000 AXPZ20 KNHC 021557 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Mon Oct 2 2023 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 1540 UTC. ...SPECIAL FEATURES... South of Southwestern Mexico (EP98): Showers and thunderstorms associated with a 1007 mb low pressure along a tropical wave near 11N104.5W continue to show signs of organization. Scattered moderate isolated strong convection is noted from 06N to 17N between 100W and 109W. Winds of 20 to 25 kt and seas to 7 ft are likely currently occurring with this area of low pressure. Additional development is expected, and a tropical depression will likely form later today. The system is forecast to move west-northwestward today, then meander northwestward to north- northwestward through the end of the week. The system has a high chance of tropical cyclone formation within the next 48 hours. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for the latest on this system. ...TROPICAL WAVES... Please refer to the Special Features section above for information on a tropical wave along 104W/105W (EP98). ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N86W to 1007 mb low pressure near 11N104.5W to 1008 mb low pres near 12N124W to 11.5N140W. Scattered moderate isolated strong convection is noted from 03N to 16N between 77W and 100W, from 05.5N to 09N between 110W and 122W, and from 08N to 12N between 133W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Refer to the section above for details on a developing area of 1007 mb low pressure near 11N104.5W. A weakening cold front extends across the central Gulf of California near 28N111.5W across Baja California near 27N112.5W to 25N115.5W. Surface ridging prevails elsewhere across the offshore waters of Mexico. Winds across the northern Gulf of California are starting to diminish, and are now likely moderate to locally fresh from the NW. Fresh N-NE winds are in the Gulf of Tehuantepec. Winds are mainly moderate or weaker elsewhere, except moderate to locally fresh nearshore Baja California from Punta Eugenia southward. Seas are 6-9 ft west of Baja California in NW swell, and 3-5 ft in the Gulf of California. Seas are 6-7 ft elsewhere in primarily southerly swell. For the forecast, the area of low pressure near 11N104.5W is expected to develop into a tropical cyclone within the next 48 hours, and it could be a couple hundred nm offshore Colima and Jalisco late this week. Elsewhere, moderate seas will not vary much into the middle of the week. Moderate to fresh N winds will pulse in the immediate area of the Gulf of Tehuantepec, mainly at night. Moderate to fresh winds will pulse nearshore Baja California from near Punta Eugenia southward today into Tue. Winds will be moderate or weaker elsewhere through the week. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Winds are moderate or weaker across the offshore waters. Seas are 5-7 ft in S swell. Scattered moderate to strong convection is occurring offshore of Colombia, Panama and Costa Rica. For the forecast, winds will be moderate or weaker across the offshore waters through most of the week, except moderate to fresh from the Equator to 06N this afternoon through Tue, then from 04N to 10N from Tue night through Wed morning. Seas will not vary much through Mon night, then will build slightly where the moderate to fresh winds are. New long-period southerly swell will build seas slightly offshore Ecuador to the Galapagos Islands by mid-week. Looking ahead, an area of low pressure is expected to form a few hundred nm south of the coast of Central America during the second half of this week. Environmental conditions are forecast to be favorable for gradual development of the low after it forms, and a tropical depression could develop late this week or over the weekend while the disturbance moves generally westward to west-northwestward at around 10 kt. ...REMAINDER OF THE AREA... Refer to the section above for details on a developing area of 1009 mb low pressure near 11N104.5W. The weakening cold front extending westward across the northern waters has dissipated. However, moderate to locally fresh NE winds and 7-10 ft seas still prevail north of 23N and west of 122W. A weak 1008 mb low pressure is embedded in the monsoon trough near 12N124W with moderate winds in the NW semicircle. Seas are around 8 ft in that area. Winds are moderate or weaker elsewhere. Seas are 7-10 ft in SE swell S of 10N and W of 95W, and 6-8 ft across the remainder of the open waters in mixed swell. For the forecast, other than the potential for tropical cyclone formation with the developing area of low pressure near 11N104.5W, seas north of 22N will slowly subside Tue into Tue night. The low pressure area embedded in the ITCZ near 12.5N123.5W is forecast to continue to produce moderate to fresh winds and seas to 8 ft on the NW side before weakening mid-week. Winds of moderate or weaker will prevail across the remainder of the open waters through the next several days. Meanwhile, southerly swell of 7-9 ft will wax and wane through the week from around 05N southward. $$ Hagen