Eastern Pacific Tropical Weather Discussion
059 AXPZ20 KNHC 192058 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Sat Sep 19 2026 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 2045 UTC. ...SPECIAL FEATURES... Gale warning (EP99): Persistent but disorganized shower and thunderstorm activity is associated with a broad area of low pressure well south-southwest of the southwestern coast of Mexico. Environmental conditions are conducive for development, and a tropical depression is expected to form over the next couple of days as the system moves generally northward off the coast of southwestern Mexico. There is a high chance of tropical cyclone formation in the next 48 hours. Regardless of development, this system is forecast to bring increasing winds and seas over the offshore waters from Guerrero to Jalisco tonight through Thu night. In anticipation of tropical cyclone development, a gale warning has been issued for these areas. Western East Pacific (EP98): A broad area of low pressure located well southwest of the southern tip of the Baja California Peninsula continues to produce disorganized showers and thunderstorms. Environmental conditions are conducive for development, and a tropical depression is expected to form over the next several days as it moves westward to west-northwestward at 10 to 15 mph across the western East Pacific.There is a high chance of tropical cyclone formation in the next 48 hours. Please refer to the latest NHC Tropical Weather Outlook at website: www.hurricanes.gov for more details on these Invests. ...TROPICAL WAVES... A tropical wave moving across the western Caribbean Sea with axis near 82/83W extends southward across Panama and its offshore waters. It is moving westward near 10 to 15 kt. Nearby convection is discussed in the ITCZ/monsoon trough section below. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 12N105W to 10N127W to 16N140W. Scattered moderate and isolated strong convection is noted N of 03N and east of 107W, and from 05N to 12N between 120W and 128W. Scattered moderate convection is noted from 08N to 18N between 130W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see SPECIAL FEATURES above for more on a gale warning associated with EP99, which has a high chance for TC development in the next 48 hours. Moderate to fresh winds, and moderate seas, prevail over the Gulf of Tehuantepec, as well as west of the Baja California peninsula. Light to gentle winds, and slight seas, are in the Gulf of California. Elsewhere, light to gentle winds, and moderate seas, prevail. For the forecast, aside from conditions associated with Invest EP99, moderate to locally fresh NW winds will prevail across the offshore Baja California waters. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate winds are across the Gulf of Papagayo extending downstream to near 87W. Moderate or weaker winds prevail elsewhere. Moderate seas prevail over the offshore waters in long- period southwest swell. For the forecast, moderate to fresh NE to E winds will pulse in the Papagayo region through early Sun before diminishing. Gentle to moderate winds and moderate seas will prevail elsewhere. ...REMAINDER OF THE AREA... Please see SPECIAL FEATURES above for more in EP98, with a high chance for TC development in the next 48 hours. The remnant low of former Tropical Depression Fifteen-E has shifted west of the area. A second area of low pressure, EP98, is centered near 11N122.5W. Both of these features are embedded within the monsoon trough. The pressure gradient between these features and a 1025 mb high centered N of the area near 33N137W is supporting moderate to fresh, locally strong, winds N of the monsoon trough to near 23N and W of 120W. Moderate to rough seas cover these waters. Elsewhere, moderate winds and moderate seas are N of the monsoon trough. Fresh to strong southerly winds are feeding into EP99, where rough seas prevail. Elsewhere S of the monsoon trough, light to gentle winds, and moderate seas, prevail. For the forecast, outside of conditions with EP98 and EP99, gentle to moderate winds and moderate seas will prevail.