000 AXNT20 KNHC 241044 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT THU JUL 23 2015 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE IN THE TROPICAL ATLC EXTENDS ALONG 38W FROM 9N-17N MOVING W 5-10 KT OVER THE PAST 24 HOURS. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS N OF ANY DEEP MOISTURE. THE NOAA/NESDIS AEROSOL PRODUCT AND THE FIRST VISIBLE SATELLITE IMAGERY INDICATES THAT THE WAVE REMAINS EMBEDDED WITHIN A PLUMB OF AEROSOLS OR SAHARAN DUST LIMITING ANY ASSOCIATED CONVECTION. TROPICAL WAVE IN THE CENTRAL CARIBBEAN EXTENDS ALONG 78W/79W S OF 18N TO ACROSS PANAMA MOVING W NEAR 20 KT OVER THE PAST 24 HOURS. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN A BROAD AREA OF MODERATE TO DEEP MOISTURE THAT COVERS THE CARIBBEAN W OF 74W. NO ASSOCIATED DEEP CONVECTION BUT IS ENHANCING THE ACTIVITY ASSOCIATED WITH THE UPPER LOW. TROPICAL WAVE THAT WAS IN THE W CARIBBEAN IS NOW INLAND OVER CENTRAL AMERICA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 21N16W ALONG 11N23W TO 8N30W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 7N38W 8N51W TO SOUTH AMERICA NEAR 6N58W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 120 NM OF LINE FROM THE COAST OF AFRICA NEAR 12N16W TO 6N26W AND FROM 8N-11N BETWEEN 46W-53W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE WITHIN 120 NM S OF THE ITCZ BETWEEN 31W- 48W. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE IS ANCHORED OVER THE FLORIDA PANHANDLE COVERING THE E GULF WHILE THE UPPER LOW CENTERED IN THE SW GULF NEAR 24N94W COVERS THE REMAINDER OF THE GULF. THE UPPER RIDGE IS PROVIDING DIFFLUNCE ALOFT TO GENERATE SCATTERED TO NUMEROUS SHOWERS WITH ISOLATED THUNDERSTORMS ACROSS THE NE GULF N OF 28N E OF 87W. A WEAK SURFACE RIDGE EXTENDS FROM THE W ATLC THROUGH THE STRAITS OF FLORIDA TO NE TEXAS WITH A 1018 MB HIGH NEAR 25N84W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 60 NM OF THE W COAST OF FLORIDA S OF 28N INCLUDING THE FLORIDA KEYS LEAVING THE REMAINDER OF THE GULF WITH CLEAR SKIES THIS MORNING. SURFACE RIDGE WILL PERSIST THROUGH SUN. A TROUGH OF LOW PRESSURE MAY ENTER THE NE GULF SUN NIGHT. CARIBBEAN SEA... AN UPPER LOW IS CENTERED JUST W OF HAITI IN THE WINDWARD PASSAGE WITH AN UPPER TROUGH COVERING THE CARIBBEAN W OF 70W. THIS UPPER TROUGH COUPLED WITH THE TROPICAL WAVE IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 18N BETWEEN THE WINDWARD PASSAGE AND 80W AND N OF 21N BETWEEN 80W-84W. AN UPPER RIDGE ANCHORED IN THE TROPICAL ATLC EXTENDS ACROSS THE E CARIBBEAN. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE OVER THE SW CARIBBEAN S OF 12N W OF 73W TO OVER CENTRAL AMERICA LEAVING THE REMAINDER OF THE CARIBBEAN WITH MOSTLY CLEAR SKIES THIS MORNING. W ATLC SURFACE RIDGE WILL MAINTAIN MODERATE TO FRESH TRADE WINDS WITH STRONG TO OCCASIONAL NEAR GALE CONDITIONS OCCURRING OFF THE COAST OF COLOMBIA AND VENEZUELA THROUGH SUN. THE CENTRAL CARIBBEAN TROPICAL WAVE WILL MOVE ACROSS THE W CARIBBEAN THROUGH SAT. A SECOND TROPICAL WAVE WILL ENTER THE E CARIBBEAN SUN. ...HISPANIOLA... SKIES HAVE CLEARED ACROSS THE ISLAND THIS MORNING WITH SOME LINGERING SHOWERS/THUNDERSTORMS IN THE WINDWARD PASSAGE. THIS ACTIVITY IS DUE TO THE UPPER LOW OVER THE WINDWARD PASSAGE AND THE TROPICAL WAVE MOVING AWAY FROM THE ISLAND. AS THIS UPPER LOW MOVES W...IT WILL GIVE THE ISLAND SOUTHERLY FLOW ALOFT TODAY AND SAT WITH AN UPPER RIDGE SETTING UP ON SUN. MOISTURE ASSOCIATED WITH THE TROPICAL WAVE WILL LINGER THROUGH THIS MORNING. SAT AND SUN WILL SEE A SLIGHT BREAK IN THE MOISTURE BUT WITH DAYTIME HEATING COULD STILL PRODUCE A CHANCE OF SHOWERS AND POSSIBLE THUNDERSTORMS DURING THE AFTERNOON/EVENINGS HOURS. ATLANTIC OCEAN... AN E/W ELONGATED UPPER RIDGE IS ANCHORED IN THE W ATLC NEAR 30N68W COVERING THE W ATLC N OF 25N W OF 57W AND IS PROVIDING DIFFLUENCE ALOFT TO GENERATE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 75 NM OF LINE FROM 30N73W TO S FLORIDA NEAR MIAMI INCLUDING THE N BAHAMA ISLANDS. THE UPPER LOW CENTERED OVER THE WINDWARD PASSAGE COVERS THE W ATLC S OF 25N AND IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 23N TO OVER THE WINDWARD PASSAGE BETWEEN 72W-75W. AN N-NE/S-SW ELONGATED UPPER LOW IS CENTERED IN THE CENTRAL ATLC NEAR 25N51W SUPPORTING A SURFACE TROUGH THAT EXTENDS FROM 29N47W TO 21N51W AND GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 180 NM EITHER SIDE OF THE TROUGH AND FROM 27N-31N BETWEEN 54W- 59W. THE ATLC BASIN IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1028 MB HIGH N OF THE DISCUSSION AREA NEAR 33N36W AND EXTENDING A RIDGE AXIS THROUGH A 1022 MB HIGH NEAR 26N55W THEN W THROUGH THE STRAITS OF FLORIDA AND INTO THE GULF OF MEXICO. SURFACE RIDGE WILL RETREAT EASTWARD AND WEAKEN TONIGHT AND SAT AS A WEAK LOW MOVES OFF THE SE U.S. COAST. THE LOW WILL THEN MOVE N OF THE AREA SUN NIGHT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW