000 AXNT20 KNHC 210547 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE JUL 21 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE OFF THE COAST OF AFRICA EXTENDS ALONG 19W FROM 6N- 15N MOVING W NEAR 10 KT OVER THE PAST 12 HOURS. WAVE COINCIDES WITH A BROAD 700 MB TROUGH THAT COVERS THE AREA BETWEEN AFRICA AND THE CAPE VERDE ISLANDS AS DEPICTED BY THE GLOBAL MODEL. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN A LOW AMPLITUDE SURGE OF MODERATE MOISTURE. THE NOAA/NESDIS AEROSOL PRODUCT AND THE LAST VISIBLE SATELLITE IMAGERY INDICATES THAT THE WAVE IS EMBEDDED WITHIN A PLUMB OF AEROSOLS OR SAHARAN DUST LIMITING ANY ASSOCIATED CONVECTION. TROPICAL WAVE IN THE W TROPICAL ATLC EXTENDS ALONG 50W/51W FROM 6N-16N MOVING W 20-25 KT OVER THE PAST 24 HOURS. WAVE IS EMBEDDED WITHIN A 700 MB TROUGH AS DEPICTED BY THE GLOBAL MODEL. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN AN SURGE OF MODERATE TO DEEP MOISTURE. HOWEVER THE NOAA/NESDIS AEROSOL PRODUCT AND THE LAST VISIBLE SATELLITE IMAGERY INDICATES THAT THE WAVE IS ALSO EMBEDDED WITHIN A PLUMB OF AEROSOLS OR SAHARAN DUST LIMITING ANY ASSOCIATED CONVECTION. TROPICAL WAVE IN THE E CARIBBEAN EXTENDS ALONG 63W S OF 20N TO INLAND OVER VENEZUELA MOVING W NEAR 20 KT OVER THE PAST 24 HOURS. WAVE COINCIDES WITH A LOW AMPLITUDE 700 MB TROUGH S OF 16N AS DEPICTED BY THE GLOBAL MODEL. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN AN SURGE OF DEEP MOISTURE THAT EXTENDS NE OF THE WAVE. THE NOAA/NESDIS AEROSOL PRODUCT AND THE LAST VISIBLE SATELLITE IMAGERY INDICATES THAT THE WAVE IS ALONG THE LEADING EDGE OF A PLUMB OF AEROSOLS OR SAHARAN DUST. HOWEVER S OF THE AEROSOLS OR SAHARAN DUST IS SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 11N-14N BETWEEN 61W-64W. TROPICAL WAVE IN THE CENTRAL CARIBBEAN EXTENDS ALONG 70W S OF 17N TO INLAND OVER VENEZUELA MOVING W-SW 20-25 KT OVER THE PAST 24 HOURS. WAVE IS TRAILING THE 700 MB TROUGH THAT COVERS THE CENTRAL CARIBBEAN AS DEPICTED BY THE GLOBAL MODEL. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN A LOW AMPLITUDE SURFACE OF MODERATE TO DEEP MOISTURE. THE NOAA/NESDIS AEROSOL PRODUCT AND THE LAST VISIBLE SATELLITE IMAGERY INDICATES THAT THE WAVE IS ALSO EMBEDDED WITHIN A PREVIOUS PLUMB OF AEROSOLS OR SAHARAN DUST AGAIN LIMITING ANY ASSOCIATED CONVECTION. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS BEGINS W OF THE EASTERN MOST TROPICAL WAVE NEAR 9N21W AND EXTENDS TO 7N31W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 6N41W TO 8N49W. SCATTERED MODERATE CONVECTION IS WITHIN 75 NM OF LINE FROM 10N15W TO 6N24W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 120 NM N OF MONSOON TROUGH BETWEEN 24W-30W...WITHIN 60 NM EITHER SIDE OF THE ITCZ BETWEEN 30W-35W...AND WITHIN 90 NM N OF THE ITCZ BETWEEN 39W- 43W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE REMAINS OVER E TEXAS COVERING THE NW GULF WHILE A SECOND UPPER RIDGE HAS DEVELOPED TO THE E OVER E GEORGIA COVERING THE NE GULF. THE UPPER LOW CENTERED OVER THE NE YUCATAN PENINSULA COVERS THE S GULF. THE DIURNAL SURFACE TROUGH IS