000 AXPZ20 KNHC 141521 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1403 UTC Wed Sep 14 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Hurricane Orlene centered near 20.1N 119.1W at 14/1500 UTC or about 540 nm west-southwest of the southern tip of the Baja California Peninsula moving west at 2 kt. Estimated minimum central pressure is 984 mb. Maximum sustained wind speed is 70 kt with gusts to 85 kt. Numerous moderate and isolated strong convection is within 90 nm northwest of the center of Orlene. Orlene is forecast to move west or west-southwest while accelerating by later today. This motion should continue through Thursday night while Orlene gradually weakens. See latest NHC forecast/advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. ...TROPICAL WAVES... A tropical wave is analyzed along 97W/98W north of 13N moving west at 5 to 10 kt. Scattered moderate convection is south- southwest of the Gulf of Tehuantepec north of 12N between 95W and 98W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 08N84W to 19N99W to 1009 mb low pressure near 13N101W then terminating near 09N114W. The monsoon trough resumes at 14N120W and continues west to 13N130W to 16N140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A surface ridge is being squeezed between troughing over the northern Gulf of California and northwest Mexico. This tightens the gradient allowing northerly winds off Baja California Norte to increase this morning to 15 to 20 kt. Meanwhile southerly winds over the northern Gulf of California are diminishing as low pressure north of the region weakens. Although the area of main winds and seas associated with Hurricane Orlene is well west of Clarion Island and move farther west, southerly swell to 8 ft in still impacting the waters beyond 150 nm off Baja California Sur. This is expected to subside through the afternoon. Farther south, clusters of showers and thunderstorms are active again today in the Gulf of Tehuantepec, in part due to a tropical wave moving through the region. The wave is moving slowly west and will become less distinct over the couple of several days as a 1009 mb low pressure area centered along the monsoon trough near 13N101W becomes slightly better organized. While no significant development is expected in the next couple of days, most global models continue to show slow development of the system into early next week as it drifts northwest toward the Revillagigedo Islands with winds to 25 kt and seas 8 to 9 ft along the Mexican coast from Manzanillo to Cabo Corrientes by late Saturday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle winds are expected south of 07N through Sunday. Mainly moderate southwest to west low level flow is expected across the waters southward. Combined seas of 4 to 7 ft are forecast across the entire area through the period in long- period southwest swell. Scattered showers and thunderstorms are possible each night over the offshore waters. REMAINDER OF THE AREA... A sub-tropical ridge is rebuilding from west to east across the northern waters. This ridge will support increasing trades to fresh levels through the end of the week which will build fresh seas to 8 to 9 ft from 13N to 20N west of 135W. The winds will diminish and seas will subside this weekend as Orlene moves west weakening the ridge. Farther east, southwest winds will increase by late Thursday into the monsoon trough from 07N to 09N between 100W and 110W, south of developing low pressure currently centered near 13N101W. $$ CHRISTENSEN