000 AXPZ20 KNHC 292200 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC WED SEP 29 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 CENTERED ALONG 10N10W 9N110W TO A 1010 MB LOW NEAR 11N117W TO 10N127W TO A 1010 MB LOW NEAR 13N134W TO 12N140W. SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 120 NM S OF THE AXIS BETWEEN 133W-136W...AND 60 NM S OF THE AXIS BETWEEN 100W-107W. ...DISCUSSION... W OF 125W... LARGE SCALE FEATURES WILL REMAIN SOMEWHAT BLOCKED DURING THE NEXT 48 HOURS AS MAIN ENERGY FOCUS STAYS N OF 32N IN VERY ACTIVE NORTHERN JET STREAM BRANCH. A MID/UPPER LEVEL ANTICYLONE NEAR 22N136W WITH A RIDGE EXTENDING TO WELL NNE OF THE AREA WITH A CREST AT 35N12W WAS DRIFTING E AHEAD OF A SHORTWAVE TROUGH LIFTING ENE THROUGH THE FAR NW CORNER OF THE AREA. AT THE SURFACE...A STATIONARY FRONT WAS JUST W OF THE AREA DRAPED FROM 32N141W TO WELL SW TO JUST N OF THE HAWAIIAN ISLANDS. SLY UPPER LEVEL FLOW WAS INCREASING AHEAD OF THE TROUGH IN A VERY PRONOUNCED JET STREAM WITH WINDS IN THE RANGE OF 40-60 KT. SATELLITE WATER VAPOR IMAGERY DEPICTED MODERATE SUBSIDENCE WITH LIMITED MOISTURE OVER MOST OF THIS PORTION OF THE REGION WITH STABLE ENVIRONMENTAL CONDITIONS AS WAS NOTED BY THE BROKEN STRATOCUMULUS CLOUD FILED N OF 20N. DEEP CONVECTION RELATED TO THE ITCZ WAS UNDER A DIFFLUENT FLOW ALOFT LOCATED TO THE SW OF THE ANTICYCLONE...AND WAS INDUCING FURTHER DIVERGENCE ALOFT W OF ABOUT 133W. THIS WAS ALSO INDUCING SCATTERED MODERATE/ISOLATED STRONG CONVECTION WITHIN 120 NM E AND W QUADRANTS OF THE 1010 MB LOW NEAR 13N134W. E OF 125W... A MID/UPPER LEVEL CYCLONIC CIRCULATION OVER THE FAR NE CORNER OF THE AREA AT 32N119W MOVING NW AT 15 KT. A TROUGH EXTENDED SW FROM THE CIRCULATION TO NEAR 25N124W. THE CYCLONIC CIRCULATION ...AND ITS ASSOCIATED TROUGH WERE TRAPPED BETWEEN TWO ANTICYCLONES...THE ONE NEAR 22N136W...AND ONE EXTENDING FROM THE WESTERN U.S. TO AN UPPER LEVEL ANTICYCLONE NEAR 20N114W. ANOTHER RIDGE EXTENDS FROM THE ANTICYCLONE NEAR 20N114W SE TO 16N103W. THE RIDGE WAS OVER A 1007 MB SURFACE LOW NEAR 17N106W...AND WAS CONTINUING TO PROVIDE ANTICYCLONIC OUTFLOW TO SUPPORT SCATTERED MODERATE/ISOLATED STRONG CONVECTION THAT WAS WITHIN 120 NM W OF THE LOW. THIS LOW WAS SITUATED ON THE FAR WESTERN PERIPHERY OF AN ELONGATED MONSOONAL GYRE THAT HAS PERSISTED ACROSS THE FAR EPAC...SRN MEXICO...AND CENTRAL AMERICA THE PAST WEEK OR SO...AND THAT HAS EXTENDED INTO THE W CARIBBEAN IN RECENT DAYS. THIS LOW IS FORECAST TO MOVE SE TO NEAR 15.5N104W IN 24 HOURS...BUT REMAIN EMBEDDED WITHIN ALONG THE NORTHERN EDGE OF THE MONSOONAL GYRE AND IS NOT EXPECTED TO BECOME MUCH BETTER 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 AFFECTING THE EASTERN E HALF OF THE UNITED STATES...GULF OF MEXICO AND SOUTHEASTERN MEXICO. 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 CYCLONIC CIRCULATION DENOTING A 1004 MB LOW...POSSIBLY THE REMNANT LOW OF MATTHEW...WAS JUST W OF THE COAST OF GUATEMALA NEAR 14N92W. ASCAT DATA FROM FROM SHORTLY PAST 1500 UTC THIS MORNING CONFIRMED THE BROAD AREA OF S TO SW 20-25 KT WINDS TO THE SE OF THE LOW AS MENTIONED ABOVE WITH THE MONSOONAL GYRE. IN ADDITION...THE BUOY ARRAY ALONG 95W ALSO CONFIRMED THESE SAME WIND SPEEDS AS CROSS-EQUATORIAL SE TO S WINDS WERE BECOMING CONFLUENT S TO SW INTO THE MONSOON TROUGH GYRE OVER THE EASTERN PORTION OF THE REGION. N WINDS OF 20 TO 25 KT ARE EXPECTED TO BEGIN THROUGH THE ISTHMUS OF TEHUANTEPEC IN ABOUT 36 HOURS...AND INCREASE TO 20 KT IN 48 HOURS PERHAPS ENERGIZING THE LOW OVER THE NEXT 48 HOURS. ELSEWHERE...15-17 SEC LONG PERIOD SWELL CONTINUES TO PUSH SE FROM THE N CENTRAL PACIFIC INTO THE WESTERN PORTION OF THE DISCUSSION AREA CREATING SEAS IN THE 8 TO 10 FT RANGE W OF A LINE FROM 30N116W TO 12N108W TO THE EQUATOR AT 136W. BY 24 HOURS...THESE SEAS ARE FORECAST TO CONFINED TO W OF 113W. AS THE SWELL TRAIN GRADUALLY SUBSIDES BEYOND 24 HOURS...SEAS ARE THEN FORECAST TO SUBSIDE TO 9 FT NW OF A LINE FROM 30N125W TO 20N110W TO THE EQUATOR AT 48 HOURS. WAVEWATCH MODELS FORECAST A SECOND SURGE OF NW SWELLS TO REACH THE FAR NW WATERS BY THE END OF THE WEEK WITH SEAS BUILDING AGAIN TO THE 8 TO 10 FT RANGE. $$ AGUIRRE