758 AXPZ20 KNHC 122110 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Thu Jul 12 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. ...TROPICAL WAVES... A tropical wave has entered the eastern Pacific Ocean from Central America and is located near 87W N of 08N. The wave is moving W at 10-15 kt. It can be observed from the 700 mb rawindsonde winds from Panama, San Jose, San Andres, and Belize; Central American surface winds, as well as a maximum in total precipitable water. No significant deep convection is occurring over the eastern Pacific in association with the wave, though there exists scattered moderate convection within 180 nm of the wave axis over Nicaragua, Honduras, Belize, and the Yucatan of Mexico. A tropical wave is from 08N to 18N along 108W, moving W at 15 kt. This weak wave is only observable via 700 mb trough diagnostics. No significant deep convection is observed in association with this wave. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from a 1008 mb low over Colombia near 10N75W to 07N95W to a 1008 mb low at 12N134W to 09N140W. There is no ITCZ over the eastern Pacific at this time. Scattered moderate convection occurs within 180 nm of the trough between 92W and 98W as well as between 118W and 137W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: A 1020 mb high pressure in the Gulf of Mexico and northerly winds east of a diurnally-occurring surface trough is enhancing the nocturnal drainage flow in the Gulf of Tehuantepec. Additionally, the tropical wave near 87W may also enhance these winds this evening. An ASCAT scatterometer pass showed peak winds of 25 kt N in the northernmost Gulf of Tehuantepec at 1620 UTC. Peak winds may reach near gale each late night/early morning through Monday before relaxing on Tuesday. Peak seas will reach 8-10 ft. A weak pressure gradient is present west of Baja California contributing toward gentle and moderate winds today. These will continue for the next several days. A 18-20 second long-period swell from the southwest will reach these waters, but will have less than 8 ft seas. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Strong nocturnal NE to E winds, with 8 to 10 ft seas, are expected in the Gulf of Papagayo late night/early morning hours through Tuesday. A 1442 UTC ASCAT scatterometer pass showed 25 kt NE winds in the Gulf of Papagayo earlier today. Gentle to moderate easterly winds are expected elsewhere north of the monsoon trough, with gentle southerly winds forecast south of the trough axis. Little change is expected through Tuesday. A 18-20 second long-period swell from the southwest will reach these waters, but will have less than 8 ft seas. REMAINDER OF THE AREA... A 1008 mb low pressure center is analyzed near 12N134W. The low will move slowly W during the next couple of days before leaving our area with little tropical development. A recently arriving ASCAT scatterometer pass from 1804 UTC showed 25 kt with this system in its northern semicircle and that the system may have opened up into a trough. Peak seas with the system should be 8- 9 ft. $$ Landsea