000 AXNT20 KNHC 180604 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE AUG 18 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 0545 UTC. ...SPECIAL FEATURES... A TROPICAL WAVE IS OVER THE CENTRAL ATLC ASSOCIATED WITH A 1011 MB LOW PRESSURE CENTER EMBEDDED IN THE MONSOON TROUGH NEAR 09N33W. THE SYSTEM IS MOVING W AT 10-15 KT OVER A PERIOD OF 24 HOURS. CIRA LAYER PRECIPITABLE WATER IMAGERY FROM THE SURFACE TO 850 MB SHOW THE WAVE IS ASSOCIATED WITH A BROAD AREA OF MODERATE MOISTURE THAT ALONG WITH A DIVERGENT WIND ENVIRONMENT ALOFT SUPPORT SCATTERED MODERATE CONVECTION FROM 06N TO 11N BETWEEN 30W AND 39W. SAHARAN DRY AIR AND DUST ENGULF THE SYSTEM...THUS HINDERING CONVECTION ELSEWHERE. THERE IS A HIGH CHANCE THIS SYSTEM WILL DEVELOP INTO A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE IS SEVERAL MILES NE OF FRENCH GUIANA WITH AXIS NEAR 51W...MOVING W AT 10-15 KT OVER THE PAST 24 HOURS. CIRA LAYER PRECIPITABLE WATER IMAGERY FROM THE SURFACE TO 850 MB SHOW THE WAVE IS WITHIN A MODERATE MOIST ENVIRONMENT. MIDDLE TO UPPER LEVEL DIVERGENCE SUPPORT SCATTERED MODERATE CONVECTION AND TSTMS FROM 06N TO 12N BETWEEN 47W AND 53W. DRY AIR INTRUSION IN THE WAVE ENVIRONMENT FROM A SAHARAN AIRMASS HINDER CONVECTION ELSEWHERE. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 17N16W SW TO THE SPECIAL FEATURES 1011 MB LOW NEAR 09N33W TO 07N40W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N40W TO 05N50W. ASIDE FROM CONVECTION ASSOCIATED WITH THE SPECIAL FEATURES LOW AND TROPICAL WAVE ALONG 51W...ISOLATED MODERATE CONVECTION IS FROM 07N-15N E OF 27W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL LOW EXTENDS FROM SOUTHERN TEXAS TO NE MEXICO AND PART OF THE NW GULF WHILE A BROAD RIDGE COVERS THE REMAINDER BASIN. DIVERGENT WIND FLOW BETWEEN THESE TWO FEATURES ALOFT ALONG WITH MOISTURE INFLOW ACROSS THE BASIN FROM THE CARIBBEAN SEA SUPPORT SCATTERED MODERATE CONVECTION AND TSTMS S OF 23N W OF 90W AND ISOLATED SHOWERS FROM 24N TO 28N BETWEEN 87W AND 94W. UPPER LEVEL DIVERGENCE IS ALSO OVER FLORIDA SUPPORTING ISOLATED SHOWERS THAT EXTENDS INTO THE E GULF WATERS S OF 27N E OF 84W. OTHERWISE...A WEAK SURFACE RIDGE AXIS EXTENDS ACROSS THE CENTRAL FLORIDA PENINSULA TO THE SW GULF WITH MOSTLY GENTLE TO MODERATE E-SE FLOW THAT IS EXPECTED THROUGH TUESDAY NIGHT LATE. THEREAFTER...THE S-SE WINDS WILL INCREASE SLIGHTLY ACROSS THE WESTERN GULF AS AN AREA OF LOW PRESSURE DEVELOPS ACROSS THE SOUTHERN PLAINS TUESDAY NIGHT INTO WEDNESDAY. CARIBBEAN SEA... SHALLOW MOISTURE OVER THE NW BASIN IS ENHANCING SHOWERS OVER SOUTHERN-CENTRAL CUBA ADJACENT WATERS. THE OTHER AREA OF CONVECTION IS WITHIN 60 NM OFF THE COASTS OF COLOMBIA AND PANAMA BETWEEN 73W AND 79W WHERE SHOWERS AND TSTMS ARE BEING ENHANCED BY AN AREA OF LOW PRESSURE OVER NORTHERN COLOMBIA. DRY AIR SUBSIDENCE FROM ALOFT AND STRONG DEEP LAYER WIND SHEAR HINDER CONVECTION ELSEWHERE IN THE CENTRAL AND SOUTHERN CARIBBEAN. NE TO E WINDS OF 20 TO 25 KT ARE FROM 11N TO 13.5N BETWEEN 70W AND 75W WITH SEAS TO 9 FT. THESE CONDITIONS ARE EXPECTED TO PREVAIL IN THIS REGION FOR THE NEXT TWO DAYS. THE NEXT TROPICAL WAVE WILL ENTER THE E CARIBBEAN WED NIGHT. ...HISPANIOLA... SHALLOW MOISTURE ALONG WITH THE PRESENCE OF AN UPPER LOW CENTERED BETWEEN EASTERN CUBA AND JAMAICA SUPPORT CLOUDINESS ACROSS THE ISLAND WITH POSSIBLE ISOLATED SHOWERS. SIMILAR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH TUESDAY EVENING WITH THE UPPER LOW MOVING SW OF JAMAICA AND DRY AIR MOVING ACROSS THE ISLAND. ATLANTIC OCEAN... SCATTERED TO ISOLATED SHOWERS CONTINUE ACROSS CENTRAL AND SOUTHERN FLORIDA BEING ENHANCED BY A DIFFLUENT ENVIRONMENT ALOFT. SIMILAR CONVECTION IS BETWEEN THE PENINSULA AND THE NORTHERN AND CENTRAL BAHAMAS BEING SUPPORTED BY A SURFACE TROUGH EXTENDING FROM 27N79W TO 19N78W. OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1027 MB HIGH CENTERED OVER THE AZORES ISLANDS. FOR TROPICAL WAVES SEE SECTION ABOVE. THERE IS A HIGH CHANCE OF TROPICAL CYCLONE DEVELOPMENT ASSOCIATED WITH THE EASTERNMOST TROPICAL WAVE. SEE SPECIAL FEATURES FOR DETAILS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR