000 AXPZ20 KNHC 232144 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Mon Oct 23 2023 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 1800 UTC surface analysis and satellite imagery through 2130 UTC. ...SPECIAL FEATURES... Tropical Storm Otis is centered near 13.1N 97.6W, or about 265 nm SSE of Acapulco, Mexico at 23/2100 UTC, moving NNW at 6 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Peak seas are about 16 ft. Scattered moderate to strong convection is noted within 180 nm of the center in the W semicircle and 90 nm E semicircle. Otis is expected to maintain a north-northwestward motion during the next few days. On the forecast track, Otis is expected to reach the coast of southern Mexico on Wed. Gradual strengthening is forecast, and Otis is expected to be near hurricane strength before it reaches southern Mexico. Otis is expected to produce heavy rainfall through Friday across Guerrero and the western coastal sections of Oaxaca. This rainfall will produce flash and urban flooding, along with mudslides in areas of higher terrain. Swells generated by Otis will begin to affect portions of the southern coast of Mexico on Tue. These swells are likely to cause life-threatening surf and rip current conditions. 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 Otis NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N86W to 10N89W, then resumes west of Otis from 11N101W to 09N107W to 1011 low pres near 10N123W to 09N127W. A surface trough extends from 14N132W to 09N133W. Scattered moderate isolated strong convection is noted from 03N to 09N between 81W and 88W, and from 04N to 09N between 96W and 118W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the SPECIAL FEATURES section above for more details on Tropical Storm Otis. The pressure gradient between the subtropical ridge to the west of the Baja California Peninsula and Norma is supporting fresh northwest to north-northwest winds to the west of Baja California. Seas are 6-8 ft with these winds. Over the central and northern Gulf of California, fresh winds are present along with 3 to 5 ft seas. In the southern Gulf of California, and at the entrance to the Gulf, fresh winds and seas of 8 to 9 ft are still occurring, as the remnants of Norma dissipate well inland. The remainder of the southwestern Mexican offshore waters outside of Otis has gentle W to NW winds and seas 6 to 7 ft in mixed swell. For the forecast, the remnants of Norma will dissipate by this evening inland over Mexico near 25N107W. Seas in the southern Gulf of California will subside to 7 ft by this evening and to 5 ft overnight. Tropical Storm Otis will move to near 15N98.5W midday Tue, strengthen to a 60 kt tropical storm and make landfall in Mexico near 17N100W midday Wed, weaken to a remnant low near 18N101W midday Thu before dissipating Thu night. Elsewhere, fresh winds will continue through this evening across the Baja California offshore waters and in the Gulf of California. Northwest swell offshore Baja California Sur will continue to subside through this evening. A new set of long-period northwest swell will enter the offshores of Baja California Norte north of Punta Eugenia this evening and then subside Wed morning. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please see the SPECIAL FEATURES section above for more details on Tropical Storm Otis, which is giving some fresh winds and seas of 7 to 9 ft across the waters well offshore of western Guatemala. Outside of Otis, generally gentle winds persist north of the monsoon trough. South of the monsoon trough, moderate to locally fresh south to southwest winds prevail. Seas are 6-8 ft between Ecuador and the Galapagos Islands in mixed southwest and northwest swell. Seas are 5-7 ft elsewhere. For the forecast, Otis will move to near 15N98.5W midday Tue, then strengthen to a 60 kt tropical storm and make landfall in Mexico near 17N100W midday Wed. Elsewhere, moderate to locally fresh winds will continue across the South America and Galapagos Islands offshore waters through today. Otherwise, gentle to moderate winds will prevail across the area through Wed night. Looking ahead, westerly wind speeds could increase north of the Equator toward the end of the work week. Mixed swell will keep seas in the 6 to 8 ft range across most of the waters through most of the week. ...REMAINDER OF THE AREA... A north-south oriented surface ridge extends across the waters between 130W and 140W. This is supporting mainly moderate anticyclonic winds between 130W and 140W, and moderate N winds east of 130W. The exception is moderate to fresh NW to N winds north of 25N and east of 127W. Moderate south to southwest winds are south of the monsoon trough as seen in recent ASCAT data. Moderate northwest swell continues to propagate across most of the waters between 94W-115W. Seas are 8-10 ft west of the Galapagos Islands to 115W, mainly south of 10N. For the forecast, moderate to fresh N winds will continue through this evening north of 23N and east of 130W as high pressure continues to the north of the area and tightens the pressure gradient. Meanwhile, a new set of long-period northwest swell is forecast to spread south of 30N and to the east of 130W beginning this evening, building seas of 8-10 ft north of 26N, with the highest seas expected north of 29N. $$ Hagen