000 AXPZ20 KNHC 182149 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sun Dec 18 2022 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 1800 UTC surface analysis and satellite imagery through 2130 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Panama near 08N78W to 06N92W to 06N106W. The ITCZ extends from 06N106W to 07N120W to beyond 07N140W. Scattered moderate convection is noted from 02N to 08N between 78W and 100W and from 06N to 11N between 127W and 136W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A weak high pressure regime extends southward into the Baja California offshore waters. Scatterometer data from this afternoon shows light to gentle winds continuing to prevail across the Baja California offshore waters, Gulf of California, and southwest Mexico. Seas across these waters range 3-4 ft, with 1-2 ft in the Gulf of California. Scatterometer data also showed strong northerly winds in the Gulf of Tehuantepec. Seas are likely 7 ft in that area. Light to gentle winds prevail elsewhere in the southern Mexico offshore waters with 4-5 ft seas. For the forecast, strong to near gale northerly winds will continue through Mon morning in the Gulf of Tehuantepec. Seas will drop below 8 ft by early Mon morning. Conditions will rapidly improve on Mon afternoon. Strong northerly winds will return to the Gulf of Tehuantepec by Tue afternoon. Gale-force winds are expected with this event starting Tue evening and continuing through Wed morning. Seas may build to near 12 ft Tue night into Wed. Conditions will improve on Thu afternoon briefly before the next gap wind event begins on Fri. Meanwhile, strong NW winds are expected to develop in the Gulf of California Mon night and diminish on Wed. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh easterly breezes are present in the Gulf of Papagayo region, extending westward to 89W. Seas are 6 ft in these waters. Light to gentle variable winds prevail elsewhere north of the monsoon trough with 3-4 ft. Light to gentle S-SW winds and seas of 4-5 ft are found south of the monsoon trough. Gentle or weaker winds and slight to moderate seas are noted across the South American offshore waters. For the forecast, moderate to fresh easterly winds will continue in the Papagayo region through the upcoming week, pulsing to strong at night. Seas are expected to build near 8 ft at the time of the strong winds. Moderate to locally fresh northerly winds likely tonight and Mon night in the Gulf of Panama. Gentle winds will continue to prevail across the South American offshore waters through most of the week with moderate seas. REMAINDER OF THE AREA... A weak 1015 mb low pressure is centered near 27N126W and a surface trough extends southwestward to 25N135W. A few shallow showers are noted near the trough axis. Scatterometer data showed moderate winds northwest of the low. The remainder of the area is dominated by high pressure system located well north of the eastern tropical Pacific. Scatterometer depicted a frontal system, west of 140W, bringing fresh to strong winds and 8 ft seas in waters N of 25N and W of 137W. Elsewhere, light to variable winds are occurring N of 18N and W of 115W with seas 4-7 ft. Moderate to locally fresh winds are noted from the ITCZ to 18N and W of 115W, with gentle to moderate southerly winds south of the ITCZ. Seas range 7-9 ft. Elsewhere, moderate or weaker winds with slight to moderate seas are prevalent. For the forecast, moderate to locally fresh trade winds and 8-9 ft swell S of 20N and W of 125W are expected through midweek before it merges with large swell that will propagate into the waters by Wed. The frontal system currently located W of the forecast waters will continue to bring fresh to strong southerly winds N of 27N and W of 130W through Mon with seas to 8 ft. Looking ahead, high pressure will shift east while strengthening through early next week. This will yield a broad zone of fresh tradewinds S of 20N and W of 120W starting Tue and continuing through most of the week. Another frontal system will approach the NW waters on Tue night into Wed, bringing strong winds and potential gale force winds N of 20N and W of 130W on Wed afternoon. Large swell with seas building to near 20 ft will also propagate through this area Tue night through most of the week. $$ AReinhart