000 AXPZ20 KNHC 161501 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1229 UTC Wed Jan 16 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. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A trough extends from 02N79W to 02N83W to 04N88W. The ITCZ continues from 04N88W to 03N96W to 04.5N104W. It resumes from 05N108W to 07.5N140W. Scattered moderate convection within 180 nm N of the ITCZ between 120W and 127W. ...DISCUSSION... OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Gulf of Tehuantepec: Winds have diminished below gale force over the gulf this morning. Seas are still reaching near 12 ft approximately 120 nm downstream of the gulf, but will subside below 12 ft later today. Winds will diminish to 20 kt or less Friday night, with a relatively tranquil period to late Sat. Looking ahead, a powerful cold front will move across the western Gulf of Mexico, through southern Mexico into the Gulf of Tehuantepec by Sat night. This front will usher in a significant gap wind event. Winds are expected to reach storm force, with seas building in excess of 20 ft, through and downstream of the Gulf of Tehuantepec on Sun. Marine interests transiting through the Gulf of Tehuantepec Sun into early next week should make precautions accordingly. Light to gentle breezes prevail off Baja California and across the Gulf of California. Moderate N winds persist off Cabo Corrientes, and light breezes elsewhere off the Mexican coast outside of Tehuantepec. NW swell of 8 to 10 ft persists in the offshore waters of Baja California and the Revillagigedo Islands. Little change is expected until late Thu with the arrival of a weakening cold front into northern Baja California Norte. While the front will dissipate as it moves across Baja California and the Gulf of California through Fri, it will be accompanied by a new round long-period NW swell of 12 to 17 ft across the waters off Baja California. This swell will start to impact the waters off Baja California Norte starting Thu night, bringing dangerous surf and large breaking waves across Baja California Norte through Friday. Over the Gulf of California, high pressure building over the Great Basin north of the area will support fresh to strong NW winds extending the length of the Gulf from Fri night through Sat. The strength, fetch and duration of the winds will support wave heights to 8 ft in the southern Gulf of California by Sat night. Winds and seas will diminish by Sun as the high pressure weakens and shifts east. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... The pressure gradient between high pressure north of the area and the equatorial trough will maintain strong gap winds across Papagayo and Panama through early Sat. Over Papagayo, fresh to strong gap winds persist as far as 300 nm to the W-SW of the Gulf, with winds pulsing to near- gale force during the overnight and early morning hours. Seas will build to 8 to 10 ft. Winds will diminish to 20 kt or less Sat and much of Sunday before once again strengthening on Sun night. Over Panama, fresh to strong northerly gap winds will impact mainly the western Gulf of Panama extending into the waters south of the Azuero peninsula through the end of the week. Winds will diminish Sat, and once again strengthen Sun night. REMAINDER OF THE AREA... Low pres of 1010 mb is centered near 04.5N106W. Fresh to strong winds are noted within 270 nm north of the low pressure, with seas in the 10 to 12 ft range in the area of strong winds. The low pressure will move westward over the next 24 to 36 hours before dissipating by early Fri. A cold front is just reaching the far NW part of the discussion area near 30N140W. This front had ushered in a set of large, long period, NW swell into the area, with seas currently reaching near 14 ft over the NW waters. Seas will further build and peak near 25 ft late tonight into Thu as the front pushes eastward. The leading edge of the front will continue eastward across the waters north of 28N through Thu, weakening Fri as it moves into Baja California. The front will leave a stalled segment along 28N, with the western portion of the front lifting north as a warm front through Thu. The NW swell will continue to spread SE the next few days while subsiding. Elsewhere, seas in excess of 8 ft cover much of the forecast waters west of 95W. A ridge will build cross the waters north of 25N in the wake of the front. This will support a broad area of fresh to strong trade winds developing over the tradewind belt north of the ITCZ by Fri. $$ AL