000 AXPZ20 KNHC 010308 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 035 UTC Mon Jan 1 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 0300 UTC. ..SPECIAL FEATURES... Gale Warning: An earlier ASCAT pass indicates gale force winds just NW of the area, between deepening low pressure just N of the area and high pressure to its west. This area of gale force winds will shift into the NW waters overnight as the low pressure center drifts southward into the forecast waters. Winds will diminish below gale force on Monday as high pressure west of the area weakens and the pressure gradient loosens. This event will usher in a fresh set of NW swell into the area. Seas will peak near 18 ft during the period of gale force winds and will slowly subside afterwards while propagating southeast across the forecast waters. By midweek, seas 8 ft or greater associated to this swell will cover much of the forecast waters north of 10N and west of 120W. Refer to the latest high seas forecast issued under AWIPS/WMO headers HSFEP2/FZPN03 for more details. Gulf of Tehuantepec Gale Warning: Winds and seas will increase Monday as strong high pressure building behind a cold front moving across the western Gulf of Mexico helps tighten the pressure gradient over the forecast area. Winds will increase to gale force over the Gulf of Tehuantepec by late Monday. This gale event is expected to be strong and long- lasting, with gale force winds persisting for much of the next week, and peaking near 45 kt. Swell associated to 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 105W 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 08N78W to 08N87W to 07N97W. The ITCZ extends from 07N97W to 12N120W. It resumes from 10N128W to 08N140W. Scattered moderate isolated strong convection was noted from 05N to 10N between 80W and 86W. Scattered moderate isolated strong convection was noted within 60 nm north of the ITCZ between 130W and 134W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see special features section above for more details about the upcoming gale force gap wind event in the Gulf of Tehuantepec. Relatively tranquil marine conditions will persist through next 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 6 to 8 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 next 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... Please see special features section above for more details about gale force winds in the NW corner of the forecast area, and associated swell. A surface trough along 129W from 15N to 20N will persist and shift northward through Tue ahead of an advancing cold front. Strong winds and seas to 8 ft are expected with the associated surface trough by Mon as it moves northward, extending from 26N127W to 21N130W. Winds associated to this trough will diminish to 20 kt or less Tuesday, while seas to 8 ft merge with NW swell propagating across the area. $$ AL