000 AXPZ20 KNHC 152158 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Wed Feb 15 2017 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. ...SPECIAL FEATURES... A Gale Warning is in effect for the waters N of 27N between 128W and 135W. A deep low pressure system will cross north of the area late Thursday through late Friday, pushing a cold front across the north waters. The front will reach a position from 30N125W to 24N130W to 21N140W early Friday afternoon. Expect very large seas and gale force winds, likely in the 35-40 kt range, in association with this low/front across the north waters. Seas are forecast to build to 18-25 ft within the area of the strongest winds. This low pressure is also forecast by the GFS computer model to bring increasing winds and building seas across the offshore waters W of Baja California Norte late Friday into Saturday. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The ITCZ and associated convection remains south of the Equator. This normally occurs during March and April. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure of 1023 mb centered near 26N128W extends a ridge SE to beyond the Revillagigedo Islands, producing mainly gentle to moderate northerly winds across the offshore waters W of Baja California with seas of 4-6 ft. Scatterometer data indicate moderate to locally fresh NW winds across the northern part of the Gulf of California with seas to near 5 ft. Elsewhere mainly light to gentle northerly winds are noted with seas of 2-3 ft except to 3-4 ft near the entrance of the Gulf. By late Thursday, a new set of long period NW swell will reach the waters W of Baja and N of 26N, then spread south across all waters W of Baja California Peninsula by late Fri. The aforementioned high pressure will move slightly south and weaken over the next 24 hours, as a cold front moves across the north forecast waters. High pressure building behind a cold front currently moving over the Gulf of Mexico will allow a pulse of fresh to strong gap winds into the Gulf of Tehuantepec this evening into Thursday morning. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Mainly gentle to moderate NE-E winds are expected across the Gulf of Papagayo. Winds are forecast to increase to 15-20 kt Thursday night and Friday, and again Sunday and Sunday night. In the Gulf of Panama and downstream, expect northerly winds in the 10-15 kt range, especially at night. Cross equatorial long period SW swell continues to affect the waters between Ecuador and the Galapagos Islands (except in the lee of the islands), raising seas to 6-7 ft. This is forecast to persist tonight, with this swell event affecting the pacific coast of Panama and Costa Rica. REMAINDER OF THE AREA... A cold front has reached the far NW corner of the forecast area and extends from 30N138W to 29N140W. Fresh to strong SW winds are ahead of the front to a line from 30N132W to 27N140W. Fresh to strong W-NW winds are aslo noted in the wake of the front. This front will move across the north waters reaching a position from 30N128W to 26N140W while weakening some. A second and stronger cold front will enter the NW waters by Thursday night merging with the first front on Friday. Gale conditions are expected behind the front and strong to near gale force winds are forecast ahead of the front. Please, see Special Features for details. $$ GR