000 AXPZ20 KNHC 171436 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1402 UTC Fri Nov 17 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. INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N83W to 10N90W to 08N100W TO 09N125W where it transitions to the intertropical convergence zone, and extends from 09N125W to 11N136W to beyond 08N140W. Scattered moderate convection is noted from 08N to 12N between 114W and 123W. Similar convection is noted from 12N to 15N between 134W and 136W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak 1018 mb surface high centered near 25N124W is forecast to dissipate within 24 hours. This system will be reinforced by a stronger high pressure from the N on Sat. Under this weather pattern, expect gentle to moderate northerly winds across the offshore waters W of Baja California today, with moderate to fresh NW to N flow, and building seas of 6-7 ft N of 25N Sat morning through late Sun. Gulf of Tehuantepec: Pulses of strong to near gale force northerly drainage flow, with seas building to a max of 11 ft, are forecast overnight late tonight into early Sat morning, diminishing afterward as the high pressure over the eastern slopes of the Sierra Madre mountains weakens. Another strong cold front will enter the Gulf of Mexico late Sat, followed by strong high pressure building into northeast and central Mexico through Sun. This will support a return of strong gap winds in the Gulf of Tehuantepec by early Sun, reaching gale force early Sun afternoon through Mon morning. Marine guidance indicates winds of 35-40 kt and building seas of 14-15 ft by Sun night. Gulf of California: Strong high pressure building north of the area over the Great Basin will support fresh to strong NW winds across the northern Gulf of California by mid-day Sat, spreading into the central and southern portions of the gulf late Sat into Sun, before diminishing late Sun. Seas are forecast to build to 6 or 7 ft across the central gulf early on Sun. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Moderate to locally fresh NE drainage winds are forecast during the overnight hours through the middle of next week with seas building to 5 ft downstream near 10N87W. Light and variable winds, and 3 to 5 ft seas, are expected elsewhere to the N of 09N, while moderate to locally fresh southerly winds, and 4 to 7 ft seas, are forecast S of 09N through the middle of next week. REMAINDER OF THE AREA... A 1011 mb surface low is centered near 30N134W with a weakening cold front extending SW to 20N140W. Long-period NW-N swell in the form of 7 to 9 ft seas currently w of the low and front will subside to less than 8 ft today. The low will shift slow E and wash out by late Sat night. Strong SE return flow will develop N of 22N W of 137W on Sat night, with these strong southerly winds spreading E across the waters N of 26N to the W of 130W on Mon night with seas of 7 to 11 ft, all ahead of a cold front reaching from 32N137W to 28N140W late Wed with seas building 12 to 16 ft W of the front. Gentle to moderate trade winds and 4 to 6 ft seas will persist farther S through Sat, with moderate to locally fresh anticyclonic flow on Sat night into Sun. $$ GR