081 AXPZ20 KNHC 110330 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Wed Jul 11 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...TROPICAL WAVES... A tropical wave is analyzed north of 10N along 98W moving W at 15 kt. Scattered moderate convection is observed S of 13N within 90 nm either side of the wave axis. A tropical wave is analyzed from 08N to 18N along 119W moving W at 10 to 15 kt. Scattered moderate isolated strong convection is observed from 10N to 15N within 180 nm W and 90 nm E of the wave axis. A tropical wave is analyzed from 08N to 19N along 129W moving W at 15 kt. Scattered moderate convection is observed well east of the wave axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends westward from 09N78W to 07N98W. The ITCZ continues from 07N99W to 09N116W, then resumes from 09N130W to 07N140W. Except for convection associated with the tropical waves, scattered moderate convection is within 120 to 180 nm S of the convergence zone axis between 85W and 106W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: High pressure in the Gulf of Mexico and northerly winds east of a trough in the Bay of Campeche will enhance the nocturnal drainage flow in the Gulf of Tehuantepec, with winds in excess of 30 kt each night through early Fri. Surface troughing west of Baja California is supporting a weak pressure pattern N of 15N W of 96W across the offshore waters promoting mainly gentle winds. The trough W of Baja California will meander over the region the next couple of days, which will help maintain weak flow over the region through Sunday. 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 seas to 10 ft, are expected in the Gulf of Papagayo Fri night and Sat. Gentle to moderate easterly winds are expected elsewhere north of the monsoon trough, with gentle southerly winds forecast south of the trough axis. REMAINDER OF THE AREA... A surface trough that extends from 26N126W to 21N128W will drift westward the next couple of days. The pressure gradient Nw of the trough axis with support fresh NE trade winds, and enhance residual mixed swell in the region to produce an area of 8 ft seas from 23N to 26N W of 135W during the next 24-48 hours, then shift west of 140W on Thu. GFS model guidance indicates a sharp surface trough will develop along the convergence zone boundary in association with a tropical wave along 119W during the next 24-36 hours. The pressure gradient between the developing trough and high pressure N of 30N may induce an area of strong NE winds N and NW of the trough axis. The GFS model shows winds in excess of 30 kt in this area Thu and Fri, and an area of low pressure may be intitiated along the trough/wave axis near 13N or 14N as this development occurs, with seas building to 10-12 ft by Sat. Cross-equatorial southerly swell of 7-8 ft will affect southern waters mainly south of 02S between 100W and 115W during the next 24 hours, then subside by Wed night. $$ Mundell