000 AXPZ20 KNHC 190910 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Fri Jan 19 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A tight pressure gradient across southern Mexico is expected to relax today, and gap winds will gradually diminish below gale force by this afternoon. A plume of NE swell associated with the strong winds in the area the past few days will propagate well away from Tehuantepec, and mix with open ocean long period NW swell. Max seas this morning will remain around 12-14 ft near strongest winds, then gradually subside through the weekend. No new gale force wind events are likely until early Tue. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough axis extends from 07N78W to 05N104W. The ITCZ continues from 05N104W to 07N140W. Scattered moderate convection is from 05N to 11N between 113W and 126W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the special features section for information about the gale warning today in the Gulf of Tehuantepec. Winds in the Gulf of California will turn southerly this evening ahead of an approaching cold front, then become fresh to strong behind the front in the northern gulf tonight. The front will gradually become ill defined on Sat as it moves southward with moderate to fresh NW flow expected. The pressure gradient will begin to tighten across the area Sun, leading to fresh to strong winds across the entire gulf Sunday evening and night. Elsewhere across the offshore waters of Mexico, large NW swell continues to propagate SE across the area, with seas of 8-11 ft. This large swell is producing high surf along coasts and outer reefs of Baja California and mainland Mexico. Another pulse of NW swell associated with an intense low pres system north of the area will reach Baja California Norte waters this morning. Seas will peak near 13-15 ft today, and seas of 12 ft or greater will spread across the offshore waters this weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh NE gap winds prevailing between Papagayo and Tehuantepec will pulse to strong each night through Saturday morning, then diminish thereafter. Winds will be strongest offshore Papagayo early this morning. Mainly light to gentle offshore winds will prevail elsewhere N of 09N, with light to gentle southerly flow S of 09N. NE swell originating from the Tehuantepec gale wind event along with longer period NW swell will spread across the area today, building offshore seas to 5-7 ft. REMAINDER OF THE AREA... Large long period NW swell continues to propagate SE across the forecast waters, with seas of 8-12 ft. A weakening cold front from 30N128W to 23N140W has a reinforcing set of NW swell with seas up to 13-16 ft. The front will re-energize north of 30N as high pressure builds to the NW, with N-NE winds increasing to fresh to strong. The front will then wash out to a shear line this weekend as it approaches southern California and NW Mexico. $$ Mundell