000 AXPZ20 KNHC 060935 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT AUG 06 2011 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...SPECIAL FEATURES... TROPICAL STORM EUGENE IS CENTERED NEAR 18.9N 127.1W AT 06/0900 UTC MOVING W-NW OR 285 DEGREES AT 11 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1005 MB. MAXIMUM SUSTAINED WINDS HAVE DECREASED TO 35 KT WITH GUSTS TO 45 KT. A 0420 UTC JASON ALTIMETER PASS WENT RIGHT OVER EUGENE MEASURING A MAXIMUM OF 16-17 FT SEAS. A 0528 UTC ASCAT SCATTEROMETER PASS INDICATED FRESH TO STRONG WINDS OCCURRING WITHIN 300 NM IN THE N AND 180 NM IN THE S SEMICIRCLES OF EUGENE. INFRARED SATELLITE IMAGERY INDICATES THAT NO DEEP CONVECTION REMAINS ALTHOUGH THE CIRCULATION ITSELF REMAINS VIGOROUS. ADDITIONAL WEAKENING IS FORECAST AS THE CYCLONE CONTINUES TO MOVE OVER COLDER WATER AND BEGINS TO ENCOUNTER INCREASING VERTICAL WIND SHEAR. EUGENE IS FORECAST TO WEAKEN TO A POST-TROPICAL/REMNANT LOW IN 12 HOURS. SEE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS TCPEP5/ WTPZ35 KNHC AND FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS TCMEP5/WTPZ25 FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH IS ALONG 10N86W TO 08N100W TO 17N108W THEN RESUMES NEAR 15N126W TO 11N136W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 11N136W TO 10N140W. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 06N TO 08.5N BETWEEN 103W AND 105W. ...DISCUSSION... AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE NORTHERN BAJA CALIFORNIA PENINSULA NEAR 29N115W WITH AN UPPER RIDGE REACHING FROM THE ANTICYCLONE TO 25N130W TO A COL NEAR 12N137W. TROPICAL STORM EUGENE CONTINUES TO MOVE W-NW AROUND THE SOUTHERN PERIPHERY OF THIS UPPER RIDGE. AN UPPER LEVEL TROUGH IS CLIPPING THE FAR NW CORNER OF THE AREA FROM 32N140W TO JUST NE OF THE BIG ISLAND OF HAWAII. THIS TROUGH WILL REMAIN BLOCKED BY THE ANTICYCLONE DURING THE NEXT 24-48 HOURS. VERY DRY AIR UNDER MODERATE TO STRONG SUBSIDENCE IS NOTED BY WATER VAPOR SATELLITE IMAGERY N OF 15N W OF 130W AND N OF 24N W OF THE BAJA CALIFORNIA PENINSULA. OTHERWISE...PRIMARILY EASTERLY UPPER LEVEL WINDS DOMINATE THE REMAINDER OF THE DISCUSSION AREA ALOFT. AT THE SURFACE...1035 MB HIGH PRES CENTERED NW OF THE FORECAST REGION NEAR 41N149W EXTENDS A RIDGE AXIS SE TO 26N121W. THE PRES GRADIENT BETWEEN THE RIDGE AND EUGENE IS RESULTING IN FRESH NE WINDS FROM 20N TO 25N W OF 130W. A 0704 UTC ASCAT PASS CAPTURED A SMALL AREA OF SE 20 KT WINDS FROM 03N TO 06N W OF 135W. EXPECT THESE WINDS TO DIMINISH TO LESS THAN 20 KT WITHIN THE NEXT 12-24 HOURS. A TIGHT PRES GRADIENT IS RESULTING IN 20 KT NORTHERLY WINDS N OF 28N WITHIN 120 NM W OF THE BAJA CALIFORNIA PENINSULA AS CAPTURED BY 0715 UTC EXPERIMENTAL HI-RES COASTAL ASCAT WINDS. THESE WINDS ARE FORECAST TO DIMINISH TO LESS THAN 20 KT IN 24 HOURS AS THE PRES GRADIENT WEAKENS. A WEAK AREA OF LOW PRES IS CENTERED NEAR 19N109W. DEEPER CONVECTION HAS DISSIPATED DURING THE PAST SEVERAL HOURS AND ENVIRONMENTAL CONDITIONS ARE NOT CONDUCIVE FOR DEVELOPMENT DURING THE NEXT 24-48 HOURS AS IT MOVES W-NW AROUND 10 KT. CROSS-EQUATORIAL SOUTHERLY SWELL CONTINUES TO PROPAGATE ACROSS THE REGIONAL WATERS MAINLY S OF 10N AND W OF 95W BUILDING SEAS TO 10 FT. THIS SWELL WILL GRADUALLY DECAY AND BECOME CONFINED TO W OF 100W IN 24 HOURS...THEN TO W OF 105W IN 48 HOURS. $$ LEWITSKY