USHERING IN SOME SCATTERED LOW LEVEL SHOWERS OVER THE FAR E CARIBBEAN N OF 14N W OF THE TROPICAL WAVE AND ARE BEING ENHANCED BY THIS TROPICAL WAVE. THE CARIBBEAN TROPICAL WAVE WILL CONTINUE TO MOVE QUICKLY ACROSS THE BASIN AND THROUGH THE CENTRAL CARIBBEAN THU AND ACROSS W CARIBBEAN AND INTO CENTRAL AMERICA FRI AND SAT. THE ATLC SURFACE RIDGE IS PRODUCING FRESH TO STRONG TRADE WINDS ACROSS THE CENTRAL CARIBBEAN THIS EVENING BUT WILL DIMINISH SLIGHTLY AHEAD OF THE TROPICAL WAVE AS IT MOVES ACROSS THE CENTRAL CARIBBEAN THU THEN INCREASE AGAIN FRI BEHIND THE WAVE. ANOTHER TROPICAL WAVE IS EXPECTED TO REACH THE E CARIBBEAN SAT AND SUN. HISPANIOLA... AN ELONGATED UPPER LOW CENTERED OVER THE CENTRAL BAHAMAS IS N OF HISPANIOLA. GLOBAL MODELS SHOW THAT THIS UPPER LOW WILL CONTINUE TO MOVE NW AWAY FROM HISPANIOLA ALLOWING ANOTHER UPPER LOW TO MOVE IN FROM THE E ON SAT. A TROPICAL WAVE WILL MOVE ACROSS THE ISLAND THU INTO FRI INCREASING SHOWERS/THUNDERSTORMS. THE TYPICAL AFTERNOON SHOWERS AND THUNDERSTORMS WILL THEN REMAIN POSSIBLE OVER THE ISLAND THROUGH THE WEEKEND. ATLANTIC OCEAN... THE UPPER RIDGE AXIS THAT EXTENDS FROM THE NW CARIBBEAN ACROSS THE GULF OF MEXICO AND NE FLORIDA CONTINUES TO OVER SOUTH CAROLINA COAST COVERING THE W ATLC W OF 78W AND PROVIDING DIFFLUNCE ALOFT TO GENERATE ISOLATED SHOWERS/THUNDERSTORMS W OF 78W. AN ELONGATED UPPER LOW IS CENTERED OVER THE CENTRAL BAHAMAS AND IS GENERATING ISOLATED SHOWERS WITH POSSIBLE ISOLATED THUNDERSTORMS FROM 20N-26N BETWEEN 70W-75W. A LARGE SURFACE RIDGE DOMINATES THE ATLC ANCHORED BY A SERIES OF HIGHS WELL N OF THE DISCUSSION AREA. SURFACE RIDGE WILL CHANGE LITTLE THROUGH SAT THEN WEAKEN SUN. THE N PORTION OF A TROPICAL WAVE MOVING ACROSS THE E CARIBBEAN WILL MOVE W ACROSS THE SOUTHERN BAHAMAS LATE TONIGHT THROUGH THU EVENING FOLLOWED BY YET ANOTHER TROPICAL WAVE MOVING W THROUGH S PORTIONS OF THE AREA FRI THROUGH SUN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW