000 AXNT20 KNHC 152357 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE JUL 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS N OF THE ITCZ WITH AXIS EXTENDING FROM 18N46W TO 9N48W MOVING W AT 15-20 KT. NO CONVECTION IS OCCURRING AT THIS TIME AS THE WAVE REMAINS EMBEDDED IN THE DRY AIR OF THE SAHARAN AIR LAYER. TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN WITH AXIS EXTENDING FROM 19N76W TO 12N78W MOVING W AT 20-25 KT. SSMI TPW IMAGERY SHOW A MODERATE MOIST ENVIRONMENT IN THE NORTHERN PORTION OF THE WAVE WHERE SCATTERED HEAVY SHOWERS AND TSTMS ARE BEING ENHANCED BY AN UPPER LEVEL TROUGH. THIS SHOWER ACTIVITY IS AFFECTING CENTRAL AND EASTERN CUBA...JAMAICA AND WESTERN HISPANIOLA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 7N29W. THE INTERTROPICAL CONVERGENCE ZONE AXIS BEGINS NEAR 7N29W AND THEN CONTINUES ALONG 7N45W TO 9N60W. SCATTERED MODERATE CONVECTION IS NOTED FROM 6N-8N BETWEEN 27W-30W...FROM 6N-10N BETWEEN 37W-45W AND FROM 9N-14N W OF 54W. ...DISCUSSION... GULF OF MEXICO... MOISTURE ASSOCIATED WITH A SURFACE TROUGH AHEAD OF A COLD FRONT THAT EXTENDS FROM MAINE SW TO NORTHERN LOUISIANA IS CONVERGING WITH A MOIST AIRMASS IN THE GULF. THIS IS CREATING ATMOSPHERIC INSTABILITY AND GENERATING HEAVY SHOWERS AND TSTMS ACROSS THE NORTHERN GULF N OF 27N E OF 95W. A MID-UPPER LEVEL TROUGH WITH BASE OVER THE NORTHERN GULF COASTLINE SUPPORT THIS CONVECTION AS WELL. AN UPPER LEVEL RIDGE COVERS THE CENTRAL AND SOUTHERN GULF AND GENERATES A DIFFLUENT ZONE OVER THE FLORIDA PENINSULA. THIS DIFFLUENT FLOW ALONG WITH ABUNDANT MOISTURE IN THE REGION IS SUPPORTING HEAVY SHOWERS AND TSTMS OVER CENTRAL AND NORTHERN FLORIDA PENINSULA AS WELL AS OFFSHORE WATERS OF SE FLORIDA. THE RIDGE ALOFT IS SUPPORTING A 1016 MB HIGH ANCHORED N OF THE YUCATAN PENINSULA NEAR 23N88W WHICH IS PROVIDING ANTICYCLONIC FLOW OF 5-10 KT S OF 27N. NORTH OF 27N WESTERLY FLOW OF 15 KT DOMINATES. OTHERWISE...SCATTERED SHOWERS AND TSTMS ARE NOTED OVER THE CENTRAL BAY OF CAMPECHE S OF 22N. A COLD FRONT WILL SWEEP ACROSS THE NE WATERS WEDNESDAY. CARIBBEAN SEA... AN UPPER LEVEL LOW CENTERED OVER THE SW N ATLC WATERS NEAR 27N71W EXTENDS A TROUGH S TO THE COAST OF VENEZUELA AND COLOMBIA. THIS TROUGH ALONG WITH A TROPICAL WAVE JUST S OF EASTERN CUBA IS SUPPORTING SCATTERED HEAVY SHOWERS AND TSTMS OVER CENTRAL AND EASTERN CUBA...JAMAICA AND NORTH-CENTRAL HISPANIOLA. SIMILAR CONVECTION IS NOTED ON ADJACENT WATERS OF SW CUBA. THE MONSOON TROUGH EXTENDS ACROSS SOUTHERN COSTA RICA AND PANAMA TO A 1009 MB LOW OVER NORTHERN COLOMBIA AND IS SUPPORTING SCATTERED MODERATE CONVECTION S OF 11N BETWEEN 77W-83W. A TIGHT PRESSURE GRADIENT BETWEEN THE LOW AND STRONG RIDGING N OF THE AREA IN THE NW ATLANTIC IS SUPPORTING FRESH TO STRONG TRADE WINDS MAINLY ACROSS THE SOUTH CENTRAL CARIBBEAN. BY FRIDAY MORNING THE WAVE OVER THE CENTRAL BASIN WILL MOVE INTO N CENTRAL AMERICA WHILE A NEW WAVE ENTERS THE E CARIBBEAN. ...HISPANIOLA... AN UPPER LEVEL LOW ANCHORED OVER THE SW N ATLC WATERS EXTENDS A TROUGH THROUGH THE CENTRAL CARIBBEAN WHICH ALONG A TROPICAL WAVE NEARBY ARE CAUSING ATMOSPHERIC INSTABILITY AND THE DEVELOPMENT OF SCATTERED SHOWERS AND TSTMS OVER NORTHERN-CENTRAL HISPANIOLA. ISOLATED SHOWERS ARE OCCURRING ELSEWHERE. WEATHER CONDITIONS ARE FORECAST TO IMPROVE BY WED MORNING AS A DRY AIRMASS APPROACHES THE ISLAND BY THE SOUTH. ATLANTIC OCEAN... AN UPPER LEVEL CYCLONE IS CENTERED NEAR 27N71W TO THE NE OF THE BAHAMAS AN CONTINUES TO SUPPORT ISOLATED SHOWERS AND TSTMS W OF 72W. FARTHER EAST...A SURFACE TROUGH EXTENDS FROM 30N62W TO 27N68W SUPPORTING SCATTERED HEAVY SHOWERS AND TSTMS FROM 23N-32N BETWEEN 60W-66W. OTHERWISE...BESIDES THE TROPICAL WAVE...THE CENTRAL AND EASTERN ATLC ARE UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1028 MB HIGH CENTERED NEAR 34N51W WHICH IS SUPPORTING FAIR WEATHER ACROSS THE REGION. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR