000 AXPZ20 KNHC 270938 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Aug 27 2016 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Hurricane Lester centered near 17.9 117.4W at 27/0900 UTC moving west or 280 degrees at 10 kt. Estimated minimum central pressure is 987 mb. Maximum sustained wind speed is 75 kt with gusts to 90 kt. Additional strengthening is forecast during the next 48 hours. Numerous moderate to strong convection is within 75 nm NE and 45 nm SW semicircles. Lester will continue on a general westward motion, with an increase in forward speed during the next couple of days. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP3/WTPZ23 KNHC for more details. Tropical Storm Madeline centered near 14.5N 138.4W at 27/0900 UTC moving west-northwest or 300 degrees at 9 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Satellite imagery shows a cluster of numerous moderate to strong convection within about 90 nm N of the center. Numerous moderate to isolated strong convection is in band to the west of center from 12.5n to 15n between 138w and 140w. Madeline will continue on a general west- northwest motion in the next couple of days with a decrease in forward speed, and is expected to move into the Central Pacific tonight. Madeline is forecast to strengthen to a hurricane once it moves well west of 140W by Sunday night. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP4/WTPZ24 KNHC for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 12N94W to low pressure near 11N109W, then resumes near 13N118W to 12N122W to 14N127W. Clusters of moderate to isolated strong convection are within about 90 nm of the coast of Central America between 86W and 92W. A cluster of similar convection is also noted near 15N94W in the Gulf of Tehuantepec. Scattered moderate convection is from 08N to 11N between 113W and 117W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The outer circulation of Lester continues to impact the far southwest portion of zone PMZ015 which includes the Revillagigedo Islands. Marine conditions will gradually improve beginning today as Lester moves away from this area. Moderate to locally fresh northerly winds will persist across the pacific waters of Baja along with 4 to 6 ft seas. In the northern Gulf of California, moderate to locally fresh southerly winds will prevail this morning due to the presence of a weak low pressure center. These winds will build seas temporarily to 2 to 4 ft. Otherwise, mainly light and variable winds will prevail with seas 2 ft or less. By Tuesday night, marine guidance suggests building seas to 8-9 ft in NW swell across zone PMZ011 and regional waters. In the Gulf of Tehuantepec, northerly winds will pulse to fresh levels during the overnight and early morning hours through early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light and moderate winds will continue to prevail on either side of the monsoon trough for the next several days, with combined seas of 4 to 7 ft mainly in cross equatorial southerly swell. ELSEWHERE... A broad surface ridge covers the remainder of the area, extending from 1019 mb high pressure near 30N130W. A weak surface trough, likely the remnants of Kay, extends from 27N133W to 22N135W. a recent scatterometer pass shows the wind shift associated with this trough forecast to move west of area on Sunday. the pressure gradient between the ridge and Lester will produce a band of moderate to fresh winds roughly between 18N-22N, with combined seas ranging from 5 to 7 feet. The monsoonal flow is forecast to increase to the SE and S of Lester tonight and Sunday. Marine guidance indicates an area of SW winds in the 20-25 kt range covering the forecast waters from 07N-10N between 110W-125W on Sunday. $$ GR