000 AXNT20 KNHC 160557 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SAT AUG 16 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. ...SPECIAL FEATURES... TROPICAL WAVE EXTENDS FROM 15N20W TO 21N19W MOVING W AT 5 KT. A 1009 MB LOW IS EMBEDDED WITHIN THE MONSOON TROUGH AT THE SOUTHERN EXTENT OF THE WAVE AXIS NEAR 15N20W. IN ADDITION...THE WAVE COINCIDES WITH 700 MB GLOBAL MODEL INDICATED TROUGHING EXTENDING FROM THE LOW CENTER TO THE N-NE ALONG THE W AFRICA COAST TO 24N15W. SCATTERED MODERATE CONVECTION IS FROM 14N-16N BETWEEN 19W-22W. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 11N34W TO 18N34W MOVING W AT 10 KT. A 1010 MB LOW IS EMBEDDED WITHIN THE MONSOON TROUGH AT THE SOUTHERN EXTENT OF THE WAVE AXIS NEAR 11N34W. IN ADDITION...WEAK 700 MB TROUGHING IS NOTED ON GLOBAL MODEL DATA BETWEEN 30W-40W WITH 850 MB RELATIVE VORTICITY FOCUSED IN CLOSE PROXIMITY TO THE LOW. WIDELY SCATTERED MODERATE CONVECTION IS TO THE SE OF THE LOW OCCURRING FROM 08N-11N BETWEEN 28W-33W. TROPICAL WAVE EXTENDS FROM 08N60W TO 20N59W MOVING W AT 15-20 KT. BROAD 700 MB TROUGHING ACCOMPANIES THE WAVE BETWEEN 55W-65W WITH A 850 MB RELATIVE VORTICITY MAXIMUM NOTED ALONG THE SOUTHERN EXTENT OF THE WAVE AXIS FOCUSED NEAR 12N60W. THE WAVE REMAINS FAIRLY DRY DUE TO THE SAHARAN AIR LAYER SURROUNDING THE WAVE TO THE EAST AND WEST. ISOLATED MODERATE CONVECTION IS FROM 10N-14N BETWEEN 61W-65W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 15N17W TO 15N20W TO 12N23W TO 11N34W TO 09N40W TO 09N44W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N44W TO 14N56W. ISOLATED MODERATE CONVECTION IS FROM 11N-13N BETWEEN 23W- 25W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH EXTENDS OVER THE WESTERN GULF FOCUSED NEAR 27N92W EXTENDING S-SW TO A BASE OVER EAST-CENTRAL MEXICO NEAR 21N98W. MOISTURE CONTINUES TO ADVECT NORTHEASTWARD ON THE EASTERN PERIPHERY OF THE TROUGH WITH ISOLATED SHOWERS AND TSTMS OCCURRING IN THE VICINITY OF 27N92W. OTHERWISE...AT THE SURFACE...A SURFACE RIDGE AXIS EXTENDS ALONG 26N FROM THE SW NORTH ATLC TO 90W. GENERALLY LIGHT SOUTHWESTERLY WINDS ARE OCCURRING NORTH OF THE RIDGE AXIS ACROSS THE NE GULF WITH RELATIVELY LOWER PRESSURE ANALYZED ACROSS GEORGIA AND SOUTH CAROLINA. WITH AMPLE LOW-LEVEL MOISTURE CONVERGENCE IN PLACE... AND A MARGINALLY DIFFLUENT ENVIRONMENT ALOFT DUE TO THE BASE OF MIDDLE TO UPPER LEVEL TROUGHING OVER THE EASTERN U.S. SEABOARD...WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING ACROSS THE FLORIDA STRAITS AND EASTERN GULF WATERS E OF 85W THIS EVENING. LOOKING AHEAD...THE RIDGE IS EXPECTED TO REMAIN IN PLACE ACROSS THE GULF AND GRADUALLY SHIFT NORTHWARD TO ALONG 28N LATE SUNDAY INTO MONDAY. CARIBBEAN SEA... A TROPICAL WAVE ALONG 60W IS IMPACTING THE EASTERN CARIBBEAN BRINGING INCREASE MOISTURE AND ISOLATED SHOWERS AND TSTMS E OF 65W THIS EVENING. THE WAVE IS EXPECTED TO CONTINUE MOVING WESTWARD INTO THE CENTRAL CARIBBEAN LATE SATURDAY INTO SUNDAY. OTHERWISE...THE OTHER MAJOR FEATURE IMPACTING THE BASIN IS AN UPPER LEVEL LOW CENTERED NEAR 20N81W OVER THE NW CARIBBEAN. THE UPPER LEVEL LOW ALONG WITH LOW-LEVEL MOISTURE CONVERGENCE IS GENERATING ISOLATED SHOWERS AND TSTMS FROM 10N-20N BETWEEN 81W- 86W. FINALLY...FRESH TO STRONG TRADES ARE PERSISTING GENERALLY S OF 17N BETWEEN 69W-82W. ...HISPANIOLA... CURRENTLY ISOLATED SHOWERS ARE CONTINUING TO DIMINISH ACROSS WESTERN PORTIONS OF THE ISLAND WITH OVERALL FAIR CONDITIONS EXPECTED THROUGH THE OVERNIGHT HOURS INTO SATURDAY. A MOSTLY DRY AND STABLE ENVIRONMENT REMAINS ALOFT OVER THE ISLAND...HOWEVER WITH THE APPROACH OF A TROPICAL WAVE LATE SATURDAY INTO SUNDAY...PRECIPITATION PROBABILITIES WILL INCREASE AND A GOOD CHANCE SCATTERED SHOWERS AND TSTMS SATURDAY GIVEN PEAK DAYTIME HEATING AND INSTABILITY. ATLANTIC OCEAN... GENERALLY WESTERLY AND SOMEWHAT DIFFLUENT FLOW IS NOTED OVER THE SW NORTH ATLC BETWEEN AN UPPER LEVEL ANTICYCLONE CENTERED NEAR 26N77W AND A MIDDLE TO UPPER LEVEL TROUGH NOTED ON WATER VAPOR IMAGERY OVER THE EASTERN U.S. SEABOARD. WHILE WEAK RIDGING PREVAILS ALONG 26N...WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING FROM 25N-29N BETWEEN 73W-78W THIS EVENING. OTHER SCATTERED SHOWER AND TSTM ACTIVITY IS OCCURRING ACROSS A PORTION OF THE FLORIDA STRAITS BETWEEN 79W-82W. FARTHER EAST...ACROSS THE CENTRAL AND EASTERN ATLC...A SURFACE RIDGE IMPACTS MUCH OF THE REGION WITH AXIS EXTENDING FROM 32N25W TO 28N36W TO A 1021 MB HIGH CENTERED NEAR 25N55W. THE ONLY EXCEPTION NOTED IS A STATIONARY FRONT ANALYZED ON THE NORTHERN PERIPHERY OF THE RIDGING FROM 33N40W TO 31N43W. ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE BOUNDARY. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN