000 AXNT20 KNHC 201038 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT MON JUL 20 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 CENTRAL TROPICAL ATLC EXTENDS ALONG 43W/44W FROM 6N-17N MOVING W 15-20 KT OVER THE PAST 24 HOURS. WAVE IS TRAILING THE 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 W TROPICAL ATLC EXTENDS ALONG 55W/56W FROM 8N-22N MOVING W 10-15 KT OVER THE PAST 24 HOURS. WAVE COINCIDES WITH A LOW AMPLITUDE 700 MB TROUGH S OF 14N AS DEPICTED BY THE GLOBAL MODEL. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN AN SURGE OF DEEP MOISTURE THAT EXTENDS N OF 26N. 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 9N-11N BETWEEN 51W-53W AND FROM 10N-13N BETWEEN 53W-56W. TROPICAL WAVE IN THE E CARIBBEAN EXTENDS ALONG 62W/63W FROM 10N- 19N MOVING W NEAR 10 KT OVER THE PAST 24 HOURS. WAVE IS TRAILING THE 700 MB TROUGH THAT COVERS THE FAR E CARIBBEAN AND EXTENDS N INTO THE CENTRAL ATLC AS DEPICTED BY THE GLOBAL MODEL. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN AN AREA OF MODERATELY DRY AIR. 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 EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 14N17W ALONG 8N23W TO 9N33W WHERE THE ITCZ BEGINS AND CONTINUES TO E OF THE EASTERN MOST TROPICAL WAVE NEAR 11N42W THEN RESUMES W OF THE WAVE NEAR 11N45W TO THE NEXT WAVE NEAR 9N53W THEN RESUMES NEAR 10N57W TO SOUTH AMERICA NEAR 8N59W. SCATTERED MODERATE CONVECTION IS FROM 6N-9N BETWEEN 28W-32W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE COVERS THE N GULF AND INTO THE W ATLC ANCHORED OVER E TEXAS WHILE AN INVERTED UPPER TROUGH OVER THE W CARIBBEAN IS GIVING THE S GULF EASTERLY FLOW ALOFT. A SURFACE TROUGH EXTENDS FROM NE FLORIDA INTO THE GULF NEAR 29.5N83.5W TO 29N89W AND IS GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS N OF 27N E OF 89W. THE DIURNAL SURFACE TROUGH IS OVER THE E BAY OF CAMPECHE ALONG 92W S OF 21N GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 20N E OF 94W. THE REMAINDER OF THE GULF IS DOMINATED BY A SURFACE RIDGE THAT EXTENDS FROM THE W ATLC ACROSS S FLORIDA TO NE MEXICO WITH A 1018 MB HIGH NEAR 24N86W. THIS IS LEAVING THE REMAINDER OF THE GULF WITH FAIR WEATHER THIS MORNING. SURFACE RIDGE WILL SHIFT TO THE E GULF TODAY THEN CHANGE LITTLE THROUGH MID WEEK. CARIBBEAN SEA... AN INVERTED UPPER TROUGH EXTENDS FROM GUATEMALA INTO THE GULF OF HONDURAS TO E CUBA COVERING THE W CARIBBEAN W OF 80W. AN UPPER RIDGE ANCHORED IN THE TROPICAL ATLC EXTENDS AN UPPER RIDGE AXIS ACROSS THE LESSER ANTILLES NEAR MARTINIQUE ALONG 14N73W TO 15N80W. THE SOUTHERLY FLOW ALOFT ACROSS THE S CARIBBEAN IS ADVECTING UPPER MOISTURE OVER THE S CARIBBEAN BRINGING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF LINE FROM COLOMBIA NEAR 10N75W 11N81W TO NICARAGUA NEAR 13N84W. ISOLATED SHOWERS/ THUNDERSTORMS REMAIN OFF THE COAST OF CUBA FROM 18N-21N BETWEEN 78W-80W. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE OVER SW HAITI. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN WITH MOSTLY CLEAR SKIES THIS MORNING. ATLC SURFACE RIDGE WILL MAINTAIN FRESH TO OCCASIONALLY STRONG TRADE WINDS ACROSS THE S/CENTRAL CARIBBEAN THROUGH MID WEEK. E CARIBBEAN TROPICAL WAVE WILL MOVE ACROSS THE CENTRAL CARIBBEAN TUE THROUGH WED NIGHT. THE NEXT TROPICAL WAVE WILL ENTER THE E CARIBBEAN EARLY TUE AND MOVE THROUGH THE E CARIBBEAN BY WED NIGHT. THE THIRD TROPICAL WAVE WILL MOVE INTO THE E CARIBBEAN THU. ...HISPANIOLA... CURRENTLY...SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE OVER SW HAITI. AN UPPER TROUGH OVER THE CENTRAL ATLC DIPS S OVER THE N PORTION OF THE ISLAND. THIS UPPER TROUGH WILL ENCOMPASS THE ISLAND BY TONIGHT AND WILL PERSIST THROUGH MID WEEK. MOISTURE WILL INCREASE LATE TONIGHT AHEAD OF A SERIES OF TROPICAL WAVES THAT MOVE ACROSS THE ISLAND TUE THROUGH THE END OF 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 23N W OF 70W. AN UPPER LOW IS IN THE N/CENTRAL ATLC NEAR 30N51W EXTENDING AN UPPER TROUGH SW ALONG 24N65W TO OVER THE N PORTION OF HISPANIOLA. AN UPPER RIDGE IS TO THE S ANCHORED NEAR 15N53W COVERING THE TROPICAL ATLC. BETWEEN THESE UPPER FEATURES...IS AN AREA OF DIFFLUNCE ALOFT THAT IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 23N-27N BETWEEN 50W-55W. THE ATLC BASIN IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1024 MB HIGH NEAR 29N45W WITH A RIDGE AXIS EXTENDING THROUGH 26N69W INTO THE GULF OF MEXICO OVER S FLORIDA. SURFACE RIDGE WILL SHIFT SLIGHTLY S TUE NIGHT THE CHANGE LITTLE THROUGH MID WEEK. THE N PORTION OF THE TROPICAL WAVE ALONG 53W/54W WILL MOVE ACROSS THE SW ATLC MON THROUGH WED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW