000 AXNT20 KNHC 130005 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON AUG 12 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2322 UTC. ...TROPICAL WAVES... A TROPICAL WAVE ASSOCIATED WITH A 1010 MB LOW EMBEDDED WITHIN THE MONSOON TROUGH EXTENDS AN AXIS FROM 19N33W TO 11N33W WHICH IS MOVING W NEAR 10 KT. TOTAL PRECIPITABLE WATER IMAGERY SHOW THAT FOR THE MOST PART THE WAVE IS EMBEDDED IN A HIGH MOIST ENVIRONMENT AT THE LOWER LEVELS. HOWEVER...METEOSAT SATELLITE IMAGERY SHOW SAHARAN DUST AND DRY AIR SPREADING OVER THE WAVE ENVIRONMENT N OF THE MONSOON TROUGH WHERE CONVECTIVE ACTIVITY IS MINIMAL. SCATTERED MODERATE CONVECTION IS FROM 07N-11N BETWEEN 27W-36W. A TROPICAL WAVE EXTENDS FROM 21N58W TO 11N56W MOVING W NEAR 15 KT. THE WAVE CONTINUES ON THE LEADING EDGE OF A SAHARAN DUST OUTBREAK AND METEOSAT SATELLITE IMAGERY SHOW SOME DRY AIR SPREADING OVER ITS ENVIRONMENT WHICH IS INHIBITING ANY DEEP CONVECTION. ISOLATED RAINSHOWERS ARE WITHIN 170 NM EITHER SIDE OF THE WAVE AXIS. A DISTURBANCE IN THE CENTRAL CARIBBEAN IS NOW BEING ANALYZED AS A TROPICAL WAVE WITH AXIS EXTENDING FROM 20N70W TO 12N73W. TOTAL PRECIPITABLE WATER IMAGERY SHOW THE WAVE IS EMBEDDED IN A HIGH MOIST ENVIRONMENT S OF 18N. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 13N-18N BETWEEN 66W-78W BEING AMPLIFIED BY THE MONSOON TROUGH AXIS. THIS WAVE IS ALSO SUPPORTING SIMILAR CONVECTION OVER HISPANIOLA. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE WEST AFRICAN COAST NEAR 16N16W TO 13N28W 08N37W 07N45W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N45W TO 08N52W. BESIDES THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE ALREADY DISCUSSED...A CLUSTER OF MODERATE/ISOLATED STRONG CONVECTION IS FROM 11N-17N E OF 19W. SCATTERED MODERATE CONVECTION IS WITHIN 110 NM EITHER SIDE OF A LINE BETWEEN 20W-27W AND 36W-40W. ...DISCUSSION... GULF OF MEXICO... ANTICYCLONIC WIND FLOW IN THE RANGE OF 5-15 KT DOMINATES THE GULF WATERS ANCHORED BY A 1018 MB HIGH NEAR 29N84W. IN THE SW GULF...A SURFACE TROUGH THAT ENTERED EASTERN MEXICO EARLIER THIS AFTERNOON CONTINUES TO ENHANCE ISOLATED SHOWERS SW OF A LINE FROM 25N95W TO 19N92W. ANOTHER SURFACE TROUGH IS ALONG THE YUCATAN PENINSULA TO GUATEMALA ENHANCING NUMEROUS MODERATE CONVECTION AND TSTMS THAT EXTEND S OF 21N E OF 91W OVER THE BAY OF CAMPECHE. AN UPPER LEVEL ANTICYCLONE CENTERED OVER NORTHERN MEXICO AND ANOTHER CENTERED OVER THE SW N ATLC LEAVE A COL OR AREA OF LOW PRESSURE BETWEEN ALABAMA AND LOUISIANA. THIS IS SUPPORTING LOW LEVEL CONVERGENCE AND LIFTING OF MOIST AIR WHICH IS ENHANCING SCATTERED MODERATE CONVECTION AND TSTMS THAT EXTENDS WITHIN 60 NM OFF THE NORTHERN GULF COAST BETWEEN 86W- 93W. OTHERWISE...FAIR WEATHER IS OVER THE REMAINDER BASIN SUPPORTED BY DRY AIR IN THE LOWER AND MIDDLE LEVELS. HIGH PRESSURE IS EXPECTED TO PERSISTS ACROSS THE BASIN WITHIN THE NEXT 48 HOURS. CARIBBEAN SEA... AN UPPER LEVEL LOW IS CENTERED OVER THE YUCATAN CHANNEL AND STRETCHES A TROUGH AXIS EASTWARD TO 22N66W. BOTH WATER VAPOR AND TOTAL PRECIPITABLE WATER IMAGERY SHOW MODERATE MIDDLE TO LOWER LEVELS MOISTURE IN THE WESTERN CARIBBEAN WHICH ALONG WITH THE UPPER LOW SUPPORT SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS OVER CUBA AS WELL AS N OF 16N W OF 76W. A 1010 MB LOW NEAR 11N81W EMBEDDED WITHIN THE MONSOON TROUGH AXIS IS ENHANCING NUMEROUS MODERATE CONVECTION FROM 11N-16N W OF 80W. THE AXIS OF THE MONSOON TROUGH MOVES ACROSS COSTA RICA TO THE LOW TO 12N73W WHICH IS ENHANCING SCATTERED SHOWERS S OF THE AXIS. A DISTURBANCE IN THE CENTRAL CARIBBEAN IS NOW BEING ANALYZED AS A TROPICAL WAVE WITH AXIS EXTENDING FROM 20N70W TO 12N73W. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 13N- 18N BETWEEN 66W-78W BEING AMPLIFIED BY THE MONSOON TROUGH AXIS. THIS WAVE IS ALSO SUPPORTING SIMILAR CONVECTION OVER HISPANIOLA. RAINSHOWERS ARE EXPECTED TO PERSISTS ACROSS THE BASIN WITHIN THE NEXT 48 HOURS ASSOCIATED WITH THIS TROPICAL WAVE AND A NEW WAVE THAT IS EXPECTED TO ENTER THE EASTERN CARIBBEAN TUESDAY AFTERNOON. HISPANIOLA... A TROPICAL WAVE IS MOVING ACROSS THE ISLAND THIS EVENING WITH AXIS EXTENDING FROM 20N70W TO 12N73W. THE WAVE IS SUPPORTING SCATTERED MODERATE CONVECTION AND TSTMS ACROSS THE ENTIRE ISLAND AS WELL AS ADJACENT WATERS. RAINSHOWERS ASSOCIATED WITH THIS WAVE ARE EXPECTED TO PERSIST UNTIL EARLY WEDNESDAY. ATLANTIC OCEAN... AS OF 2100 UTC...THE HIGH OVER THE SW N ATLC HAS DISSIPATED. UPPER LEVEL DIFFLUENCE FROM THE UPPER LEVEL ANTICYCLONE OVER THE SW N ATLC AND THE CYCLONIC CIRCULATION CENTERED OVER THE YUCATAN CHANNEL IS ENHANCING RAINSHOWERS BETWEEN THE BAHAMAS AND THE EASTERN FLORIDA PENINSULA FROM 23N-27N W OF 77W AS WELL AS THE FLORIDA STRAITS. AN UPPER LEVEL LOW CENTERED NEAR 29N56W IS SUPPORTING A SURFACE TROUGH ALONG 30N52W TO 24N55W. STRONG DEEP LAYER ENVIRONMENTAL SHEAR MAINTAINS THE CONVECTION ASSOCIATED WITH THIS TROUGH W OF IT...SCATTERED MODERATE FROM 24N-29N BETWEEN 55W-62W. OTHERWISE...ASIDE FROM THE TROPICAL WAVES ALREADY DISCUSSED ABOVE...SURFACE RIDGING AND DRY AIR IN THE LOWER AND MIDDLE LEVELS SUPPORT FAIR WEATHER IN THE REMAINDER BASIN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS