882 AXPZ20 KNHC 110321 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 028 UTC Sat Jan 11 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: The next gap wind event over the Gulf of Tehunatepec is expected to commence Sat evening as a cold front moving across the Gulf of Mexico reaches the Isthmus of Tehuantepec. High pressure building in the wake of the front will provide a tight pressure gradient over the area and bring an increase in winds funneling into the Gulf of Tehuantepec. Winds will rapidly increase to 30 to 40 kt with seas forecast to peak near 13 or 14 ft by early Sun morning. Winds will diminish below gale force by Sun night as the area of high pressure shifts eastward, and the pressure gradient loosens. 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 1005 mb low pressure over northern Colombia near 10N75W to 04N85W. The ITCZ continues from 04N85W to 06N110W to 07N123W to beyond 07N140W. Scattered moderate convection is noted within 120 nm N of the ITCZ between 120W and 124W...and from 12N to 14N between 122W and 125W. 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 tonight. A new set of NW swell will propagate into the waters off Baja California Norte Sun. Seas associated to this swell event 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 northerly winds across the southern Gulf of California, and also across the waters between Cabo Corrientes and Los Cabos through Sat night. Seas are forecast to build to 8 to 9 ft outside the Gulf of California. 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 1043 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. This weather pattern 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 across the northern forecast waters from a 1038 mb high pressure located near 41N150W. 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 24N W of 120W. Seas are in the 9 to 12 ft range within this area of winds based on recent altimeter data. These marine conditions are forecast to persist through the upcoming weekend as a strong high pressure prevails NW of the forecast region. 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 27N between 118W and 130W by Sun evening. $$ GR