000 AXNT20 KNHC 290001 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE JUL 28 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... GALE WARNING... A GALE WARNING WILL GO INTO EFFECT OVERNIGHT TONIGHT AND END THU NIGHT FOR THE AREA FROM 11N-14N BETWEEN 74W-78W IN THE SW CARIBBEAN. THESE GALE FORCE WINDS WILL BE THE RESULT OF A STRONG PRESSURE GRADIENT BETWEEN W ATLC HIGH PRESSURE AND LOWER PRESSURE OVER THE SW CARIBBEAN AND SOUTH AMERICA. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE IN THE E TROPICAL ATLC EXTENDS ALONG 31W/32W FROM 11N-20N MOVING W 15-20 KT OVER THE PAST 24 HOURS. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN A LOW AMPLITUDE SURGE OF DEEP MOISTURE. THE NOAA/NESDIS AEROSOL PRODUCT AND THE LAST VISIBLE SATELLITE IMAGERY INDICATES THAT THE WAVE REMAINS WITHIN A PLUMB OF AEROSOLS OR SAHARAN DUST LIMITING ANY ASSOCIATED CONVECTION. TROPICAL WAVE IN THE W TROPICAL ATLC EXTENDS ALONG 51W/52W FROM 9N-19N MOVING W NEAR 20 KT OVER THE PAST 24 HOURS. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN A SURGE OF MODERATE MOISTURE. THE NOAA/NESDIS AEROSOL PRODUCT AND THE LAST 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 74W/75W S OF 18N TO OVER SOUTH AMERICA MOVING W 20-25 KT OVER THE PAST 24 HOURS. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN A WEAK SURGE OF MODERATE MOISTURE. THE NOAA/NESDIS AEROSOL PRODUCT AND THE VISIBLE SATELLITE IMAGERY INDICATES THAT THE WAVE REMAINS WITHIN A PLUMB OF AEROSOLS OR SAHARAN DUST LIMITING ANY ASSOCIATED CONVECTION. TROPICAL WAVE IN THE W CARIBBEAN EXTENDS ALONG 88W FROM S OF 19N TO OVER CENTRAL AMERICA MOVING W-SW 15-20 KT OVER THE PAST 24 HOURS. THE TOTAL PRECIPITABLE WATER IMAGERY SHOWS THE WAVE IS EMBEDDED WITHIN A EDGE OF SURGE OF MODERATE TO DEEP MOISTURE. WAVE IS ALONG THE COAST OF THE YUCATAN PENINSULA WITH ANY ACTIVITY INLAND OVER THE YUCATAN. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 16N17W ALONG 10N32W TO 11N43W WHERE THE ITCZ BEGINS AND CONTINUES TO E OF THE TROPICAL WAVE NEAR 10N50W THEN RESUMES W OF THE WAVE NEAR 9N53W TO SOUTH AMERICA NEAR 7N58W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 7N TO THE MONSOON TROUGH AND WITHIN 120 NM N OF THE MONSOON TROUGH BETWEEN 18W-30W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER RIDGE COVERS THE GULF OF MEXICO AND THE E CONUS ANCHORED OVER THE LOWER MISSISSIPPI VALLEY. A 1012 MB LOW IS OVER THE FLORIDA PENINSULA NEAR GAINSVILLE WITH A SURFACE TROUGH EXTENDING W ALONG 28N86W TO 29N88W WITH A SECOND SURFACE TROUGH EXTENDING E INTO THE W ATLC. SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE OVER THE NE GULF N OF 26N TO THE SURFACE TROUGH E OF 87W TO ACROSS FLORIDA. A WEAK SURFACE RIDGE EXTENDS FROM THE W ATLC THROUGH THE STRAITS OF FLORIDA TO LOUISIANA WITH A 1018 MB HIGH NEAR 25N84W. AN UPPER LOW OVER THE NW CARIBBEAN IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND AND ALONG THE IMMEDIATE COAST OF CUBA W OF 82W AND ACROSS THE YUCATAN CHANNEL TO NE YUCATAN PENINSULA. THIS IS LEAVING THE REMAINDER OF THE GULF WITH CLEAR SKIES THIS EVENING. LOW PRESSURE OVER FLORIDA WILL MOVE INTO THE W ATLC OVERNIGHT. THE SURFACE RIDGE WILL PERSIST THROUGH THU. CARIBBEAN SEA... AN UPPER LOW IS CENTERED OVER THE CAYMAN ISLANDS COVERING THE NW CARIBBEAN GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND AND ALONG THE IMMEDIATE COAST OF CUBA W OF 83W AND ACROSS THE YUCATAN CHANNEL N OF 21N. A SECOND UPPER LOW IS CENTERED OVER THE VIRGIN ISLANDS COVERING THE E CARIBBEAN E OF 68W. AFTERNOON SHOWERS/THUNDERSTORMS HAVE DEVELOPED INLAND OVER JAMAICA BUT ARE BEGINNING TO DISSIPATE. THE NOAA/NESDIS AEROSOL PRODUCT AND THE VISIBLE SATELLITE IMAGERY INDICATES THE CARIBBEAN IS COVERED A PLUMB OF AEROSOLS OR SAHARAN DUST. THIS IS LEAVING THE REMAINDER OF THE CARIBBEAN WITH MOSTLY CLEAR SKIES THIS EVENING. W ATLC SURFACE RIDGE WILL MAINTAIN NEAR GALE TRADE WINDS THROUGH THU INCREASING GALE FORCE OVERNIGHT TONIGHT THROUGH THU NIGHT ALONG THE COAST OF COLOMBIA. W CARIBBEAN TROPICAL WAVE WILL MOVE OVER THE YUCATAN TONIGHT. E CARIBBEAN TROPICAL WAVE CONTINUE W MOVING ACROSS THE W CARIBBEAN WED AND THU. A THIRD TROPICAL WAVE WILL ENTER THE E CARIBBEAN ON WED NIGHT AND THE CENTRAL CARIBBEAN BY THU NIGHT. ...HISPANIOLA... SKIES REMAIN CLEAR ACROSS THE ISLAND THIS EVENING. THE UPPER LOW OVER THE VIRGIN ISLANDS WILL SHIFT W TO OVER HISPANIOLA WED NIGHT THEN PERSIST THROUGH THU. MOISTURE WILL INCREASE AGAIN THU NIGHT AHEAD OF THE NEXT TROPICAL WAVE. HOWEVER DAYTIME HEATING COULD STILL PRODUCE A CHANCE OF OF ISOLATED SHOWERS AND POSSIBLE THUNDERSTORMS DURING THE AFTERNOON/EVENINGS HOURS THROUGH THU. ATLANTIC OCEAN... THE UPPER RIDGE OVER THE E CONUS AND GULF OF MEXICO EXTENDS OVER THE FAR W ATLC N OF 26N W OF 76W WITH A BROAD UPPER TROUGH JUST N OF THE DISCUSSION AREA SUPPORTING A STATIONARY FRONT THAT EXTENDS ALONG 32N BETWEEN BERMUDA AND A WEAK 1014 MB LOW NEAR 32N76W THEN TO 31N80W. A SURFACE TROUGH EXTENDS FROM THE 1012 MB LOW OVER FLORIDA INTO THE W ATLC NEAR SAINT AUGUSTINE TO 31N79W. THIS IS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF A LINE FROM 26N77W 29N70W TO 32N62W. SCATTERED TO NUMEROUS SHOWERS/ISOLATED THUNDERSTORMS ARE N OF 27N TO THE SURFACE TROUGH AND W OF 79W TO INLAND OVER FLORIDA. A SURFACE RIDGE COVERS THE E ATLC ANCHORED BY A 1026 MB HIGH ABOUT 250 NM S-SW OF THE AZORES WITH A NARROWING RIDGE AXIS S OF THE W ATLC FRONTAL SYSTEM AND EXTENDS THROUGH 32N38W TO A 1020 MB HIGH NEAR 26N60W THEN THROUGH THE STRAITS OF FLORIDA INTO THE GULF OF MEXICO. THIS NARROW RIDGE AXIS WILL SHIFT SLIGHTLY S TONIGHT AND WED. THE LOW OVER FLORIDA WILL MOVE INTO THE W ATLC TONIGHT THEN SHIFT N OF THE AREA BY THU. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW