000 AXPZ20 KNHC 130930 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue Sep 13 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from the coast of Costa Rica/Nicaragua near 11N86W to 14N98W to a 1008 mb low near 15N108W to 11N120W to 13N130W to beyond 09N140W. Scattered moderate to isolated strong convection is noted from 05N to 16N between 80W and 110W. Scattered moderate convection is noted from 06N to 14N between 110W and 133W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Light to gentle variable winds are noted across the offshore waters of Baja California and in the Gulf of California. Moderate winds are occurring near the Baja California coastline. Seas range 4-6 ft off of Baja California and 1-3 ft in the Gulf. Meanwhile, fresh to locally strong northerly winds are occurring across the Gulf of Tehuantepec, with seas 5-6 ft. Gentle to moderate winds prevail across most of the southern Mexico offshore waters with seas 5-7 ft. A 1008 mb low is analyzed just outside the Jalisco offshore waters near 15N108W. This low is bringing fresh SW winds in the Guerrero offshore waters, S of 14N with seas to 8 ft. Scattered showers and thunderstorms are observed across most the southwest Mexican offshore waters. For the forecast, winds across the Baja California offshore waters will increase moderate to fresh later on Wed and into Thu as high pressure builds across the area. Winds will become light to gentle across the Gulf of Tehuantepec later today. A trough of low pressure located along the coast of southern Mexico continues to produce general disorganized shower activity. This system is forecast to interact and merge with the disturbance off the southwestern coast of Mexico around midweek, and environmental conditions are expected to become more conducive for development by that time. A tropical depression is likely to form during the latter part of this week while the system moves slowly westward near the coast of southern and southwestern Mexico. Expect increasing winds and building seas offshore southern Mexico late in the week. This system has a low chance of formation in the next 48 hours and high chance in the next 5 days. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light to gentle winds are noted across the Central American offshore waters, with moderate SW winds noted S of 08N. Seas range 5-7 ft in S to SW swell. Gentle to moderate winds are noted off the Colombia offshores waters. Moderate to fresh southerly winds are noted across the offshores waters of Ecuador and the Galapagos Islands. Cross- equatorial long- period south to southwest swell continues to propagate through the South American forecast waters, with 5-7 ft seas across most of these waters. Wave heights up to 8 ft are noted in the Galapagos Islands and Ecuador offshore waters. A moist and unstable environment is leading to scattered showers and thunderstorms across the majority of the Central American offshore waters and off the Colombia coast. For the forecast, winds across the Central American offshore waters will increase to fresh later in the week as broad low pressure south of southwestern Mexico organizes. Winds over the Galapagos Islands and Ecuador offshore waters will diminish to gentle to moderate by Wed and continue through the rest of the week. The cross-equatorial swell across the Ecuador and Galapagos Islands offshore waters will linger in the area today and 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... Relatively weak high pressure remains over the area north of the monsoon trough and west of 125W. The related light pressure gradient is allowing for gentle to moderate trade winds north of the monsoon trough and west of 105W, with seas ranging 6-7 ft. Moderate to fresh southerly winds are south of the monsoon trough. Wave heights of 7-9 ft in long- period south to southwest swell are noted S of 14N between 103W and 125W. An area of wave heights to 8 ft is also over the far western part of the area from 11N to 15N and W of 130W due to persistent fresh northeast wind in that area. Cross- equatorial swell is also lingering across the southern forecast waters, S of 03N with seas 8-9 ft. Meanwhile, the remnant low tropical cyclone Kay is west of the Baja California Norte offshore waters near 27N121W, with a central pressure of 1013 mb. ASCAT data pass overnight showed gentle to moderate winds near the low center. Wave heights of 6-7 ft are in the general area of the low. For the forecast, the remnant low of Kay will weaken to a trough today. The weak high pressure is expected to continue over the next few days, with gentle to moderate winds north of the monsoon trough. Moderate to fresh southwest winds and associated wave heights of 8-9 ft in southerly swell will continue south of the monsoon trough through 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 12 ft near the strongest winds. The long- period cross- equatorial swell will continue through most of the week, with 8 ft seas subsiding toward the end of the week. The area of wave heights to 8 ft over the far western waters will subside by early this morning. $$ AReinhart