000 AXPZ20 KNHC 240357 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Oct 24 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 00000 UTC surface analysis and satellite imagery through 0345 UTC. ...SPECIAL FEATURES... Tropical Storm Otis is centered near 13.6N 97.9W, or about 230 nm south-southeast of Acapulco, Mexico at 24/0300 UTC, moving north-northwest 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. Satellite imagery shows that Otis is a sheared system as numerous moderate to strong type convection is displaced within 120 nm of its center in the SW quadrant. Similar convection is within 60 nm of the center in the NE quadrant. Otis is forecast to maintain its current motion for the next few days. On the present 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 rainfall totals of 5 to 10 inches with maximum amounts of 15 inches through Fri 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. Tropical storm conditions are expected and hurricane conditions are possible within the warning area beginning Tue night. Swells generated by Otis will begin to affect portions of the southern coast of Mexico on Tuesday. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office, and 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 axis extends from extreme northwest Colombia to Tropical Depression Twenty-One near the southeast coast of Nicaragua, and continues southwestward to northwestern Costa Rica and to near 11N92W. It resumes at 11N101W to 08N108W to 09N120W to low pressure of 1010 mb near 10N134W and to 08N140W. Numerous moderate to strong convection is noted from 04N to 08N between 100W-105W. Numerous moderate to isolated strong convection is from 04N to 09N between 82W-87W, Scattered moderate convection is within 120 nm south of the trough between 112W-120W. ...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 to strong west to northwest winds are present along seas of with seas of 3-5 ft seas. In the southern Gulf of California, and at the entrance to the Gulf, gentle to moderate west to northwest winds and seas of 5-7 ft are found there as the remnants of Norma dissipate just inland the coast of Mexico near 25N107W. The remainder of the southwestern Mexican offshore waters outside of Otis is under generally gentle west to northwest winds and seas 6-7 ft in mixed swell. For the forecast, the remnants of Norma will soon dissipate. Tropical Storm Otis will strengthen as it moves to near 14.4N 98.3W Tue morning with maximum sustained winds 50 kt gusts 60 kt, then reach near 15.5N 98.9W Tue evening with maximum sustained winds 55 kt gusts 65 kt, move to near 16.4N 99.5W Wed morning with maximum sustained winds 60 kt gusts 75 kt and begin to weaken as it moves inland Mexico near 17.3N 100.3W Wed evening with maximum sustained winds 50 kt gusts 60 kt. Otis will weaken to a remnant low near 18.0N 101.0W Thu morning and dissipate Thu evening. Fresh to strong west to northwest winds in the central and northern Gulf of California will diminish by early Tue afternoon. Elsewhere, fresh northwest winds will continue through this evening across the Baja California offshore waters. Seas of 8 to 9 ft in northwest swell offshore central and northern Baja California will subside Wed. ...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 7-9 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, Tropical Storm Otis will strengthen as it moves to near 14.4N 98.3W Tue morning with maximum sustained winds 50 kt gusts 60 kt, then reach near 15.5N 98.9W Tue evening with maximum sustained winds 55 kt gusts 65 kt, move to near 16.4N 99.5W Wed morning with maximum sustained winds 60 kt gusts 75 kt and begin to weaken as it makes landfall in Mexico near 17.3N 100.3W Wed evening with maximum sustained winds 50 kt gusts 60 kt. Elsewhere, moderate to locally fresh southerly winds will continue across the South America and Galapagos Islands offshore waters through early Tue, then again Thu into early on Fri. 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 as broad low pressure is likely to form over the far eastern Pacific waters. Mixed swell will keep seas in the 6 to 8 ft range across most of the waters through most of the rest of the week. ...REMAINDER OF THE AREA... A north-south oriented surface ridge extends across the waters between 130W-140W. This is supporting mainly moderate anticyclonic winds between 130W-140W, and moderate north winds east of 130W. The exception is moderate to fresh northwest to north winds north of 25N and east of 127W. Moderate south to southwest winds are south of the monsoon trough as seen in the latest ASCAT data passes across that part of the area. Moderate northwest swell continues to propagate across most of the waters between 94W-115W. Seas are 8-9 ft due to long-period northwest swell west of the Galapagos Islands to 115W, mainly south of about 09N. For the forecast, moderate to fresh north winds are north of 23N and east of 130W as high pressure continues to the north of the area and tightens the pressure gradient. These winds will diminish on Tue. Meanwhile, long- period northwest swell entering the far NE part of the area is forecast to spread south of 30N to near 26N and east of 130W building seas to 8-9 ft. The swell will decay on Wed allowing for those seas to subside to a peak of 7 ft. $$ Aguirre