000 AXNT20 KNHC 221751 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT AUG 22 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...SPECIAL FEATURES... HURRICANE DANNY IS CENTERED NEAR 15.4N 52.0W AT 22/1500 UTC OR ABOUT 575 NM E OF THE LEEWARD ISLANDS...MOVING WNW AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 984 MB. MAXIMUM SUSTAINED WIND SPEED IS 80 KT WITH GUSTS TO 95 KT. NUMEROUS MODERATE CONVECTION EXTENDS FROM 14N TO 18N BETWEEN 49W AND 53W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... AN EASTERN ATLC TROPICAL WAVE EXTENDS FROM 18N28W THROUGH A 1010 MB LOW NEAR 12N27W TO 08N26W...MOVING W AT AROUND 20 KT. SSMI TPW INDICATES A DEEP SURGE OF MOISTURE THROUGH THE CAPE VERDE ISLANDS TO 18N IS ASSOCIATED WITH THIS WAVE. THE WAVE IS EMBEDDED IN A LARGE LOW LEVEL MONSOON GYRE. SCATTERED MODERATE CONVECTION IS FROM 10N TO 18N BETWEEN 24W AND 31W. A WESTERN CARIBBEAN TROPICAL WAVE EXTENDS FROM 19N83W TO 08N82W...MOVING W AT 20 TO 25 KT OVER THE PAST 24 HOURS. THIS WAVE COINCIDES WITH A BROAD 700 MB TROUGH BETWEEN 80W AND 90W. DEEP MOISTURE IS CONFINED S OF 14N IN THE ENVIRONMENT OF THE WAVE. SCATTERED MODERATE CONVECTION IS S OF 11N W OF 76W. SOME OF THIS CONVECTION IS LIKELY ASSOCIATED WITH THE E PACIFIC MONSOON TROUGH OVER PANAMA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 17N16W INTO A 1010 MB LOW CENTERED NEAR 12N27W TO 08N30W TO 07N41W. ASIDE FROM CONVECTION ASSOCIATED WITH THE TROPICAL WAVE ALONG 26/27W...SCATTERED MODERATE CONVECTION IS FROM 06N TO 12N BETWEEN 13W AND 24W. CLUSTERS OF STRONG CONVECTION ARE MOVING OFFSHORE AFRICA FROM 16N TO 20N E OF 18W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LOW IS CENTERED OVER THE SW GULF NEAR 20N92W WHILE AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 29N79W WITH A RIDGE AXIS EXTENDING ACROSS THE NORTHERN GULF. THE UPPER LOW SUPPORTS ISOLATED THUNDERSTORMS FROM 20N TO 24N W OF 95W...AND FROM 22N TO 27N BETWEEN 82W AND 91W. A 1017 MB SURFACE HIGH IS CENTERED NEAR 28N87W...SUPPORTING ANTICYCLONIC SURFACE WINDS OVER THE GULF BASIN. GENTLE TO MODERATE E TO SE WINDS COVER THE WESTERN GULF. LIGHT TO GENTLE WINDS COVER THE EASTERN GULF. THE UPPER LEVEL RIDGE AXIS WILL REMAIN IN PLACE WHILE THE UPPER LOW MOVES W OVER MEXICO OVER THE NEXT 24 HOURS. UPPER LEVEL DIFFLUENCE BETWEEN THESE TWO FEATURES WILL SUPPORT CONVECTION OVER THE CENTRAL GULF TONIGHT THROUGH SUNDAY. CARIBBEAN SEA... AN ELONGATED UPPER LEVEL TROUGH EXTENDS FROM THE CENTRAL ATLC TO THE CENTRAL CARIBBEAN. AN UPPER LEVEL ANTICYCLONE COVERS THE SW CARIBBEAN AND CONNECTS ACROSS THE WESTERN CARIBBEAN WITH THE WESTERN ATLC UPPER LEVEL ANTICYCLONE. UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE RIDGE OVER THE SW CARIBBEAN IS COMBINING WITH A TROPICAL WAVE TO SUPPORT SCATTERED MODERATE CONVECTION OVER THAT PORTION OF THE BASIN. PLEASE SEE THE TROPICAL WAVES SECTION FOR MORE DETAILS. DRY AIR AND SUBSIDENCE COVERS THE CENTRAL AND EASTERN CARIBBEAN. MODERATE TO FRESH TRADE WINDS ARE S OF 18N ACROSS THE CARIBBEAN. GENTLE TO MODERATE TRADE WINDS ARE FOUND N OF 18N. OVER THE NEXT 24 HOURS CONVECTION WILL CONTINUE OVER THE SW CARIBBEAN. GRADUALLY INCREASING SEAS WILL BEGIN TO AFFECT THE LESSER ANTILLES TONIGHT WELL IN ADVANCE OF HURRICANE DANNY. ...HISPANIOLA... SHALLOW MOISTURE SUPPORTS ISOLATED THUNDERSTORMS OVER THE ISLAND TODAY. THIS ACTIVITY WILL DIMINISH AFTER SUNSET. EXPECT SIMILAR CONDITIONS ON SUNDAY. ATLANTIC OCEAN... AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 29N79W WITH A LARGE UPPER LOW CENTERED NEAR 31N66W. THE UPPER LOW SUPPORTS A SURFACE TROUGH THAT ENTERS OUR AREA OF DISCUSSION NEAR 31N65W TO 25N73W. ISOLATED MODERATE CONVECTION IS WITHIN 150 NM OF THE SURFACE TROUGH W OF 65W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION ARE WITHIN 200 NM SE OF THE SURFACE TROUGH E OF 65W. A CENTRAL ATLC SURFACE TROUGH EXTENDS FROM 21N46W TO 27N49W AND IS A SURFACE REFLECTION OF AN UPPER LOW NEAR 34N49W. ISOLATED MODERATE CONVECTION IS WITHIN 100 NM OF THE TROUGH N OF 29N. HURRICANE DANNY IS OVER THE CENTRAL TROPICAL ATLC. PLEASE REFER TO THE SPECIAL FEATURES SECTION FOR MORE DETAILS. A TROPICAL WAVE IS OVER THE EASTERN ATLC. PLEASE REFER TO THE TROPICAL WAVES SECTION FOR MORE DETAILS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO