000 AXPZ20 KNHC 022200 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC FRI OCT 02 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2145 UTC. ...SPECIAL FEATURE... TROPICAL STORM OLAF...WAS CENTERED NEAR 23.8N 117.2W AT 02/2100 UTC OR ABOUT 405 NM...750 KM...WEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA...WITH MAXIMUM SUSTAINED WINDS OF 35 KT WITH GUSTS TO 45 KT. OLAF WAS MOVING N OR 010 DEG AT 8 KT WITH AN ESTIMATED MINIMUM CENTRAL PRESSURE OF 1004 MB. SOUTHERLY SHEAR IS TAKING ITS TOLL ON OLAF WITH THE DEEP CONVECTION BEGINNING TO SEPARATE FROM THE LOW LEVEL CENTER. CURRENTLY CONVECTION IS CONFINED TO THE N SEMICIRCLE OF THE STORM WITHIN A BAND OF SCATTERED TO NUMEROUS STRONG THUNDERSTORMS 60-90 NM EITHER SIDE OF A LINE THROUGH 25N117W 25N115W TO 23N115.5W. NO CONVECTION WAS NOTED IN THE S SEMICIRCLE. OLAF HAS A FAIRLY LARGE CIRCULATION AS CONFIRMED BY THE SHIP WITH CALL SIGN 3FXY2 WHICH REPORTED 32 KT WINDS SOME 150 NM N OF THE CENTER OF OLAF. THE SHEAR IS FORECAST TO INCREASE FURTHER AND THIS COMBINED WITH A TRACK TOWARD BAJA CALIFORNIA OVER COOLER WATERS SHOULD RESULT IN THE DISSIPATION OF THE SYSTEM WITHIN 48 HOURS. ADDITIONAL INFORMATION CAN BE FOUND UNDER AWIPS/WMO HEADERS MIATCMEP3/WTPZ23 KNHC. ...ITCZ... AXIS WAS CENTERED ALONG 09N84W TO 09N90W TO 09N100W TO 08N110W TO 11N117W...THEN RESUMES AT 14N120W TO 11N130W TO 10N140W. SCATTERED MODERATE TO STRONG WITHIN 60 NM N OF THE ITCZ BETWEEN 131W AND 136W. SCATTERED MODERATE WITHIN 120 NM S OF THE ITCZ BETWEEN 115W AND 117W...BETWEEN 129W AND 113W AND W OF 135W. ...DISCUSSION... AMPLIFIED POSITIVELY TILTED UPPER PATTERN REMAINS IN PLACE S OF 32N WITH A SHEAR AXIS EXTENDING FROM A CYCLONIC CIRCULATION OVER SOUTHERN CALIFORNIA SOUTHWESTWARD THROUGH 32N133W TO A CYCLONIC CIRCULATION JUST W OF THE AREA NEAR 26N144W TO A BASE NEAR 13N147W. SATELLITE DERIVED WINDS INDICATED A 80-90 KT JET SE OF THE TROUGH WHICH EXTENDED THROUGH 19N140W TO 28N130W THEN CURVED EWD ACROSS EXTREME NORTHERN BAJA CALIFORNIA AND THE SW CONUS. THIS JET WAS ADVECTING MAINLY UPPER LEVEL OUTFLOW MOISTURE FROM OLAF NORTHEAST OVER MEXICO AND AND THE SW CONUS. MODERATE TO STRONG SUBSIDENCE WITH DRY STABLE AIR IN THE MIDDLE AND UPPER LEVELS OF THE ATMOSPHERE WAS NOTED NEAR THE CIRCULATION OFF CALIFORNIA...AND SWEEPING AROUND THE SOUTHERN END OF THE POSITIVELY TILTED TROUGH GENERALLY S OF 18N W OF 120W. DOWNSTREAM...AN UPPER LEVEL BROAD BLOCKING ANTICYCLONIC CIRCULATION IS CENTERED NEAR 23N110W...WITH RIDGE N TO THE NORTHERN COAST OF THE BAJA PENINSULA. OLAF IS SITUATED IN THE FAR WESTERN PERIPHERY OF THIS ANTICYCLONE AND IS NOW UNDERGOING DIFFLUENT BUT SHEARING SOUTHERLY FLOW. 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 1035 MB HIGH NEAR 39N144W AND COVERED THE DISCUSSION AREA N OF 18N W OF 120W. THE RIDGE COMBINED WITH THE LOWER PRESSURES IN THE TROPICS AND IN THE VICINITY OF TROPICAL STORM OLAF CONTINUES TO RESULT IN A LARGE AREA OF NE TRADES OF 20-25 KT W OF A LINE FROM 30N116W TO 20N120W TO 11N140W. AS NOTED IN EARLIER DISCUSSIONS 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. $$ COBB