000 AXPZ20 KNHC 290839 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 839 UTC Sat Feb 29 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 0600 UTC surface analysis and satellite imagery through 0900 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure extending from the western Gulf of Mexico southward across eastern Mexico is supporting a strong pressure gradient across the isthmus of Tehuantepec. A scatterometer pass from 03 UTC indicated northerly gale force winds across the area, which are forecast to continue through tonight. Seas across this area will peak around 18-21 ft, then subside by the end of the weekend as the gale force winds diminish. Looking ahead, another gale force gap wind event is possible Wed night. Gulf of Papagayo Gale Warning: A strong pressure gradient across Central America and the western Caribbean is supporting near gale force winds across the Papagayo region as noted by an earlier scatterometer pass. Winds are forecast to increase to minimal gale force today, then continue into early Sun before diminishing Sun afternoon. Seas will build as high as 14 ft downstream by tonight. Winds will remain strong through early next week, approaching near gale each night. Pacific High Seas Gale Warning: A broad mid to upper-level trough W of 140W reaches from an upper low near 24N147W through the Hawaiian Islands. Divergence aloft on the southeast side of the upper trough is inducing a pair of surface troughs along 135W from 05N to 25N. Scattered showers and a few thunderstorms are active from 08N to 14N between 135W and 140W. The enhanced pressure gradient between the troughs and very strong high pressure building northwest of the region is supporting fresh to near gale force winds which are forecast to strengthen to minimal gale force by late this afternoon. These winds will continue into early Sun before shifting west of 140W along with the surface troughing. Associated seas will build to 12-17 ft within the strongest winds. Please read the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03/HSFEP2 NHC or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The ITCZ extends from 07N85W to 03N95W to 08N135W. Scattered moderate to isolated strong convection is noted from 08N to 14N between 135W and 140W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for more details about a gale warning in the Gulf of Tehuantepec region. Gentle to moderate winds prevail across the Baja California offshore waters with a weak pressure pattern in place across the region. The pattern will start to change later today as a sharp mid to upper level trough approaches the area from the north. An associated surface low will form over the southwest United States, along with a weak cold front moving into Baja California Norte and the northern Gulf of California. Fresh to strong SW to W gap winds will develop over the northern Gulf of California starting tonight, reaching near gale force by late Sun with seas to 7 ft. The upper trough will shift eastward through early next week, allowing the front to weaken and stall over the central Gulf of California Mon into Tue. Meanwhile, fresh to strong winds and very large northerly swell will enter the waters off Baja California Norte between the low pressure inland and building high pressure farther west. Seas will approach 18 ft near Guadalupe Island by late Mon. Seas will be 8 to 12 ft in NW swell by late Tue, from the Revillagigedo Islands to off Baja California Norte by Tue. Looking ahead, winds and seas will diminish into mid week as high pressure builds over the area, although NW swell to 9 ft will linger near the Revillagigedo Islands. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see the Special Features section above for more details about a gale warning in the Papagayo region. Large NW swell generated by the Tehuantepec gales will combine with easterly swell from the Papagayo region to maintain rough seas offshore of Guatemala and El Salvador through this weekend. Seas will reach as high as 15 ft well offshore of Guatemala later today. Wave heights will subside by early next week as the gap winds diminish. Elsewhere, strong winds will pulse over and downstream of the Gulf of Panama through this weekend. Seas will peak to 9 ft each day well downstream of the Gulf, diminishing by mid week. REMAINDER OF THE AREA... Please see the Special Features section above for more details about a Pacific high seas gale warning. Fresh to locally strong trade winds prevail W of 120W north of the ITCZ to 20N. Seas are generally 8 to 11 ft in this region. Elsewhere, a large area of 8 to 12 ft seas in N to NE swell extends well downstream of the Tehuantepec region. NW swell of 8-10 ft over the NW corner will gradually spread to the southeast through the weekend. A cold front will move into the waters north of 20N Sun through Sun night, followed by strengthening NW winds and building seas. Associated and reinforcing NW swell will move southward across the region through early next week, with seas 12 ft or greater expected north of 25N east of 130W by Mon night. Marine conditions are forecast to gradually improve Tue through Wed night with a weaker pressure pattern in place. $$ Christensen