000 AXPZ20 KNHC 090336 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 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 0000 UTC surface analysis and satellite imagery through 0200 UTC. ...SPECIAL FEATURES... Gale Warning: Strong northerly gap winds this evening will increase to gale force across the Gulf of Tehuantepec tonight around 0600 UTC as strong high pressure expands eastward across the Gulf of Mexico. Gale conditions will prevail through Thu night, with winds rapidly diminishing 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 late Thu morning, followed by reinforcing large long period NW swell. Strong to gale force SW to W winds are expected north of 27N on either side of the front around midday Thu through early Fri. Fresh to strong winds will persist on either side of the front through Fri, as it continues eastward, with seas of 10-15 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 03.5N74W TO 07N87W TO 04N100W. The ITCZ continues from 04N100W TO 06.5N113W to beyond 04N140W. Scattered moderate convection is noted from 03N to 07N between 85W and 93W, and from 03N to 06.5N between 135W and 139W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weakening ridge dominates the offshore waters west of Baja California, producing gentle to moderate anticyclonic winds, and variable winds generally less than 15 kt across the offshore waters. Lingering NW swell producing seas 4-6 ft across the will subside slightly tonight. A strong cold front currently moving across the open waters W of 125W accompanies a deep low pressure system across the NE pacific near 42N135W. This powerful system has generated very large NW swell behind the cold front, with late morning satellite altimeter data showing seas of 25 to 35 ft from 30N to 36N along 135W today. This powerful NW swell will move into the offshore waters of Baja California Norte early Wed morning and build through early Thu morning as it reaches the waters of Baja California Sur. Peak seas of 10-15 ft across the northern waters late Wed night will propagate SE and peak around 8-12 ft across the southern waters midday Thu, then subside very slowly Thu night through early Sat. In addition to generating high and hazardous seas across the offshore waters, this large long period swell will create very high and dangerous surf along the coasts and outer reefs of Baja Wed night through Thu, and produce very strong rip currents in the surf zone, and likely areas of coastal erosion. Gulf of California: Moderate to locally fresh NW winds prevail over all but the far northern Gulf this evening, with seas 3-6 ft. Winds will gradually diminish from north to south through Wed. Then, mainly gentle to moderate winds will prevail 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. 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 across the NW forecast waters extends from 30N127W TO 21.5N140W. Late morning scatterometer data indicated that the gale force winds associated with an intense low pressure system centered well north of the area near 42N135W were just N of 32N, with 20-25 kt winds E of the cold front N of 27.5N. Winds will continue to gradually diminish S of 30N through tonight as the front continues to move eastward and the low pressure system begins to lift northeastward. The expansive sized area of gale force and greater winds north of the area has generated seas to 36 ft in large long period NW swell along 35N, and will move into the waters W of 120W tonight, then into the offshore waters of Baja California in the next 24 hours. The front will weaken and become ill defined between 120W and Baja California Wed night, as the swell continues to propagate SE into the Mexican coastal waters. $$ Stripling