000 AXPZ20 KNHC 211600 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Tue Sep 21 2021 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...SPECIAL FEATURES... A Gale Warning has been issued for the Gulf of Tehuantepec Wed night into Thu. An early season cold front is expected to enter the NW Gulf of Mexico early Wed and reach from the NE Gulf to central Bay of Campeche by late Thu. High pressure building in the wake of the front across the eastern slopes of the Sierra Madre Mountains and the western Gulf of Mexico will support this gap wind event forecast to reach minimal gale force Wed night into Thu. Seas are forecast to build to 9-11 ft with this event. Please, refer to 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. ...TROPICAL WAVES... The axis of a tropical wave is along 106W and from 06N to 20N, moving west at 10 to 15 kt. Scattered moderate to isolated strong convection is noted from 08N to 12N between 100W and 109W. The axis of a tropical wave is along 116W from 06N to 20N, moving west at 10 to 15 kt. Scattered moderate to isolated strong convection is seen 09N to 17N between 111W and 121W. The axis of a tropical wave is along 129 from 05N to 17N, moving west at around 10 kt. Convection remains limited near the wave axis. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to 10N96W to 15N110W to 1011 mb low pressure located near 14N118W to 09N125W to another 1011 mb low pressure situated near 08N134W to 06N137W. The ITCZ continues from 06N137W to beyond 06N140W. Aside from the convection associated with the tropical waves, scattered moderate to strong convection is noted N of 04N E of 80W to the coast of Colombia, from 08N to 10N between 84W and 90W, and from 10N to 12N between 89W and 92W. Scattered moderate convection is from 08N to 10N between 97W and 100W, and from 07N to 10N W of 130W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge dominates the offshore forecast waters of Baja California producing mainly gentle to moderate NW-N winds. Seas are in the 5 to 7 ft N of Punta Eugenia and 3 to 5 ft elsewhere. Light to gentle winds are seen elsewhere offshore of SW Mexico with seas in the 3 to 5 ft range. Light to gentle SE-S winds prevail in the Gulf of California. Some shower activity is still noted over the southern Gulf of California. For the forecast, a ridge will continue to dominate the offshore waters of Baja California. A gap wind event is expected in the Gulf of Tehuantepec. Please, see the Special Features section for more details. In the Gulf of California, abundant moisture will persist across the central and southern parts of the Gulf tonight and Wed, with winds veering to the NW and N. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gentle to moderate southerly winds will prevail across the offshore waters of Costa Rica, Panama, Colombia and Ecuador during the forecast period, with seas of 4-6 ft in SW swell. Mainly light and variable winds are forecast across the offshore waters from Guatemala to northern Costa Rica, with seas of 3-5 ft also in SW swell. In the Papagayo region expect moderate to locally fresh NE-E winds today, then mainly gentle winds are expected. REMAINDER OF THE AREA... A broad area of low pressure located about 900 miles southwest of the southern tip of the Baja California peninsula is producing disorganized shower activity. Environmental conditions are forecast to be somewhat conducive for development, and a short-lived tropical cyclone could form in 2 or 3 days while the system moves generally northwestward at 10 to 15 mph. By the weekend, however, the system is forecast to move over cooler waters and into a more stable environment, which should inhibit further development. The latest Tropical Weather Outlook gives this system a low chance of tropical cyclone formation through 48 hours, and a medium change through 5 days. Please, refer to the latest Tropical Weather Outlook, at www.hurricanes.gov for more details. The northern forecast waters are under the influence of a ridge anchored by a 1024 mb high pressure located near 36N135W. The pressure gradient between the ridge and lower pressures near the monsoon trough/ITCZ supports moderate to locally fresh trades between 10N-20N W of 120W, with seas of 5-7 ft. $$ GR