000 AXNT20 KNHC 061202 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...SPECIAL FEATURES... TROPICAL STORM ERNESTO IS CENTERED NEAR 15.2N 81.0W AT 06/1200 UTC OR ABOUT 127 NM E OF CABO GRACIAS A DIOS ON THE NICARAGUA/ HONDURAS BORDER AND ABOUT 329 NM E OF ISLA ROATAN HONDURAS MOVING W AT 10 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 12N-20N BETWEEN 76W-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 DEPRESSION FLORENCE IS CENTERED NEAR 16.2N 38.8W AT 06/0900 UTC OR ABOUT 1400 NM E OF THE NORTHERN LEEWARD ISLANDS MOVING W AT 10 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1009 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUSTS TO 40 KT. NO SIGNIFICANT DEEP CONVECTION IS NOTED IN THE VICINITY OF THE DEPRESSION ON SATELLITE IMAGERY...HOWEVER WIDELY SCATTERED SHOWERS ARE FROM 15N-20N BETWEEN 36W-43W. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 12N20W TO 18N18W MOVING W AT 10-15 KT. EXAMINING LONG-TERM SATELLITE IMAGERY AND UPPER AIR TIME SECTION ANALYSES FROM DAKAR SENEGAL...IT APPEARS THIS WAVE EMERGED OFF THE COAST AROUND 05/0000 UTC. A WEAK 1011 MB LOW IS CENTERED AT THE SOUTHERN EXTENT OF THE WAVE AXIS NEAR 12N20W AS A FEW WESTERLY WINDS WERE DEPICTED ON A RECENT 05/2308 UTC ASCAT PASS. TOTAL PRECIPITABLE WATER IMAGERY ALSO SHOWS MAXIMUM VALUES FROM 08N-14N BETWEEN 19W-24W. TROPICAL WAVE EXTENDS FROM 09N59W TO 15N56W MOVING W AT 10-15 KT. THE WAVE IS DIFFICULT TO DISCERN ON INFRARED SATELLITE IMAGERY AS IT REMAINS ON THE WESTERN EXTENT OF THE ITCZ. HOWEVER...EXAMINING TOTAL PRECIPITABLE WATER IMAGERY...MAXIMUM VALUES OCCUR IN THE VICINITY OF THE WAVE AXIS NEAR 11N57W. ISOLATED MODERATE CONVECTION AND SCATTERED SHOWERS ARE OCCURRING FROM 10N-15N BETWEEN 53W-62W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 15N17W TO 11N22W TO 12N30W TO 08N39W. THE INTERTROPICAL CONVERGENCE ZONE EXTENDS FROM 08N39W TO 07N44W TO 11N57W. SCATTERED MODERATE CONVECTION IS FROM 07N-14N BETWEEN 22W-26W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 04N-07N BETWEEN 38W-44W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER LEVEL LOW CENTERED NEAR 23N94W IMPACTS THE ENTIRE GULF THIS MORNING 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 96W-98W...AND FROM 23N-27N BETWEEN 89W-98W. 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 81W/82W ACROSS WESTERN CUBA TO THE WEST-CENTRAL FLORIDA PENINSULA. WITH OVERALL DIFFLUENCE PREVAILING ALONG 80W AS WELL...SCATTERED SHOWERS AND TSTMS ARE OCCURRING MOSTLY NORTH OF ERNESTO'S CORE CONVECTION ACROSS PORTIONS OF THE NW CARIBBEAN SEA AND THE FLORIDA STRAITS FROM 22N-26N BETWEEN 77W-83W. ANOTHER AREA OF WIDELY SCATTERED SHOWER AND TSTMS ACTIVITY IS OCCURRING ACROSS THE FLORIDA PANHANDLE STRETCHING WESTWARD TO NEAR MOBILE BAY . LOOKING AHEAD...THE SURFACE RIDGING CURRENTLY IN PLACE IS FORECAST TO SHIFT NORTH AND WEAKEN SLIGHTLY AS ERNESTO TRACKS WEST-NORTHWESTWARD OVER THE NEXT FEW DAYS. WINDS ARE EXPECTED TO REMAIN VERY LIGHT AND PRIMARILY CONTAIN NORTHERLY AND EASTERLY COMPONENTS THROUGH EARLY TUESDAY. CARIBBEAN SEA... TROPICAL STORM ERNESTO CONTINUES TO IMPACT THE WESTERN CARIBBEAN THIS MORNING 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 SCATTERED SHOWERS AND TSTMS OCCURRING TO THE NORTH OF THE CENTER ACROSS THE CAYMAN ISLANDS AND ADJACENT COASTAL WATERS OF JAMAICA AND CUBA FROM 19N-23N BETWEEN 76W-86W. LOW-LEVEL MOISTURE AND SCATTERED SHOWERS TRAIL TO THE EAST-SOUTHEAST ACROSS EASTERN CUBA...THE WINDWARD PASSAGE...AND HISPANIOLA WITH THE CONTINUED POSSIBILITY OF LOCALLY HEAVY RAINFALL TODAY OVER JAMAICA... CUBA...AND THE CAYMAN ISLANDS. 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 58W WILL BEGIN TO PROVIDE ISOLATED SHOWER ACTIVITY TO THE WINDWARD ISLANDS AND EXTREME SE CARIBBEAN. ATLANTIC OCEAN... ASIDE FROM TROPICAL DEPRESSION FLORENCE IN THE TROPICAL CENTRAL ATLC MENTIONED ABOVE...A NARROW UPPER LEVEL RIDGE AXIS EXTENDS FROM 31N84W TO THE LARGER UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE CENTRAL CARIBBEAN SEA NEAR 17N75W. 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 22N-31N W OF THE BAHAMAS AND W OF 79W. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED NEAR 34N48W AND EXTENDS AN UPPER LEVEL TROUGH AXIS FROM THE LOW ALONG 22N62W TO ANOTHER UPPER LEVEL LOW CENTERED NEAR 25N70W. THIS LARGELY REFLECTS TO THE SURFACE AS VERY WEAK AND BROAD SURFACE TROUGHING N OF 24N BETWEEN 52W-64W WHERE MOISTURE CONVERGENCE IS GENERATING ISOLATED SHOWERS AND TSTMS FROM 22N-27N BETWEEN 54W-59W. THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A PAIR OF 1025 MB HIGHS CENTERED NEAR 38N22W AND 34N36W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN