000 AXPZ20 KNHC 132145 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2025 UTC Mon Jan 13 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: The pressure gradient between a ridge across the eastern slopes of Sierra Madre Mountains and the equatorial trough will support strong to near gale force winds across the Tehuantepec region through the remainder of the week. Winds are expected to pulse to minimal gale force tonight and Tue night with the added component of nocturnal drainage flow. Strong northerly gap winds associated with this ongoing event will cover a area downwind of Tehuantepec, generally to near 11N or 12N. Seas of 11 or 12 ft are expected during the period of maximum winds each night through early morning. Gulf of Papagayo Gale Warning: Strong to near gale force daytime winds will continue to blow across the Papagayo region as a strong wind flow in the SW Caribbean funnels through the gap. Winds will increase to minimal gale force during the overnight and early morning hours with the assistance of the nocturnal drainage flow. Seas will build to 8 to 12 ft each late night following the pulse of peak winds. This pattern will continue through Wed and also support strong offshore gap winds across the waters of northern Nicaragua and downwind of Lake Managua, as well as the Gulf of Fonseca. 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 03N80W to 05N91W. The ITCZ continues from 05N91W to 06N120W to beyond 06N140W. Scattered moderate convection is noted within 90 nm N of the ITCZ between 110W and 120W. Scattered moderate isolated strong convection is noted within 90 nm either side of the ITCZ W of 134W. Scattered moderate is within 90 nm N of the ITCZ between 110W and 120W...and from 02N to 07N between 125W and 131W. 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. Elsewhere, a surface ridge extends from the NE pacific SE across the offshore forecast waters W of Baja California to just SE of the Revillagigedo Islands. The pressure gradient between this ridge and a trough over the Gulf of California will support moderate to fresh northerly winds W of Baja California through the forecast period. NW swell is propagating through the waters off Baja California Norte, producing seas of 8 to 12 ft from Punta Eugenia northward and 4 to 8 ft southward to 20N. This swell will spread southward and build seas across the waters of Baja California Sur today before seas begin to slowly subside area wide Tue through Wed. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see above for more on the gale force gap wind event across the Gulf of Papagayo region. The pressure gradient responsible for the gale force gap wind events in Tehuantepec and Papagayo is also supporting fresh to strong northerly winds across the Gulf of Panama. The strongest winds will occur mainly at night through morning, with downstream seas building to 5-8 ft. Elsewhere, swell generated in the gap wind areas from Tehuantepec and Papagayo will propagate into the Guatemala and El Salvador offshore waters over the next several days to build seas to 6-9 ft. REMAINDER OF THE AREA... A surface ridge extends across the northern forecast waters from a 1041 mb high pressure located N of the Hawaiian Islands near 40N153W. The pressure gradient between the ridge and lower pressure in the vicinity of the ITCZ to the south of the ridge is producing a large area of fresh to strong trade winds that roughly covers the waters N of the ITCZ from 07N to 26N W of 130W, and from 07N to 15N between 120W and 130W. Seas are in the 9 to 12 ft range in NW swell across this area of strong winds. The ridge will weaken, which will loosen the pressure gradient and decrease associated winds and seas across this area through Wed. Long-period NW swell propagating over the northern waters will spread SE across the forecast area through early this week. This swell will propagate SE and produce seas of 8 ft or greater across most of the forecast waters N of the Equator and W of 110W by Tue evening. $$ GR