000 AXNT20 KNHC 172352 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU JUL 17 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... TROPICAL WAVE IS EAST OF THE CAPE VERDE ISLANDS WITH AXIS EXTENDING FROM 16N20W TO 7N19W MOVING W AT 10 KT. THE WAVE IS EMBEDDED IN THE MOIST ENVIRONMENT OF THE MONSOON TROUGH WHICH IS SUPPORTING SCATTERED MODERATE CONVECTION AHEAD OF THE WAVE FROM 7N-13N BETWEEN 18W-28W. TROPICAL WAVE IS OVER THE CENTRAL ATLC EMBEDDED IN THE ITCZ WITH AXIS EXTENDING FROM 12N40W TO 4N40W MOVING W AT 15-20 KT. ISOLATED SHOWERS ARE FROM 5N-10N BETWEEN 38W-45W. TROPICAL WAVE IS 350 NM SE OF THE WINDWARD ISLANDS WITH AXIS EXTENDING FROM 13N54W TO 5N57W MOVING W AT 20 KT. SSMI TPW SHOW THE WAVE IS EMBEDDED IN A VERY MOIST ENVIRONMENT THAT SUPPORTS SCATTERED MODERATE CONVECTION FROM 4N-12N BETWEEN 53W-58W. TROPICAL WAVE IS JUST N OF THE ITCZ WITH AXIS EXTENDING FROM 13N46W TO 6N48W MOVING W AT 15 KT. THE WAVE IS EMBEDDED IN THE DRY ENVIRONMENT OF THE SAHARAN AIR LAYER WHICH IS HINDERING CONVECTION AT THE TIME. TROPICAL WAVE FORMERLY ANALYZED E-NE OF THE LESSER ANTILLES HAS VANISHED. SURFACE HIGH PRESSURE AND A DRY ENVIRONMENT AT THE LOWER-LEVELS CONTRIBUTED TO THE WEAKENING OF THE WAVE. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA TO GUINEA-BISSAU NEAR 13N16W AND THEN INTO THE E ATLC ALONG 11N22W TO 8N33W. THE ITCZ BEGINS NEAR 8N34W TO 7N40W...IT THEN RESUMES NEAR 6N42W AND CONTINUES ALONG 7N55W. IN ADDITION TO THE CONVECTION ASSOCIATED WITH THE WAVES...SCATTERED MODERATE CONVECTION IS FROM 7N-11N BETWEEN 29W-38W AND FROM 6N-8N BETWEEN 44W-50W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL TROUGH EXTENDS ALONG THE EASTERN CONUS TO A BASE OVER CENTRAL FLORIDA. OVER THE GULF...AN ANTICYCLONE IS CENTERED NEAR 26N91W. THE FLOW IN THE EASTERN PERIPHERY OF THE UPPER HIGH IS GENERATING A DIFFLUENT ENVIRONMENT OVER THE CENTRAL-SOUTHERN FLORIDA WHICH IS SUPPORTING SCATTERED SHOWERS S OF 28N...INCLUDING THE FLORIDA STRAITS. A DIFFLUENT ENVIRONMENT IS ALSO OVER THE NW GULF BEING GENERATED BY THE FLOW IN THE WESTERN PERIPHERY OF THE UPPER HIGH AND AN UPPER LOW CENTERED OVER THE COASTLINE OF NE MEXICO. THIS IS SUPPORTING SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS N OF 27N W OF 91W. THE ANTICYCLONE ALOFT ALSO SUPPORTS A 1016 MB HIGH ANCHORED NEAR 25N86W WHICH IS PROVIDING VARIABLE WINDS OF 5-15 KT ACROSS THE GULF. OTHERWISE...MID-LEVEL WESTERLY WIND FLOW E OF 90W SUPPORT A WEAK STATIONARY FRONT ALONG 29N83W TO 28N89W TO 29N94W. THE FRONT IS EXPECTED TO DISSIPATE BY FRIDAY MORNING. SURFACE RIDGING AND RETURN FLOW WILL DOMINATE ACROSS THE REGION FOR THE NEXT TWO DAYS. CARIBBEAN SEA... A MID-LEVEL ANTICYCLONE IS OVER THE NW CARIBBEAN WHICH ALONG A SHORT-WAVE TROUGH OVER THE SW N ATLC IS CAUSING A DIFFLUENT ENVIRONMENT OVER CUBA TO SUPPORT HEAVY SHOWERS AND TSTMS ISLAND- WIDE. FARTHER EAST...JUST N OF PUERTO RICO...A MID-LEVEL ANTICYCLONE IS GENERATING DIFFLUENT FLOW NW OF HISPANIOLA THAT IS SUPPORTING SCATTERED MODERATE CONVECTION OVER CENTRAL HAITI AND ISOLATED SHOWERS ACROSS THE REMAINDER ISLAND. SCATTERED MODERATE CONVECTION IS INLAND FROM HONDURAS TO PANAMA WHICH EXTENDS WITHIN 20 NM OF THE COASTLINE. OTHERWISE...FAIR WEATHER DOMINATES ELSEWHERE INFLUENCED BY DRY AIR SUBSIDENCE FROM ALOFT. HIGH PRESSURE ACROSS THE NORTHERN CARIBBEAN CONTINUE TO SUPPORT A TIGHTER PRESSURE GRADIENT OVER THE SOUTHERN-CENTRAL CARIBBEAN. THIS IS GENERATING A MODERATE TO FRESH BREEZE S OF 17N BETWEEN 66W-80W. TROPICAL WAVE CURRENTLY NEAR 350 NM SE OF THE WINDWARD ISLANDS IS FORECAST TO ENTER THE E CARIBBEAN FRIDAY MORNING. ...HISPANIOLA... A MID-LEVEL ANTICYCLONE N OF PUERTO RICO IS GENERATING DIFFLUENT FLOW NW OF HISPANIOLA THAT IS SUPPORTING SCATTERED MODERATE CONVECTION OVER CENTRAL HAITI AND ISOLATED SHOWERS ACROSS THE REMAINDER ISLAND. SHOWER ACTIVITY IS EXPECTED TO CONTINUE THROUGH SAT NIGHT. ATLANTIC OCEAN... A MID-LEVEL SHORT-WAVE TROUGH IS OVER THE SW N ATLC AS WELL AS UPPER-LEVEL DIFFLUENCE. THIS ENVIRONMENT ALONG WITH ABUNDANT MOISTURE IN THE REGION CONTINUE TO SUPPORT HEAVY SHOWERS AND TSTMS N OF 21N W OF 68W. OTHERWISE...THE CENTRAL AND EASTERN ATLC ARE UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1031 MB HIGH CENTERED NEAR 36N51W. BESIDES SURFACE HIGH PRESSURE...MOSTLY DRY AIR ACROSS THE REMAINDER BASIN SUPPORTS FAIR WEATHER. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR