000 AXPZ20 KNHC 131556 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sun Dec 13 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 1530 UTC. ...SPECIAL FEATURES... Gulf of Tehunatepec Gale Warning: The next gap winds event over the Tehuantepec region is expected Mon afternoon through early Tue morning. Winds are forecast to briefly reach gale force by Mon evening and night, with seas to 12 ft. Building high pressure across the western Gulf of Mexico and the eastern slopes of the Sierra Madre mountains in Mexico will support this event. Looking ahead, minimal gale conditions and building seas to 9 or 11 ft are expected again in the Tehuantepec area Wed night through Thu night as another cold front moves across the Gulf of Mexico. 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 extends from a 1010 mb low pressure over northern Colombia near 09N74W to 05N77W to 05N100W to 07N116W. The ITCZ continues from 07N116W to beyond 07N140W. Scattered moderate isolated strong convection is noted within about 60 nm N of the monsoon trough E of 81W. Scattered showers and isolated thunderstorms are also noted north of the monsoon trough between 89W to 103W. North of the ITCZ, scattered moderate convection is noted between 127W to 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A Gale Warning has been issued for the Tehuantepec region. Please, see the Special Features section for more details. A ridge dominates the offshore forecast waters of Baja California. The pressure gradient between the ridge and a meandering trough over the Gulf of Baja California supports fresh to strong NW-N winds N of 24N E of 121W, with seas 8 to 9 ft. These moderate to fresh northerly winds will persist over the next 24 hours. A new set of long period NW swell will reach the waters N of Punta Eugenia on Mon building seas to 8-12 ft. This swell event will propagate across the waters N of Cabo San Lazaro by Mon evening. Gulf of California: Building high pressure over the Great Basin region of U.S. will bring an increase in winds and seas across the Gulf of California today. Fresh to strong NW-N winds will spread across much of the Gulf from north to south, with seas building to 8 ft over the north waters this morning, and then over the central waters by this evening. In addition, fresh to locally strong winds will funnel through the Baja California passes into the offshore waters today. Wind and seas will diminish across the Gulf of California Mon morning. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Moderate to fresh NE-E winds will prevail in the Papagayo region over the next several days with seas of 5-7 ft today, then 4-6 ft middle of the week. These winds return with seas building back to 7 ft by the end of the week into next weekend. Gentle to moderate northerly winds are expected in the Gulf of Panama with similar sea heights. Elsewhere, gentle to moderate winds will prevail on either side of the monsoon trough. Seas of 5-8 ft in SW swell between Ecuador and the Galapagos Islands will gradually subside to 4-6 ft by Mon night. REMAINDER OF THE AREA... High pressure of 1025 mb located near 30N127W extends a ridge SE across the northern forecast waters to near the Revillagigedo Islands. The pressure gradient between the ridge and lower pressures in the vicinity of the ITCZ/Monsoon Trough is supporting a large area of fresh trade winds 09N to 25N W of 120W. Seas are in the 8-10 ft range based on altimeter data. The high pressure will strengthen some Mon night into Tue producing a large area of fresh to locally strong trades roughly from 10N to 20N W of 125W. A new set of long period NW swell is moving into the NW corner of the forecast area. This swell event will propagate SE, covering most of the area N of 10N W of 115W. Seas are forecast to build to 8-12 ft, with the highest seas N of 27N. Additional pulses of NW swell will reach 30N140W on Tue. $$ Torres