000 AXNT20 KNHC 051739 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT MON AUG 05 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 10N55W TO 19N51W MOVING W AT 10-15 KT. THE WAVE WAS REPOSITIONED FARTHER SOUTH BASED ON OVERALL CONTINUITY OVER THE PAST 24 TO 48 HOURS AS WELL AS EXAMINATION OF SATELLITE BASED WINDS...SCATTEROMETER DATA...AND THE 700 MB GLOBAL MODEL STREAMLINES AND RELATIVE VORTICITY FIELDS. THIS WAVE HAS APPEARED TO HAVE ABSORBED MID-LATITUDE MID-LEVEL ENERGY ACROSS THE CENTRAL ATLC AND ENERGY PROPAGATING CROSS-EQUATORIAL FROM THE SOUTH ATLC ALONG THE SOUTH AMERICAN COAST. SAHARAN DUST AND THE SAHARAN AIR LAYER CONTINUES TO PLAY A ROLE IN LIMITING CONVECTION ASSOCIATED WITH THE WAVE. CURRENTLY NO SIGNIFICANT DEEP CONVECTION IS NOTED ON SATELLITE IMAGERY. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 11N19W TO 12N27W TO 10N36W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N36W TO 09N40W TO 12N44W TO 10N48W TO 10N53W TO 06N57W. SCATTERED MODERATE CONVECTION IS FROM 06N-12N BETWEEN 12W-26W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 07N-13N BETWEEN 27W-33W...AND FROM 11N-13N BETWEEN 42W-48W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER SOUTHEASTERN TEXAS NEAR 30N96W AND IS PROVIDING THE GULF WITH NORTHERLY WINDS ALOFT E OF 87W AND EASTERLY WINDS ALOFT W OF 87W. WHILE WATER VAPOR INDICATES A MAJORITY OF THE AIRMASS IS RELATIVELY DRY AND STABLE...THE AREA N OF 26N E OF 91W IS LADEN WITH NOTICABLE MOISTURE. THE DOMINATE SURFACE FEATURE IS A 1019 MB HIGH CENTERED NEAR 24N86W THAT CONTINUES TO PROVIDE OVERALL CLEAR SKIES AND FAIR CONDITIONS THIS AFTERNOON. HOWEVER WITH LOW- LEVEL MOISTURE CONVERGENCE FOCUSED ALONG A WEAK SURFACE TROUGH ANALYZED AT 05/1500 UTC FROM NORTHERN FLORIDA NEAR 30N82W TO 30N88W...ISOLATED SHOWERS AND TSTMS ARE OCCURRING ACROSS THE NE GULF WATERS FROM 25N-29N BETWEEN 82W-91W. OTHERWISE...A FEW ISOLATED SHOWERS ARE OCCURRING S OF 22N W OF 94W...BUT THE SURFACE RIDGE IN PLACE IS FORECAST TO DRIFT SLOWLY WESTWARD AND ANCHOR IN THE VICINITY OF 25N90W THROUGH LATE WEDNESDAY. CARIBBEAN SEA... NORTH-NORTHEASTERLY FLOW ALOFT DOMINATES ACROSS THE WESTERN CARIBBEAN BETWEEN A ANTICYCLONIC CIRCULATION CENTERED OVER THE SOUTHERN U.S. PLAINS AND AN UPPER LEVEL LOW CENTERED NORTH OF HISPANIOLA NEAR 21N69W. WATER VAPOR IMAGERY INDICATES DRY AIR AND OVERALL SUBSIDENCE PREVAILS WEST OF THE UPPER LEVEL TROUGH AXIS EXTENDING FROM OVER HISPANIOLA NEAR 19N71W TO 12N77W... HOWEVER WIDELY SCATTERED SHOWERS AND TSTMS ARE OCCURRING S OF A LINE FROM CENTRAL NICARAGUA NEAR 13N84W TO THE NORTHERN COLOMBIA COAST NEAR 09N76W. SOME OF THE ONGOING CONVECTION IS LIKELY ENHANCED DUE TO THE CLOSE PROXIMITY OF THE MONSOON TROUGH AXIS ANALYZED ALONG 09N. OTHERWISE...EAST OF THE TROUGH AXIS...WATER VAPOR IMAGERY INDICATES A MOSTLY DRY AND STABLE ATMOSPHERE AS WELL WITH MOSTLY CLEAR SKIES AND FAIR CONDITIONS THIS AFTERNOON. A FEW PASSING ISOLATED LOW-TOPPED SHOWERS ARE POSSIBLE ACROSS THE SE CARIBBEAN AND LESSER ANTILLES. LOW-LEVEL MOISTURE IS EXPECTED TO INCREASE AS A TROPICAL WAVE ALONG 54W REACHES 60W BY LATE TUESDAY. HISPANIOLA... CURRENTLY DRY AIR ALOFT IS NOTED ON WATER VAPOR IMAGERY AS AN UPPER LEVEL LOW IS CENTERED NORTH OF THE ISLAND NEAR 21N69W. THE OVERALL STABILITY PROVIDED ALOFT WILL MAINTAIN MOSTLY CLEAR SKIES THIS AFTERNOON WITH ONLY A VERY SLIGHT CHANCE OF LATE AFTERNOON AND EVENING ISOLATED SHOWERS AND TSTMS. ATLANTIC OCEAN... AN UPPER LEVEL RIDGE REMAINS ANCHORED OVER THE SOUTHERN U.S. PLAINS AND STRETCHES UPPER LEVEL RIDGING EASTWARD TO 72W. THE NORTHERLY FLOW ALOFT OVER THE SW NORTH ATLC FALLS WITHIN AN AREA OF MID-LEVEL TROUGHING BETWEEN 60W-80W THAT SUPPORTS A COLD FRONT EXTENDING FROM 32N70W TO THE GEORGIA COAST NEAR 32N81W. A SURFACE TROUGH ALSO EXTENDS FROM THE COLD FRONT NEAR 30N74W SW TO THE FLORIDA KEYS NEAR 25N81W. SCATTERED SHOWERS AND TSTMS ARE OCCURRING WITHIN 240 NM EAST OF THE COLD FRONT E OF 71W...AND FROM 23N-30N BETWEEN 70W-80W IN ASSOCIATED WITH THE SURFACE TROUGH. THE FRONT WILL BE SLOW TO EXIT NORTH OF THE REGION WITH GENERALLY SURFACE TROUGHING REMAINING ACROSS THE SW NORTH ATLC W OF 70W THROUGH WEDNESDAY. FARTHER EAST...A SURFACE RIDGE ANCHORED BY A 1030 MB HIGH CENTERED NEAR 35N36W IS PROVIDING MUCH OF THE CENTRAL AND EASTERN ATLC WITH DRY AND STABLE CONDITIONS. ONE EXCEPTION IS THE WESTWARD MOVEMENT OF THE TROPICAL WAVE ALONG 54W ON THE SOUTHWESTERN PERIPHERY OF THE RIDGE AND A SURFACE TROUGH ANALYZED FROM 21N54W TO 25N52W TO THE NORTH OF THE WAVE. THE SURFACE TROUGH IS LIKELY ENERGY THAT HAS FRACTURED AWAY FROM THE TROPICAL WAVE AND WILL CONTINUE TO ROUND THE RIDGE AND MERGE WITH THE AFOREMENTIONED TROUGHING IN THE COMING DAYS. A FEW ISOLATED SHOWERS ARE POSSIBLE IN THE VICINITY OF THE SURFACE TROUGH AXIS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN