000 AXPZ20 KNHC 200921 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Feb 20 2024 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 140W. The following information is based on satellite imagery, weather observations, radar, and meteorological analysis. Based on 0600 UTC surface analysis and satellite imagery through 0830 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The pressure gradient between high pressure over E Mexico and low pressure near the equator is sustaining gale force N winds over the Gulf of Tehuantepec through Wed morning. The 0316 UTC and 0408 UTC ASCAT scatterometer overpasses measured peak winds of around 35 kt. Maximum sustained winds should remain at minimal gale and seas should peak around 11 ft. The gap winds should steadily weaken Wed and dissipate by Thu morning. Seas should drop below 8 ft by Thu morning. Very Large NW Swell: A 997 mb gale center west of the Oregon- California continues to generate very large NW swell over our discussion area. The leading edge of seas 12 ft or greater currently extends from 30N117W to 08N138W with a period of 12-15 seconds. The Sentinel-3B altimeter measured around 18 ft seas near 27N126W at 0600 UTC. These very large wave heights will remain over an extensive area today while continuing to propagate southeastward. As the low weakens today, the generated swell will steadily decay and will drop below 12 ft by tonight. Please read the latest High Seas and Offshore Waters Forecasts issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFAT2.shtml https://www.nhc.noaa.gov/marine/offshores_eastpac.php for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The equatorial trough extends from the coast of the Colombia- Panama border near 08N78W to 05N99W. The ITCZ is analyzed from that point to 03N128W at a break for a trough extending from 05N128W to 01S131W. The ITCZ resumes at 01N137W to beyond 01N140W. Scattered moderate convection exists south of 05N and east of 96W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section above for information about a Tehuantepec Gale Warning and the very large NW swell. A weak 1022 mb high near 24N120W is sustaining only moderate or weaker winds across the forecast waters, aside from the on-going Tehuanteper gap wind event. Seas are 8-10 ft in the waters between Point Eugenia and Puerto Angel, and 1-2 ft over the Gulf of California. For the forecast, winds outside of the Gulf of Tehuantepec should generally remain moderate or weaker for the next several days. The very large, long-period WNW swell will continue to impact the waters west of Baja California Norte today before gradually diminishing on Wed. Elsewhere north of the Revillagigedo Islands, the same swell will produce seas of 8-11 ft through Wed night. Looking ahead, the next Tehuantepecer should begin Fri night, but it may remain below gale force. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR High pressure over Central America along with low pressure near the equator is forcing fresh to strong and locally near gale NE to E winds over the Gulf of Papagayo region overnight. N winds over the Gulf of Panama are fresh and locally strong. Seas are 6-8 over the Gulf of Papagayo region and 4-7 ft elsewhere. For the forecast, the fresh to strong and locally near gale NE to E winds over the Gulf of Papagayo region are expected through Thu. The forcing will become slightly stronger Wed night, and gales are anticipated at that time. While the winds will diminish Thu night through Fri night, a resumption of fresh to strong winds are expected again over the Gulf of Papagayo region on Sat. Similarly, fresh to locally strong N to NE winds will continue over the Gulf of Panama through Thu night before diminishing on Fri. Large NW swell generated from the nearby gale force Tehuantepecer will impact the waters of Guatemala and El Salvador through Wed. ...REMAINDER OF THE AREA... Please read the Special Features section above for information about the ongoing very large NW swell. A dissipating cold front extends from 30N121W to 16N139W. NE winds south of 20N behind the front are fresh. Cyclonic winds on the south side of the 997 mb gale center west of the Oregon- California are fresh to moderate north of 26N. A weak 1022 mb high is centered near 24N120W. The trades are gentle to moderate across the remainder of the area, as the pressure gradient between the high and the ITCZ is weak. As described above, the sea state is dominated by a very large NW swell. The leading edge of the 8 ft seas extends from 20N108W to 00N120W. To the east of that line, seas are 4-7 ft. For the forecast, a stronger surface high will become re- established over the NW portion of our waters on Wed and Thu, leading to the trades increasing to fresh and locally strong from 05N-18N west of 120W. On Fri and Sat, a new extratropical low will move slowly eastward along our 30N border, causing strong to near gale N winds in its W semicircle. After the currently very large NW swell steadily diminishes by Thu morning, lowered seas of 6-8 ft are expected across most of the waters Thu and Fri. On Fri, a new round of very large NW swell associated with the extratropical low will begin pushing southeastward. $$ Landsea