Tropical Weather Discussion
Issued by NWS
Issued by NWS
799 AXPZ20 KNHC 140311 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Fri Aug 14 2026 Tropical Weather Discussion for the eastern Pacific Ocean from 03.4S to 30N, east of 120W including the Gulf of California, and from the Equator to 30N, between 120W and 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 0240 UTC. ...SPECIAL FEATURES... Tropical Storm Hernan is centered near 16.8N 132.0W at 14/0300 UTC, moving south at 4 kt. Estimated minimum central pressure is 1004 mb. Maximum sustained wind speed is 35 kt with gusts to 45 kt. Peak seas are around 13 ft or 4 m. Hernan is a very sheered tropical cyclone with numerous moderate isolated strong convection noted between 120 nm and 510 nm in the NE quadrant of Hernan. Hernan is moving toward the south, and this general motion is expected to continue with a turn towards the south- southwest on Fri. A gradual turn to the west is forecast on Sat with that motion continuing through the weekend. Hernan is forecast to become a tropical depression on Friday and a post- tropical cyclone early Sat. Please read the latest HIGH SEAS FORECAST issued by the National Hurricane Center at website - https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and the latest Hernan NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...TROPICAL WAVES... The axis of a tropical wave is near 95.5W north of 01N to the northwest of the Galapagos Islands, moving slowly west around 5 kt. Nearby convection is discussed in the ITCZ/monsoon trough section below. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 1007 mb low pressure over northern Colombia near 10N74W to 08.5N84W to 07N102W. The ITCZ extends from 07N102W to 08N130W. Isolated to widely scattered moderate and isolated strong convection is from 05N to 09N between 77W and 80W, from 03N to 11N between 90W and 102W, from 04N to 14N between 102W and 110W, from 03N to 09N between 110W and 120W, and from 00N to 09N between 120W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Moderate to locally fresh winds prevail over the Gulf of Tehuantepec. Moderate to locally fresh SW gap winds are impacting the northern Gulf of California. NW moderate to locally fresh winds are nearshore of Baja California, mainly the southern portion. Gentle to moderate winds are found elsewhere. Moderate seas are over the open waters off Mexico, with slight to moderate seas over the Gulf of California. For the forecast, pulses of fresh to strong gap winds are expected across the Gulf of Tehuantepec through early next week, near gale-force overnight at times, along with occasionally rough seas. Moderate to locally fresh NW winds are forecast off Baja California through the next several days. A moderate pressure gradient will promote mostly gentle to moderate winds across the remainder offshore waters of Mexico along with moderate seas. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh easterly gap winds and moderate seas persist across and downstream the Gulf of Papagayo. Moderate to locally fresh NW to N winds are in the Gulf of Panama, with similar wind speeds but out of the south near the Gulf of Guayaquil. Gentle to moderate winds and moderate seas in S to SW swell prevail elsewhere. For the forecast, fresh to strong NE to E gap winds and occasionally rough seas will pulse across the Papagayo region through early next week. Moderate to locally fresh northerly winds will pulse in the Gulf of Panama through Fri night. Moderate winds may freshen south of the monsoon trough this weekend. Gentle to moderate winds are forecast elsewhere. Large southerly swell will start to move into the region starting tonight and Fri, then again early next week, with rough seas from offshore Ecuador to the Galapagos Islands. Light to gentle winds and moderate seas in SW swell are expected elsewhere. ...REMAINDER OF THE AREA... Please see Special Features section above for more on Tropical Storm Hernan. Broad ridging dominates the waters north of 20N. Outside the immediate area impacted by Hernan, the pressure gradient between the ridge, Hernan, and Tropical Storm Lala in the central Pacific is supporting fresh to locally strong winds, and rough seas, from 13N to 26N between 128W and 140W. Rough seas in southerly swell cover the waters south of 06N between 96W and 127W. Gentle to moderate winds, and moderate seas prevail elsewhere, locally fresh south of the Equator and west of 100W. For the forecast, Tropical Storm Hernan will weaken to a tropical depression near 16.2N 132.1W Fri morning, move to 15.8N 133.1W Fri evening, become a remnant low and move to 15.4N 134.8W Sat morning, 15.0N 136.9W Sat evening, 15.0N 139.0W Sun morning, and dissipate Sun evening when remnant rough seas should also subside. Elsewhere, southerly swell will maintain rough seas over the discussion waters south of 05N between 95W and 130W through the end of the week, then south of 02N between 95W and 125W this weekend. Another set of southerly swell is forecast to bring rough seas to the waters south of 06N between 90W and 125W early next week. Main moderate or weaker winds will prevail elsewhere, except locally fresh near a passing tropical wave currently near 95.5W, and in the northwest waters where the pressure gradient will be regionally tight. $$ Lewitsky