000 AXNT20 KNHC 191041 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED AUG 19 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 1030 UTC. ...SPECIAL FEATURES... TROPICAL STORM DANNY IS LOCATED NEAR 11.3N 40.2W AT 0900 UTC...MOVING WEST AT 12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 05N TO 13N BETWEEN 36W AND 42W. SOME ADDITIONAL STRENGTHENING IS FORECAST DURING THE NEXT 48 HOURS AND DANNY COULD BECOME A HURRICANE ON THURSDAY. PLEASE SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS TCMAT4/WTNT24 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE IS EAST OF THE CAPE VERDE ISLANDS WITH AXIS NEAR 21W...MOVING W AT 5-10 KT OVER THE PAST 21 HOURS. CIRA LAYER PRECIPITABLE WATER IMAGERY SHOW THE WAVE IS WITHIN A MODERATE MOIST ENVIRONMENT EXTENDING FROM THE SURFACE TO 700 MB. HOWEVER...METEOSAT ENHANCED IMAGERY SHOW SAHARAN DRY AIR AND DUST IN THE WAVE ENVIRONMENT...WHICH IS KEEPING THE WAVE DEVOID OF CONVECTION. A TROPICAL WAVE IS WITHIN 220 NM E-SE OF THE LESSER ANTILLES WITH AXIS NEAR 58W...MOVING W AT 10-15 KT OVER THE PAST 24 HOURS. CIRA LAYER PRECIPITABLE WATER IMAGERY SHOW THE WAVE IS WITHIN A MODERATE MOIST ENVIRONMENT EXTENDING FROM THE SURFACE TO 700 MB THAT ALONG WITH A DIFFLUENT ENVIRONMENT ALOFT SUPPORT A CLUSTER OF MODERATE CONVECTION AND ISOLATED TSTMS FROM 06N TO 09N BETWEEN 57W AND 60W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 14N18W...THEN RESUMES W OF A TROPICAL WAVE NEAR 12N22W TO E OF T.S. DANNY NEAR 11N34W. THE ITCZ BEGINS W OF T.S. DANNY NEAR 09N42W TO E OF THE WESTERNMOST TROPICAL WAVE NEAR 08N53W. ASIDE THE CONVECTION ASSOCIATED WITH DANNY AND THE TROPICAL WAVE...SCATTERED MODERATE CONVECTION IS FROM 07N TO 14N BETWEEN 23W AND 35W AND FROM 04N TO 11N BETWEEN 41W AND 52W. ...DISCUSSION... GULF OF MEXICO... A BROAD MIDDLE TO UPPER LEVEL RIDGE CONTINUE OVER THE GULF ANCHORED NEAR 26N87W...WHICH IS SUPPORTING AN OVERALL STABLE ENVIRONMENT ACROSS THE BASIN. THE ONLY AREA OF CONVECTION IS OFF THE SE COAST OF TEXAS AND SW COAST OF LOUISIANA N OF 27N WHERE HEAVY SHOWERS AND TSTMS ARE BEING FUELED BY MOISTURE INFLOW FROM THE CARIBBEAN SEA AND SUPPORTED BY DIFFLUENCE BETWEEN THE UPPER RIDGE AND AN UPPER TROUGH WITH BASE NEAR CENTRAL MEXICO. BROAD SURFACE HIGH PRESSURE ACROSS THE ATLC EXTENDS A RIDGE AXIS W-SW ACROSS THE FLORIDA PENINSULA TO THE SW GULF...THUS PROVIDING SE WIND FLOW OF LESS THAN 15 KT BASIN-WIDE. SURFACE RIDGE WILL EXTEND ACROSS THE N GULF THROUGH THU. CARIBBEAN SEA... AN UPPER LOW COVERS THE CARIBBEAN W OF 76W GENERATING A DIFFLUENT ENVIRONMENT OVER THE FAR NW BASIN...WHICH ALONG WITH SHALLOW MOISTURE SUPPORT SHOWERS AND THUNDERSTORMS N OF 19N BETWEEN 79W AND 84W OR COASTAL WATERS OF WESTERN AND CENTRAL CUBA. SCATTERED MODERATE CONVECTION AND TSTMS ARE OBSERVED WITHIN 60 NM OFF THE COASTS OF COSTA RICA AND NORTHERN PANAMA SUPPORTED BY THE EPAC MONSOON TROUGH. DRY AIR AND STRONG DEEP LAYER WIND SHEAR HINDER CONVECTION ELSEWHERE ACROSS THE CARIBBEAN. FRESH TO STRONG TRADES WILL CONTINUE OVER THE S/CENTRAL CARIBBEAN INCREASING TO NEAR GALE FORCE OFF THE NW COAST OF COLOMBIA ON WED NIGHT. TROPICAL WAVE WILL ENTER THE E CARIBBEAN LATE TODAY AND MOVE INTO CENTRAL CARIBBEAN WATERS THURSDAY. ...HISPANIOLA... EXCEPT FOR PORTIONS OF WESTERN HAITI AND THE WINDWARD PASSAGE WHERE MODERATE SHALLOW MOISTURE IS OBSERVED IN CIRA LAYER PRECIPITABLE WATER IMAGERY...DEEP LAYER DRY AIR IS OVER THE ISLAND SUPPORTING FAIR WEATHER. CLOUDINESS WITH POSSIBLE ISOLATED SHOWERS CONTINUE MAINLY OFF THE WESTERN COAST OF HAITI. MOISTURE AND THE CHANCE OF SHOWERS AND TSTMS IN THE REGION MAY INCREASE THU NIGHT WITH THE PASSAGE OF A TROPICAL WAVE ACROSS THE CENTRAL CARIBBEAN. ATLANTIC OCEAN... THE MAIN FEATURE IN THE BASIN IS TROPICAL STORM DANNY WHICH COULD HAVE THE POTENTIAL TO STRENGTHEN INTO A HURRICANE DURING THE NEXT COUPLE OF DAYS. SEE SPECIAL FEATURES FOR MORE DETAILS. THE SECOND FEATURE OF INTEREST ARE TWO TROPICAL WAVES DISCUSSED IN THE WAVES SECTION. OTHERWISE...THE ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED BY A 1021 MB HIGH NEAR 29N48W. THE SURFACE RIDGE ACROSS THE W ATLC WILL SHIFT S AS A WEAK TROUGH PASSES E ACROSS N PORTION OF THE W ATLC S OF BERMUDA ON WED WITH LOW DEVELOPING NEAR S OF BERMUDA ON THU NIGHT. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR