000 AXPZ20 KNHC 212204 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC THU OCT 21 2010 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. ...ITCZ... AXIS CENTERED ALONG 9N85W 8N93W 8N106W 9N119W 8N130W 9N140W. SCATTERED MODERATE CONVECTION IS WITHIN 30 NM OF AXIS BETWEEN 130W-132W. ...DISCUSSION... A DEEP LAYERED UPPER LEVEL TROUGH MOVING QUICKLY E ENTERS THE FAR NE PORTION THROUGH 32N126W...AND STRETCHES SW TO W OF THE AREA AT 24N140W. ITS ASSOCIATED SURFACE COLD FRONT MOVING E ABOUT 20 KT IS ANALYZED FROM 30N130W TO 27N131W THEN WEAKENS TO 23N140W. WINDS ARE LESS THAN 20 KT ON EITHER SIDE OF THE FRONT ...HOWEVER TO THE NW OF THE FRONT SEAS ARE 8 TO 12 FT IN NW SWELLS WHILE WITHIN 120 NM SE OF FRONT SEAS ARE UP TO 8 FT ALSO IN NW SWELLS. AS THE UPPER TROUGH RACES EASTWARD TO INLAND THE WESTERN U.S. AND BAJA CALIFORNIA BUY EVENING...THE FRONT WILL THE QUICKLY BEGIN TO WEAKEN FROM 30N126W TO 26N132W TO 24N140W IN 24 HOURS...THEN DISSIPATE BY 48 HOURS AT WHICH TIME SEAS ARE EXPECTED TO BE UP TO 8 FT IN SUBSIDING NW SWELLS N OF 18N BETWEEN 111W AND A LINE FROM 32N127W TO 25N132W TO 19N140W. A VERY PRONOUNCED JET STREAM BRANCH ENTERS THE REGION THROUGH 22N140W...AND STRETCHES NE TO 24N130W WHERE IT BEGINS TO ROUND THE BASE OF THE UPPER TROUGH...AND CONTINUES EASTWARD TO ACROSS CENTRAL BAJA CALIFORNIA. JET CORE WINDS ARE IN THE RANGE OF 60-90 KT. A PLUME OF UPPER LEVEL MOISTURE DERIVED FROM THE DEEP CENTRAL TROPICAL PACIFIC IS PRESENT WITHIN 350 NM S OF THE JET STREAM BRANCH AS NOTED ON SATELLITE WATER VAPOR IMAGERY. THE MOISTURE IS BEING REFLECTED AS SCATTERED TO BROKEN CIRRUS CLOUDS. A MODEST MID/UPPER LEVEL RIDGE IS OVER THE FAR NORTHEASTERN PORTION OF THE AREA ALONG 118W N OF 21N. AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 14N107W WITH AN UPPER LEVEL RIDGE AXIS EXTENDING W ALONG 14N TO W OF THE AREA ...AND EASTWARD TO NEAR 98W. UPPER LEVEL DIFFLUENCE AND MOIST SOUTHWESTERLY FLOW ALOFT WITHIN THE WESTERN PERIPHERY OF THE RIDGE W OF 130W IS ENHANCING SCATTERED MODERATE CONVECTION ALONG THE ITCZ BETWEEN 130W-132W WITH THE RESULTANT UPPER LEVEL TO DEBRIS MOISTURE ADVECTING NORTHWARD TO NEAR 15N. SATELLITE WATER VAPOR IMAGERY SHOWS AMPLE MODERATE SUBSIDENCE RESULTING IN DRY ENVIRONMENTAL CONDITIONS THROUGHOUT S OF 22N AND E OF ABOUT 130W WITH ONLY SCATTERED LOW CLOUDS NOTED THERE ELSEWHERE N OF THE ITCZ. AN UPPER LEVEL TROUGH LOCATED WELL E OF THE AREA OVER THE CENTRAL AND SW GULF OF MEXICO EXTENDS ITS AXIS SW TO A BASE OVER THE GULF OF TEHUANTEPEC NEAR 16N96W WHERE A COL REGION IS OBSERVED. AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE WESTERN CARIBBEAN AND EXTENDS AN UPPER LEVEL RIDGE AXIS OVER HONDURAS AND NICARAGUA TO NEAR 14N95W. TO S OF THE RIDGE AXIS ALONG 14N...SCATTERED MAINLY MODERATE CONVECTION IS OCCURRING JUST INLAND AND ALONG THE COAST OF COSTA RICA AS WELL AS THAT ALONG MUCH OF PANAMA...BUT IS WEAKENING AS IT MOVES FURTHER OFFSHORE ACROSS THE EPAC WATERS. ELSEWHERE AT THE SURFACE...A 1021 MB HIGH IS CENTERED AT 26N131W WITH A RIDGE AXIS SE TO NEAR 22N120W TO 14N113W. NE TRADES OF 15 TO 20 KT ARE NOTED S OF THE RIDGE AND N OF THE ITCZ WITHIN THE AREA FROM 11N TO 17N W OF 124W. THE HIGH IS FORECAST TO DISSIPATE OVER THE NEXT 24 HOURS...HOWEVER ANOTHER HIGH JUST NW OF THE AREA NEAR 29N142W IS FORECAST TO MOVE SE TO NEAR 25N137W WITH A PRESSURE OF 1023 MB IN 24 HOURS. THE ASSOCIATED PRESSURE GRADIENT CREATED BY IT AND LOW PRESSURE WITH THE ITCZ WILL MAINTAIN THE AREA OF NE TRADES WITH LITTLE OVERALL CHANGE THROUGH THE NEXT 48 HOURS. SEAS WITHIN THIS AREA ARE EXPECTED TO BUILD TO 9 FT IN NW SWELL DURING THIS TIME. AS THE FRONTAL TROUGH DISSIPATES AND HIGH PRESSURE RE-ESTABLISHES ITSELF OVER THE FORECAST WATERS N OF 18N...THIS WILL INDUCE A STRONGER PRESSURE GRADIENT ALONG THE BAJA CALIFORNIA COAST IN ABOUT 30 HOURS AND INTO 48 HOURS WITH NW TO N WINDS TO 20 KT WITHIN 90 NM OF THE COAST N OF 24N. SEAS TO 8 FT IN NW SWELLS ARE FORECAST TO AFFECT THOSE WATERS. FINALLY...SOUTHWESTERLY MONSOON FLOW OF 15 TO 20 KT OVER THE WATERS FROM 02N TO 08N BETWEEN 80W AND 92W IS FORECAST TO EXPAND WESTWARD TO 102W IN 24 HOURS WITH SEAS INCREASING TO 10 FT IN SW CROSS-EQUATORIAL SWELLS THAT WILL COVER MOST OF THE PACIFIC WATERS FROM THE EQUATOR TO 8N BETWEEN CENTRAL AMERICA AND 112W AS SUGGESTED BY WAVEWATCH III MODEL GUIDANCE. $$ AGUIRRE