307 AXPZ20 KNHC 302017 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1820 UTC Mon Jul 30 2018 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. ...SPECIAL FEATURES... A broad 1008 mb low pressure is centered along the monsoon trough near 11N111W, NW of Clipperton Island (located at 10.2W 109.2W). This system is producing a concentrated area of showers and thunderstorms from 10N to 13N between 110W and 113W. Environmental conditions are expected to gradually become more conducive for development, and a tropical depression could form during the next few days while the disturbance moves generally westward at 10 kt. The latest Tropical Weather Outlook gives this system a medium change of tropical cyclone formation through 48 hours. ...TROPICAL WAVES... A tropical wave is along 91W N of 05N. No significant convection is noted at this time. Only isolated showers are seen near the wave's axis between 09N and 12N. Another tropical wave is along 130W and extends from 09N to 20N. Scattered moderate convection is observed ahead of the wave axis from 09N to 13N between 130W and 137W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends 10N85W to 13N100W to low pressure located near 11N111W to 09N120W to 11N130W to 10N135W. The ITCZ continues from 10N135W to 09N140W. Outside of the convection associated with the tropical waves and low pressure, scattered moderate convection is noted N of 05N between 78W and 84W. This convective activity extends over parts of Panama and Costa Rica. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Mainly gentle to moderate winds will prevail across the Gulf of Tehuantepec. Wind are forecast to increase across the Tehuantepec area late this week as a low pressure area develops to the south. Elsewhere, a weak ridge will dominate the offshore forecast waters W of the Baja California Peninsula, maintaining a weak pressure gradient, with light to gentle NW winds across the region and 3 to 5 ft seas. Then, seas are expected to build to 5-7 ft in long period swell late this week, but mainly N of Punta Eugenia. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Moderate easterly flow is expected through the week, occasionally pulsing to fresh. Gentle to occasionally moderate E winds are forecast elsewhere N of the monsoon trough which is meandering between 08N and 10N. Moderate to locally fresh southerly winds are forecast S of the monsoon trough through the week accompanied by 5 to 7 ft seas. REMAINDER OF THE AREA... Elsewhere, a ridge will persist north of 20N west of 120W through the week, supporting moderate N to NE winds and 4 to 6 ft seas in that area based on latest altimeter passes. Moderate to locally fresh southerly winds are forecast elsewhere S of the monsoon trough or roughly S of 10N for the next several days. An area of low pressure is expected to form several hundred miles south of the Gulf of Tehuantepec late this week. Gradual development of this system is possible thereafter as it moves west-northwestward off the coast of Mexico. This is forecast to bring an increase in winds and seas across the Tehuantepec area Fri night through Sat night. $$ GR