000 AXPZ20 KNHC 021506 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1506 UTC Tue Jan 2 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 1500 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The pressure gradient between high pressure along the eastern coast of Mexico and a surface trough over the eastern north Pacific is supporting a gale force gap wind event over the Gulf of Tehuantepec. An overnight ASCAT pass confirmed gale force over this area, reaching 40 kt. This event will be strong and long lived, peaking near 45 kt and lasting much of the week. Seas will peak near 18 ft Wed night into Thu morning. Swell associated with this event will push downstream of the Gulf of Tehuantepec, with seas 8 ft or greater reaching as far south as 05N and west to 108W by midweek. Refer to the latest high seas forecast issued under AWIPS/WMO headers HSFEP2/FZPN03 for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 1010 mb low pressure near 07N77W to 05N100W. The intertropical convergence zone continues from 05N100W to 09N120W, then resumes from 10N135W to 09N140W. Scattered moderate convection is evident from 04N to 07N between 82W and 85W. Scattered moderate convection is also noted from 12N to 15N between 120W and 125W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see special features section above for more details about the gale force gap wind event in the Gulf of Tehuantepec. Relatively tranquil marine conditions will persist through the week with light to gentle winds prevailing across the forecast waters. Seas in the range of 3 to 5 ft will continue in the offshore waters, while seas in the 1 to 3 ft range will prevail in the Gulf of California. NW swell of 5 to 7 ft will propagate into the waters off Baja California Norte later in the week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... NE winds will pulse to fresh to strong in the Gulf of Papagayo through the middle of the week. Winds will further increase to near gale force Thursday as high pressure builds north of the area. Light to gentle NE to E winds will prevail elsewhere N of 09N, with gentle to moderate S to SW winds expected S of 09N. REMAINDER OF THE AREA... A deep layered trough is drifting east between 130W and 135W. An associated 1009 mb low pressure area is centered near 29N134W, with an accompanying cold front reaching from 30N128W to 25N134W. The upper trough continues to support scattered moderate showers and thunderstorms ahead of the cold front from 26N to 29N between 125W and 128W. Scattered moderate showers and thunderstorms are also ongoing along a trough near the ITCZ, from 12N to 15N between 120W and 125W. An earlier scatterometer satellite pass indicated fresh to strong winds west of the low. A fresh set of NW swell has propagated into the area, with seas near 13 ft over the far NW waters near 30N140W. The low will shift N of the area late tonight while weakening, and winds will diminish to 20 kt or less. Seas will continue to propagate southeast across the forecast waters while slowly subsiding. By midweek, seas 8 ft or greater associated to this swell will cover much of the forecast waters north of 10N and west of 125W by late Wed. $$ Christensen