000 AXPZ20 KNHC 210324 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC THUD OCT 21 2010 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 CENTERED ALONG 08N85W TO 08N119W TO 10N129W TO 09N140W. SCATTERED MODERATE CONVECTION WITHIN 60 NM OF AXIS FROM 131W TO 134W AND WITHIN 30 NM OF AXIS W OF 135W. ...DISCUSSION... A DEEP LAYERED UPPER TROUGH IS JUST CROSSING INTO THE FAR NW CORNER OF THE DISCUSSION AREA EXTENDING FROM 32N140W SW TO THE HAWAIIAN ISLANDS. THE ASSOCIATED SURFACE COLD FRONT IS NOTED WITHIN ABOUT 60 NM E OF THE TROUGH WHILE A LOW LEVEL PRE-FRONTAL TROUGH AHEAD OF IT IS MARKED AS A 120 NM WIDE BAND OF OVERCAST TO BROKEN LOW AND MID CLOUDS WITH SCATTERED SHOWERS AND ISOLATED WEAK TSTMS ENTERING THE AREA FROM 32N137W TO SW OF THE AREA AT 26N140W. SOUTHWESTERLY SURFACE WINDS IN THE RANGE OF 15 TO 20 KT WITH SEAS 8 TO 10 FT DUE TO NW SWELLS ARE WITHIN 60 NM IN ADVANCE OF THE FRONT N OF 29N. W OF THE FRONT WINDS ARE LESS THAN 20 KT...HOWEVER NW SWELLS ARE FORECAST TO CREATE SEAS UP TO 11 FT THROUGH THE NEXT 24 HOURS. SEAS WILL THEN GRADUALLY SUBSIDE TO 9 FT IN ABOUT 48 HOURS AS THE FRONT WEAKENS TO A FRONTAL TROUGH FROM 32N123W TO NEAR 25N126W. SUBSIDING NW SWELLS WILL ALLOW FOR SEAS TO MAX OUT TO 9 FT BY THEN OVER THE AREA N OF 15N AND W OF 115W. AN UPPER LEVEL ANTICYCLONE IS CENTERED NEAR 13N117W WITH AN UPPER RIDGE EXTENDING NW TO A CREST AT 33N135W. UPPER DIFFLUENCE IS ENHANCING CONVECTION ALONG THE ITCZ BETWEEN 128W AND 136W WITH THE RESULTANT MOISTURE ADVECTED N AND NE WITHIN 120 NM EITHER SIDE OF A LINE FROM 11N132W TO 17N128W THEN NARROWS TO NEAR 19N115W WHERE THIS MOISTURE PLUME EVAPORATES. CONSIDERABLE DEBRIS MOISTURE...ORIGINATING FROM THE ITCZ CONVECTION BETWEEN 137W AND 145W...IS ADVECTED N MERGING WITH A WELL ESTABLISHED TROPICAL PLUME...ORIGINATING IN THE CENTRAL PACIFIC...WITH THE COMBINED MOISTURE PLUME CONTINUING N AROUND THE W PERIPHERY OF THE UPPER RIDGE...ALL WITHIN 360 NM EITHER SIDE OF A LINE FROM 14N146W TO 28N135W THEN TURNING E AND NARROWING TO NEAR 25N117W WHERE THE MOISTURE SEEMS TO COMPLETELY EVAPORATE. AN UPPER LEVEL CYCLONIC CIRCULATION NEAR THE SOUTHERN CALIFORNIA/NORTHERN BAJA BORDER IS SLOWLY MOVING EASTWARD WITH AN UPPER TROUGH EXTENDING S TO A BASE NEAR 22N112W. THIS SYSTEM IS ATTENDANT BY DEEP LEVEL ATMOSPHERIC MOISTURE LEADING TO ISOLATED SHOWERS AND TSTMS OVER EXTREME NORTHERN BAJA CALIFORNIA AND VICINITY WITH THE ASSOCIATED CYCLONIC FLOW COVERING THE AREA N OF 22N AND E OF 124W. THE CYCLONIC CIRCULATION IS FORECAST