000 AXPZ20 KNHC 222147 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Tue May 22 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 1200 UTC surface analysis and satellite imagery through 1545 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends west from the Pacific coast of Colombia at 09N78W across the northern Gulf of Panama and then across Panama and southern Costa Rica continuing almost due west to 07N123W where scatterometer winds indicate a transition to an ITCZ which continues west to beyond to 08.5N140W. Scattered moderate isolated strong convection is noted within areas bounded by a lines from 14N100W to 12N87W to 03N80W to 05N104W to 14N100W, and from 13N115W to 03N122W to 09N140W to 13N115W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A northwest to southeast ridge will meander beyond 250 nm seaward of northern and central Mexico for the next few days. Moderate northwest flow is observed west of 100W, and light to gentle northwest flow is observed east of 100W. An area of 6 to 8 ft seas currently noted east of 115W will subside to 4 to 7 ft by early Wed. Little change then forecast through Thu afternoon when a tightening pressure gradient will produce a moderate to locally fresh northwest breeze west of the Baja Peninsula. Locally strong conditions are forecast near 26N113W on Fri night. Gulf of California: A moderate nocturnal southwest breeze is expected along 30N for the next several days. A moderate northwest breeze is forecast to begin across the southern Gulf of California on Thu. Gulf of Tehuantepec: Moderate nocturnal drainage flow is expected this week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Mixed swell resulting in 6 to 8 ft seas currently across the offshore waters near 09N90W will subside to 4 to 7 ft overnight. Elsewhere, light SW winds are expected for the next several days to the south of 10N with 3 to 5 ft seas. REMAINDER OF THE AREA... A surface high is centered near 31N140W with a ridge extending southeast to near 13N108W. Little change to the moderate trades currently observed south of the ridge through Thu, but the 5 to 8 ft seas currently observed near 12N123W are forecast to subside to 4 to 7 ft overnight. The pressure gradient is forecast to tighten as a surface low develops along the ITCZ near 10N132W late this week resulting in fresh to possibly strong trades within 480 nm north of low with seas building to 8 ft. Further north...the surface high will dissipate as the ridge shifts south on Wed allowing a cold front to reach along a position from 32N137W to 30N142W overnight. The front will continue east eventually losing identity from 32N126W 24N128W on Thu night into Fri. Although only fresh winds northerly winds are forecast west of the front, northwest swell will maintain an area of 6 to 8 ft seas across the waters from 29N to 32N through Fri morning. $$ Nelson