ALONG THE W COAST OF THE YUCATAN GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 20N BETWEEN 91W-93W. A SURFACE RIDGE EXTENDS FROM THE W ATLC ACROSS THE STRAITS OF FLORIDA THROUGH A 1017 MB HIGH NEAR HAVANA CUBA TO 23N90W. ISOLATED SHOWERS ARE POSSIBLE ACROSS THE N GULF N OF 27N LEAVING THE REMAINDER OF THE GULF WITH FAIR WEATHER TONIGHT. SURFACE RIDGE WILL CHANGE LITTLE THROUGH THU. TROUGH WILL DEVELOP OVER THE NE GULF WED NIGHT THEN DRIFT E-SE THU. CARIBBEAN SEA... AN UPPER LOW IS CENTERED OVER NE YUCATAN PENINSULA NEAR CANCUN COVERING THE NW CARIBBEAN AND INTO THE GULF OF MEXICO. AN UPPER RIDGE ANCHORED IN THE TROPICAL ATLC EXTENDS AN UPPER RIDGE AXIS ACROSS THE WINDWARD ISLANDS NEAR GRENADA ALONG 14N72W TO 14N84W. AN UPPER TROUGH OVER THE W/CENTRAL ATLC EXTENDS S OVER THE ISLANDS BETWEEN THE VIRGIN ISLANDS AND HISPANIOLA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE OVER THE SW CARIBBEAN WITHIN 90 NM ALONG THE COAST OF PANAMA. ISOLATED SHOWERS/THUNDERSTORMS ARE ACROSS THE FAR E CARIBBEAN E OF 66W ASSOCIATED WITH THE TROPICAL WAVE. ISOLATED SHOWERS PERSIST OVER CENTRAL HISPANIOLA. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN WITH MOSTLY CLEAR SKIES TONIGHT. W ATLC SURFACE RIDGE WILL MAINTAIN FRESH TO OCCASIONALLY STRONG TRADE WINDS ACROSS THE S/CENTRAL CARIBBEAN THROUGH THU. CENTRAL CARIBBEAN TROPICAL WAVE WILL MOVE INTO THE W CARIBBEAN TUE NIGHT THROUGH THU. THE E CARIBBEAN TROPICAL WAVE WILL MOVE INTO THE CENTRAL CARIBBEAN WED AND WED NIGHT. THE THIRD TROPICAL WAVE WILL MOVE INTO THE E CARIBBEAN WED AFTERNOON. ...HISPANIOLA... CURRENTLY...ISOLATED SHOWERS ARE ACROSS THE CENTRAL PORTION OF THE ISLAND. AN UPPER TROUGH OVER THE W/CENTRAL ATLC COVERS THE ISLANDS FROM THE VIRGIN ISLANDS TO HISPANIOLA AND WILL PERSIST THROUGH MID WEEK. MOISTURE WILL INCREASE LATE TUE EVENING AHEAD OF A TROPICAL WAVE THAT MOVE ACROSS THE ISLAND TUE NIGHT WITH A SECOND TROPICAL WAVE MOVING ACROSS THE ISLAND LATER IN THE WEEK. THIS WILL INCREASE THE CHANCE OF SHOWERS AND POSSIBLE THUNDERSTORMS STARTING TUE AFTERNOON. ATLANTIC OCEAN... AN UPPER RIDGE COVERS THE W ATLC N OF 27N W OF 70W. AN UPPER TROUGH EXTENDS FROM A N UPPER LOW IN THE N/CENTRAL ATLC NEAR 32N43W ALONG 26N56W TO A SECOND WEAKER UPPER LOW NEAR 23N64W THEN CONTINUING TO 23N71W. AN UPPER RIDGE IS TO THE S ANCHORED NEAR 13N50W COVERING THE TROPICAL ATLC. BETWEEN THESE UPPER FEATURES IS A MID LEVEL LOW CENTERED NEAR 25N47W GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS FROM 23N- 29N BETWEEN 44W-52W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 15N-23N BETWEEN 60W-65W INCLUDING THE LEEWARD AND VIRGIN ISLANDS ASSOCIATED WITH THE TROPICAL WAVE IN THE E CARIBBEAN. THE ATLC BASIN IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1024 MB HIGH NEAR 28N46W WITH A RIDGE AXIS EXTENDING THROUGH 27N63W INTO THE GULF OF MEXICO THROUGH THE STRAITS OF FLORIDA. SURFACE RIDGE WILL CHANGE LITTLE THROUGH THU. THE N PORTION OF THE TROPICAL WAVE ALONG 53W/54W WILL MOVE ACROSS THE SW ATLC THROUGH THU. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW