000 AXNT20 KNHC 060540 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT MON AUG 06 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... TROPICAL STORM ERNESTO IS CENTERED NEAR 15.0N 79.9W AT 06/0600 UTC OR ABOUT 190 NM E OF CABO GRACIAS A DIOS ON THE NICARAGUA/ HONDURAS BORDER AND ABOUT 395 NM E OF ISLA ROATAN HONDURAS MOVING W AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1003 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 13N-19N BETWEEN 75W-81W. 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 STORM FLORENCE IS CENTERED NEAR 16.2N 37.9W AT 06/0300 UTC OR ABOUT 805 NM W OF THE CAPE VERDE ISLANDS MOVING W AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1008 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. MOST OF THE SIGNIFICANT DEEP CONVECTION HAS DIMINISHED IN THE VICINITY OF FLORENCE...HOWEVER SCATTERED SHOWERS ARE FROM 15N-22N BETWEEN 34W-44W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 08N60W TO 14N55W MOVING W AT 15 KT. THE WAVE IS DIFFICULT TO DISCERN ON INFRARED SATELLITE IMAGERY AS IT REMAINS EMBEDDED WITHIN THE ITCZ WHICH EXTENDS BETWEEN 48W-63W. HOWEVER...EXAMINING TOTAL PRECIPITABLE WATER IMAGERY... MAXIMUM VALUES OCCUR IN THE VICINITY OF THE WAVE AXIS BETWEEN 54W-62W. ALSO 700 MB GLOBAL MODEL DATA INDICATES A VERY WEAK TROUGH AXIS ALONG 56W. MOST OF THE STRONGER WINDS ALOFT HOWEVER ARE WEST OF THE WAVE AND LIKELY INFLUENCING TROPICAL STORM ERNESTO INSTEAD. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 13N17W TO 10N22W TO 09N32W. THE INTERTROPICAL CONVERGENCE ZONE EXTENDS FROM 10N48W TO 12N57W TO 10N62W. SCATTERED MODERATE CONVECTION IS FROM 11N-14N BETWEEN 15W-18W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 08N-13N BETWEEN 19W-25W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER LEVEL LOW CENTERED NEAR 24N93W IMPACTS THE ENTIRE GULF THIS EVENING AS MIDDLE TO UPPER LEVEL MOISTURE CONTINUES TO CIRCULATE ACROSS MUCH OF THE WESTERN GULF WITH ISOLATED SHOWERS AND TSTMS OCCURRING FROM 20N-23N BETWEEN 87W-91W...AND FROM 22N-27N BETWEEN 90W-97W. AT THE SURFACE...WEAK SURFACE RIDGING IS SLOWLY ERODING DUE TO THE APPROACH OF TROPICAL STORM ERNESTO IN THE WESTERN CARIBBEAN SEA AND A VERY BROAD AREA OF SURFACE TROUGHING EXTENDS FROM ERNESTO ALONG 80W ACROSS CUBA TO THE CENTRAL FLORIDA PENINSULA. WITH OVERALL DIFFLUENCE PREVAILING ALONG 80W AS WELL...SCATTERED SHOWERS AND TSTMS ARE OCCURRING ACROSS PORTIONS OF THE FLORIDA STRAITS AND WESTERN CUBA... INCLUDING ADJACENT COASTAL WATERS OF THE FLORIDA KEYS. ANOTHER AREA OF WIDELY SCATTERED SHOWER AND TSTMS ACTIVITY IS OCCURRING ACROSS THE FLORIDA PANHANDLE STRETCHING WESTWARD TO MOBILE BAY AND EXTREME SOUTHERN MISSISSIPPI. LOOKING AHEAD...THE SURFACE RIDGING CURRENTLY IN PLACE IS FORECAST TO SHIFT NORTHWARD AND WEAKEN SLIGHTLY AS ERNESTO TRACKS WEST-NORTHWESTWARD OVER THE NEXT FEW DAYS. WINDS ARE EXPECTED TO REMAIN VERY LIGHT AND PRIMARILY CONTAIN A NORTHERLY COMPONENT THROUGH EARLY TUESDAY. CARIBBEAN SEA... TROPICAL STORM ERNESTO CONTINUES TO IMPACT THE WESTERN CARIBBEAN THIS EVENING AS IT TRACKS WEST. ERNESTO REMAINS MOVING ON THE SOUTHERN PERIPHERY OF A LARGE MID-LEVEL SUBTROPICAL RIDGE ACROSS THE SW NORTH ATLC WATERS. WHILE RECENT CONVECTION PERSISTS NEAR THE CENTER OF ERNESTO...SATELLITE IMAGERY INDICATES WIDELY SCATTERED SHOWERS AND TSTMS OCCURRING WELL TO THE NORTH OF THE CENTER ACROSS WESTERN CUBA AND THE ADJACENT COASTAL CARIBBEAN WATERS FROM 20N-25N BETWEEN 77W-86W. SCATTERED SHOWERS TRAIL TO THE EAST-SOUTHEAST ACROSS EASTERN CUBA...THE WINDWARD PASSAGE... AND HISPANIOLA WITH THE CONTINUED POSSIBILITY OF LOCALLY HEAVY RAINFALL OVER JAMAICA...HISPANIOLA...CUBA...AND THE CAYMAN ISLANDS. AS ERNESTO SKIRTS SOUTH OF JAMAICA. ELSEWHERE...DRY AIR ALOFT IS NOTED ON WATER VAPOR IMAGERY OVER THE EASTERN CARIBBEAN E OF 70W WITH MOSTLY CLEAR SKIES PREVAILING THROUGH THE OVERNIGHT HOURS. HOWEVER BY MIDDAY MONDAY...THE APPROACH OF THE TROPICAL WAVE ALONG 57W WILL BEGIN TO PROVIDE ISOLATED SHOWER ACTIVITY TO THE WINDWARD ISLANDS. ATLANTIC OCEAN... ASIDE FROM TROPICAL STORM FLORENCE IN THE TROPICAL CENTRAL ATLC MENTIONED ABOVE...A NARROW UPPER LEVEL RIDGE AXIS EXTENDS FROM 30N83W TO THE LARGER UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE CENTRAL CARIBBEAN SEA NEAR 18N76W. THIS RIDGE AXIS AND THE ASSOCIATED DIFFLUENCE ALOFT CONTINUES TO SUPPORT SCATTERED SHOWERS AND TSTMS OVER THE FLORIDA STRAITS AND ADJACENT FLORIDA PENINSULA COASTAL WATERS FROM 20N-27N W OF THE BAHAMAS. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED NEAR 34N49W AND EXTENDS AN UPPER LEVEL TROUGH AXIS FROM THE LOW ALONG 23N60W TO ANOTHER UPPER LEVEL LOW CENTERED NEAR 26N71W. THIS LARGELY REFLECTS TO THE SURFACE AS VERY WEAK AND BROAD SURFACE TROUGHING N OF 24N BETWEEN 53W-65W WHERE MOISTURE CONVERGENCE IS GENERATING ISOLATED SHOWERS AND TSTMS FROM 23N-26N BETWEEN 52W-57W...AND ISOLATED SHOWERS FROM 22N-28N BETWEEN 67W-73W. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1026 MB HIGH CENTERED NEAR 34N35W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN