000 AXPZ20 KNHC 102122 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1949 UTC Fri Jan 10 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: A cold front will move across the western Gulf of Mexico Sat. High pressure will build in the wake of the front over the eastern slopes of Sierra Madre Mountains. The pressure gradient between this ridge and the equatorial trough over the eastern north Pacific will support gale force winds in the 30 to 40 kt range over the Gulf of Tehuantepec Sat evening through Sun. Winds will diminish below gale force by Sun night as the area of high pressure shifts eastward, and the pressure gradient loosens. Associated seas are forecast to peak near 13 or 14 ft by early Sun morning. Please read 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 this gale warning. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from a 1006 mb low pressure over northern Colombia near 10N75W to 04N84W. The ITCZ continues from 04N84W to 05N110W to 07N125W to beyond 08N140W. Scattered moderate convection is noted within 120 nm N of the ITCZ between 120W and 127W...and W of 136W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for more details on the upcoming gale force gap wind event in the Gulf of Tehuantepec. A surface ridge extends across the offshore forecast waters W of Baja California. The pressure gradient between this ridge and a trough over the Gulf of California will support moderate to fresh winds W of Baja California through the forecast period. Seas in the 6-8 ft range will prevail today. A new set of NW swell will propagate into the waters off Baja California Norte Sun. Seas associated to this swell will peak near 14 ft W of Baja California Norte late Sun through Mon. The swell will spread southward, with seas greater than 8 ft prevailing W of the entire Baja California peninsula by Tue. The pressure gradient will also support fresh to strong winds across the southern Gulf of California through Sat night. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A tight N to S pressure gradient between high pressure of 1041 mb across the western Atlantic and the equatorial trough is supporting strong to near gale force NE to E winds across and downstream of the Gulf of Papagayo. A tight pressure gradient will continue across Central America through Tue, which will continue to support fresh to strong daytime winds pulsing to near gale force each night. Seas will build to 8-10 ft each late night following the pulse of peak winds. Northerly swell generated from the upcoming gale force gap wind event in the Tehuantepec region will move SE into the Guatemala and El Salvador offshore waters on Sun. REMAINDER OF THE AREA... A surface ridge extends from high pressure of 1036 mb located NW of the forecast region near 37N150W across the northern forecast waters. The pressure gradient between the ridge and lower pressure in the vicinity of the ITCZ is producing a large area of fresh to strong trade winds that covers the waters N of the ITCZ to about 25N W of 115W. Seas are in the 9 to 13 ft range within this area of winds. These marine conditions are forecast to persist through the upcoming weekend as the strong high pressure prevails. A set of long-period NW swell will reach the NW waters late Sat, spreading SE across the forecast area through early next week. Seas are forecast to peak 14 or 15 ft roughly N of 28N between 119W and 130W by Sun evening. $$ GR