000 AXPZ20 KNHC 050249 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC WED OCT 05 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0230 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH IS ALONG 11N86W TO 13N94W TO LOW PRES 11N114W 1008 MB TO LOW PRES 11N120W 1008 MB TO 10N126W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N126W TO 08N140W. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 75 NM EITHER SIDE OF THE MONSOON TROUGH BETWEEN 93W AND 97W AND WITHIN 120-180 NM S OF A LINE FROM 07N93W TO 11N103W. SIMILAR CONVECTION IS WITHIN 60 NM N OF A LINE FROM 11N103W TO 14N113W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 120-180 NM OF THE FIRST LOW AND WITHIN 180-240 NM IN THE NW SEMICIRCLE OF THE SECOND LOW. NO SIGNIFICANT CONVECTION IS NOTED WITH THE ITCZ. ...DISCUSSION... A SHARP UPPER TROUGH REACHES FROM SOUTHERN ARIZONA TO ACROSS NW MEXICO FROM 31N110W TO 29N121W TO 27N137W WITH A WEST TO EAST ORIENTED UPPER RIDGE ALONG 33N BEHIND THE UPPER TROUGH. MID TO UPPER LEVEL MOISTURE IS STREAMING IN ALONG THIS RIDGE INTRUDING ON THE NORTHERN BAJA CALIFORNIA PENINSULA. A STATIONARY UPPER LOW IS OVER 20N140W WITH LIMITED ASSOCIATED MOISTURE NOTED ON WATER VAPOR IMAGERY. ANOTHER AND MUCH LARGER UPPER LOW IS OVER 01N137W WITH VERY DRY AIR NOTED S OF 07N W OF 120W. OTHERWISE MAINLY UPPER ANTICYCLONIC FLOW DOMINATES THE REMAINDER OF THE AREA S OF 25N E OF 130W WITH A UPPER RIDGE AXIS ALONG 16N E OF 130W. ABUNDANT DEEP LEVEL MOISTURE IS ALONG AND NEAR THE MONSOON TROUGH AIDED BY DIFFLUENCE OVER AND NEAR THE UPPER RIDGE. DEBRIS CLOUDINESS FROM THE ABOVE DESCRIBED CONVECTION SPREADS S TO NEAR 04N BEFORE IT DISSIPATES IN DRY AIR...AND ALSO SPREADS TO THE N OF THE MONSOON TROUGH TOWARD W CENTRAL MEXICO EVAPORATING AS IT ENCOUNTERS DRY AIR FROM 20N-28N E OF 125W. AT THE SURFACE...A FRONTAL TROUGH EXTENDS FROM 32N114W TO ACROSS THE NORTHERN BAJA CALIFORNIA PENINSULA TO 27N122W. EARLIER SCATTEROMETER PASSES INDICATED ONLY 5-10 KT NEAR THIS BOUNDARY IN THE OPEN PACIFIC...ALTHOUGH AN AREA OF NW SWELL TO 9 FT IS PROPAGATING E-SE BEHIND THE FEATURE ACROSS THE AREA N OF 26N W OF 124W. THIS FRONTAL TROUGH WILL DISSIPATE DURING THE NEXT 12-24 HOURS ALTHOUGH A NEW COLD FRONT WILL DROP INTO THE NORTHERN PORTION EXTENDING FROM 30N122W TO 27N130W TO 27N135W BY TOMORROW EVENING WITH 8 FT NW SWELL N OF 28N W OF 110W. THE COLD FRONT DISSIPATES BY 48 HOURS WITH 8-11 FT MIXED SW AND NW SWELL COVERING THE AREA N OF 25N W OF 120W. MODEL GUIDANCE CONTINUES TO INDICATE SW-W 20-25 KT WINDS IN THE FAR NORTHERN GULF OF CALIFORNIA PULSING THROUGH THE NEXT 48 HOURS WITH PEAK INTENSITY OCCURRING PRIOR TO THE FRONTAL TROUGH AND COLD FRONT PASSAGES. SEAS SHOULD REMAIN LESS THAN 8 FT. A SMALL AREA OF 20 KT NE TRADES WERE CAPTURED BY A 1916 UTC ASCAT PASS FROM 12N TO 18N W OF 135W WITH SEAS TO 8 FT. THESE TRADES WILL SHRINK AND WILL EXTEND FROM 10N TO 13N W OF 136W IN 24 HOURS THEN SHIFTING SLIGHTLY S FROM 09N TO 12N W OF 135W IN 48 HOURS. A 20-30 KT GULF OF TEHUANTEPEC EVENT CONTINUES THIS EVENING ALTHOUGH WINDS WILL DIMINISH TO 20-25 KT IN 24 HOURS THEN TO LESS THAN 20 KT IN 48 HOURS AS THE PRES GRADIENT RELAXES. SEAS UP TO 11 FT WILL GRADUALLY SUBSIDE TO LESS THAN 8 FT BY 48 HOURS. TWO 1008 MB AREAS OF LOW PRES ARE EMBEDDED IN THE MONSOON TROUGH. THE EASTERN LOW NEAR 11N114W WILL WEAKEN WHILE DRIFTING W THROUGH 24 HOURS WHILE A NEW LOW FORMS NEAR 11N109W. MODEL GUIDANCE DEVELOPS THIS NEW LOW AND IT HAS A LOW CHANCE OF TROPICAL CYCLONE FORMATION THROUGH 48 HOURS. ANOTHER LOW IS CURRENTLY NEAR 10N120W. THIS LOW WILL NOT MOVE MUCH THROUGH 24-48 HOURS AND AN AREA OF 20 KT WINDS IS FORECAST TO PERSIST ON THE NORTHERN SIDE OF THE LOW. SW MONSOONAL FLOW OF 20-25 KT WILL PERSIST AND EXPAND S OF THE MONSOON TROUGH AND THESE LOWS THROUGH 48 HOURS. OTHERWISE...CROSS-EQUATORIAL SW SWELL WITH PEAK WAVE PERIODS OF 20-22 SECONDS AND SEAS TO 9 FT WILL GRADUALLY PROPAGATE NORTHWARD REACHING THE MEXICO AND CENTRAL AMERICAN COASTS THROUGH THE REMAINDER OF THE WEEK...WHILE INTERACTING WITH THE AREAS DESCRIBED ABOVE. $$ LEWITSKY