000 AXPZ20 KNHC 301528 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Thu Sep 30 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...TROPICAL WAVES... A tropical wave extends its axis along 89W and N of 05N, moving slowly west at 5 to 10 kt. Scattered moderate convection is noted S of 10N between 87W-92W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to 1010 mb low pres near 09N92W to 09N96W to 1007 mb low pres near 17N106W to 1008 mb low pres near 13N131W to 12N140W. Scattered moderate convection is observed from 05N to 13N and E of 99W, from 16N to 20N between 102W and 108W, and from 09N to 16N and W of 110W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A broad area of low pressure is located a couple of hundred miles south-southwest of Manzanillo, Mexico, continues to produce disorganized showers and thunderstorms. Associated winds are mainly gentle to moderate, and nearby seas are 5 to 6 ft. Moderate NW winds are noted offshore of Baja California, while mainly gentle to moderate winds prevail elsewhere offshore of Mexico. NW swell is supporting seas of 7 to 10 ft west of Baja California, with the highest seas north of Punta Eugenia. Seas are mainly 4 to 6 ft elsewhere in mixed long period swell, except 3 ft or less in the Gulf of California north of the entrance area. For the forecast, any development of the broad area of low pressure during the next day or two should be slow to occur while it moves toward the west-northwest at 5 to 10 kt and reaches an area of stronger upper-level winds by Fri. Moderate NW-N winds offshore of Baja California will diminish by the end of the week. Moderate to fresh gap winds may develop in the Gulf of Tehuantepec this weekend, increasing to fresh to strong Sun night. Otherwise, light to gentle winds will prevail. Large NW swell propagating southeast and offshore of Baja California will subside by the end of the week. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Light to gentle E-SE winds are noted north of the monsoon trough, with moderate S-SW winds south of the monsoon trough. Seas are mainly in the 4 to 6 ft range in mixed long period mixed swell. For the forecast, winds in the Papagayo region will occasionally pulse to moderate at nighttime. Otherwise, light to gentle winds will prevail north of the monsoon trough, with mainly moderate S-SW winds south of the monsoon trough. A moderate cross- equatorial SW swell will propagate through the regional waters during the next several days. REMAINDER OF THE AREA... High pressure prevails across the remainder of the basin. A set of NW-N swell supports seas of 8 to 12 ft north of 22N, while an area of 7 to 8 ft in fresh trades mixed with the swell is from 13N to 22N west of 124W. Seas are mainly 5 to 7 ft across the remainder of the open waters. Mainly moderate to locally fresh trades prevail elsewhere north of the convergence zone, with moderate southerly flow south of the monsoon trough. For the forecast, the NW-N swell will continue to propagate through the northern and central waters through later today while gradually decaying. Reinforcing fresh northerly swell will pump seas back up to around 8 ft near 30N between 125W and 135W into the weekend. Trades are forecast to diminish this weekend into early next week as the pressure gradient loosens. $$ ERA