000 AXPZ20 KNHC 301603 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC THU SEP 30 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1545 UTC. ...ITCZ... AXIS CENTERED FROM A 1008 MB LOW NEAR 9N114W TO 9N124W TO A 1012 MB LOW 14N132W TO 11N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 60 NM OF THE AXIS BETWEEN 135W-138W. ...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 WAS NEAR 23N132W WITH A RIDGE EXTENDING SW TO W OF THE AREA AT 20N140W. TO ITS N...A 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 WELL N OF THE AREA S TO JUST NW OF 140W ALONG 31N14W TO 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 WERE 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 WAS UNDER A DIFFLUENT FLOW ALOFT LOCATED TO THE SW OF THE ANTICYCLONE. A WEAK 1016 MB HIGH CENTER WAS ANALYZED NEAR 28N134W. WEAK HIGH PRES WAS PRESENT N OF 20N130W. THE 1012 MB LOW IS FORECAST TO REMAIN NEARLY STATIONARY OVER THE NEXT 24 TO 48 HOURS. E OF 120W... A MID/UPPER LEVEL CYCLONIC CIRCULATION WAS JUST N OF THE FAR NE CORNER OF THE AREA AT 33N120W MOVING N AT 150KT. A TROUGH EXTENDED SSW FROM THE CIRCULATION TO NEAR 25N122W. THE CYCLONIC CIRCULATION...AND ITS ASSOCIATED TROUGH WERE TRAPPED BETWEEN TWO ANTICYCLONES...THE ONE NEAR 23N132W...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 1004 MB SURFACE LOW NEAR 16N105W...AND WAS CONTINUING TO PROVIDE ANTICYCLONIC OUTFLOW TO SUPPORT SCATTERED MODERATE/ISOLATED STRONG CONVECTION THAT WAS WITHIN 90 NM S AND 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. THIS LOW IS FORECAST TO MOVE SW TO NEAR 15.5N107W 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. THE WIND REGIME ASSOCIATED WITH THE MONSOONAL GYRE WAS 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 6N TO 10N BETWEEN 88W AND 110W WITH SEAS 8 TO 10 FT IN MERGING NW AND SW SWELL. A SURFACE LOW OF 1008 MB LOW WAS INLAND GUATEMALA NEAR 15N90W... AND IS FORECAST TO REMAIN STATIONARY OVER THE NEXT 34 HOURS. TO THE SW OF THE LOW...A BROAD AREA OF S TO SW 20-25 KT WINDS WERE OVER THE AREA CONFINED FROM 5N TO 10N BETWEEN 100W AND 115W ...AND ALSO N OF 8N E OF 95W WITH SEAS 8 TO 10 FT IN MIXED SW AND NW SWELL. FURTHER S...CROSS-EQUATORIAL SE TO S WINDS WERE NOTED. N WINDS OF 20 TO 25 KT ARE EXPECTED TO BEGIN THROUGH THE ISTHMUS OF TEHUANTEPEC IN ABOUT 18 HOURS...THEN INCREASE TO 30 KT IN 24 HOURS AND CONTINUE THROUGH THE NEXT 48 HOURS. ELSEWHERE...DECAYING 10-14 SEC LONG PERIOD SWELL PROPAGATING SE FROM THE N CENTRAL PACIFIC WITH MAX SEAS HEIGHTS UP TO 10 FT...EXPECTED TO LAST OVER THE NEXT 48 HOURS NW OF LINE FROM 30N120W TO 10N135W PER WAVEWATCH MODEL GUIDANCE. $$ AGUIRRE