000 AXPZ20 KNHC 041526 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1525 UTC Thu May 4 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning...A strong cold front moving across the Gulf of Mexico will reach the southwest portion this afternoon and tonight. High pressure is forecast to surge southward along the eastern Mexico coast in the wake of the front. Winds across the Gulf of Tehuantepec will quickly increase to fresh to strong from the N late tonight, then reach minimal gale force around sunrise Friday. Gale force winds will then persist until around sunrise Saturday before diminishing to fresh to strong through Saturday evening. Seas will build to 14 ft Friday morning through afternoon, then gradually subside to less than 8 ft by Sunday morning. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough axis extends from 08N78W to 10N97W to 08N116W. The intertropical convergence zone axis extends from 05N114W to 06N125W to 04N134W. Scattered moderate, isolated strong convection is within 240 nm SW of the trough between 91W and 96W, and also within 210 nm S of the trough between 99W and 102W. Similar convection is within an area bounded by 08N135W to 08N127W to 05N120W to 04N120W to 03N133W to 08N135W. Scattered moderate convection is from 02N to 05N within 120 nm W of the coast of Colombia, and also within 120 nm SW of the coast of El Salvador. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See the special features section for information on the Gulf of Tehuantepec Gale warning. Mainly light to moderate NW winds will prevail across the waters NW of Cabo Corrientes through Friday morning, with light to moderate W to SW winds prevailing E of Cabo Corrientes to Puerto Angel. Mainly light and variable winds prevail in the Gulf of California. Combined seas of 5-7 ft prevail in the open waters of the Pacific, with seas 2 ft or less in the Gulf of California except up to 4 ft near the entrance. A cold front will approach the SW United States and NW Mexico by the end of the week, then move across NW Mexico Friday night through Sunday. Winds will increase slightly across the Pacific waters of Baja California Friday through Saturday night ahead of the front, then become fresh to near gale force in the northern Gulf of California ahead of the front Friday night into early Saturday. Behind the front, fresh to strong winds are forecast offshore of Baja California Norte and in the northern Gulf of California. Seas will build to 8-12 ft in N swell N of 22N W of Baja California behind the front through early next week. Seas will build to 5-8 ft in the northern Gulf of California where the strong winds will occur. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle onshore winds will prevail during the day, and gentle to moderate offshore winds during the night through the next several days. Offshore winds in the Gulf of Papagayo will increase to moderate to fresh late Saturday night into early Sunday. Seas will remain mainly ranging from 4-6 ft. Looking ahead, global models continue to indicate the chance of low pressure developing along the east to west trough in the tropical eastern Pacific, between Central America and 95W late in the weekend into early next week. Little movement of this possible low pressure area initially, which could lead to heavy rainfall across portions of the region from Costa Rica NW toward SW Guatemala. REMAINDER OF THE AREA... High pressure of 1016 mb centered near 22N121W extends a ridge to the E and W of the center. A weak trough extends into the area from 32N123W to 23N133W. An overall weak and broad pressure pattern results from these features with fairly tranquil boating conditions. Combined seas are 4-6 ft across the majority of these open Pacific waters. A cold front approaching the NW waters this morning will usher in fresh to strong northerly winds behind it as stronger high pressure builds in its wake. A new set of NW swell will also accompany the front with seas of 8 ft or greater covering much of the area N of 20N W of 120W this weekend. Moderate to fresh trades will cover this area for the early part of next week along with combined seas of 5-8 ft, except 8-14 ft seas over the NE portion due to stronger winds N of the area off southern California. $$ LEWITSKY