000 AXPZ20 KNHC 091533 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1319 UTC Wed Jan 9 2019 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... Gale Warning: Gale conditions will prevail across the Gulf of Tehunatepec today through Thu night, with seas building up to 15 or 16 ft tonight. This gap wind event will be associated with a strong high pressure building across the western Gulf of Mexico. Winds are forecast to rapidly diminish on Friday as winds in the Gulf of Mexico sharply veer to the south. Please see the latest High Seas Forecast product under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details. Gale Warning: A strong cold front is forecast to reach the NW corner of the discussion area near 30N140W by early Thu afternoon, followed by reinforcing large long period NW swell. Gale force winds, likely in the 30-40 kt range, are expected on either side of the front, but mainly N of 28N Thu afternoon through early Fri. Seas are forecast to build up to 20-22 ft behind the front. Fresh to strong winds will persist on either side of the front through Fri, as it continues eastward, with seas of 12-17 ft in NW swell in the wake of the front. See the latest High Seas Forecast product under AWIPS/WMO headers HSFEP2/FZPN03 KNHC for more details. .INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from Colombia near 04N75W to 07N86W to 05N96W. The ITCZ continues from 05N96W to 08N120W to 06N140W. Scattered moderate convection is noted from 04N to 06.5N W of 135W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak ridge, anchored by a 1020 mb high pressure located near 26N121W, dominates the waters west of Baja California, producing light anticyclonic winds across the offshore waters. A cold front near 125W is associated with a deep low pressure system well north of the area. This system has generated very large NW swell, with latest satellite altimeter data showing seas of 20 to 23 ft near 28N125W. This powerful NW swell will reach the offshore waters of Baja California Norte later today, and build across these waters through early Thu morning. Peak seas of 10-15 ft across the northern waters late tonight will reach 8-12 ft in southern waters on Thu, then slowly subside Thu night through early Sat. In addition to generating high and hazardous seas across the offshore waters, this large long period swell train, with a leading edge period of 18 to 20 seconds, will create very high and dangerous surf along the coasts and outer reefs of Baja California Wed night through Thu, and produce very strong rip currents in the surf zone, and localized areas of coastal erosion. Gulf of California: Recent scatterometer data indicate moderate NW winds over all but the far northern Gulf, with seas of 3-5 ft. Gentle to moderate winds are expected across the Gulf through Fri. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gulf of Papagayo: Fresh NE to E winds will prevail across the Gulf region, and become fresh to strong across and downstream of the Gulf of Papagayo each night through the weekend with the assistance of the nocturnal drainage flow. Gulf of Panama: Moderate to fresh northerly winds downstream to near 05N with seas to 6 ft will continue through the weekend. REMAINDER OF THE AREA... A cold front moving eastward across the north waters extends from 30N125W to 22N135W. The front will weaken and become ill defined between 120W and Baja California tonight. Winds have diminished to 20 kt or less on either side of the front across the forecast waters. However, large seas up to 23 ft in large long period NW swell, associated with this front, will propagate across the waters west of 115W early this afternoon, and into the offshore waters of Baja California later today. $$ GR