000 AXPZ20 KNHC 240901 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0901 UTC Tue Oct 24 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Storm Warning: Earlier scatterometer pass indicated winds just below gale force. With the added component of nocturnal drainage flow, winds are likely reaching minimal gale force. Winds are forecast to further increase to storm force tonight as a reinforcing cold airmass builds north of the area, with seas building to near 24 ft by midweek. The storm force winds should diminish Wednesday evening, with gale force winds persisting into Thursday. Winds may once again increase to gale force this weekend. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 11N91W to 07N111W to 09N135W. The ITCZ extends from 09N135W to 09N140W. Scattered moderate isolated strong convection was noted over forecast waters from 06N to 09N between 77W and 86W. Scattered moderate convection was noted from 10N to 12N between 115W and 126W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the special features section above for information on a developing storm event in the Gulf of Tehuantepec. Northwest swell with wave heights of 8 to 9 ft will prevail off Baja California Norte today before subsiding below 8 ft. Gentle breezes associated with a weak pressure pattern along with slight to moderate seas will prevail by late week. High pressure over the Great Basin region of the western United States is maintaining fresh to strong winds over the northern Gulf of California. These winds are expected to continue through Wednesday, before diminishing as the area of high pressure shifts eastward and the pressure gradient weakens. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate winds will prevail N of the monsoon trough, with fresh to strong winds S of the monsoon trough. The fresh to strong winds will support building seas of 8 to 10 ft SW of western Panama and Costa Rica. NW swell originating from the Gulf of Tehuantepec will propagate into the offshore waters of Guatemala and El Salvador by midweek. Broad low pressure may develop along the monsoon trough by the end of the week, drifting to the NW. REMAINDER OF THE AREA... NW swell with seas in the 8 to 10 ft range continues across much of the forecast waters north of 05N and west of 110W. The swell will decay through midweek with seas less than 8 ft expected by Wednesday evening. Tranquil marine conditions are then expected through early Friday, when a fresh set of NW swell will move into the northwest waters. Seas will rapidly build and peak near 14 ft near 30N140W Friday night before beginning to subside. $$ AL