000 AXPZ20 KNHC 192119 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue Oct 19 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...TROPICAL WAVES... A tropical wave is along 93W north of 02N to near the western Guatemala and Mexico border, moving westward at around 10 kt. Associated convection is described below. A tropical wave extends along 129W from 02N to 15N, moving westward at around 10 kt. Associated convection is described below. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from 1009 mb low pressure near 11N75W to 1010 mb low pressure near 10N90W to 10N100W to 1012 mb low pressure near 12N111W to 10N128W to 12N140W. Scattered moderate and isolated strong convection is noted from 03N to 08N between 77W and 84W, from 10N to 15N between 97W and 102W, and from 07N to 11N between 125W and 133W. Scattered moderate convection is noted from 06N to 08N between 92W and 100W, from 07N to 11N between 112W and 122W, and from 10N to 14N between 138W and 104W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh to strong N-NE winds are over the Gulf of Tehuantepec where seas are also to 7 ft. Moderate NW-N winds are in the northern Gulf of California. Gentle to moderate NW-N winds prevail elsewhere across the Mexican Offshore waters. Seas are 4 to 6 ft across the majority of the remainder of the waters, except 2 to 4 ft in the Gulf of California. For the forecast, winds will continue to pulse to fresh to strong in the Gulf of Tehuantepec through the end of the week, with mainly gentle to moderate winds elsewhere. Winds will increase slightly to moderate to fresh offshore of Baja California this weekend. An area of disturbed weather located a few hundred nautical miles south of the coasts of Guatemala and El Salvador is producing poorly organized showers and thunderstorms. Environmental conditions are expected to be conducive for gradual development of this system during the next several days, and a tropical depression could form late this week or this weekend while the system moves west-northwestward to northwestward near or just off the coast of southern Mexico. Seas will build slightly in NW swell west of Baja California through mid-week. Another set of NW swell will impact the same area by the end of the week, with a much larger set arriving this weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... An area of disturbed weather located a few hundred nautical miles south of the coasts of Guatemala and El Salvador is producing poorly organized showers and thunderstorms. Moderate to locally fresh E winds are offshore of El Salvador and Guatemala, with light to gentle winds elsewhere north of the monsoon trough. Mainly moderate S-SW winds prevail south of the monsoon trough. Seas are mainly 4 to 6 ft in mainly southerly long period swell. For the forecast, environmental conditions are expected to be conducive for gradual development of the area of disturbed weather during the next several days, and a tropical depression could form late this week or this weekend while the system moves west-northwestward to northwestward near or just off the coast of southern Mexico and west of the area. Otherwise, little change is expected through the end of the week into the weekend. REMAINDER OF THE AREA... A cold front is located NW-N of the northern waters with fresh winds straddling 30N, stronger north of 30N. Associated NW swell of 8 ft or greater is just starting to propagate southeast of 30N140W. The remnants of a cold front are located to the east with residual seas to 8 ft in NW-N swell in the vicinity of 29N125W. A weak pressure pattern prevails elsewhere with light to gentle winds from 21N to 267N, and gentle to moderate winds south of 21N and north of the monsoon trough. Gentle to moderate southerly winds prevail south of the monsoon trough. Seas are mainly 5 to 7 ft across the open waters in a mix of long period northerly and southerly swell. For the forecast, northerly swell associated with a cold front that will move into the northern waters tonight will spread southeast, with seas in excess of 8 ft dominating the waters northwest of a line from Guadalupe Island to 14N140W by late Thu. Reinforcing NW swell will follow over the same area through Sat. Trades north of the monsoon trough to 25N may increase slightly by the end of the week into the weekend as the pressure gradient tightens. $$ Lewitsky