000 AXPZ20 KNHC 272100 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1901 UTC Wed Sep 27 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 2100 UTC. ..INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N86W to 1007 mb low pressure south of the Gulf of Tehuantepec near 15N97W to 1008 mb low pressure centered near 14N120W to 10N131W to 10N140W. Scattered moderate convection is noted from 04N to 07N between 84W and 95W. Scattered moderate isolated strong convection is noted within 60 nm of the monsoon trough between 95W and 101W. Scattered moderate isolated strong convection was noted within 90 nm south of the monsoon trough between 110W and 140W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Low pressure of 1007 mb embedded within the monsoon trough persists south of the Gulf of Tehuantepec, supporting scattered showers and isolated thunderstorms. This area of low pressure will continue off the coast of southern Mexico through Sunday. Fresh to strong gap winds will develop into the Gulf of Tehuantepec by Sat night as high pressure builds north of the area in the Gulf of Mexico. Farther north, the remnant low pressure of Pilar over Cabo San Lucas will dissipate tonight. Elsewhere, a weak pressure pattern remains in place. This will support gentle to moderate breezes north of 16N through Sunday. Seas in the 3 to 5 ft foot range will prevail over the open waters through Sat. Northerly swell will propagate into the waters west of Baja California Norte Sunday, building seas to 5 to 7 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... An active monsoon trough currently passes over Central America. The trough will remain close enough to the coast, either inland or just offshore, to produce active convection, primarily during the afternoon and evening hours, over the coastal waters the next few days. Moderate SW to W winds are expected south of the trough through Sun. Long period SE to S swell will maintain 5 to 6 ft seas west of Ecuador and south of the Equator during the next few days. Looking ahead, broad low pressure developing over Central America will cause monsoonal winds to surge to fresh to strong west of Costa Rica into early next week with seas to 8 ft reaching the waters beyond 200 nm off the coast from Nicaragua to Guatemala. REMAINDER OF THE AREA... Low pressure of 1008 mb near 14N120W remains embedded within the monsoon trough. Enhanced convection associated to this feature continues as noted in the monsoon trough section above. The low is expected to weaken and become more elongated through Thu, with winds and seas gradually diminishing. Elsewhere, weak high pressure north of the area will support gentle to moderate trade winds across the region south of 20N. Looking ahead, northerly swell of 8 to 9 ft will propagate into the waters north of 25N between 120W and 130W Sun into early next week. $$ AL