000 AXPZ20 KNHC 020316 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC FRI OCT 02 2009 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 0315 UTC. ...SPECIAL FEATURE... TROPICAL STORM OLAF...THE FIFTEENTH NAMED STORM IN THE EASTERN PACIFIC BASIN FOR THE 2009 SEASON...WAS CENTERED NEAR 20.7N 117.8W AT 02/0300 UTC OR ABOUT 565 NM...905 KM...WEST-SOUTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA WITH MAXIMUM SUSTAINED WINDS OF 35 KT WITH GUSTS TO 45 KT. OLAF IS MOVING N OR 315 DEG AT 11 KT WITH AN ESTIMATED MINIMUM CENTRAL PRESSURE OF 1002 MB. LAST VISIBLE SATELLITE IMAGERY SHOWED THAT OLAF HAS ACQUIRED AN INCREASING SYMMETRICAL STRUCTURE TO ITS OVERALL CLOUD PATTERN AS IT PULLS FURTHER AWAY FROM THE MONSOON TROUGH TO ITS S. INFRA-RED SATELLITE IMAGERY SHOWED DEEPENING CONVECTION OVER TO THE NE AND E OF THE CENTER WITH NUMEROUS STRONG CONVECTION WITHIN 180 NM OF THE CENTER IN THE NE QUADRANT. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN OF THE CENTER WITHIN 150 NM S SEMICIRCLE. A LARGE OUTER ENVELOPE OF 20-25 KT WINDS WHICH EXTENDED OUTWARD UP TO 360 NM IN THE E SEMICIRCLE WITH SEAS BUILDING UP TO 13 FT IN S TO SW SWELL. THE WINDOW FOR ADDITIONAL STRENGTHENING IS NARROWING AS WATER VAPOR IMAGERY INDICATED MODERATE TO STRONG SOUTHERLY SHEAR NOT TOO FAR W OF THE TROPICAL CYCLONE. SO OLAF IS FORECAST TO ONLY SLIGHTLY INCREASE IN INTENSITY THROUGH FRI MORNING BEFORE IT BEGINS TO WEAKEN. ADDITIONAL INFORMATION CAN BE FOUND UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC. ...TROPICAL WAVE... THE TROPICAL WAVE EARLIER NOTED FROM 08N TO 16N ALONG 107W HAS BECOME ABSORBED INTO THE LARGE CIRCULATION OF TROPICAL STORM OLAF. ONLY ISOLATED SHOWERS AND TSTMS ARE WITHIN 30 NM OF 17N108W. ...ITCZ... AXIS IS CENTERED ALONG 7N78W TO 8N90W TO 08N100W TO 15N114W ...THEN RESUMES AT 14N120W TO 11N130W TO 10N140W. SCATTERED MODERATE TO STRONG FROM 5N TO 9N BETWEEN 79W-83W. SCATTERED MODERATE ISOLATED/STRONG CONVECTION IS WITHIN 60 NM S OF THE AXIS BETWEEN 128W-131W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 109W-113W. ...DISCUSSION... RATHER AMPLIFIED PATTERN IN PLACE S OF 30N WITH A SHARP SHEAR AXIS EXTENDING FROM SOUTHERN CALIFORNIA WESTWARD THROUGH 32N127W TO A CYCLONIC CIRCULATION JUST W OF THE AREA NEAR 28N141W. A MORE SIGNIFICANT TROUGH CONTINUED SSW FROM THE CIRCULATION TO A BASE NEAR 14N144W. SATELLITE DERIVED WINDS INDICATED A 70-95 KT JETSTREAM SE OF THE TROUGH WHICH EXTENDED FROM 14N140W TO 22N135W TO NORTHERN BAJA CALIFORNIA. MODERATE TO STRONG SUBSIDENCE WITH DRY STABLE AIR IN THE MIDDLE AND UPPER LEVELS OF THE ATMOSPHERE WAS NOTED WITHIN THE SHEAR AXIS AND SWEEPING AROUND THE BACKSIDE OF TROUGH N OF 13N W OF 138W. DOWNSTREAM...AN UPPER LEVEL BROAD BLOCKING ANTICYCLONIC CIRCULATION IS CENTERED NEAR 22N108W...WITH RIDGE N TO THE NORTHERN COAST OF THE BAJA PENINSULA. THIS SAME AREA OF ANTICYCLONIC FLOW IS ALSO SUPPORTING OLAF'S DEEPENING CONVECTION. UPPER LEVEL DIFFLUENT FLOW SW OF THE ANTICYCLONIC CIRCULATION IS ENHANCING CONVECTIVE ACTIVITY IN THE VICINITY OF TROPICAL STORM OLAF. AN INVERTED TROUGH IN THE DEEP TROPICS WITH AXIS FROM THE EQUATOR AT 98W TO 10N90W WAS NEARLY STATIONARY. MODERATE TO STRONG SUBSIDENCE IS WITH THE TROUGH S OF 7N E OF 100W. AT THE SURFACE... STRONG RIDGE OF HIGH PRES EXTENDED SE FROM A 1038 MB HIGH NEAR 40N143W AND COVERED THE DISCUSSION AREA N OF 20N W OF 115W. THE RIDGE COMBINED WITH THE LOWER PRESSURES IN THE TROPICS AND IN THE VICINITY OF TROPICAL STORM OLAF HAS RESULTED IN A LARGE AREA OF NE TRADES OF 20-25 KT W OF A LINE FROM 30N116W TO 20N125W TO 14N140W...EXCEPT FROM 21N-25N W OF 135W WHERE NE WINDS OF 25-30 KT WERE NOTED. AS NOTED ABOVE THE WIND FIELD ASSOCIATED WITH OLAF IN THE W SEMICIRCLE HAS MERGED INTO THE LARGER AREA OF TRADES WITH A LARGE AREA OF 8-13 FT SEAS NOTED. SEAS OVER THE FAR SRN WATERS S OF ABOUT 8N ARE UP TO 9 OR 10 FT DUE TO LONG PERIOD SRN HEMISPHERIC SWELLS. THESE CONDITIONS ARE FORECAST BY WAVE MODEL GUIDANCE TO GRADUALLY BECOME DIFFUSE THROUGH THE NEXT 48 HOURS OR SHORTLY THEREAFTER. $$ AGUIRRE