000 AXNT20 KNHC 190542 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE AUG 19 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 13N36W TO 22N37W MOVING W AT 20-25 KT. THE WAVE COINCIDE WITH 700 MB TROUGHING ALOFT AND A MAXIMUM IN 850 MB RELATIVE VORTICITY NOTED ALONG THE MONSOON TROUGH AXIS AND IN THE VICINITY OF 16N37W. NO SIGNIFICANT CONVECTION IS OCCURRING WITH THE WAVE AT THIS TIME. TROPICAL WAVE EXTENDS FROM 12N50W TO 19N51W MOVING W AT 20-25 KT. 700 MB TROUGHING ASSOCIATED WITH THE WAVE HAS BECOME DIFFICULT TO DISCERN IN GLOBAL MODEL DATA...HOWEVER SUBTLE INDICATION IS THAT THE AXIS HAS CROSSED 50W DURING THE PAST 6 TO 12 HOURS. 850 MB RELATIVE VORTICITY IS ALSO FOCUSED IN THE VICINITY OF 14N51W. NO SIGNIFICANT DEEP CONVECTION IS ASSOCIATED WITH THE WAVE AT THIS TIME. TROPICAL WAVE EXTENDS FROM 12N87W TO 23N85W MOVING W AT 25 KT. BROAD 700 MB TROUGHING ACCOMPANIES THE WAVE OVER THE NW CARIBBEAN SEA AND PORTIONS OF CENTRAL AMERICA WITH A 850 MB RELATIVE VORTICITY MAXIMUM NOTED OVER THE GULF OF HONDURAS NEAR 16N87W. WIDELY SCATTERED MODERATE TO STRONG CONVECTION IS FROM 17N-24N BETWEEN 84W-88W...AND FROM 12N-16N BETWEEN 86W-91W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 15N17W TO A 1012 MB LOW PRES NEAR 11N23W TO 13N37W TO 11N49W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 11N49W TO 09N60W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 07N-14N BETWEEN 22W-29W...AND WITHIN 120 NM EITHER SIDE OF A LINE FROM 12N45W TO 09N52W. SCATTERED MODERATE CONVECTION IS FROM 09N-13N BETWEEN 33W-41W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL LOW IS CENTERED NEAR 25N97W THAT INFLUENCES MUCH OF THE WESTERN GULF W OF 90W THIS EVENING. WHILE SURFACE RIDGING EXTENDS ALONG 28N ACROSS THE BASIN...AMPLE DYNAMICS ASSOCIATED WITH THE UPPER LEVEL LOW IS ADVECTING MOISTURE NORTHWARD ON THE EASTERN PERIPHERY OF THE LOW GENERATING ISOLATED SHOWERS FROM 20N-23N BETWEEN 94W-98W...AND FROM 24N-27N BETWEEN 89W-97W. OTHERWISE...THE SURFACE RIDGE EXTENDING FROM THE SW NORTH ATLC IS PROVIDING FOR OVERALL FAIR CONDITIONS AND MOSTLY CLEAR SKIES ACROSS THE EASTERN GULF AND FAR NW GULF WATERS THIS EVENING. ONE EXCEPTION ACROSS THE EASTERN GULF IS A TROPICAL WAVE MOVING THROUGH THE YUCATAN CHANNEL PRODUCING SCATTERED SHOWERS AND ISOLATED TSTMS S OF 25N BETWEEN 80W-85W. THE RIDGE AXIS IS EXPECTED TO REMAIN ANCHORED ALONG 28N THROUGH WEDNESDAY THEN SHIFT SLIGHTLY NORTHWARD AND REMAIN ACROSS THE LOWER MISSISSIPPI RIVER VALLEY THROUGH THE UPCOMING WEEKEND. CARIBBEAN SEA... A TROPICAL WAVE ALONG 86W IS BRINGING INCREASED MOISTURE AND CONVECTION TO THE NW CARIBBEAN AND YUCATAN CHANNEL THIS EVENING. WIDELY SCATTERED SHOWERS AND TSTMS ARE OCCURRING FROM 12N-24N BETWEEN 82W-89W. OTHERWISE...THE REMAINDER OF THE BASIN EAST OF THE TROPICAL WAVE IS RELATIVELY TRANQUIL WITH MOSTLY CLEAR SKIES. A FEW ISOLATED SHOWERS AND TSTMS ARE OCCURRING IN THE WINDWARD PASSAGE REGION AND ACROSS THE SW CARIBBEAN...HOWEVER NO SIGNIFICANT DEEP CONVECTION IS NOTED ON SATELLITE IMAGERY. MODERATE TO FRESH TRADES ARE PERSISTING GENERALLY S OF 17N BETWEEN 70W-80W. ...HISPANIOLA... CURRENTLY...CONDITIONS THIS EVENING REMAIN FAIRLY TRANQUIL AFTER EARLIER CONVECTION CONTINUES TO DIMINISH AND REMAIN OFFSHORE ACROSS THE WINDWARD PASSAGE WATERS. VERY LITTLE MOISTURE AND OVERALL DRYING ALOFT IS EXPECTED TO INFLUENCE HISPANIOLA DURING THE NEXT 24 HOURS. TRADES ARE FORECAST TO PERSIST ALONG WITH THE USUAL POSSIBILITY OF AFTERNOON AND EVENING CONVECTION DUE TO PEAK DAYTIME HEATING AND INSTABILITY ON TUESDAY. ATLANTIC OCEAN... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE SW NORTH ATLC NEAR 27N79W THAT CONTINUES TO SUPPORT SURFACE RIDGING ALONG 28N. TO THE NORTH OF THE SURFACE RIDGE AXIS...UPPER LEVEL NW FLOW PREVAILS N OF 28N W OF 62W PROVIDING OVERALL FAIR SKIES FOR THE OVERNIGHT PERIOD INTO TUESDAY. LINGERING MOISTURE AND ISOLATED SHOWERS AND TSTMS ARE HOWEVER OCCURRING S OF 26N W OF 78W DUE TO MARGINAL UPPER LEVEL DIFFLUENCE OVER THE FLORIDA STRAITS AND BAHAMAS. THE SURFACE RIDGE IS PROVIDING MOSTLY FAIR CONDITIONS ANCHORED BY A 1019 MB HIGH CENTERED NEAR 26N64W AND FORECAST TO REMAIN NEARLY STATIONARY. FARTHER EAST...THE SURFACE RIDGING BREAKS DOWN ACROSS THE CENTRAL ATLC AS A SURFACE TROUGH EXTENDS FROM 32N42W SW TO 24N53W. TO THE EAST...A COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N28W AND EXTENDS SW TO 28N37W. ISOLATED SHOWERS ARE POSSIBLE WITHIN 90 NM EITHER SIDE OF BOTH BOUNDARIES. OTHERWISE...A SURFACE RIDGE EXTENDS ACROSS THE EASTERN ATLC STEMMING FROM A 1021 MB HIGH CENTERED NEAR 34N20W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN