000 AXNT20 KNHC 190003 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON AUG 18 2014 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 IS IN THE CENTRAL ATLANTIC WITH AXIS EXTENDING FROM 19N33W TO 12N34W MOVING W AT 20 KT. SAHARAN DRY AIR IS IN THE ENVIRONMENT OF THE WAVE WHICH IS HINDERING CONVECTION. ANOTHER TROPICAL WAVE IS OVER THE CENTRAL TROPICAL ATLANTIC WITH AXIS EXTENDING FROM 19N43W TO 11N46W...MOVING W AT 15 KT. A CLUSTER OF MODERATE CONVECTION IS LOCATED SOUTHEAST OF THE WAVE AXIS FROM 11N-13N BETWEEN 42W-46W COINCIDING WITH A REGION OF DEEPER MOISTURE AND UPPER LEVEL DIFFLUENCE. A TROPICAL WAVE IS OVER THE W CARIBBEAN WITH AXIS EXTENDING FROM 22N84W TO 10N86W...MOVING W AT 20-25 KT. MID LEVEL DIFFLUENCE ALONG WITH MODERATE LOW LEVEL MOISTURE IS ENHANCING ISOLATED HEAVY SHOWERS AND THUNDERSTORMS NORTH OF 19N BETWEEN 82W-85W. ALSO...SIMILAR CONVECTION IS OCCURRING IN NICARAGUA AND HONDURAS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE WEST AFRICAN COAST NEAR 15N16W TO A 1010 NM LOW AT 11N21W TO A 1010 MB LOW AT 12N29W TO 12N39W TO 9N53W. THE INTERTROPICAL CONVERGENCE ZONE AXIS BEGINS NEAR 9N53W TO 8N60W. SCATTERED MODERATE CONVECTION IS FROM 7N-13N E OF 27W AND FROM 7N-13N BETWEEN 30W-40W. ...DISCUSSION... GULF OF MEXICO... WEAK SURFACE RIDGING IS CENTERED ACROSS THE NORTHEASTERN GULF OF MEXICO SUPPORTING 5-15 KT ANTICYLONIC WINDS. THE NORTHERN END OF A TROPICAL WAVE MOVING ACROSS THE NORTHWESTERN CARIBBEAN WILL CONTINUE TO PRODUCE SHOWERS AND THUNDERSTORMS ACROSS THE SOUTHEASTERN GULF...YUCATAN CHANNEL...AND THE YUCATAN PENINSULA TONIGHT THROUGH TUESDAY. CONVECTION LOCATED OVER THE YUCATAN MAY SHIFT WEST INTO THE BAY OF CAMPECHE TONIGHT INTO TUESDAY. ACROSS THE WESTERN GULF...MID LEVEL DIVERGENCE ALONG WITH DEEP LAYER MODERATE MOISTURE IS ENHANCING SCATTERED MODERATE CONVECTION WITH ISOLATED TSTMS SOUTH OF 27N WEST OF 93W. THE TROPICAL WAVE WILL MOVE OUT OF THE SOUTHWEST BASIN BY WEDNESDAY MORNING WITH SURFACE RIDGING DOMINATING ELSEWHERE. CARIBBEAN SEA... A TROPICAL WAVE IS OVER THE W CARIBBEAN ENHANCING ISOLATED HEAVY SHOWERS AND TSTMS. SEE TROPICAL WAVE SECTION ABOVE. UPPER LEVEL DIVERGENCE AND THE MONSOON TROUGH ARE SUPPORTING SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ACROSS THE EXTREME SOUTHWESTERN BASIN FROM PANAMA NORTH TO 12N BETWEEN 84W AND 76W. LOW-LEVEL MOISTURE CONVERGENCE ALONG CUBA IS ENHANCING SCATTERED HEAVY SHOWERS AND THUNDERSTORMS WHICH EXTEND WITHIN 20 NM OF THE COASTLINE. ELSEWHERE...FAIR WEATHER DOMINATE BEING SUPPORTED BY STRONG DEEP LAYER ENVIRONMENTAL SHEAR AND DRY AIR. DUST AND HAZE IS BEING REPORTED BY MANY OF THE LESSER ANTILLES AS WELL AS HISPANIOLA ASSOCIATED WITH THE PASSAGE OF A SAHARAN AIRMASS. A TIGHTER PRESSURE GRADIENT OVER THE CENTRAL AND SW BASIN CONTINUE TO SUPPORT 20-25 KT WINDS S OF 17N. TRADES OF 10-15 KT DOMINATE ELSEWHERE. THE TROPICAL WAVE CURRENTLY OVER THE WESTERN BASIN WILL ENTER THE YUCATAN PENINSULA EARLY MORNING TUESDAY LEAVING LINGERING SHOWERS OVER THE NW BASIN. THE NEXT TROPICAL WAVE IS EXPECTED TO ENTER THE EASTERN CARIBBEAN BY THU MORNING. HISPANIOLA... DIURNALLY DRIVEN CONVECTION HAS SHIFTED FROM THE MOUNTAINOUS REGION OF WESTERN DOMINICAN REPUBLIC TO HAITI WHERE SCATTERED HEAVY SHOWERS AND THUNDERSTORMS ARE NOTED. A SAHARAN AIRMASS IS ON THE REMAINDER ISLAND WHERE HAZE AND DUST HAVE BEEN REPORTED. THIS CONVECTION WILL DISSIPATE LATER TONIGHT AS THE SAHARAN AIRMASS CONTINUES TO MOVE WESTWARD THROUGH TUE NIGHT. ATLANTIC OCEAN... A LINE OF SHOWERS AND TSTMS ASSOCIATED WITH THE SEA BREEZE HAS MOVED INTO THE SW N ATLC WATERS N OF 27N W OF 79W. A PATCH OF LOW LEVEL MOISTURE ASSOCIATED WITH THE TROPICAL WAVE MOVING ACROSS THE WESTERN CARIBBEAN ALONG WITH A REGION OF MIDDLE TO UPPER LEVEL DIFFLUENCE SUPPORT SCATTERED SHOWERS AND ISOLATED TSTMS ON THE STRAITS OF FLORIDA AND THE CENTRAL BAHAMAS. FARTHER EAST...A 1020 MB HIGH IS ANCHORED NEAR 26N66W WHICH IS FORECAST TO STALL DURING THE NEXT 24 HOURS. OVER THE CENTRAL ATLC...THERE IS A WEAKNESS IN THE SURFACE RIDGE BEING REFLECTED AS A 1015 MB LOW NEAR 30N43W FROM WHICH A SURFACE TROUGH EXTENDS SW TO 24N50W. THERE IS NO CONVECTION ASSOCIATED WITH THESE TWO FEATURES. EAST OF THE LOW CENTER...THE TAIL OF A WEAK STATIONARY FRONT IS BEING ANALYZED FROM 30N32W TO 28N36W WITH NO CONVECTION ASSOCIATED WITH IT. SURFACE RIDGING AND FAIR WEATHER DOMINATE ELSEWHERE. OTHERWISE...SEE THE TROPICAL WAVES SECTION ABOVE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NAR/ASL