000 AXPZ20 KNHC 181542 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1308 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 1200 UTC surface analysis and satellite imagery through 1500 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 04N80W to 06N87W to 05N97W. The ITCZ continues from 05N97W to 06N120W to beyond 08N140W. Scattered moderate convection is from 06N to 09N W of 129W. 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 W 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 Gulf of California, mainly S of 29N. Strong high pressure building over the Great Basin of United States will set up a tight pressure gradient in the Gulf of California, and support fresh to strong winds over the central and southern Gulf of California through early Sun. These winds will spread out across the waters between Cabo Corrientes and Los Cabos today and tonight. 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... A ridge extends across the northern forecast waters between Baja California and 140W. Latest scatterometer data indicate fresh to strong trades across the southern periphery of the ridge, over the waters from 08N to 15N W of 130W and from 08N to 20N between 120W and 130W. This area of winds will gradually shrink in size Sun and Mon as a low pressure system, mentioned below, moves NE across the waters N of 20N. Just W of the region, a 1012 mb low pressure is analyzed near 26N142W with a trailing cold front to near 16N145W. The low pressure and associated cold front are forecast to move across the NW forecast region later today through at least Mon. Fresh to strong winds are expected ahead and behind the front through Mon. A new set of long period NW swell will follow the low/front with building seas of 12 to 15 ft W of a line from 30N135W to 25N140W by Mon morning. Looking ahead, the pressure gradient between high pressure building in the wake of the exiting low pressure system and lower pressures in the vicinity of the ITCZ is forecast to support fresh to strong NE winds between the ITCZ to around 20N west of 130W Tue and Wed. $$ GR