000 AXPZ20 KNHC 211547 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Dec 21 2020 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 Tehunatepec Gale Warning: A ridge along the eastern slopes of the Sierra Madre Mountains in Mexico behind a cold front currently moving across the SE Gulf of Mexico is supporting minimal gale-force winds over the Tehuantepec region which will continue through Tue morning. Seas will peak around 11-12 ft with this event. Looking ahead, marine guidance suggests a stronger gap wind event in the Tehuantepec area by Thu. Strong gale force winds of 40-45 kt and very rough seas of 14-18 ft are possible Thu afternoon through Fri night. Marine interests should be aware of this upcoming gap wind event to avoid hazardous marine conditions. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from northern Colombia near 10N74W to 05N80W to 07N87W to 06N93W. The ITCZ axis extends from 06N93W to 08N120W to 07N140W. A trough is within the ITCZ along 129W. A cluster of moderate and isolated strong convection is noted just E of the trough axis covering from 08N to 10N between 127W and 129W. Similar convection is seen from 06N to 09N between 120W and 127W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please, see Special Features for details about the ongoing Gulf of Tehuantepec Gale-force event. A stronger gap wind event is expected in the Tehuantepec area by Thu. Gulf of California: Gentle to moderate NW-N winds will prevail across the Gulf of California through Wed. Fresh to locally strong northerly winds are expected Wed night trough Thu night as another high pressure area settles over the Great Basin area of U.S.. Mainly gentle to moderate NW-N winds will prevail across the offshore waters of Baja California through the week, with moderate to fresh winds N of Cabo San Lazaro on Fri. This will be the result of the pressure gradient between a high pressure of 1021 mb over the NE waters near 26N128W and a meandering trough over the Gulf of California. Long period NW swell impacting the waters N of Cabo San Lazaro will continue to subside to 4-7 ft by tonight. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Fresh to strong NE-E winds will pulse across the Papagayo region through the next several days as high pressure remains in place over the W Caribbean. Gentle to moderate winds will prevail on either side of the monsoon trough. No significant swell events are forecast to reach the forecast area over the next several days. Looking ahead, swell generated in the Tehuantepec region are expected to affect the offshore waters of Guatemala and El Salvador Thu night through Fri night, with seas of up to 13-14 ft. REMAINDER OF THE AREA... High pressure located N of the area dominates the forecast waters N of the ITCZ. The pressure gradient between the high pressure and lower pressures near the ITCZ is supporting moderate to fresh NE to E trades, with the strongest winds from 10N to 20N W of 120W. Seas are in the 8-10 ft range. A weak trough may develop over the west-central waters by mid-week increasing trades to fresh to strong W of 130W. A weak low pressure may develop along the monsoon trough near 07N103W by Tue morning with fresh to strong winds and seas of 8-10 ft within about 90-120 nm N semicircle of the low center. The low will move westward, reaching to near 07N109W by Wed morning. A decaying cold front may reach 30N140W by Thu night, and move across the NW corner of the forecast region on Fri. Moderate to fresh N winds and a new swell event are expected in the wake of the front. $$ GR