000 AXNT20 KNHC 071203 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE AUG 07 2012 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. ...SPECIAL FEATURES... TROPICAL STORM ERNESTO IS CENTERED NEAR 17.8N 84.4W AT 07/1200 UTC OR ABOUT 154 NM NE OF ISLA ROATAN HONDURAS AND ABOUT 219 NM E OF BELIZE CITY MOVING WNW AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 989 MB. MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 65 KT. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 15N-20N BETWEEN 79W-85W. SCATTERED MODERATE CONVECTION IS ELSEWHERE FROM 14N-23N BETWEEN 79W-92W. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT5/WTNT35 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 12N28W TO 18N27W MOVING W AT 15 KT. A 1009 MB LOW IS CENTERED AT THE SOUTHERN EXTENT OF THE WAVE AXIS NEAR 12N28W AND AN EARLIER 06/2248 UTC ASCAT PASS DEPICTED THE CIRCULATION EMBEDDED WITHIN THE MONSOON TROUGH AXIS. A MAXIMUM IN TOTAL PRECIPITABLE WATER IMAGERY IS ALSO OBSERVED BETWEEN 23W-31W WITH SCATTERED MODERATE CONVECTION OCCURRING FROM 09N-12N BETWEEN 27W-34W. TROPICAL WAVE EXTENDS FROM 13N46W TO 20N44W MOVING W-NW AT 15-20 KT. THE REMNANT LOW OF FLORENCE IS ANALYZED ALONG THE WAVE AXIS AS A 1008 MB LOW CENTERED NEAR 17N45W. SCATTERED MODERATE CONVECTION IS FROM 16N-18N BETWEEN 45W-48W. TROPICAL WAVE EXTENDS FROM 11N64W TO 19N64W MOVING W AT 15 KT. WEAK CYCLONIC FLOW IS NOTED IN LOW-LEVEL GLOBAL MODEL STREAMLINE ANALYSES ACROSS THE EASTERN CARIBBEAN AS A MOISTURE MAXIMUM IS NOTED ON TOTAL PRECIPITABLE WATER IMAGERY BETWEEN 58W-67W. SCATTERED SHOWERS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF A LINE FROM 17N61W TO 11N66W AND S OF 12N BETWEEN 66W-70W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 19N16W TO 16N22W TO 12N28W TO 11N40W. THE INTERTROPICAL CONVERGENCE ZONE EXTENDS FROM 11N40W TO 09N54W TO 10N60W. NO SIGNIFICANT CONVECTION IS NOTED ON SATELLITE IMAGERY. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL LOW CENTERED NEAR 24N97W CONTINUES TO IMPACT MUCH OF THE WESTERN GULF WATERS W OF 90W WHILE AN UPPER LEVEL RIDGE IS CENTERED OVER THE YUCATAN CHANNEL NEAR 22N85W AND EXTENDS AN AXIS NORTHWARD TO OVER SOUTHERN GEORGIA. THE UPPER LEVEL LOW REMAINS FAIRLY BROAD AND OVER THE PAST 24 HOURS...MOISTURE AND SHOWER ACTIVITY HAS REMAINED LIMITED TO ONLY A FEW ISOLATED SHOWERS NEAR THE CENTER OCCURRING FROM 22N-26N BETWEEN 94W-98W. FURTHER SUPPRESSING ANY SIGNIFICANT CONVECTION OVER THE WESTERN GULF IS THE PRESENCE OF A WEAK SURFACE RIDGE WITH AXIS EXTENDING FROM 30N90W TO THE EAST-CENTRAL MEXICO COAST NEAR 23N98W. PRIMARILY LIGHT ANTICYCLONIC WINDS ARE EXPECTED TO CONTINUE ACROSS THE WESTERN GULF THIS MORNING WITH EXPECTED STRENGTHENING OF NORTHEAST TO EAST WINDS BY EARLY WEDNESDAY S OF 24N WITH THE APPROACH OF TROPICAL STORM ERNESTO ACROSS THE YUCATAN PENINSULA