000 AXPZ20 KNHC 161525 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Fri Oct 16 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: Strong N to NE winds are ongoing in the Gulf of Tehuantepec this morning, as NE winds increase across the SW Gulf of Mexico ahead of a cold front. Winds across Tehuantepec will increase to gale force this evening through Sat night, then diminish to fresh to strong through early next week. Seas should peak with this gale event at near 15 ft Sat morning and remain at 8 ft or higher through at least Tue. ...TROPICAL WAVES... A tropical wave axis is near 99W from 02N to 16N, moving W at 10-15 kt. Associated convection is described below. A tropical wave axis is near 119W from 01N to 17N, moving W at 10-15 kt. Associated convection is described below. A tropical wave axis is near 129W from 03N to 19N, moving W at 10-15 kt. Associated convection is described below. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from near 10N85W to 09N110W to 1008 mb low pressure near 12N130W to 11N130W. The ITCZ axis extends from 10.5N133W to 11N140W. Scattered moderate isolated strong convection is noted from 06N to 09N between 89W and 91W, from 11N to 12N between 130W and 132W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section for more details on the developing Gale Warning in the Gulf of Tehuantepec. Recent scatterometer satellite data and ship observations indicated moderate to fresh NW winds off mainly the coast of Baja California Sur this morning. These winds are on the periphery of a 1015 mb surface high pressure centered well west of Baja California near 28N122W. Moderate to locally fresh NW flow is indicated off Cabo Corrientes as well, but this has diminished a bit from yesterday. Farther south, thunderstorms are active in the Gulf of Tehuantepec, likely due in part to convergence of gap winds pushing into the Gulf. Looking ahead to early next week, pressure will lower slightly over the southwest US, enough to allow increased NW winds off Baja California Norte by late Mon. Little change is expected elsewhere. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Light to gentle winds will prevail north of the monsoon trough, except for moderate to fresh NE to E winds in the Papagayo region tonight and Sat night. Moderate S to SW winds are expected south of the monsoon trough for the next couple of days becoming fresh Sun through Tue. Mainly moderate long-period S swell will prevail across the waters through the weekend, and maintain seas of 5-7 ft. Seas will build in southerly swell Sun night through Tue. Scattered showers and thunderstorms will be common in the Central American zones due to the proximity of the monsoon trough for at least the next couple of days as is described above. REMAINDER OF THE AREA... A moderate pressure gradient prevails between high pressure well north of the area and low pressure along the ITCZ, supporting generally moderate to fresh E trades west of 125W. Farther east, a surface trough along roughly 127W from 20N to 25N is breaking up the ridging enough to maintain gentle to moderate winds farther south. Northerly swell is moving across the northern waters north of 25N and west of 120W, producing seas of 6-8 ft. These conditions will shift gradually westward into the weekend. Seas of 5 to 8 ft in S swell dominates the remainder of the waters. $$ Christensen