000 AXPZ20 KNHC 201604 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Wed Oct 20 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 is along 94W north of 04N, moving westward at around 10 kt. A 1010 mb low pressure is along the wave axis near 11N94W. Scattered moderate to isolated strong convection is noted from 10N to 16N between 90W AND 100W. A tropical wave is along 131W from 04N to 16N, moving westward at around 10 kt. Scattered moderate to isolated strong convection is from 08N to 11N between 123W and 131W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from northern Costa Rica near 10N84W to 11N94W to 09N103W to 12N112W to 09N125W to 12N134W to 12N140W. Aside from the convection associated with the tropical waves mentioned above, scattered moderate to isolated strong convection can be found N of 06 between 78W and 84W, from 07N to 10N between 100W and 108W, from 09N to 11N between 112W and 114W, and from 09N to 12N W of 134W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure of 1019 mb extends a ridge across the Baja California peninsula producing gentle to moderate NW to N winds. Fresh to strong northerly winds area noted within about 15 nm of a line from 16N95W to 15N95.5W to 13.5N97W, including the Gulf of Tehuantepec. Seas in this area are below 8 ft. Gentle to moderate winds prevail in the Gulf of California. For the forecast, a broad area of disturbed weather is producing some disorganized showers and thunderstorms within a couple of hundred miles of the coasts of southern Mexico, Guatemala, and El Salvador. At 1200 UTC, a tropical wave and a low pressure of 1010 mb is analyzed in this area. Environmental conditions are expected to be conducive for gradual development of this system during the next few days, and a tropical depression is likely to form by late this week or this weekend while the system moves slowly west-northwestward to northwestward near or just offshore the coast of southern Mexico. This system could bring an increase in winds and seas in the Tehuantepec region toward the end of the week. Otherwise, moderate to fresh NW-N winds are expected N of Punta Eugenia Fri through Sun night. Seas are forecast to build to 10 or 11 ft in NW swell. In the Gulf of California, mainly gentle to moderate NW winds will prevail. Winds will veer to the S and then SW in the northern part of the Gulf by Fri night as a weakening cold front approaches from the W. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... As previously mentioned, a broad area of disturbed weather is producing some disorganized showers and thunderstorms within a couple of hundred miles of the coasts of southern Mexico, Guatemala, and El Salvador. This system has a low chance of tropical cyclone formation through 48 hours, and high chance through 5 days. Please, see the latest Tropical Weather Outlook at www.hurricanes.gov Mainly gentle to moderate S to SW are expected across the forecast area with seas of 3 to 5 ft in SW swell. By Sat night into Sun, expect building seas of 6-7 ft in SW swell between Ecuador and the Galapagos Islands. REMAINDER OF THE AREA... A cold front has reaches 30N140W. Seas of 8-11 ft in NW swell follow the front forecast to dissipate by Thu. A reinforcing cold front will move across the NW forecast waters Thu trough Fri while gradually weakening. Seas of 12-14 ft are expected in the wake of the front forecast to reach from 30N126W to 26N140W by Fri evening. Seas in excess of 8 ft will dominate the waters NW of a line from Punta Eugenia to 10N140W on Sat. $$ GR