000 AXPZ20 KNHC 182200 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2200 UTC Sat Jan 18 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 1800 UTC surface analysis and satellite imagery through 2100 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: High pressure over the Gulf of Mexico will maintain strong to minimal gale force N winds across the Tehuantepec region through Sun. Seas in excess of 8 ft reach several hundred miles downstream of the Gulf, mixing with longer period NW swell. Looking ahead, a cold front will move across the Gulf of Mexico Sun and Mon, and induce a stronger and much broader gale wind event across the Tehuantepec region Sun night through Tue night, then diminishing on Wed. Winds will peak around 40 kt, with seas building to 16 or 17 ft. Winds will be greatest during the overnight and early morning hours with the assistance of the nocturnal drainage flow. Papagayo region Gale Warning: A broad persistent ridge across the Caribbean and Central America is supporting strong to near gale force NE to E winds across and downstream of the Papagayo region, extending downstream more than 200 nm. Winds will pulse to minimal gale force this morning, then frequent gusts to gale force are expected, particularly during the overnight and early morning hours. Seas will peak between 10 and 12 ft during this period of peak winds. Fresh to strong NE to E winds will prevail across the region most of the forecast period. Please see the latest High Seas Forecast issued by the National Hurricane Center under AWIPS/WMO headers FZPN03 KNHC/HSFEP2 or at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details on these two Gale Warnings. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from near 05N77W to 03N82W to 06N100W. The ITCZ continues from 06N100W to beyond 10N140W. No significant convection noted. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see above for more on the latest gale force gap wind event in the Gulf of Tehuantepec. A surface ridge dominates the offshore forecast waters west of Baja California and extends to near the Revillagigedo Islands. Latest ship observations and scatterometer data show moderate to fresh NW winds off the coast of Baja California and fresh to locally strong winds across the central Gulf of California. The high pressure will shift south through Sun, supporting fresh to occasionally strong winds off Cabo Corrientes into Mon. Looking ahead, a cold front will approach Baja California Norte and Guadalupe Island Tue and Tue night, accompanied by NW swell of 8-10 ft, before stalling and dissipating Wed. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see above for more on the latest gale force gap wind event in the Papagayo region. The pressure gradient responsible for the gap wind events in southern Mexico and Central America is also supporting fresh to strong NE to E winds across the Nicaragua Lake in Nicaragua and offshore of the Gulf of Fonseca, as well as fresh to locally strong northerly winds in the Gulf of Panama, mainly at night. Winds across the Gulf of Panama and downstream S of the Azuero Peninsula to near 04N will persist through Sun morning, with downstream seas building to 6-7 ft. REMAINDER OF THE AREA... Latest scatterometer satellite data shows moderate to fresh trade winds west of 125W between the ITCZ and 20N. Strong to near gale force SE winds are noted near 22N140W, very close to 1014 mb low pressure centered near 21N141W. Concurrent altimeter satellite data shows seas of 8 to 10 ft over much of the area, likely a combination of northerly swell with shorter period trade wind swell. The low pressure will deepen as it moves to the east-northeast, reaching 29N130W by Mon. Winds may increase to minimal gale force at times through Sun within 240 nm of the low pressure. The low pressure will slow and weaken starting late Sun, as it drifts toward Baja California Norte, eventually dissipating west of Guadalupe Island by mid week. Looking ahead farther south, a trough trailing from the low pressure will stall from the ITCZ and 18N, between 130W and 140W. Global guidance is suggesting fresh to strong winds may develop west of the trough into mid week as high pressure builds over the subtropics in the wake of the low pressure. $$ Christensen