000 AXNT20 KNHC 062344 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU AUG 06 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 10N37W TO 17N40W MOVING W AT 15-20 KT. THE WAVE COINCIDES WITH A BROAD 700 MB TROUGH BETWEEN 34W- 45W THAT LIES WEST OF A LOW-LEVEL MONSOONAL GYRE FOCUSED ON A 1011 MB LOW CENTERED ALONG THE MONSOON TROUGH AXIS NEAR 13N26W. THE WAVE IS EXPECTED TO CONTINUE WESTWARD AND GRADUALLY LOSE AMPLITUDE THROUGH LATE FRIDAY AS IT ENTERS THE CENTRAL TROPICAL ATLC. NO SIGNIFICANT CONVECTION IS OCCURRING WITH THE WAVE AT THIS TIME. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE AFRICAN COAST NEAR 16N17W INTO A 1011 MB LOW NEAR 13N26W TO 09N30W TO 09N46W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N46W TO 10N55W. ISOLATED MODERATE CONVECTION IS FROM 06N-10N BETWEEN 26W- 32W. ...DISCUSSION... GULF OF MEXICO... NORTHEASTERLY FLOW ALOFT INFLUENCES MUCH OF THE GULF BASIN THIS EVENING WITH WATER VAPOR IMAGERY INDICATING MOST OF THE MOISTURE LYING N OF 28N E OF 91W. THE MOISTURE STEMS FROM A VIGOROUS MID- LEVEL SHORTWAVE TROUGH OVER THE OHIO AND TENNESSEE RIVER VALLEYS WITH TROUGHING EXTENDING OVER THE NE GULF WATERS AND NORTHERN FLORIDA GENERATING SCATTERED SHOWERS AND TSTMS N OF 27N E OF 91W ON MAXIMUM LOW-LEVEL MOISTURE CONVERGENCE MOSTLY ALONG THE GULF COASTLINE. OTHERWISE...A SURFACE RIDGE AXIS EXTENDS FROM THE CENTRAL FLORIDA PENINSULA W-SW TO THE MEXICO COAST NEAR TUXPAN. THE RIDGE SUPPORTS GENERALLY GENTLE TO MODERATE BREEZE CONDITIONS. THE SURFACE RIDGE IS EXPECTED TO REMAIN QUASI- STATIONARY THROUGH SUNDAY MAINTAINING THE GENTLE TO MODERATE ANTICYCLONIC BREEZE CONDITIONS. CARIBBEAN SEA... MUCH OF THE CARIBBEAN IS UNDER THE INFLUENCE OF AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED NEAR 16N70W. WATER VAPOR IMAGERY INDICATES DRY AIR ALOFT AND STRONG SUBSIDENCE GENERALLY E OF 82W PROVIDING FOR CLEAR SKIES AND FAIR CONDITIONS THIS EVENING ACROSS MUCH OF THE CENTRAL AND EASTERN CARIBBEAN. MOISTURE INCREASES SLIGHTLY ACROSS THE NW CARIBBEAN WITHIN SOUTHERLY FLOW ALOFT BETWEEN THE RIDGING AND A LARGE AND BROAD UPPER LEVEL LOW CENTERED OVER THE GULF OF TEHUANTEPEC REGION IN THE EASTERN PACIFIC NEAR 14N96W. GIVEN THE FAVORABLE MIDDLE TO UPPER LEVEL LIFTING DYNAMICS IN PLACE AND AMPLE LOW-LEVEL MOISTURE CONVERGENCE ACROSS THE NW CARIBBEAN AND PORTIONS OF CENTRAL AMERICA...SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS ARE OCCURRING ACROSS INLAND PORTIONS OF CENTRAL AMERICA AND THE NW CARIBBEAN W OF 83W THIS EVENING. THE PRIMARY MARINE IMPACT REMAINS FRESH TO STRONG TRADES S OF 16N BETWEEN 68W-78W. ...HISPANIOLA... A FEW ISOLATED SHOWERS ARE OCCURRING ACROSS THE ISLAND THIS EVENING...BUT THIS ACTIVITY IS LIKELY TO DIMINISH THROUGH THE EVENING HOURS DUE TO A LACK OF DAYTIME HEATING AND OVERALL INSTABILITY. SKY CONDITIONS SHOULD REMAIN MOSTLY CLEAR DURING THE OVERNIGHT HOURS INTO FRIDAY AS AN UPPER LEVEL ANTICYCLONE IS CENTERED SOUTH OF THE ISLAND NEAR 16N70W PROVIDING DRY AIR ALOFT AND STRONG SUBSIDENCE. ATLANTIC OCEAN... THE SW NORTH ATLC IS GENERALLY INFLUENCED BY A SURFACE RIDGE WITH AXIS EXTENDING WEST TO THE FLORIDA PENINSULA FROM A 1019 MB HIGH CENTERED NEAR 28N73W. ISOLATED SHOWERS AND TSTMS ARE OCCURRING ON THE NORTHERN FRINGE OF THE RIDGING AS A PAIR OF 1010 MB LOWS ARE CENTERED OVER THE CAROLINAS. THE CONVECTIVE ACTIVITY IS MOSTLY N OF 27N BETWEEN 64W-70W...AND N OF 30N BETWEEN 73W-82W. FARTHER EAST...A CUT-OFF UPPER LEVEL LOW IS CENTERED NEAR 25N60W THAT SUPPORTS A SURFACE TROUGH EXTENDING FROM 21N60W TO 30N58W. ISOLATED SHOWERS AND POSSIBLE ISOLATED TSTMS ARE OCCURRING FROM 20N-32N BETWEEN 52W-62W. OTHERWISE... THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1025 MB HIGH NORTH OF THE DISCUSSION AREA CENTERED NEAR 35N45W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN