000 AXPZ20 KNHC 200338 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC WED MAY 20 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 0300 UTC. ...ITCZ... AXIS ALONG 07N81W TO 06N90W TO 09N99W TO 09N107W TO 12N117W TO 05N133W TO 04N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 150 NM OF AXIS E OF 122W. ISOLATED MODERATE CONVECTION WITHIN 60 NM OF AXIS FROM 129W-136W. .DISCUSSION... LARGE AMPLITUDE MID/UPPER TROUGH EXTEND FROM CYCLONIC VORTEX AT 34N123W TO 11N105W SPLITTING RIDGE ALOFT WHICH RUNS E-W WITH TWO ANTICYCLONES...ONE AT 11N121W AND ANOTHER AT 07N98W. RIDGE ALLOWS PLENTY OF TROPICAL MOISTURE TO ENCROACH INTO E PAC ON ITS SOUTHERN PERIPHERY ALONG ITCZ E OF 124W. E PAC REMAINS VERY DRY ALOFT W OF UPPER TROUGH WITH SOME CONVECTIVE DEBRIS MOISTURE MOVING NE INTO CENTRAL MEXICO E OF TROUGH AXIS. WINDS ALOFT W OF TROUGH REMAIN QUASI-ZONAL WITH DUE W JET CORE OF 90 KT. WEAK SURFACE TROUGH FROM 17N117W TO 08N120W HAS EMBEDDED LOW PRES 1008 MB ALONG ITCZ AT 11N120W. FAVORABLE UPPER ENVIRONMENT AND PLENTY OF LOW LEVEL MOISTURE FEED LOW PRES BUT STILL LACK ANY ORGANIZED CIRCULATION AND IS MOVING INTO VERY DRY AND STABLE ZONE AHEAD. CHANCES OF ITS DEVELOPMENT CONSIDERED VERY LOW. ELSEWHERE AT THE SURFACE... PREVIOUS HIGH PRES NEAR 28N126W HAS DISSIPATED AS COLD FRONT APPROACHES NORTHERN FRINGES OF FORECAST WATERS. FRONT EXPECTED TO MOVE E INTO CALIFORNIA WITH NEW HIGH PRES 1032 MB MOVING W INTO AREA JUST N OF E PAC. GRADIENT BETWEEN HIGH PRES AND LOW PRES 1003 MB OVER ARIZONA CAUSING GALE FORCE WINDS ALONG CENTRAL CALIFORNIA COASTAL WATERS AND BUILDING MODERATE N-NW SWELL SPREADING S JUST N OF 25N E OF 117W BY THU. GAP WINDS...GULF OF TEHUANTEPEC GALE FORCE WIND EVENT SUBSIDED AS HIGH PRES FORCING N WINDS WEAKENS. WINDS HAVE DIMINISHED BUT STILL TO REMAIN CLOSE TO 25-30 KT NEXT 24 HRS AND TO LESS THAN 20 KT BY THU. $$ WALLY BARNES