000 AXPZ20 KNHC 052232 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Thu Nov 5 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 2130 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: Northerly gales continue across the Gulf this afternoon. An afternoon scatterometer satellite pass missed the core winds funneling out of the Gulf but did show NW winds to gale force across eastern portions of this strong wind plume. Peak seas are estimated to be 18 ft. Swell generated from this Tehuantepec event will produce a large area of 12 ft or greater seas that will extend about 500 nm southwest of the Gulf of Tehuantepec. High pressure north of the area supporting the gales is starting to weaken, and the gap winds have responded in both strength, and direction, partially due to the influence by Eta persisting over Honduras. Winds will gradually diminish through Fri, hold at or near gale force Fri, and diminishing below gale force Fri afternoon. Marine interests transiting across or in the vicinity the Gulf of Tehuantepec should be aware of this gap wind event, and take necessary action to avoid hazardous marine conditions over the affected waters. Please refer to the latest High Seas Forecast issued by the National Hurricane Center at: https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for further details. Potential Heavy Rainfall event: Hurricane Eta is moving slowly across central Nicaragua, and producing a surge of moist southwesterly flow across the tropical eastern Pacific that will support heavy to torrential rainfall across portions of Central America through Thu. Eta is likely to cause life-threatening flash flooding and river flooding across portions of Central America, along with landslides in areas of higher terrain. Eta is expected to produce rainfall accumulations of 15 to 30 inches (375 to 750 mm) across central and northern Honduras into NE Guatemala, while SW onshore winds are expected to yield rainfall accumulations of 10 to 20 inches (250 to 500 mm) across coastal sections from NW Costa Rica to Nicaragua to far southern Honduras. Please refer to statements provided by your local national meteorological agency for more details. Farther west, Tropical Storm Odalys is centered near 18.5N 123.6W at 2100 UTC moving W at 6 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. The center of Odalys has become completely exposed, with SW wind shear keeping isolated moderate convection N through NE of the center, from 90 to 240 nm in the N semicircle. Afternoon scatterometer satellite passes indicated winds to 35 kt in the NW quadrant. Odalys will continue moving W during the next 24 hours and gradually weaken to a Tropical Depression tonight and then a 30 kt post tropical remnant low late Fri afternoon as it reaches cooler waters and drier more stable air. Please read the latest NHC Public Advisory at https://www.nhc.noaa.gov/text/MIATCPEP5.shtml and Forecast/ Advisory at https://www.nhc.noaa.gov/text/MIATCMEP5.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 12N92W to 10N98W to 08N113W to 09N118W, then resumes south of Odalys near 14N125W to low pres 1012 mb near 10N137W. ITCZ extends from 10N137W to beyond 09.5N140W. Scattered moderate isolated strong convection is observed from 08.5N to the coasts between 84W and 95W, from 08N to 12N between 106W and 112W, and within 90 nm either side of trough and ITCZ W of 125W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section above for details on the Gulf of Tehuantepec Gale Warning. Afternoon scatterometer satellite data indicated moderate NW winds across most the offshore waters of Baja California, and gentle to light winds farther south, outside of the Tehuantepec area. Altimeter satellite passes confirmed seas are reaching 8 ft in the waters W through SW of the Revillagigedo Islands, and 7-8 ft across the outer offshore waters of Baja California Sur. These seas are related in part to swell generated by T.S. Odalys. Elsewhere 4 to 6 ft primarily in NW swell north of 20N, and SW swell south of 20N. A slightly tighter gradient is in place over the Gulf of California where moderate to fresh NW winds and 3 to 5 ft seas, possibly to 6 ft, are noted. Meanwhile, mid to upper level low pressure area over the northern Pacific is becoming more organized, and is expected to move along the US west coast through late Fri, bringing a strong cold front into Baja California Norte by late Fri. This pattern will support fresh to strong westerly gap winds into the northern Gulf of California late Fri through Sat, and perhaps into Sun. NW swell will also follow the front, with combined seas in excess of 8 ft encompassing the waters off Baja California through Sun, reaching the area near Socorro Island by late Sun. Peak seas may reach as high as 16 ft off northern Baja California Norte by Sun. Gentle winds will persist south of Cabo Corrientes outside of the Gulf of Tehuantepec plume, with seas of 4 to 6 ft in mostly southerly swell. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR... Tropical Depression Eta remains centered over northwestern Honduras near 15.7N 87.7W at 2100 UTC moving NNW at 7 kt. Estimated minimum central pressure is 1005 mb. Maximum sustained wind speed is 30 kt with gusts to 40 kt. Midday scatterometer satellite data confirmed the presence of areas of fresh to locally strong southwesterly winds extending from 03N into the coasts of NW Costa Rica, Nicaragua and El Salvador, and fresh southerly winds across the coastal waters of the remainder of Costa Rica and Panama. Eta has started to lift slowly out toward the north, which will allow these winds and seas to diminish somewhat Fri through Fri night. Meanwhile, complex seas of up to 15 ft persist off the rest of the offshore waters of El Salvador and Guatemala, in a mix of swell emerging from the prolonged gale event in the nearby Tehuantepec region, and longer period SW swell. Fresh SW winds and 8 to 10 ft seas in SW swell persist off the coast of western Panama and Costa Rica. Better marine conditions are noted off eastern Panama and the coast of Colombia. Winds and seas will diminish through Fri off Panama and Costa Rica, and the swell from the Tehuantepec gap event will begin to subside as well. However, fresh to occasionally strong onshore SW winds off Nicaragua will persist into Fri, maintaining 8 to 12 ft seas with SW swell. These winds will diminish by Sat, and seas will subside to less than 8 ft by Sun. Moderate SW winds and 4 to 6 ft seas in SW swell will prevail by Mon. REMAINDER OF THE AREA... Please refer to the Special Features section above for details on Tropical Storm Odalys. Ridging dominates north of 20N, anchored by strong high pressure of 1045 mb located well north of the Hawaiian Islands. Moderate to occasionally fresh NE trade winds persist from 10N to 28N, outside of the immediate area of T.S. Odalys, west of 119W. A large envelope of seas greater than 8 ft surrounds Odalys, reaching up to 420 nm to the south and southeast of the storm, in a mix of SW swell and shorter period swell generated from Odalys. A belt of seas 8 to 9 ft also persists west of Odalys, from 17N to 22N to beyond 140W, due to a mix of SW swell and a component of waves driven by the trade winds. No significant shower or thunderstorm activity is evident. Odalys will gradually dissipate and it moves westward across the area from 15N to 20N between 125W and 130W tonight through Sat. Meanwhile, a strong cold front will move south of 32N by early Fri morning, push southward, then largely stall and dissipate near 20N by late Sat into early Sun. Fresh to occasionally strong N to NE winds will follow the front, along with NW to N swell. This swell will mix with the lingering swell from Odalys and S to SW will create seas greater than 8 ft for most of the area north of 12N and west of 110W by early next week. Farther east, seas greater than 8 ft in a mix of SW swell and NE swell emerging out of Tehuantepec dominate the waters mainly south of 14N and east of 115W. This area of seas will begin to subside rapidly Fri through Sat to below 8 ft in primarily SW swell ans this ongoing Tehuantepec gale event begins to wind down. $$ Stripling