000 AXPZ20 KNHC 151522 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1520 UTC Thu Sep 15 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 122.0W at 15/1500 UTC or about 650 nm west-southwest of the southern tip of the Baja California Peninsula moving west at 8 kt. Estimated minimum central pressure is 985 mb. Maximum sustained wind speed is 70 kt with gusts to 85 kt. Scattered moderate and isolated strong convection is within 60 nm of the center. Orlene is forecast to move west while accelerating and start gradually weakening in the next 24 hours. See latest NHC forecast/ advisory under AWIPS/WMO headers MIATCMEP1/WTPZ21 KNHC for more details. ...TROPICAL WAVES... A tropical wave is analyzed along 99W/100W north of 08N moving west at 5 to 10 kt. Scattered moderate convection is noted from 13N to 16N between 98W and 103W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 11N85W to 1008 mb low pressure near 12N105W to 10N130W to 11N140W. Scattered moderate convection is noted within 180 nm south of the trough axis between 95W and 105W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Surface ridging reaches from 1026 mb high pressure near 37N140W through Baja California Sur, supporting moderate to locally fresh northerly flow off the Pacific coast of the Baja California peninsula and 4 to 6 ft. The winds will diminish through Friday with gentle to moderate winds persisting into Sunday off the Pacific coast of Baja California with light winds over the Gulf of California. Meanwhile a broad and still somewhat disorganized area of low pressure centered about 400 nm southwest of Acapulco along the monsoon trough is expected to deepen slightly over the next couple of days. Most global model depictions show it becoming a little better organized as it moves to the north- northwest in the next three days, reaching the Revillagigedo Islands by Sunday, with a high chance of tropical cyclone development beyond 48 hours. Even if it does not develop into a tropical cyclone, there is a good potential for strong southerly winds between the Revillagigedo Islands and Cabo Corrientes and Cabo San Lucas Sunday into Monday with seas to at least 12 ft. In the Gulf of Tehuantepec, northerly winds will occasionally pulse to moderate to fresh during the overnight and early morning hours through the weekend, however, strong northerly flow is forecast late Monday night into early Tuesday with development of another low pressure area farther south. 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 early next week. Mainly moderate southwest to west low level flow is expected across the waters southward. Combined seas of 4 to 6 ft are likely across the entire area through the weekend into early next week, in long- period southwest swell. Scattered showers and isolated thunderstorms are possible each night in the offshore waters. REMAINDER OF THE AREA... A sub-tropical ridge building from west to east across northern waters will support fresh trades through the end of the week which will build seas to 8 to 9 ft from 12N to 21N west of 135W. Winds and seas will diminish this weekend as the ridge weakens and Orlene moves west. Southwest winds feeding into the monsoon trough are expected to increase later this morning from 07N to 11N between 90W and 100W, south of the developing low pressure area near 12.5N104W, diminishing through Fri as the low pressure moves north. $$ CHRISTENSEN