000 AXPZ20 KNHC 112205 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2045 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 1800 UTC surface analysis and satellite imagery through 2130 UTC. ...SPECIAL FEATURES... ...A GALE WARNING FOR THE GULF OF TEHUANTEPEC... Gale-force winds continue over the Gulf of Tehuantepec. A high pressure ridge along the Sierra Madre Oriental is maintaining 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. Sea heights will range from 10 feet to 13 feet in the current conditions. Sea heights could build to 17 feet on Tuesday due to the long duration and sustained wind speeds. The leading edge of the resultant 8 foot seas, propagating away from the source region, is forecast to reach 08N100W on Tuesday. Winds could remain at or above gale force through Wed. High pres over the western Gulf should weaken and shift east on Thursday, allowing winds over the Gulf of Tehuantepec to subside. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough passes W from NW Colombia near 09N76W through Panama to 09N79W to 07N98W to 07N107W to 1008 mb low pressure centered near 12N119W to another 1008 mb low pressure centered near 09N128W to a third 1008 mb low centered near 12N136W to 10N140W. Scattered moderate and isolated strong convection is present from 09N to 14N between 116W and 128W and from 11N to 15N between 128W and 137W. ...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 over the Gulf of California. Moderate to fresh N to NW winds will prevail over the waters W of Baja California through Tuesday night and the pressure gradient W of Baja California will tighten Sun night and Mon as high pressure shifts eastward closer to the coast. Expect fresh to locally strong NW winds N of 25N and E of 119W from early Monday to early Tuesday, with seas building to 8 ft on Tuesday. Long period NW swell propagating SE across the waters W of Baja California will slowly decay, allowing seas to subside from between 6 and 9 ft tonight to between 5 and 7 ft on Monday and slowly subside through Sunday. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light and 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 propagating southeastward are maintaining seas at or above 8 ft N of 10N and W of 112W. Seas in most of this are will subside below 8 ft by Mon morning as the swell decay. A 1008 mb low pressure is centered near 12N119W. Consensus global model guidance indicates that this low center should 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 300 nm N semicircle on Sun, with associated seas of 9-13 ft by Sunday afternoon, and to 16 feet by Monday afternoon. Gradual development of this system is possible before upper-level winds become unfavorable for development by the middle of next week. $$ CAM