000 AXNT20 KNHC 231046 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT FRI AUG 23 2013 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 07N53W TO 16N47W MOVING W AT 10-15 KT. THE WAVE REMAINS LOW-AMPLITUDE AND EMBEDDED WITHIN THE ITCZ AXIS. CONVECTION REMAINS LIMITED WITH ONLY A FEW ISOLATED SHOWERS OCCURRING WITHIN 210 NM EITHER SIDE OF THE WAVE AXIS. TROPICAL WAVE EXTENDS FROM 12N83W TO 17N85W TO 22N85W MOVING W AT 5-10 KT. THE WAVE REMAINS WITHIN BROAD LOW-LEVEL...SURFACE TO 700 MB...TROUGHING LOCATED ACROSS THE WESTERN CARIBBEAN SEA WITH TOTAL PRECIPITABLE WATER IMAGERY INDICATING MAXIMUM VALUES GENERALLY BETWEEN 80W-87W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 10N-23N BETWEEN 79W-88W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N17W TO 10N20W TO 14N29W TO 12N34W TO 12N41W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 12N41W TO 11N50W. SCATTERED MODERATE CONVECTION IS FROM 08N-13N BETWEEN 17W-27W. ISOLATED MODERATE CONVECTION IS FROM 06N-15N BETWEEN 35W-47W. A SURFACE TROUGH IS ANALYZED NORTH OF THE MONSOON TROUGH AXIS FROM 14N32W TO 19N39W WITH A WEAK 1011 MB LOW CENTERED ALONG THE AXIS NEAR 17N36W. THIS IS LIKELY ANOTHER IMPULSE OF WESTWARD MOVING ENERGY OR PERHAPS A TROPICAL WAVE THAT MOVED OFF OF AFRICA EARLIER IN THE WEEK. LOW-LEVEL CYCLONIC MOTION IS NOTED IN THE CLOUD FIELD SURROUNDING THE SURFACE LOW WITH ISOLATED MODERATE CONVECTION OCCURRING FROM 16N-18N BETWEEN 34W-38W. ...DISCUSSION... GULF OF MEXICO... UPPER LEVEL DIFFLUENT FLOW IS NOTED ON WATER VAPOR IMAGERY OCCURRING OVER THE WESTERN GULF DUE TO AN UPPER LEVEL RIDGE EXTENDING FROM OVER CENTRAL MEXICO TO THE WESTERN GULF NEAR 26N97W. MIDDLE TO UPPER LEVEL DIFFLUENCE IS GENERATING ISOLATED SHOWERS AND TSTMS OVER THE WESTERN GULF THIS MORNING WEST OF 95W. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED OVER THE YUCATAN CHANNEL NEAR 22N86W. THIS UPPER LEVEL FEATURE ALONG WITH A MID-LEVEL VORTICITY MAXIMUM OVER THE NE GULF NEAR 26N88W AND A SURFACE TROUGH ANALYZED FROM 23N91W TO 30N88W IS GENERATING SCATTERED SHOWERS AND WIDELY SCATTERED TSTMS N OF 23N BETWEEN 83W-94W. MOST OF THIS CONVECTIVE ACTIVITY IS FOCUSED SE OF THE MISSISSIPPI RIVER DELTA REGION FROM 26N-30N BETWEEN 86W-89W. LOOKING AHEAD...GENERALLY E-SE WINDS ARE EXPECTED TO PREVAIL THROUGH THE UPCOMING WEEKEND AS A SURFACE RIDGE CONTINUES TO BE ANCHORED OVER THE SE CONUS AND SW NORTH ATLC. CARIBBEAN SEA... AN UPPER LEVEL LOW IS CENTERED OVER THE YUCATAN CHANNEL NEAR 22N86W AND ALONG WITH A TROPICAL WAVE ALONG 84W/85W CONTINUES TO GENERATE SCATTERED SHOWERS AND TSTMS ACROSS THE WESTERN CARIBBEAN BETWEEN 79W-89W. THE STRONGEST CONVECTION AT THIS TIME IS LOCATED OFFSHORE OF NICARAGUA AND EASTERN HONDURAS FROM 11N- 17N BETWEEN 81W-85W. THE WAVE IS EXPECTED TO CONTINUE A SLOW WESTWARD MOVEMENT OVER THE NEXT 24 TO 48 HOURS BRINGING INCREASED PRECIPITATION CHANCES TO CENTRAL AMERICA AND THE NW CARIBBEAN WATERS OVER THE WEEKEND. FINALLY...E-SE TRADES CONTINUE ACROSS THE EASTERN CARIBBEAN WITH AN UPPER LEVEL LOW CENTERED OVER PUERTO RICO NEAR 18N67W. ISOLATED SHOWERS ARE OCCURRING FROM 14N-20N BETWEEN 63W-68W DUE TO MIDDLE AND UPPER LEVEL DIFFLUENCE EAST OF THE UPPER LEVEL TROUGH AXIS. HISPANIOLA... A FEW ISOLATED SHOWERS ARE POSSIBLE THROUGH THE MORNING AND AFTERNOON HOURS...HOWEVER AN UPPER LEVEL LOW IS CENTERED OVER PUERTO RICO NEAR 18N67W AND HISPANIOLA LIES ON THE WESTERN AND RELATIVELY DRIER SIDE OF THIS UPPER LEVEL FEATURE AS NOTED ON WATER VAPOR IMAGERY THIS MORNING. THE UPPER LEVEL LOW IS EXPECTED TO DRIFT WESTWARD OVER THE NEXT 24 TO 48 HOURS AND PROVIDE A MORE FAVORABLE ATMOSPHERE FOR AFTERNOON AND EVENING CONVECTION. THESE ADDED MIDDLE TO UPPER LEVEL DYNAMICS ALONG WITH PEAK DAYTIME HEATING AND INSTABILITY WILL INITIATE AFTERNOON SHOWERS AND TSTMS. ANY ACTIVITY THAT FORMS WILL LIKELY LAST INTO THE EVENING HOURS AND DIMINISH THEREAFTER. ATLANTIC OCEAN... AN UPPER LEVEL RIDGE AXIS EXTENDS OVER THE FLORIDA PENINSULA EASTWARD TO 27N70W PROVIDING MUCH OF THE SW NORTH ATLC WITH NORTHWESTERLY FLOW ALOFT. WITH AN MID-LEVEL SHORTWAVE TROUGH PROGRESSING OFF THE MID-ATLC COAST...MOISTURE AND CLOUDINESS IS NOTED N OF 28N W OF 68W. WITHIN THE AREA...ISOLATED SHOWERS ARE POSSIBLE...HOWEVER A SURFACE RIDGE REMAINS THE DOMINATE SURFACE FEATURE ANCHORED BY A 1019 MB HIGH CENTERED NEAR 30N73W. FARTHER EAST...A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM 32N54W SW TO 25N63W. THIS TROUGHING SUPPORTS A WEAK STATIONARY FRONT ANALYZED FROM 32N55W TO 27N61W. ISOLATED SHOWERS ARE OCCURRING WITHIN 240 NM EAST OF THE FRONTAL BOUNDARY. OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1024 MB HIGH CENTERED SW OF THE AZORES NEAR 34N32W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN