000 AXPZ20 KNHC 080245 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN AUG 08 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0230 UTC. ...SPECIAL FEATURE... AT 08/0300 UTC...THE CENTER OF TROPICAL STORM ESTELLE IS LOCATED NEAR 17.3N 109.4W MOVING TOWARD THE WEST OR 280 DEGREES AT 7 KT...AND THIS GENERAL MOTION...WITH A CONTINUED GRADUAL DECREASE IN FORWARD SPEED...IS EXPECTED DURING THE NEXT 48 HOURS. ESTIMATED MINIMUM CENTRAL PRESSURE IS 994 MB. MAXIMUM SUSTAINED WINDS ARE NOW 55 KT WITH GUSTS TO 65 KT. SOME STRENGTHENING IS POSSIBLE TONIGHT AND SUNDAY...WITH A GRADUAL WEAKENING FORECAST THEREAFTER. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. ...ITCZ... THE ITCZ AXIS IS ALONG 12N91W TO 13N105W TO 14N112W TO 11N123W TO 11N137W TO 10N138W TO 09N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 150 NM S OF THE AXIS BETWEEN 95W AND 99W. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM S OF THE AXIS BETWEEN 104W AND 110W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 90 NM S OF THE AXIS BETWEEN 110W AND 115W...AND WITHIN 90 NM N OF THE AXIS W OF 138W. ...DISCUSSION... AN UPPER LEVEL ANTICYCLONE DOMINATING THE NW WATERS IS POSITIONED NEAR 26N135W WITH AN UPPER RIDGE EXTENDING BEYOND 32N137W. A SECOND UPPER LEVEL ANTICYCLONIC CIRCULATION IS LOCATED OVER FAR SOUTHERN TEXAS NEAR THE MEXICAN BORDER WITH A RIDGE AXIS EXTENDING W ACROSS CENTRAL MEXICO AND INTO THE E PACIFIC TO NEAR 22N118W. TROPICAL STORM ESTELLE IS EMBEDDED IN THE UPPER LEVEL SOUTHEASTERLY FLOW TO THE SW OF THIS ANTICYCLONE. A WEAK UPPER LEVEL TROUGH AXIS EXTENDS FROM NORTHERN BAJA CALIFORNIA ACROSS THE GULF OF CALIFORNIA TO NW MEXICO NEAR 24N107W. CONVECTION HAS DEVELOPED BETWEEN THIS TROUGH AND THE RIDGE EXTENDING OVER CENTRAL MEXICO. AN UPPER LEVEL TROUGH ENTERS THE FORECAST AREA NEAR 32N121W AND CONTINUES SW THROUGH 26N123W TO 21N123W. VERY DRY AIR ALOFT WITH MODERATE TO STRONG SUBSIDENCE IS PRESENT ACROSS THE REGION N OF 16N AND W OF 116W. ZONAL/EASTERLY FLOW PREVAILS ACROSS THE REMAINDER OF THE DISCUSSION AREA IN THE DEEP TROPICS S OF 10N. UPPER LEVEL MOISTURE RESULTING FROM ITCZ CONVECTION IS BEING ADVECTED TO THE WEST AS A RESULT OF THE PERSISTENT EASTERLY WINDS. UPPER LEVEL DIFFLUENCE IS HELPING TO INDUCE CONVECTION ALONG THE ITCZ IN THE AREAS DESCRIBED ABOVE. AT THE SURFACE...A RIDGE DOMINATES THE NORTHERN WATERS STEMMING FROM 1027 MB HIGH PRES CENTERED WELL NW OF THE AREA NEAR 36N144W ENTERING THE DISCUSSION AREA AT 30N139W THROUGH 17N117W. NOAA CORPS SHIP 'MCARTHUR II' NEAR 29N131W HAS BEEN REPORTING 15-20 KT WINDS DURING THE PAST FEW HOURS AND HAVE ADDED AN AREA OF 15-20 KT N OF 28N BETWEEN 28N BETWEEN 124W AND 132W DUE TO A TIGHTER PRES GRADIENT BETWEEN THE RIDGE AND LOWER PRES NEAR SOUTHERN CALIFORNIA. A TROUGH IN THE GULF OF CALIFORNIA IS ALSO RESULTING IN SE-S WINDS TO 20 KT N OF 29N ALTHOUGH EXPECT THESE WINDS TO DIMINISH BY 18 HOURS AS THE TROUGH WEAKENS. A SURFACE TROUGH EXTENDS FROM 13N137W TO 06N138W. A RECENT OBSERVATION FROM A SHIP WITH CALL-SIGN 'PHAA' JUST W OF THE TROUGH INDICATED 15 KT NE WINDS. EXPECT THE TROUGH TO DISSIPATE IN THE NEXT 12-18 HOURS AS IT CONTINUES TO MOVE W AT AROUND 10 KT. ITCZ DISTURBANCES CONTINUE TO PRODUCE A BELT OF S TO SW WINDS OF 20-25 KT S OF THE ITCZ TO 07N BETWEEN 90W AND 122W AS REPORTED BY SEVERAL SHIPS IN THE AREA DURING THE PAST FEW HOURS. COMBINED SEAS ARE 8-11 FT FROM LONG PERIOD SW SWELL AND FRESHLY GENERATED WIND SEAS. THIS OVERALL WEATHER PATTERN WILL PERSIST DURING THE NEXT FEW DAYS. CROSS EQUATORIAL SW SWELLS WITH PERIODS OF 14-16 SECONDS DOMINATE THE MAJORITY OF THE FORECAST WATERS. THESE SWELLS WILL GRADUALLY DECAY THROUGH MON AS A NEW SWELL TRAIN CROSSES THE EQUATOR BETWEEN 105W AND 125W. $$ LEWITSKY