000 AXNT20 KNHC 270005 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN JUL 26 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 2345 UTC. ...TROPICAL WAVES... A TROPICAL WAVE CAME OFF THE WEST AFRICAN COAST EARLIER THIS AFTERNOON. ITS AXIS IS ALONG 19W...MOVING W AT APPROXIMATELY 10 TO 15 KT. SSMI TPW IMAGERY SHOW THE WAVE IS MAINLY ASSOCIATED WITH A MODERATE AIRMASS THAT ALONG WITH A MIDDLE TO UPPER LEVEL DIFFLUENT WIND ENVIRONMENT SUPPORT A CLUSTER OF MODERATE CONVECTION FROM 10N TO 14N BETWEEN 18W AND 22W AND SCATTERED MODERATE CONVECTION FROM 08N TO 12N E OF 19W. THE REMAINDER WAVE ENVIRONMENT IS UNDER THE INFLUENCE OF SAHARAN DRY AIR AND DUST...WHICH IS HINDERING CONVECTION. A TROPICAL WAVE IS OVER THE CENTRAL ATLC WITH AXIS ALONG 32W...MOVING W AT APPROXIMATELY 15 KT. SHALLOW MOISTURE IS AHEAD OF THE WAVE AXIS WHILE A SURGE OF MODERATE TO DEEP MOISTURE IS BEHIND IT. UPPER-LEVEL WIND DIFFLUENCE SUPPORT SCATTERED MODERATE CONVECTION SE OF THE WAVE AXIS FROM 06N TO 10N BETWEEN 25W AND 34W. SAHARAN DRY AIR AND DUST COVER THE NORTHERN WAVE ENVIRONMENT...THUS HINDERING CONVECTION. A TROPICAL WAVE IS WITHIN 360 NM E OF THE LESSER ANTILLES WITH AXIS NEAR 54W...MOVING W AT 20 KT. SSMI TPW IMAGERY AND ENHANCED METEOSAT IMAGERY SHOW DRY AIR AND DUST OVER THE ENTIRE WAVE ENVIRONMENT...THUS SUPPORTING LACK OF CONVECTION. A TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN WITH AXIS NEAR 73W ...MOVING W AT APPROXIMATELY 20 KT. SSMI TPW IMAGERY SHOW DRY AIR AHEAD OF THE WAVE AXIS AND A MODERATE TO DEEP MOIST AIRMASS BEHIND IT...WHICH IS ENHANCING ISOLATED SHOWERS AND TSTMS OVER HISPANIOLA AND SOUTHERN ADJACENT WATERS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE WEST AFRICAN COAST NEAR 10N15W TO 08N30W TO 07N42W. THE ITCZ BEGINS NEAR 07N42W AND CONTINUES TO THE COAST OF GUYANA. FOR CONVECTION INFORMATION...SEE THE TROPICAL WAVES SECTION. ...DISCUSSION... GULF OF MEXICO... SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS COVERS THE EASTERN GULF S OF 29N AND EXTENDS W-NW TO INLAND SOUTHERN LOUISIANA AND FAR EASTERN TEXAS. THIS CONVECTION IS ASSOCIATED WITH A 1010 MB LOW PRESSURE CENTER W OF TAMPA NEAR 27N83W FROM WHICH A SURFACE TROUGH EXTENDS FROM 30N82W TO THE LOW TO 25N85W. THIS LOW PRESSURE SYSTEM IS BEING SUPPORTED BY A MIDDLE LEVEL LOW CENTERED NEAR 26N84W. AT THE UPPER-LEVELS...THE SOUTHERN PERIPHERY OF A BROAD RIDGE CENTERED OVER SOUTHERN MISSISSIPPI COVERS THE GULF OF MEXICO AND SUPPORT AT 1014 MB HIGH NEAR 24N89W. VARIABLE WIND IN THE RANGE OF 5 TO 10 KT DOMINATES THE BASIN...EXCEPT OVER THE SE GULF WHERE SW TO W FLOW OF 15 KT IS OBSERVED. SHOWERS AND TSTMS ACROSS THE E GULF WILL CONTINUE THROUGH TUESDAY NIGHT...RIDGING WILL PREVAIL ELSEWHERE. CARIBBEAN SEA... AN ELONGATED UPPER-LEVEL LOW CONTINUES TO DOMINATE ACROSS WESTERN CARIBBEAN WATERS WHILE A WEAK RIDGE COVERS THE REMAINDER BASIN. THE UPPER LOW ALONG SHALLOW MOISTURE OVER THE NW BASIN SUPPORT SCATTERED SHOWERS AND TSTMS ALONG CUBA. A TROPICAL WAVE IS MOVING ACROSS THE CENTRAL BASIN WITH A SURGE OF MOISTURE E OF ITS AXIS THAT SUPPORTS SCATTERED TO ISOLATED SHOWERS AND TSTMS ACROSS HISPANIOLA AND ADJACENT SOUTHERN WATERS. DEEP LAYER DRY AIR DOMINATES ELSEWHERE...THUS SUPPORTING FAIR WEATHER. A TIGHT PRESSURE GRADIENT IS EXPECTED TO BUILD OVER THE S-SW CARIBBEAN DURING THE NEXT 24 HOURS AND GALE-FORCE WINDS ARE FORECAST TO DEVELOP TUESDAY MORNING. THE TROPICAL WAVE WILL MOVE OVER THE W BASIN BRINGING SHOWERS TO JAMAICA MONDAY...AND THE CAYMAN ISLANDS MONDAY NIGHT. THE NEXT TROPICAL WAVE WILL ENTER THE E CARIBBEAN MONDAY EVENING. ...HISPANIOLA... A TROPICAL WAVE IS MOVING ACROSS THE CENTRAL CARIBBEAN ASSOCIATED WITH A MODERATE MOIST AIRMASS E OF ITS AXIS THAT ENHANCES SCATTERED TO ISOLATED SHOWERS ACROSS THE ISLAND AND SOUTHERN ADJACENT WATERS. THE WAVE WILL BE WEST OF THE ISLAND BY MONDAY AND DRY AIR TRAILING THE WAVE WILL MOVE ACROSS THE ISLAND...THUS SUPPRESSING SHOWERS THROUGH TUESDAY MORNING. ATLANTIC OCEAN... A DIFFLUENT WIND ENVIRONMENT AT THE MIDDLE-LEVELS COVER THE FAR SW N ATLC BASIN AND ALONG WITH DEEP MOISTURE IN THIS REGION SUPPORT SCATTERED TO ISOLATED SHOWERS AND TSTMS W OF 72W...INCLUDING THE NORTHERN BAHAMAS. ANOTHER REGION OF DIFFLUENCE IN THE UPPER-LEVELS SUPPORT SIMILAR CONVECTION N OF 25N BETWEEN 53W AND 60W. THE REMAINDER BASIN N OF 16N CONTINUES UNDER THE INFLUENCE OF A BROAD SURFACE RIDGE...WHICH SUPPORT FAIR WEATHER. FOR TROPICAL WAVES INFORMATION...SEE SECTION AT THE TOP OF THE DISCUSSION. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR