000 AXNT20 KNHC 080547 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU AUG 08 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0522 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS NEAR THE CAPE VERDE ISLANDS WITH AXIS EXTENDING FROM 21N25W TO 12N26W MOVING W NEAR 10 KT. A SURGE OF DEEP MOISTURE IS TRAILING THE WAVE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY WITH DRY SAHARAN AIR PRECEDING ITS AXIS AS SEEN ON METEOSAT IMAGERY. N OF THE MONSOON TROUGH AXIS...THERE IS NO CONVECTION ASSOCIATED WITH THE WAVE. A TROPICAL WAVE IS OVER THE CENTRAL CARIBBEAN WITH AXIS EXTENDING FROM 21N71W TO 09N71W MOVING W NEAR 10 KT. THE WAVE IS EMBEDDED IN A LIGHT TO MODERATE MOIST ENVIRONMENT AS DEPICTED ON TOTAL PRECIPITABLE WATER IMAGERY. AN UPPER LEVEL LOW CENTERED NEAR 23N73W WHICH EXTENDS A TROUGH ACROSS THE CENTRAL-SOUTHERN CARIBBEAN SUPPORTS LOW DEEP LAYER ENVIRONMENTAL WIND SHEAR...THUS ENHANCING SCATTERED MODERATE CONVECTION AND TSTMS OVER THE HISPANIOLA...WINDWARD PASSAGE AND EASTERN CUBA. S OF 18N...THERE IS NO CONVECTION ASSOCIATED WITH THIS WAVE. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM THE WEST AFRICAN COAST NEAR 14N17W TO 10N26W 07N39W. THE INTERTROPICAL CONVERGENCE ZONE AXIS STARTS NEAR 07N39W AND CONTINUES ALONG 06N47W TO 06N56W. BESIDES THE CONVECTION ASSOCIATED WITH THE WAVE NEAR THE CAPE VERDE ISLANDS ALREADY DISCUSSED...SCATTERED MODERATE CONVECTION IS FROM 05N-14N E OF 32W. ...DISCUSSION... GULF OF MEXICO... AS OF 0300 UTC...ANTICYCLONIC FLOW IN THE RANGE OF 5-15 KT SPREADS ACROSS THE BASIN W OF 90W N OF 22N ANCHORED BY A 1014 MB HIGH CENTERED NEAR 27N92W. SURFACE TROUGHINESS IS E OF 90 W WHERE A TROUGH AXIS EXTENDS FROM 29N83W TO 24N83W...ACROSS WESTERN CUBA TO 21N83W IN THE W CARIBBEAN. THERE IS A HIGH MOIST ENVIRONMENT AND LOW DEEP LAYER ENVIRONMENTAL WIND SHEAR IN THIS REGION OF THE GULF WHICH IS SUPPORTING SCATTERED RAINSHOWERS WITHIN 160 NM EITHER SIDE OF THE TROUGH AXIS S OF 27N. OTHERWISE...DRY AIR SUBSIDENCE IS SUPPORTING FAIR WEATHER OVER THE WESTERN GULF. THE CENTER OF HIGH PRESSURE IS EXPECTED TO DISSIPATE EARLY ON THURSDAY. THE SURFACE TROUGH OVER THE E GULF WILL DRIFT W-NW WITHIN THE NEXT 48 HOURS GENERATING RAINSHOWERS OVER THE CENTRAL AND WESTERN GULF. CARIBBEAN SEA... TOTAL PRECIPITABLE WATER IMAGERY SHOW A MODERATE TO HIGH MOIST ENVIRONMENT OVER THE WESTERN CARIBBEAN WHERE UPPER LEVEL DIFFLUENCE FROM A BROAD HIGH CENTERED OVER LOUISIANA AND A LOW ACROSS THE CENTRAL-SOUTHER CARIBBEAN IS ENHANCING SCATTERED MODERATE CONVECTION/ISOLATED TSTMS. SIMILAR CONVECTION IS THE SOUTHERN BASIN S OF 10N E OF 78W...HOWEVER ASSOCIATED WITH THE MONSOON TROUGH AXIS WHICH EXTENDS FROM THE E PACIFIC TO A LOW CENTER OVER NORTHERN COLOMBIA. A TROPICAL WAVE IS MOVING ACROSS THE CENTRAL CARIBBEAN WITH THE NORTHERN PART OF ITS AXIS CURRENTLY OVER CENTRAL HISPANIOLA WHERE ALONG WITH THE UPPER LEVEL DIFFLUENCE IS SUPPORTING SCATTERED MODERATE CONVECTION AND TSTMS OVER THIS ISLAND...THE WINDWARD PASSAGE AND EASTERN CUBA. S OF 18N...THERE IS NO CONVECTION ASSOCIATED WITH THIS WAVE UNFAVORED BY DRY AIR AND HIGH VALUES OF DEEP LAYER ENVIRONMENTAL WIND SHEAR. A SURFACE TROUGH ASSOCIATED WITH A 1009 MB LOW EXTENDS FROM 17N63W TO 10N63W. SCATTERED MODERATE CONVECTION/ISOLATED TSTMS ARE WITHIN 120 NM W OF THE AXIS FROM 12N-14N. BOTH THE WAVE AND THE TROUGH ARE EXPECTED TO CONTINUE MOVING WESTWARD WITHIN THE NEXT 48 HOURS GENERATING RAINSHOWERS OVER THE CENTRAL AND SOUTHERN CARIBBEAN. ANOTHER SURFACE TROUGH IS EXPECTED TO MOVE ACROSS THE LESSER ANTILLES FRIDAY MORNING INCREASING THE CHANCES OF PRECIPITATION. HISPANIOLA... A TROPICAL WAVE IS MOVING ACROSS THE CENTRAL CARIBBEAN WITH THE NORTHERN PART OF ITS AXIS CURRENTLY OVER CENTRAL HISPANIOLA WHERE ALONG WITH THE UPPER LEVEL DIFFLUENCE IS SUPPORTING SCATTERED MODERATE CONVECTION AND TSTMS OVER THE ISLAND...THE WINDWARD PASSAGE AS WELL AS EASTERN CUBA. RAINSHOWERS ARE EXPECTED TO CONTINUE TO AFFECT THE ISLAND THROUGH LATE THURSDAY...HOWEVER WEATHER CONDITIONS IMPROVE ON EARLY FRIDAY WHEN A DRY AIRMASS IS EXPECTED TO MOVE ACROSS THE ISLAND. ATLANTIC OCEAN... THE ELONGATED UPPER LOW CENTERED OVER THE SE BAHAMAS IS ENHANCING ISOLATED SHOWERS AND TSTMS E OF THESE ISLANDS FROM 24N- 27N BETWEEN 72W-75W. A PREFRONTAL SURFACE TROUGH SUPPORTED BY AN UPPER LEVEL NARROW TROUGH EXTENDS FROM 32N59W TO 26N63W. ISOLATED SHOWERS ARE WITHIN 300 NM W OF ITS AXIS...HOWEVER E OF ITS AXIS A CLUSTER OF MODERATE CONVECTION WITH EMBEDDED TSTMS IS FROM 28N-33N BETWEEN 53W-58W. ANOTHER SURFACE TROUGH EXTENDS FROM 13N52W TO 09N54W WITH SCATTERED MODERATE CONVECTION WITHIN 120 NM E OF ITS AXIS FROM 10N-12N. OTHERWISE...BESIDES THE TROPICAL WAVE ALREADY DISCUSSED...SURFACE RIDGING AND FAIR WEATHER SUPPORTED BY LOWER-MIDDLE LEVELS DRY AIR DOMINATE THE REMAINDER BASIN. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ RAMOS