000 AXPZ20 KNHC 302137 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC THU SEP 30 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 2130 UTC. ...ITCZ... AXIS CENTERED FROM A 1008 MB LOW NEAR 9N114W TO 10N127W TO A 1013 MB LOW 14N134W TO 11N140W. SCATTERED MODERATE CONVECTION IS WITHIN 30 NM OF THE AXIS BETWEEN 134W-137W. ...DISCUSSION... W OF 120W... LARGE SCALE FEATURES WILL REMAIN IN A REX BLOCKED PATTERN THROUGH NEXT 48 HOURS AS MAIN ENERGY FOCUS STAYS N OF THE REGION. A MID/UPPER LEVEL ANTICYLONE IS NEAR 23N131W WITH A RIDGE EXTENDING SW TO W OF THE AREA AT 15N140W. TO ITS N...THE TAIL END OF A SHORTWAVE TROUGH MOVING E EXTENDED SW THROUGH 32N133W TO SW OF THE AREA AT 27N140W. AT THE SURFACE...A WEAKENING STATIONARY FRONT EXTENDED FROM 32N140W WELL SW TO JUST N OF THE HAWAIIAN ISLANDS WHERE IT WAS QUICKLY FRAGMENTING INTO SCATTERED LOW CLOUDS. SW TO W WINDS OF 30-40 KT ARE LOCATED AHEAD OF THE TROUGH ALONG A JET STREAM BRANCH THAT WAS JUST AHEAD OF THE TROUGH. SATELLITE WATER VAPOR IMAGERY DEPICTED MODERATE SUBSIDENCE ALLOWING FOR LIMITED DEEP ATMOSPHERIC MOISTURE OVER MOST OF THIS PORTION OF THE REGION WITH STABLE ENVIRONMENTAL CONDITIONS AS WAS NOTED BY THE BROKEN TO SCATTERED STRATOCUMULUS CLOUD FIELD N OF 20N. 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. A WEAK 1018 MB HIGH CENTER WAS ANALYZED NEAR 28N134W. WEAK HIGH PRES WAS PRESENT N OF 20N130W. THE 1013 MB LOW IS FORECAST TO REMAIN NEARLY STATIONARY OVER THE NEXT 24 TO 48 HOURS. E OF 120W... A MID/UPPER LEVEL CYCLONIC CIRCULATION HAD LIFTED N OF THE FAR NE CORNER OF THE AREA TO JUST W OF SOUTHERN CALIFORNIA. A TROUGH EXTENDED SSW FROM THE CIRCULATION TO NEAR 25N121W. THE CYCLONIC CIRCULATION...AND ITS ASSOCIATED TROUGH WERE TRAPPED BETWEEN TWO ANTICYCLONES...THE ONE NEAR 23N131W...AND ONE EXTENDING FROM THE WESTERN U.S. TO AN UPPER LEVEL ANTICYCLONE NEAR 20N114W. ANOTHER RIDGE EXTENDS FROM THE ANTICYCLONE NEAR 20N114W AND SE TO 14N103W. THE RIDGE WAS OVER A 1007 MB SURFACE LOW NEAR 15N105W ...AND WAS CONTINUING TO PROVIDE ANTICYCLONIC OUTFLOW TO SUPPORT SCATTERED STRONG CONVECTION WITHIN 240 NM SW OF THE LOW. THE LOW WAS SITUATED ON THE FAR WESTERN PERIPHERY OF A NOW DIMINISHED MONSOON GYRE THAT HAS PERSISTED ACROSS THE FAR EPAC...SRN MEXICO...AND CENTRAL AMERICA DURING THE PAST SEVERAL DAYS. WINDS OF 20 KT WITHIN 120 NM OF THE LOW CENTER ARE FORECAST TO LAST THROUGH THE NEXT 48 HOURS. THE LOW IS FORECAST TO MOVE WNW TO NEAR 16N107W IN 24 HOURS...BUT IS NOT EXPECTED TO BECOME ORGANIZED...DUE TO IT BEING UNDER THE AFFECTS OF STRONG N TO NE UPPER LEVEL WINDS SQUEEZED IN BETWEEN THE ANTICYCLONE NEAR 20N114W AND THE DEEP UPPER TROUGH THAT STRETCHES FROM THE EASTERN GULF OF MEXICO SW TO CENTRAL MEXICO AND TO 16N107W. MONSOON FLOW IN THE EASTERN SECTION OF THE AREA IS IDENTIFIED AS A BROAD AREA OF S TO SW 20-25 KT WINDS FROM 2N TO 10N BETWEEN 91W AND 108W WITH SEAS IN THE RANGE OF 8 TO 10 FT. THIS AREA IS FORECAST TO EXPAND IN 48 HOURS FROM 7N TO 13N BETWEEN 95W AND 115W WITH SEAS 9 TO 10 FT IN MERGING NW AND SW SWELLS. 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 EXPECTED TO BEGIN THROUGH THE ISTHMUS OF TEHUANTEPEC IN ABOUT 18 HOURS...AND CONTINUE THROUGH THE NEXT 48 HOURS. 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 10 FT RANGE N OF 15N AND W OF 115W IN 24 HOURS...AND NW OF A LINE FROM 30N120W TO 10N130W IN 48 HOURS WITH HIGHEST SEAS IN THE NW PART. THESE SWELLS ARE FORECAST TO HAVE PERIODS OF 15-18 SECONDS FRI...DIMINISHING TO 11-13 FT SAT. $$ AGUIRRE