LATE TUESDAY INTO WEDNESDAY. OVER THE EASTERN GULF THIS MORNING...WEAK SURFACE TROUGHING EXTENDS FROM 27N86W TO THE YUCATAN CHANNEL NEAR 22N87W AND ALONG WITH MAXIMUM MIDDLE TO UPPER LEVEL DIFFLUENCE PROVIDED BY THE UPPER LEVEL RIDGING IS GENERATING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS E OF A LINE FROM MOBILE BAY NEAR 30N88W TO 19N92W. SOME OF THIS ACTIVITY IS LARGELY TIED TO THE FAR OUTER BANDS OF CONVECTION ASSOCIATED WITH ERNESTO IN THE WESTERN CARIBBEAN SEA. LOOKING AHEAD...ERNESTO IS FORECAST TO IMPACT THE YUCATAN PENINSULA OVER THE NEXT FEW DAYS WHILE A WEAK SURFACE RIDGE AXIS EXTENDS TO THE NORTH ALONG 28N/29N THROUGH FRIDAY. CARIBBEAN SEA... TROPICAL STORM ERNESTO CONTINUES TO IMPACT THE WESTERN CARIBBEAN AS IT TRACKS WEST-NORTHWEST. ERNESTO REMAINS MOVING ON THE SOUTHERN PERIPHERY OF A MID-LEVEL SUBTROPICAL RIDGE ACROSS THE SW NORTH ATLC AND EASTERN GULF OF MEXICO WATERS. CONVECTION WITH ERNESTO REMAINS RATHER SPREAD OUT THIS MORNING ACROSS THE WESTERN CARIBBEAN AND YUCATAN PENINSULA/CENTRAL AMERICA REGION WITH SCATTERED SHOWERS AND TSTMS OCCURRING OVER THE AREA FROM 14N-23N BETWEEN 79W-92W. LOW-LEVEL MOISTURE AND WIDELY SCATTERED SHOWERS TRAIL TO THE EAST ACROSS THE ADJACENT COASTAL WATERS BETWEEN JAMAICA AND CUBA...THE WINDWARD PASSAGE...HISPANIOLA AND PUERTO RICO FROM 15N-20N BETWEEN 64W-79W. LOCALLY HEAVY RAINFALL IN ASSOCIATION WITH ERNESTO IS EXPECTED ACROSS PORTIONS OF HONDURAS AND NICARAGUA...BELIZE...AND THE YUCATAN PENINSULA WITH THE HIGH LIKELIHOOD OF FLASH FLOODING AND MUDSLIDES OVER THE HIGHER TERRAIN. ELSEWHERE OVER THE EASTERN CARIBBEAN...AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED NEAR 11N63W THAT IS PROVIDING FOR OVERALL DIFFLUENCE ALOFT ACROSS THE SE CARIBBEAN. AS THE TROPICAL WAVE ALONG 64W MOVES BENEATH THIS ENVIRONMENT... SCATTERED SHOWERS ARE EXPECTED TO CONTINUE ACROSS THE LESSER ANTILLES AND ADJACENT COASTAL WATERS THIS MORNING INTO THE AFTERNOON HOURS. ATLANTIC OCEAN... UPPER LEVEL TROUGHING IS NOTED ON WATER VAPOR IMAGERY N OF 18N BETWEEN 50W-65W WITH AN UPPER LEVEL LOW EXTENDING WEST OF THIS AREA CENTERED NEAR 22N70W. A BROAD-SCALE SURFACE TROUGH AXIS IS ANALYZED FROM 30N59W TO 23N68W AND IS PROVIDING FOCUS FOR ISOLATED SHOWERS AND TSTMS FROM 22N-30N BETWEEN 57W-62W...AND FROM 20N-24N BETWEEN 65W-72W. THE REMAINDER OF THE SW NORTH ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE WITH AXIS EXTENDING W-SW FROM A 1022 MB HIGH CENTERED NEAR 33N61W TO THE NW BAHAMAS AND CENTRAL FLORIDA PENINSULA. FARTHER EAST...UPPER LEVEL ANTICYCLONIC CIRCULATIONS ARE NOTED ON WATER VAPOR IMAGERY OVER THE EASTERN ATLC WITH A MEAN CENTER NEAR 23N33W. THIS UPPER LEVEL RIDGING LARGELY SUPPORTS A SURFACE RIDGE ANCHORED BY A 1024 MB HIGH CENTERED NEAR 33N36W WITH INFLUENCE N OF 20N BETWEEN 14W-55W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN