000 AXPZ20 KNHC 130935 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 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 0600 UTC surface analysis and satellite imagery through 0845 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A ridge across the eastern slopes of the Sierra Madre Orientales continues to support minimal gale force northerly winds across the Gulf of Tehuantepec tonight, with associated peak seas downstream near 11 ft. These winds will diminish slightly to around 30 kt before sunrise as the ridge begins to weaken. Strong to near gale force winds will then persist across the Tehuantepec region Mon through the remainder of the week, and are expected to increase again to minimal gale force Mon night through late Tue morning, and then briefly again Tue night. Strong northerly gap winds associated with this ongoing event will cover a modest area downwind of Tehuantepec, generally to near 13.5N. This will limit peak seas to 11 or 12 ft during the period of maximum winds each night through early morning. Gulf of Papagayo Gale Warning: A large and strong ridge of high pressure dominating the western Atlantic and Caribbean will support strong offshore winds to near 30 kt during the daytime hours across the Papagayo region through Wed, and extend downwind to near 91W or 92W. Winds are expected to increase to minimal gale force during the overnight and early morning hours tonight and again Mon night, producing downstream seas of 8 to 11 ft each late night following the pulse of peak winds. This pattern will continue through the entire week 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 09.5N75W to 05N79W to 05.5N91W. The ITCZ continues from 05.5N91W to 07N121W to beyond 06N140W. Widely scattered moderate isolated strong convection is noted within 90 nm N of the ITCZ west of 120W. 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 broad and strong 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. Recent scatterometer data tonight showed northerly winds of 15-20 kt across the waters from Punta Eugenia northward, while N to NE winds 10-15 kt generally prevail southward to 20N. New NW swell is propagating through the waters off Baja California Norte tonight, producing seas of 8 to 13 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. Elsewhere, variable winds at 10 kt or less generally prevail across the offshore waters from Manzanillo to Puerto Angel, where seas are in the 3-5 ft range in NW swell. Northerly winds will gradually increase to around 15 kt across the Manzanillo area by Mon morning, but otherwise, little significant change is expected in marine conditions across the area for the next few days. Seas will increase 1 to 2 ft in NW swell Mon night through Tue night as the NW swell moves through the regional waters. 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. Due to strong trade winds in the SW Caribbean, expect fresh to strong northerly winds across the Gulf of Panama to as far south to 05N between 79W and 80.5W. The strongest winds will occur mainly at night through morning, with downstream seas building 4-7 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 1042 mb high pressure located N of the Hawaiian Islands near 42N153W. 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 to near 30N to the W of 120W. Latest altimeter data indicate seas in the 10 to 13 ft range in NW swell across this area of strong winds. These marine conditions are forecast to persist through morning, before the ridge weakens and the large area of strong winds shifts SW late Mon through Tue. Winds and seas are expected to gradually subside 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. Seas associated with this swell event have peaked tonight at 14 or 15 ft over the forecast waters roughly N of 27N between 118W and 130W. 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. $$ Stripling