000 AXPZ20 KNHC 030335 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN OCT 03 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 0230 UTC. ...ITCZ... AXIS IS CENTERED ALONG 08N81W TO 11N105W TO 10N120W TO 11N132W TO LOW PRES 10N137W. SCATTERED MODERATE ISOLATED STRONG WITHIN 120 NM N OF THE AXIS BETWEEN 81W AND 88W. ...DISCUSSION... AN UPPER LEVEL CYCLONIC CIRCULATION LOCATED JUST N OF THE FAR NE CORNER OF THE DISCUSSION AREA OFF THE SOUTHERN CALIFORNIA COAST WITH A TROUGH EXTENDING SSW TO 25N121W IS LIFTING N. THE ASSOCIATED MOISTURE AND PRECIPITATION REMAINS OVER SOUTHERN CALIFORNIA WITH A SMALL BATCH OVER THE NORTHERN BAJA CALIFORNIA PENINSULA. THIS MOISTURE AREA AND PRECIPITATION WILL LIFT N WITH THE CYCLONIC CIRCULATION THROUGH SUN AS A LARGE UPPER TROUGH CURRENTLY CROSSING THE FAR NW PORTION OF THE AREA PRESSES EASTWARD INITIATING MOVEMENT OF THE LOW. AN UPPER RIDGE OVER THE SW U.S. EXTENDS SW ACROSS NW MEXICO AND SOUTHERN BAJA CALIFORNIA TO AN UPPER ANTICYCLONE NEAR 16N115W WITH ANOTHER RIDGE EXTENDING FROM THE ANTICYCLONE WNW TO 17N131W. A NARROW RIDGE IS IN BETWEEN THE UPPER LEVEL CYCLONIC CIRCULATION AND THE UPPER TROUGH OVER THE FAR NW PORTION. A JET STREAM BRANCH EARLIER NOTED AHEAD OF THE UPPER TROUGH HAS RECENTLY LIFTED NE OF THE AREA. OVER THE FAR EASTERN PORTION OF THE AREA...AN UPPER TROUGH EXTENDS FROM THE EASTERN U.S. SW TO THE WESTERN GULF OF MEXICO TO ACROSS CENTRAL MEXICO AND SW TO NEAR 14N108W. N TO NE UPPER WINDS BEHIND THE TROUGH WITH MODERATE SUBSIDENCE PRESSING SOUTHWARD ARE HAMPERING ANY DEEP CONVECTION THAT ATTEMPTS TO FORM NEAR OR ALONG THE ITCZ THROUGH THE NEXT 48 HOURS. WITH MODERATE SUBSIDENCE LEADING TO DRIER AIR ALOFT BECOMING MORE EVIDENT OVER THE FAR EASTERN PORTION OF THE REGION IN THE WAKE OF THE UPPER TROUGH...THE NOW WEAKENED MONSOON GYRE THAT HAS PERSISTED ACROSS THE FAR EASTERN PACIFIC...SRN MEXICO...AND CENTRAL AMERICA DURING THE PAST SEVERAL DAYS WILL FURTHER WEAKEN WITH TIME. TO THE SE OF THE TROUGH...A MID LEVEL RIDGE AXIS EXTENDS FROM THE N CENTRAL CARIBBEAN SW TO 16N82W AND W TO ACROSS CENTRAL AMERICA...TO FAR SOUTHEASTERN MEXICO. FAST UPPER LEVEL ELY FLOW ON THE SOUTHERN PERIPHERY OF THE RIDGE IS ADVECTING UPPER LEVEL DEBRIS MOSITURE FROM CLUSTERS OF DEEP CONVECTION OVER THE SW CARIBBEAN SEA...AND EASTERN PACIFIC WESTWARD TO NEAR 110W. CROSS-EQUATORIAL S TO SW WINDS INTO THE WEAKER MONSOON TROUGH HAVE DIMINISHED TO LESS THAN 20 KT...HOWEVER SEAS TO 9 FT IN A NW SWELL ARE EVIDENT S OF 10N BETWEEN 120W AND 135W. THESE SEAS ARE EXPECTED TO BUILD INTO THE 8 TO 10 FT RANGE IN MIXED SW AND NW SWELL S OF 17N BETWEEN 102W AND 130W...AND IN SW SWELL BETWEEN 92W AND 103W IN ABOUT 24 HOURS....THEN S OF 15N BETWEEN 92W AND 120W IN 48 HOURS. N WINDS OF 20 TO 25 KT ARE OCCURRING WITHIN 60 NM EITHER SIDE OF A LINE FROM 16N94.5W TO 14N95W...INCLUDING THE ISTHMUS OF TEHUANTEPEC...WITH SEAS TO 9 FT. A RATHER UNSEASONABLE STRONG SURFACE RIDGE BUILDING SOUTHEASTWARD ACROSS MEXICO WILL TIGHTEN THE PRESSURE GRADIENT OVER THE ISTHMUS OF TEHUANTEPEC RESULTING IN AN EARLY SEASON GALE EVENT WITH N TO NE WINDS INCREASING TO 30 TO 35 KT WITHIN 30 NM OF LINE 16N94.5W TO 14N95W WITH SEAS BUILDING 9 TO 12 FT WITHIN 12 HOURS. THE GALE FORCE WINDS ARE FORECAST TO INCREASE TO 40 KT OVERNIGHT SUN NIGHT AT WHICH TIME SEAS ARE FORECAST TO BUILD INTO THE RANGE OF 12 TO 16 FT. BY 48 HOURS...WINDS ARE FORECAST TO DIMINISH BACK TO 30 TO 35 KT WITH SEAS 12 TO 15 FT. HIGH PRES WILL STRENGTHEN OVER THE WESTERN PORTION OF THE AREA AS IT BUILDS SE ACROSS THE FORECAST WATERS. THIS WILL INCREASE THE PRES GRADIENT BETWEEN IT AND A 1010 MB LOW NEAR 101N37W ALLOWING FOR NE TO E TRADES OF 20 KT TO DEVELOP FROM 13N TO 22N W OF 134W IN ABOUT 24 HOURS...AND FROM 12N TO 22N W OF 132W IN 48 HOURS WITH SEAS BUILDING TO 9 TO 11 FT IN A NW SWELL. THIS SAME NW SWELL IS ASSOCIATED WITH A LARGE NW SWELL TRAIN WITH SEAS TO 11 FT WHICH WILL SPREAD ACROSS THE NW WATERS IN 24 HOURS. SEAS ARE FORECAST TO SLOWLY SUBSIDE TO 10 FT IN 48 HOURS. THESE SWELLS ARE FORECAST TO HAVE PERIODS OF 11-13 SEC TONIGHT AND SUN...DIMINISHING TO 9-11 SEC LATE SUN NIGHT INTO MON. $$ COBB