TO CONTINUE TO MOVE E AND FURTHER AWAY FROM THE DISCUSSION AREA THROUGH FRI. A JET STREAM BRANCH WITH WINDS IN THE RANGE OF 60-95 KT ROUNDS THE BASE OF THE CYCLONIC CIRCULATION. SW TO W UPPER LEVEL WINDS WITH SPEEDS UP TO 55 KT MARK THE ABOVE CYCLONIC FLOW N OF 22N E OF 124W. THESE WINDS ARE ADVECTING A 100 NM WIDE SWATH OF UPPER MOSITURE E OF 122W TO ACROSS SOUTHERN BAJA CALIFORNIA...AND NORTHEASTWARD TO OVER NORTHERN MEXICO AND TEXAS. AN ELONGATED UPPER LEVEL ANTICYCLONE IS NEAR 14N118W WITH A RIDGE EXTENDING ENE TO OVER SE MEXICO NEAR 17N97W...AND ANOTHER ONE SW TO 10N135W. SATELLITE WATER VAPOR IMAGERY SHOWS UPPER LEVEL MOISTURE SPREADING N ALONG RIDGE CREST. OTHERWISE...VERY DRY ENVIRONMENTAL CONDITIONS DUE TO EXTENSIVE MODERATE SUBSIDENCE ARE SUPPRESSING DEEP ATMOSPHERIC MOISTURE FROM BECOMING ESTABLISHED. A DIFFLUENT PATTERN TO THE W OF THE ANTICYCLONE IS HELPING TO SUSTAIN THE ITCZ CONVECTION W OF 130W AS DESCRIBED ABOVE. ABUNDANT MID/UPPER MOISTURE IS BEING ADVECTED EASTWARD FROM THE DEEP TROPICS OF THE CENTRAL PACIFIC TO JUST ALONG 140W. AN UPPER TROUGH WELL E OF THE AREA EXTENDS SW ACROSS THE SW GULF OF MEXICO AND TO A BASE OVER THE GULF OF TEHUANTEPEC. AN UPPER LEVEL ANTICYCLONE CENTERED OVER THE N CENTRAL CARIBBEAN RIDGES W TO A COL POINT JUST SW OF OF THE GULF OF TEHUANTEPEC. TO THE S OF THE RIDGE ACTIVE CONVECTION OVER PORTIONS OF NICARAGUA AND NORTHERN COSTA RICA IS MOVING W TOWARDS THE COAST. CIRRUS DEBRIS CLOUDS FROM THE CONVECTION IS STREAMING WESTWARD TO OVER THE FAR EPAC WATERS W TO 91W BEFORE IT DISSIPATES IN DRY AIR. ELSEWHERE AT THE SURFACE...A 1021 MB HIGH IS CENTERED AT 27N132W WITH A RIDGE SE TO NEAR 21N114W. NE TRADES OF 15 TO 20 KT ARE NOTED S OF THE RIDGE AND N OF THE ITCZ WITHIN THE AREA FROM 10N TO 16N W OF 128W. THIS AREA IS EXPECTED TO ONLY SHRINK SLIGHTLY OVER THE NEXT 48 HOURS. ONCE FRONTAL TROUGH DISSIPATED...HIGH PRES WILL BUILD E ACROSS THE NORTHERN AND CENTRAL PORTIONS OF THE REGION HELPING TO INDUCE A PRES GRADIENT ALONG BAJA CALIFORNIA IN 48 HOURS WITH NW TO N WINDS TO 20 KT WITHIN 90 NM OF THE COAST N OF ABOUT 24N. SEAS TO 8 FT IN NW SWELLS ARE FORECAST TO AFFECT THOSE WATERS. SOUTHWESTERLY MONSOON FLOW OF 15 TO 20 KT OVER THE WATERS FROM 2N TO 8N BETWEEN 80W AND 94W IS FORECAST TO EXPAND WESTWARD TO 100W IN 48 HOURS WITH SEAS INCREASING TO 8 FT IN SW CROSS- EQUATORIAL SWELLS THAT WILL COVER MOST OF THE PACIFIC WATERS FROM THE EQUATOR TO 8N BETWEEN CENTRAL AMERICA AND 110W AS SUGGEST BY WAVEWATCH MODEL GUIDANCE. $$ AGUIRRE