000 AXPZ20 KNHC 141556 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Wed Sep 14 2022 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... Showers and thunderstorms associated with a low pressure system located near 16N109W or a few hundred miles southwest of Manzanillo, Mexico, continue to show signs of organization. The chances for this low to merge with another area of disturbed weather to its east-southeast appear to be decreasing, and the system is likely to become a tropical depression during the next day or two while meandering southwest of the southwestern coast of Mexico. The latest Tropical Weather Outlook gives this system a high chance of tropical cyclone formation through 48 hours. Currently, satellite pictures show a cluster of moderate to isolated strong convection on the W side of the low center from 14N to 16N between 108W and 110W. Scattered moderate to isolated strong convection is also noted from 14N to 16N between 110W and 113W. Refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from northern Costa Rica near 10N84W to a 1008 mb low near located near 16N109W to a 1010 mb low pressure situated near 13N132W beyond 11N140W. Scattered moderate to isolated strong convection is noted from 05N to 07N between 78W and 82W, from 10N to 15N between 92W AND 100W. Similar convection is from 14N to 17N between 100W and 103W, and from 12N to 14N between 130W and 135W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Mainly gentle NW winds prevail across the offshore waters of Baja California with seas of 4-6 ft based on altimeter data. Moderate to locally fresh southerly winds are likely occurring in the northern Gulf of California with seas of 3-5 ft. Light to gentle variable winds prevail across most of the SW Mexico offshore waters with 6-7 ft seas in S to SW swell. Scattered showers and thunderstorms are observed across most the SW Mexican offshore waters, particularly E of Manzanillo. For the forecast, winds across the Baja California offshore waters will increase moderate to fresh later today and into tonight as high pressure builds across the area. Showers and thunderstorms associated with a low pressure system located near 16N109W or a few hundred miles southwest of Manzanillo, Mexico, continue to show signs of organization. Please, see the Special Features section for more details. A large area of disorganized showers and thunderstorms a couple of hundred miles off the coast of southern Mexico is associated with a trough of low pressure. Environmental conditions would be conducive for development if the system remains offshore, and a tropical depression could form while moving little off the southern coast of Mexico during the next couple of days, and then moving west-northwestward near the coast of southern and southwestern Mexico over the weekend. The latest Tropical Weather Outlook gives this system a low chance of tropical cyclone formation through 48 hours. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate SW to W winds are noted across the Central American and Colombia offshore waters north of the monsoon trough. South of the monsoon trough, winds are moderate to locally fresh. Seas are 5-7 ft in SW to S swell across the Central American and Colombia offshores. Seas are 6-8 ft across the Ecuador and Galapagos Islands offshore waters due to a cross- equatorial southerly swell. A cluster of moderate to isolated strong convection is near the Azuero peninsula. A moist and unstable environment interacting with the monsoon trough persists across the area . For the forecast, winds across the Central American offshore waters will increase to fresh later today and into tonight as a broad low pressure south of southwestern Mexico organizes over the next few days. Winds over the Galapagos Islands and Ecuador offshore waters will diminish to gentle to moderate today and continue into the weekend. The cross-equatorial swell across the Ecuador and Galapagos Islands offshore waters will slowly subside by Thu night. A very moist and unstable atmospheric environment will help maintain active weather across most of the offshore waters over the next few days. REMAINDER OF THE AREA... a 1018 mb high pressure dominates the waters north of the monsoon trough and west of 120W. The related light pressure gradient is allowing for mostly gentle to moderate trade winds north of the monsoon trough and west of 120W, with seas ranging 5-6 ft. Moderate to fresh southerly winds are south of the monsoon trough. Cross- equatorial southerly swell continues to linger across the southern waters S of 01S. For the forecast, the weak high pressure will lead to gentle to moderate winds north of the monsoon trough through Thu, with winds becoming moderate to fresh by Thu night through Sat. This will cause seas to build to near 8 ft. Moderate to fresh southwest winds and associated wave heights of 8-9 ft in southerly swell will continue south of the monsoon trough over the next few days. These winds will likely increase to strong speeds east of 110W later in the week as tropical cyclone genesis takes place offshore the southwestern coast of Mexico. Wave heights could build to near 12 ft near the strongest winds. The long-period cross-equatorial swell will continue through the rest of the week, with the 8 ft seas subsiding by the weekend. $$ GR