000 AXPZ20 KNHC 171534 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Sat Oct 17 2020 Tropical Weather Discussion for the eastern Pacific Ocean from the Equator to 32N, east of 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. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure building across the Gulf of Mexico north of the region has forced strong northerly gap winds across the Gulf of Tehuantepec since late Fri afternoon. These winds have since increased to gale force from the coast to about 15N. These gale force winds are expected to persist into Sat night. Seas downstream are 12 to 14 feet. Strong gap winds will continue to pulse through the Gulf of Tehuantepec with seas to 8 ft Sun night through the early part of the week. ...TROPICAL WAVES... A tropical wave axis extends along 106W from 03N to 17N, moving W at 15 kt. Scattered moderate convection is noted from 04N to 12N between 100W and 110W. A tropical wave axis is near 136W from 04N to 18N, moving W at 10 to 15 kt. Associated 1009 mb low pressure is near 13N134W. Scattered moderate to isolated strong convection is observed from 07N to 15N between 125W and 137W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from near 10N77W to 11N98W to 1009 mb low pressure near 13N134W. The ITCZ axis extends from 13N134W to beyond 10N140W. Scattered moderate convection is noted from 03N to 10N E of 81W, from 06N to 14N between 91W and 100W, and from 06N to 12N between 110W and 122W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for more details on the Gale Warning in the Gulf of Tehuantepec. 1015 mb high pressure is centered west of Baja California near 25N122W. The pressure gradient between the high pressure and lower pressure over the Sonoran desert is supporting moderate to fresh NW winds across the offshore waters of northern and central Baja California. Farther south, with exception of the Gulf of Tehuantepec, gentle to moderate breezes persist. Seas are generally in the 4 to 6 ft range. High pressure west of Baja California is supporting moderate to occasionally fresh NW winds off the Baja California coast and over the central Gulf of California. These winds will diminish through tonight, but winds and seas will increase off Baja California Norte by early next week as high pressure strengthens and low pressure deepens over the southwest U.S. Mostly gentle to moderate breezes and slight seas will persist elsewhere. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Gentle to moderate easterly trade winds are noted north of the monsoon trough and west of 90W, with moderate to fresh SW winds farther south from Ecuador to Costa Rica. Seas are 5 to 7 ft primarily in SW swell. The pressure gradient is subtly tightening across the southwest Caribbean, southern Central America and the tropical eastern Pacific as high pressure builds north of the area. This is supporting moderate to fresh gap winds through the Gulf of Papagayo and off southern Nicaragua. Meanwhile, SW winds will increase slightly off Panama as pressure lowers over the southwest Caribbean. These increased winds will coincide with the arrival of new longer period SW swell into the waters off Central America, allowing combined seas to reach 8 ft south of Panama by Mon. REMAINDER OF THE AREA... The pressure pattern remains fairly amplified north of 20N, with a mid/upper low centered near 28N127W and a mid/upper anticyclone centered farther west of northern Mexico. This pattern is supporting the 1015 mb surface high near 25N122W and a surface trough farther west along 127W/129W from 20N to 27N. Farther south, a tropical wave along 132W has temporarily come into phase with the southern portion of the surface trough. Recent scatterometer data indicated a surface low persists where the tropical wave intersects the monsoon trough near 13N132W. Active weather is occurring within 240 nm southeast through southwest of this low pressure. The low is moving west with the tropical wave, and will gradually open into a trough by Mon as it moves to the WNW, following behind the surface trough to it's north. However, the dry and subsident northerly deep layer flow over the region west of 130W is unfavorable for much further development at this time. High pressure will build north of 20N in the wake of the troughs, supporting fresh trade winds early next week from roughly 15N to 25N mainly west of 125W. Farther east, seas will reach 8 ft Sat into Mon near the monsoon trough east of 110W, due in part to fresh northerly swell emerging out of the Gulf of Tehuantepec and new longer period SW swell moving into the area. $$ KONARIK