000 AXPZ20 KNHC 160328 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Jan 16 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 0215 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Gale force winds continue across the Gulf of Tehuantepec tonight, but are diminishing very slowly in strength and areal coverage from recent days. Peak seas downwind of the gulf are as high as 15 ft presently. Winds will continue to diminish slightly, though remain above gale force through Tue. A cold front will move into the Gulf of Mexico on Tue with associated high pressure building behind the front to tighten the pressure gradient over the area. This will again increase winds to strong gale across Tehuantepec Tue afternoon through night. Winds are expected to finally diminish below gale force by Friday. The resultant plume of NE swell have propagated southwestward, currently reaching as far W as 120W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 05N77W TO 10N86W TO 05N91W. The ITCZ extends from 05N91W to 09N123W to beyond 09N140W. Scattered moderate to strong convection is noted from 00N to 10N between 80W and 88W. Scattered moderate convection is noted from 04N to 08N between 91W and 102W. Scattered moderate isolated strong convection is noted within 90 nm N and 60 nm S of ITCZ between 111W and 140W, except for scattered moderate to strong from 06N to 11N between 121W and 130W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... W of the Baja California Peninsula: Large NW swell that generated very high surf of 30-40 ft across the Hawaiian Islands this past weekend is propagating into the area forecast waters tonight. Buoys offshore of southern California showed wave periods in the 19 to 22 second range this evening, with seas of 8 to 12 ft. This NW swell will build across the regional forecast waters tonight through late Tue and peak at 10 to 13 ft W of Baja California Tue afternoon through Tue night, and at 7 to 10 ft across the remaining offshore waters between Baja and Tehuantepec Tue night through late Wed. This large swell will generate very high and powerful surf along the coasts and outer reefs of Baja and mainland Mexico through Wed. Another surge of NW swell will reach the offshore waters off Baja California Norte Thursday night. Seas associated to this swell will peak near 16 ft by Friday. Seas 12 ft or greater will spread across the offshore waters off the entire length of the Baja Peninsula through the weekend. Gulf of California: Light to moderate NW flow is forecast across across the entire gulf waters through Fri. See special feature section for information about the ongoing gale warning in the Gulf of Tehuantepec. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Nocturnal winds will pulse to strong across and downwind of the Gulf of Papagayo the remainder of the week. Elsewhere N of 09N gentle to moderate gap winds will diminish to light to gentle by midweek, with mixed swell maintaining seas 4 to 7 ft before the strong NW swell arrives early Thu, raising seas to 5-8 ft. S of 09N light to gentle winds will prevail. REMAINDER OF THE AREA... Large, long period NW swell is propagating SE across the forecast waters tonight. Seas W of 120W are building to 10 to 18 ft, with highest seas still over the far northwestern waters. The swell will move SE across the discussion area while slowly subsiding through late Tuesday. By Tuesday, seas 8 ft or greater covering much of the forecast waters W of 107W, and then W of 100W by Wednesday. A fresh pulse of large NW swell will enter the NW waters Wednesday night, with seas peaking near 20 ft. This swell will build seas greater than 12 ft over much of the waters N of 15N and W of 120W by Sat night. $$ Stripling