000 AXPZ20 KNHC 120845 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sun Sep 12 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 0600 UTC surface analysis and satellite imagery through 0840 UTC. ...SPECIAL FEATURES... A broad area of low pressure offshore of southern Mexico is producing a large area of disorganized showers and thunderstorms. Further development of this system is possible during the next couple of days as long as it remains over water, and a tropical depression could form tomorrow or early Monday while the system moves northwestward toward the southern and southwestern coasts of Mexico. Further development is not expected by midweek due to interaction with land. Regardless of development, this system will likely produce heavy rains across portions of southern Mexico during the next couple of days. There is a medium chance for tropical cyclogenesis within the next 48 hours. Please see the latest eastern north Pacific Tropical Weather Outlook for more information. ...TROPICAL WAVES... The axis of a tropical wave is near 83W north of 02N, moving west at 10-15 kt. Scattered moderate to isolated strong convection is noted from 04N to 14N between 83W and 90W. The axis of a tropical wave is near 96W, moving west at 10 kt. Scattered moderate to isolated strong convection is noted from 06N to 15N between 90W and 100W. Low pressure along the tropical wave will be monitored for the potential for tropical cyclogenesis. Please see Special Features section above for more information. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 11N86W to 15N95W to 08N132W. Aside from convection noted in the tropical waves section above, scattered moderate isolated strong convection is noted from 06N to 12N between 100W and 110W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for details on the developing area of low pressure with the potential for developing into a tropical cyclone. The remnant low of Olaf is centered near 24N116W. Moderate to locally fresh winds are over the western semicircle of the remnant low. Seas continue in the 7-8 ft range. Farther east, fresh to strong, locally near gale force, gap winds are funneling through the Gulf of Tehuantepec in response to developing low pressure, which is discussed in the special features section above. Elsewhere, gentle to moderate winds prevail. Seas are in the 7-9 ft range over the waters off southern Mexico in SW swell. Elsewhere, over the open waters, seas are in the 5-6 ft range. Over the Gulf of California, seas are in the 1-3 ft range. For the forecast, Seas to 8 ft will persist off Baja California into early next week as different groups of NW and S swell move into the region. Farther to the southeast, a broad area of low pressure is centered offshore of southern Mexico. Some gradual development of this system is possible during the next couple of days as long as it remains over water, and a tropical depression could form tomorrow or early Monday while the system moves northwestward toward the southern and southwestern coasts of Mexico. Regardless of development, large southwest swell will build seas off southern Mexico through early next week. Coastal areas in southern Mexico from Chiapas to Guerrero may see hazard surf and heavy rainfall Sat through early next week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Fresh SW winds prevail over the offshore waters of Guatemala and El Salvador. Seas are in the 6 to 9 ft range off Guatemala and El Salvador in SW swell. Farther south, gentle to moderate southerly winds persist off Colombia and Ecuador, with seas of 6 to 8 ft in SW swell. For the forecast, large SW swell will impact region into early next week, along with moderate winds. REMAINDER OF THE AREA... A large area of moderate to fresh S to SW winds prevail south of 10N and east of 115W. Seas to 8 ft prevail over much of the tropical waters east of 120W, partly due the local wind flow, but also due in part to a larger area of cross- equatorial SW swell. Mainly gentle to moderate winds persist west of 120W, with seas to 8 ft in southerly swell reaching as far west as 130W south of 08N and 5 to 7 ft seas elsewhere. Southwest swell will continue to propagate through the waters east of 130W through the upcoming weekend, with seas ranging between 8-11 ft through early next week. $$ AL