000 AXPZ20 KNHC 012155 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC FRI OCT 01 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 IS CENTERED ALONG 12N108W TO 10N122W TO A 1012 MB LOW NEAR 12N135W TO 11N140W. SCATTERED MODERATE CONVECTION IS WITHIN 30 NM OF THE ITCZ BETWEEN 135W-138W. ...DISCUSSION... LARGE SCALE FEATURES WILL REMAIN IN A REX BLOCKED PATTERN THROUGH NEXT 48 HOURS AS MAIN ENERGY FOCUS STAYS N OF THE REGION. AN UPPER LEVEL CYCLONIC CIRCULATION JUST N OF THE FAR NE CORNER OF THE AREA OVER SOUTHERN CALIFORNIA HAS A TROUGH EXTENDING SW TO 267N125W...HOWEVER THE ASSOCIATED MOISTURE AND PRECIPITATION IS N OF 32N E OF 125W. THE CIRCULATION IS BETWEEN AN UPPER RIDGE OVER THE CENTRAL U.S. EXTENDING SW TO AN UPPER ANTICYCLONE NEAR 17N116W AND A RATHER EXTENSIVE MID/UPPER LEVEL RIDGE THAT STRETCHED FROM PACIFIC NW SW THROUGH TO 32N131W TO A SMALL MID/UPPER LEVEL ANTICYCLONE NEAR 18N135W. A 1023 MB SURFACE HIGH IS JUST N OF THE AREA NEAR 33N133W...WITH A RIDGE SE TO NEAR 24N126W. A RATHER LARGE UPPER TROUGH WAS APPROACHING THE NW CORNER OF THE REGION...WHILE ITS ASSOCIATED SURFACE COLD FRONT IS ABOUT 240 NM W OF 32N140W. A JET STREAM BRANCH AHEAD OF THE TROUGH IS DEPICTED BY SW WINDS OF 40-80 KT IN SATELLITE DERIVED WINDS. SATELLITE WATER VAPOR IMAGERY SHOWS MODERATE SUBSIDENCE ALLOWING FOR LIMITED DEEP ATMOSPHERIC MOISTURE OVER MOST OF THIS PORTION OF THE REGION WITH STABLE ENVIRONMENTAL CONDITIONS AS NOTED BY THE MOSTLY OVERCAST STRATOCUMULUS CLOUD FIELD N OF 17N W OF 118W. ITCZ CONVECTION RELATED TO THE ITCZ AND NEAR THE 1012 MB LOW WAS UNDER A DIFFLUENT FLOW ALOFT LOCATED TO THE SW OF THE ANTICYCLONE NEAR 18N137W. OVER THE FAR EASTERN PORTION OF THE AREA...AN UPPER TROUGH EXTENDS FROM EASTERN U.S. SW TO THE WESTERN GULF OF MEXICO TO ACROSS CENTRAL MEXICO SW TO THE SURFACE LOW NEAR 15N106W. THE LOW IS ON THE FAR WESTERN EDGE OF A NOW WEAKENED MONSOON GYRE THAT HAS PERSISTED ACROSS THE FAR EPAC...SRN MEXICO...AND CENTRAL AMERICA DURING THE PAST SEVERAL DAYS. N TO NE UPPER WINDS BEHIND THE TROUGH ARE CREATING ENOUGH VERTICAL SHEAR TO HAMPER ANY DEEP CONVECTION THAT FORMS WITH THE LOW FROM ACHIEVING ANY LONGEVITY THROUGH THE NEXT 48 HOURS. WINDS OF 20 KT WITHIN 120 NM OF THE LOW CENTER ARE FORECAST TO DIMINISH TO WITHIN 90 NM OF THE LOW IN 24 HOURS...AND TO WITHIN 120 NM OF THE LOW IN THE SEMICIRCLE IN 48 HOURS. THE LOW IS FORECAST TO DRIFT TO SE OVER THE NEXT 48 HOURS. INFLOW INTO THE MONSOON ZONE IN THE EASTERN SECTION OF THE AREA IS IDENTIFIED AS SW 20 KT WINDS FROM 7N TO 13N BETWEEN 100W AND 115W WITH SEAS OF 9 TO 10 FT IN MIXED SW AND NW SWELL. THIS AREA IS FORECAST TO CHANGE LITTLE OVER THE NEXT 48 HOURS. S OF THE MONSOON FLOW...CROSS-EQUATORIAL SE TO S 15 KT WINDS ARE OCCURRING ARE NOTED. N WINDS OF 20 TO 25 KT ARE OBSERVED THROUGH THE ISTHMUS OF TEHUANTEPEC WITH TO 9 FT. WITH RIDGING BUILDING SOUTHEASTWARD ACROSS MEXICO THROUGH THE NEXT 12 TO 48 HOURS...THESE WINDS SHOULD MAXIMIZE UP TO 30 KT WITH SEAS BUILDING TO THE RANGE OF 8 TO 11 FT. WINDS MAY POSSIBLY REACH TO MINIMAL GALE FORCE BEGINNING LATE SAT NIGHT IN TO SUN. ELSEWHERE...SUBSIDING NW SWELLS OF 9 FT OVER THE NW SECTION OF THE REGION WILL BE REPLENISHED BY A LARGE NW SWELL TRAIN BEGINNING IN ABOUT 24 HOURS IN THE WAKE OF A WEAKENING FRONT THAT BEGINS TO NEAR THE NW CORNER. LATEST WAVEWATCH MODEL GUIDANCE BUILDS SEAS IN THE 8 TO 11 FT RANGE N OF 15N W OF 120W IN 24 HOURS...8 TO 10 FT FROM 15N TO 20N W OF 135W IN 48 HOURS AS HIGH PRES RIDGING BUILDS ESE ACROSS THE NORTHERN AND NW PORTIONS AS COLD FRONT DISSIPATES IN THE FAR NW CORNER. THESE SWELLS ARE FORECAST TO HAVE PERIODS OF 15-18 SEC THROUGH TONIGHT...THEN DIMINISHING TO 11-13 SEC SAT AND TO 9-12 SEC SUN. $$ AGUIRRE