000 AXPZ20 KNHC 072008 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Thu Jan 7 2021 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 1800 UTC surface analysis and satellite imagery through 2000 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure building into southern Mexico behind a cold front in the central Gulf of Mexico is inducing strong northerly gap winds this afternoon, which will reach gale-force tonight, then continue through early Sat. Seas downwind of the Gulf of Tehuantepec will rapidly increase to greater than 10 ft by early Fri, then remain 10-13 ft through Sat. Winds and seas will diminish Sat night and Sun as the cold front moves east and the pressure gradient across southern Mexico weakens. Looking ahead, another gale-force event is possible early next week. Please read the latest NWS High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 1011 mb low pressure over northern Colombia near 10N74W to 05N80W to 1012 mb low pressure near 07N89W to 07N112W. The ITCZ continues from 07N112W to 06N122W, then resumes near 06N125W to 06N140W. Clusters of scattered moderate and isolated strong convection are noted from 05N to 16N between 101W and 108W. Scattered moderate convection is noted from 04N to 08N between 86W and 90W, from 08N to 10N between 117W and 120W, from 06N to 09N between 121W and 124W, and from 05N to 08N between 129W and 134W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... See Special Features for details on a Gale Warning in the Gulf of Tehuantepec, as well as Gale Conditions Possible early next week. Moderate to fresh NW to N winds are expected across the offshore waters of Baja California and north of Cabo San Lazaro over the next several days as a ridge remains in place. Large NW swell, with seas in the 8-15 ft range, dominates the waters west of Baja California. Episodes of large NW swell will continue to propagate across the same region through early next week. Gulf of California: Gentle to moderate NW to N winds are expected across the Gulf of California through Sat. Winds are forecast to increase Sat night and Sun as high pressure settles over the Great Basin region of the United States. Winds in the northern Gulf are expected to become fresh to strong Sat night and Sun, then moderate to fresh through early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... NE to E winds in the Gulf of Papagayo region will increase Fri through early next week. Elsewhere, light to gentle winds will prevail north of the monsoon trough, except near the Gulf of Panama where northerly winds will pulse to moderate through early Sun. Gentle to moderate S to SW winds are expected south of the trough axis through Mon. Long period NW swell will continue to spread across offshore waters, with seas less than 8 ft. Large seas generated by gale- force winds in the Tehuantepec region will reach the offshore waters of Guatemala and El Salvador Fri and Sat, and then again early next week. REMAINDER OF THE AREA... Broad high pressure prevails across the waters north of 10N west of 110W. The gradient between this area of high pressure and lower pressures in the vicinity of the ITCZ is supporting moderate to fresh trade winds north of the ITCZ to 20N west of 120W, locally to strong near 09N137W. Seas are in the 8-11 ft range in a mix of primary NW swell and E-NE wind waves per recent altimeter passes. These marine conditions will persist during the next 48-72 hours. Long period NW swell continues to propagate across most of the forecast waters north of the equator and west of 100W, with sea heights of 8-11 ft south of 20N, and larger swell of 11-14 ft north of 20N. Another set of large long period NW swell is beginning to spread southeast of 30N140W, with seas expected to build to 16-18 ft tonight into early Fri. A similar set of NW swell is possible by Sat night, with even larger sea heights possible into early next week. $$ Lewitsky