000 AXPZ20 KNHC 272131 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1814 UTC Thu Dec 27 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. .INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from a 1007 mb low pressure located over Colombia near 07N75W to 03N80W to 05N87W to 05N96W. The ITCZ continues from 05N96W to 07N105W to 06N120W to beyond 06N140W. Scattered moderate isolated strong convection is noted from 05.5N to 09N between 103W and 110W...and from 05.5N to 11N between 110W and 135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of California: Winds are forecast to increase to 20-30 kt across the northern Gulf this evening, with seas building to between 5 and 7 ft as a frontal trough crosses the region. The trough will be E of the area, and inland Mexico by Fri morning. Then, strong high pressure building over the Great Basin will bring fresh to strong northerly winds across the entire length of the Gulf of California by Sat night. By that time, seas are forecast to build to 8 ft from 29N to 30N. These winds could spill out over the offshore forecast W of Baja California by Sat night. In addition, fresh to strong northerly winds are also expected to briefly affect the waters between Los Cabos and Las Tres Marias Islands on Sun morning. Gulf of Tehuantepec: Winds and seas have diminished across the Tehuantepec region as winds veer to the SE in the SW Gulf of Mexico. Nocturnal drainage flow could bring strong northerly winds to the waters N of 15N between 94.5W and 95.5W by Sun night. Marine guidance suggests another strong Tehunatepec gap wind event next week. The GFS model hints at a storm force gap wind event. Latest satellite-derived wind data indicated moderate NW to N winds across the offshore waters W of Baja California Peninsula. Seas in this area are currently running between 8 and 9 ft in NW swell while seas around 8 ft are noted near the Revillagigedo Islands. Seas generated by gale force winds near the coast of California will reach the waters N of Punta Eugenia by early Fri morning, with sea heights of 9-12 ft. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh to strong NE to E winds are expected across the area through Tue. The winds will be greatest during the overnight and early morning hours, with the assistance of the nocturnal drainage flow, and some added enhancement from the easterly gradient flow from the SW Caribbean. Seas are forecast to build to 8-10 ft while winds peak near gale force mainly at night. Gulf of Panama: Moderate to fresh N winds are expected through Tue, with seas generally in the 4 to 6 ft range. Elsewhere, gentle to moderate NE winds will prevail N of 08N, while gentle to moderate southerly winds are expected S of 08N through Tue. REMAINDER OF THE AREA... A 1034 mb high pressure system centered near 39N133W extends a ridge SE across the forecast waters to beyond the Revillagigedo Islands. The pressure gradient between the ridge and lower pressure in the vicinity of the ITCZ is supporting a large area of fresh to strong NE winds, particularly from 08N to 25N W of 120W. Seas in this area range between 9 and 13 ft based on altimeter data. These marine conditions are forecast to persist over the next couple of days. Long period NW swell will continue to propagate across the forecast waters mainly W of 110W and support seas of 8 to 11 ft. The swell will slowly decay and allow seas E of 110W to subside below 8 ft by this evening. Another set of long period NW swell has reached the NW corner of the forecast area, and will continue to propagate SE across the forecast waters over the next several days. $$ GR