000 AXNT20 KNHC 141801 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI AUG 14 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. ...TROPICAL WAVES... A W AFRICAN TROPICAL WAVE WILL BE EMERGING OFF THE COAST OVER THE NEXT 24 HOURS. OBSERVATIONS SHOW A 4 MB DROP IN SURFACE PRESSURE AS THE WAVE HAS PASSED LOCATIONS OVER W AFRICA...INDICATING A WELL DEFINED WAVE REACHING THE SURFACE. LOOK FOR THIS WAVE TO BE ADDED TO THE SURFACE ANALYSIS OVER THE NEXT 24 HOURS. A CENTRAL ATLC TROPICAL WAVE HAS AN AXIS THAT EXTENDS FROM 20N37W TO 08N38W...MOVING W AT 15 TO 20 KT OVER THE PAST 24 HOURS. THIS WAVE IS EMBEDDED IN DRY AIR N OF 09N. A 700 MB GYRE IS EVIDENT ALONG THE WAVE AXIS NEAR 16N38W. ISOLATED MODERATE CONVECTION IS FROM 06N TO 09N BETWEEN 36W AND 40W. A CENTRAL ATLC TROPICAL WAVE IS BEGINNING TO CROSS THE LESSER ANTILLES WITH AN AXIS THAT EXTENDS FROM 20N58W TO 09N61W...MOVING W AT 15 TO 20 KT OVER THE PAST 24 HOURS. THIS WAVE HAS BEEN EVIDENT ON RADAR THIS MORNING AND A RECENT WIND SHIFT FROM ENE TO SE WAS NOTED AT BARBADOS. ISOLATED MODERATE CONVECTION IS FROM 10N TO 18N BETWEEN 55W AND 62W. A TROPICAL WAVE EXTENDS FROM THE WESTERN CARIBBEAN NEAR 18N85W...ACROSS CENTRAL AMERICA...TO THE EASTERN PACIFIC NEAR 08N85W...MOVING W AT 10 TO 15 KT OVER THE PAST 24 HOURS. AN INVERTED 700 MB TROUGH IS INDICATED BETWEEN 78W AND 87W . THE NORTHERN PORTION OF THIS WAVE IS INTERACTING WITH AN UPPER LEVEL LOW CENTERED NEAR THE CAYMAN ISLANDS...WITH THE SOUTHERN PORTION OF THE WAVE INTERACTING WITH DEEP TROPICAL MOISTURE. ISOLATED MODERATE CONVECTION IS N OF 12N W OF 81W. CLUSTERS OF MODERATE TO STRONG CONVECTION ARE S OF 12N W OF 78W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH PASSES THROUGH COASTAL AFRICA NEAR 13N17W AND CONTINUES TO 10N25W TO 08N37W. THE ITCZ BEGINS W OF A TROPICAL WAVE NEAR 08N40W AND CONTINUES ALONG 09N59W. OTHER THAN CONVECTION ASSOCIATED WITH THE TROPICAL WAVE ALONG 38W...ISOLATED MODERATE CONVECTION IS FROM 05N TO 09N BETWEEN 40W TO 56W. ...DISCUSSION... ...GULF OF MEXICO... A SHARP MID TO UPPER LEVEL TROUGH ALONG THE EASTERN US COAST TO W CENTRAL FL SUPPORTS A STATIONARY FRONT THAT EXTENDS ACROSS N FL TO 30N86W TO 30N90W. THE UPPER TROUGH ALSO SUPPORTS A 1012 MB LOW CENTERED NEAR 28N85W WITH A SURFACE TROUGH EXTENDING FROM THE CENTER OF THE LOW TO 25N89W. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN 100 NM S OF THE FRONT. SCATTERED MODERATE CONVECTION WITH SCATTERED TO NUMEROUS THUNDERSTORMS ARE FROM 25N TO 28N BETWEEN 81W AND 88W. A 1015 MB HIGH IS CENTERED NEAR 23N94W SUPPORTING LIGHT ANTICYCLONIC WINDS OVER THE WESTERN GULF. GENTLE TO MODERATE WINDS ARE COVER THE EASTERN GULF. OVER THE NEXT 24 HOURS EXPECT CONVECTION TO CONTINUE OVER THE NORTHERN GULF. CARIBBEAN SEA... AN UPPER LOW IS CENTERED OVER THE CAYMAN ISLANDS NEAR 19N81W. THIS LOW IS INTERACTING WITH A TROPICAL WAVE OVER THE WESTERN CARIBBEAN TO SUPPORT CONVECTION OVER THE NW CARIBBEAN. ADDITIONAL CONVECTION OVER THE SW CARIBBEAN AND LESSER ANTILLES ARE ALSO ASSOCIATED WITH TROPICAL WAVES. PLEASE SEE THE TROPICAL WAVES SECTION FOR MORE DETAILS. GENERALLY FAIR WEATHER COVERS THE REMAINDER OF THE CARIBBEAN TODAY WITH MODERATE TO FRESH TRADE WINDS OVER THE CENTRAL CARIBBEAN...GENTLE TRADE WINDS OVER THE NW CARIBBEAN...AND MODERATE TRADE WINDS ELSEWHERE. OVER THE NEXT 24 HOURS CONVECTION WILL CONTINUE OVER THE SW CARIBBEAN. THE TROPICAL WAVE CURRENTLY CROSSING THE LESSER ANTILLES WILL SPREAD CONVECTION OVER THE VIRGIN ISLANDS TONIGHT AND PUERTO RICO ON SATURDAY. ...HISPANIOLA... MODERATE MOISTURE WITH AN UPPER LOW CENTERED WEST OF THE ISLAND SHOULD BE SUFFICIENT TO SUPPORT ISOLATED THUNDERSTORM DEVELOPMENT LATE THIS AFTERNOON INTO THE EVENING. GENERALLY FAIR WEATHER IS EXPECTED OVERNIGHT TONIGHT. A TROPICAL WAVE CROSSING THE LESSER ANTILLES TODAY SHOULD BEGIN TO INCREASE CHANCES FOR SHOWERS AND THUNDERSTORMS OVER THE DOMINICAN REPUBLIC BY SATURDAY NIGHT. ATLANTIC OCEAN... THE MID TO UPPER LEVEL TROUGH ALONG THE EASTERN US SUPPORTS A STATIONARY FRONT THAT ENTERS OUR AREA OF DISCUSSION FROM 31N77W TO 30N82W. A PRE-FRONTAL TROUGH EXTENDS FROM 31N77W TO 26N80W. SCATTERED MODERATE CONVECTION AND THUNDERSTORMS ARE FROM 23N TO 31N BETWEEN 75W AND 82W...INCLUDING THE NORTHERN BAHAMAS. FARTHER EAST...A SURFACE TROUGH IS OVER THE CENTRAL ATLC EXTENDING FROM 30N52W TO 22N44W. NO DEEP CONVECTION IS NOTED WITH THIS TROUGH. TWO TROPICAL WAVES ARE OVER THE TROPICAL N ATLC. PLEASE SEE THE TROPICAL WAVES SECTION FOR MORE DETAILS. OVER THE NEXT 24 HOURS CONVECTION WILL CONTINUE NEAR THE NORTHERN BAHAMAS...BEFORE THE SURFACE TROUGH AND STATIONARY FRONT BEGIN TO DISSIPATE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ LATTO