000 AXNT20 KNHC 151800 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI AUG 15 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1745 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS EAST OF THE CAPE VERDE ISLANDS WITH AXIS EXTENDING FROM 19N19W TO 10N20W...MOVING W AT 5-10 KT. THE SOUTHERN PORTION OF THE WAVE CONTINUES EMBEDDED IN THE MONSOON TROUGH WHERE DEEP LAYER MOISTURE AND MIDDLE TO UPPER LEVEL DIFFLUENCE SUPPORT SCATTERED MODERATE CONVECTION FROM 7N-14N BETWEEN 17W-24W. A TROPICAL WAVE IS ON THE CENTRAL ATLC WITH AXIS EXTENDING FROM 17N31W TO A 1012 MB LOW NEAR 11N31W TO 7N31W...MOVING W AT 10 KT. METEOSAT PSEUDO NATURAL AND SAL TRACKING IMAGERY INDICATE SAHARAN DUST AND DRY AIR IN THE WAVE ENVIRONMENT N OF THE LOW CENTER...WHICH IS SUPPRESSING CONVECTION IN THE NORTHERN AND CENTRAL PORTIONS OF THE WAVE. SCATTERED MODERATE CONVECTION IS MOSTLY LIMITED S OF THE MONSOON TROUGH FROM 5N-10N BETWEEN 29W- 39W. A TROPICAL WAVE IS ABOUT 90 NM E OF THE LESSER ANTILLES WITH AXIS EXTENDING FROM 19N55W TO 10N57W...MOVING W AT 20 KT. MOSTLY MODERATE DEEP LAYER MOISTURE IS ASSOCIATED WITH THIS WAVE WHICH ALONG MIDDLE TO UPPER LEVEL DIFFLUENCE SUPPORT SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS WITHIN 210 NM WEST OF ITS AXIS. A TROPICAL WAVE IS MOVING ACROSS SOUTHERN MEXICO AND E PAC WATERS WITH AXIS EXTENDING FROM THE BAY OF CAMPECHE NEAR 20N94W TO 10N97W...MOVING W AT 20 KT. ISOLATED SHOWERS AND TSTMS ARE ON THE SW GULF S OF 20N W OF 93W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE WEST AFRICAN COAST NEAR 14N17W AND THEN CONTINUES ALONG 11N25W TO 1 1012 MB LOW NEAR 11N31W TO 8N43W. THE INTERTROPICAL CONVERGENCE ZONE AXIS BEGINS NEAR 8N43W AND CONTINUES TO 11N53W. FOR INFORMATION REGARDING CONVECTION SEE THE TROPICAL WAVES SECTION. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER-LEVEL TROUGH CONTINUES ACROSS THE EASTERN CONUS WITH BASE EXTENDING SW INTO THE CENTRAL AND SW GULF. THIS TROUGH ALOFT SUPPORTS A STATIONARY FRONT ANALYZED FROM 30N85W SW TO 29N90W TO SE TEXAS NEAR 29N94W. A TROPICAL WAVE IS MOVING ACROSS SOUTHERN MEXICO AND THE E PAC WATERS. THIS WAVE IS ENHANCING ISOLATED SHOWERS AND TSTMS ON THE BAY OF CAMPECHE S OF 20N W OF 93W. OTHERWISE...A WEAK SURFACE RIDGE DOMINATES THE REMAINDER BASIN WHICH IS PROVIDING THE BASIN WITH VARIABLE WINDS OF 5-10 KT. RETURN FLOW ASSOCIATED WITH THIS RIDGE HAS BEEN ADVECTING MODERATE TO HIGH LOW-LEVEL MOISTURE FROM THE CARIBBEAN INTO THE BASIN WHICH IS FUELING HEAVY SHOWERS AND TSTMS FROM 25N-28N BETWEEN 89W-92W AS WELL AS N OF 26N E OF 87W...INCLUDING THE FLORIDA PENINSULA. ISOLATED SHOWERS ARE ELSEWHERE N OF 22N E OF 96W. SURFACE RIDGING WILL DOMINATE ACROSS THE BASIN DURING THE WEEKEND. CARIBBEAN SEA... A MIDDLE-LEVEL INVERTED TROUGH IS ON THE NW CARIBBEAN WHICH SUPPORT A SURFACE TROUGH FROM 19N80W TO 16N83W THAT ENHANCES SCATTERED SHOWERS AND TSTMS FROM 15N-19N BETWEEN 80W-84W. MODERATE DEEP LAYER MOISTURE ON THE SW CARIBBEAN ALONG WITH UPPER-LEVEL DIFFLUENCE SUPPORT A CLUSTER OF HEAVY SHOWERS AND TSTMS S OF 11N W OF 80W. DEEP LAYER DRY AIR IS ACROSS THE REMAINDER BASIN...THUS SUPPORTING FAIR WEATHER. HOWEVER...HAZINESS IS POSSIBLE OVER PORTIONS OF THE CENTRAL AND EASTERN CARIBBEAN AS THE SAHARAN DRY AIRMASS CONTINUES TO MOVE ACROSS THIS REGION DURING THE WEEKEND. A RELATIVE TIGHT PRESSURE GRADIENT ACROSS THE CENTRAL AND SW CARIBBEAN SUPPORT TRADES OF 20-25 KT IN THIS REGION. ELSEWHERE...TRADES OF 5-15 KT DOMINATE. A TROPICAL WAVE IS FORECAST TO ENTER THE E BASIN EARLY SATURDAY MORNING AND IS EXPECTED TO MOVE ACROSS HISPANIOLA SUN MORNING. HISPANIOLA... DEEP LAYER DRY AIR CONTINUES ACROSS THE ISLAND WHICH IS PROVIDING AN OVERALL STABLE ENVIRONMENT. THE DRY SAHARAN AIRMASS WILL CONTINUE TO MOVE ACROSS THE ISLAND THROUGH SATURDAY AFTERNOON THUS SUPPORTING FAIR WEATHER BUT SOME HAZINESS. ON SUNDAY...THE PASSAGE OF A TROPICAL WAVE ACROSS THE ISLAND WILL ENHANCE RAINSHOWERS. ATLANTIC OCEAN... ABUNDANT MOISTURE FROM THE GULF IS BEING ADVECTED BY SW FLOW ACROSS THE SW N ATLC WATERS WHICH ALONG MIDDLE TO UPPER LEVEL DIFFLUENCE SUPPORT HEAVY SHOWERS AND TSTMS N OF 24N W OF 70W. OTHERWISE...THE CENTRAL AND EASTERN ATLC CONTINUE UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1021 MB HIGH CENTERED NEAR 25N59W AND A 1028 MB HIGH NE OF THE AZORES ISLANDS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR