000 AXPZ20 KNHC 111602 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sat Nov 11 2017 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... ...A GALE WARNING FOR THE GULF OF TEHUANTEPEC... Gale-force winds are present in the Gulf of Tehuantepec. A tight pressure gradient continues in SE Mexico. Model guidance suggests that the current synoptic pattern will remain favorable for northerly gap wind flow to reach gale force during the next few days. The wind speeds are expected to increase to 35-40 kt by Sunday night, and continue through early next week. The sea heights range from 10 feet to 13 feet in the current conditions. The sea heights build to 17 feet on Tuesday, with the long duration and intensity of the wind speeds. The leading edge of 8 foot seas, propagating away from the source region, is forecast to reach 08N100W on Tuesday. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough passes through Panama near 08N82W, to 07N97W, to 07N105W, to a 1007 mb low pressure center that is near 11N116W, to a second 1007 mb low pressure center that is near 09N123W, to a third 1007 mb low pressure center that is near 12N135W, beyond 09N140W. Precipitation: scattered moderate to strong from 09N to 12N between 114W and 118W, from 11N to 13N between 118W and 122W, and from 08N to 11N between 120W and 128W. Isolated moderate to locally strong elsewhere within 270 nm to the north of the monsoon trough from 125W westward. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the special features section for information about the ongoing Gulf of Tehuantepec gale warning. A ridge will dominate the waters W of Baja California during the next several days, while a trough will meander along the coast of NW Mexico and into the Gulf of California. Moderate to fresh NW flow will prevail across the waters W of Baja California from today until early Monday. The pressure gradient W of Baja California will tighten Sun night and Mon as high pressure builds eastward. Expect fresh to locally strong NW winds N of 25N and E of 119W from early Monday to early Tuesday, with seas building to 9 ft. Long period NW swell producing 8-10 ft seas will propagate southeastward across the waters W of Baja California and slowly subside through Sunday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light variable winds, and seas of 4-6 ft, are expected N of 09N. Moderate to locally fresh southerly winds and seas of 5-7 ft are forecast S of 09N through early next week. REMAINDER OF THE AREA... Long period NW swell will propagate southeastward reaching to an area roughly defined from 08N to 22N from 114W westward on Sunday, and between 121W and 137W on Monday afternoon. A late-season 1007 mb low pressure center is near 09N123W this morning. Consensus global model guidance indicates that this low center may move WNW, and deepen through Tuesday. The guidance indicates the pressure gradient between this low and high pressure to the north will create a swath of 20-30 kt winds within 240 nm NW quadrant and within 150 nm E semicircle, with associated seas of 9-12 ft by Sunday afternoon, and to 16 feet by Monday afternoon. Upper level winds are expected to become more favorable Sun night through Tue night as vertical shear effects diminish. $$ Mt