000 AXPZ20 KNHC 241603 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 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 1200 UTC surface analysis and satellite imagery through 1550 UTC. ...SPECIAL FEATURES... Tropical Storm Otis is centered near 14.8N 99.1W, or about 135 nm south-southeast of Acapulco, Mexico moving north-northwest at 7 kt. Estimated minimum central pressure is 993 mb. Maximum sustained wind speed is 60 kt with gusts to 75 kt. Peak seas have increased to 20 ft. Numerous strong convection is seen within 90 nm of the center. Scattered moderate convection is elsewhere within 120 nm of the center. Otis is forecast to maintain its current motion for the next couple of days. On the forecast track, Otis is expected to reach the coast of southern Mexico late tonight or Wed. Otis is expected to strengthen into a hurricane later today, and continue to strengthen until it reaches the coastline. Otis is expected to produce heavy rainfall through Fri across Guerrero and western coastal sections of Oaxaca. This rainfall will produce flash and urban flooding, along with mudslides in areas of higher terrain. Hurricane conditions are expected within portions of the hurricane warning area by late tonight and on Wed. Tropical storm conditions are expected to first reach the coast within the warning areas later today or this evening, and then spread northwestward within the warning areas through Wed. Swells generated by Otis will affect portions of the southern coast of Mexico during the next couple of days. 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 axis extends from 08N78W to 08N83W to 13N90W. It continues SW of Otis from 10N100W to 07N107W to 1008 mb low pres near 07N122W to 1008 mb low pres near 09N135W to 07N140W. Numerous moderate to scattered strong convection is noted from 02.5N to 08N between 77W and 90W, and from 09N to 12N between 84W and 90W. Scattered moderate convection is found from 04N to 10N between 94W and 126W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the SPECIAL FEATURES section above for more details on Tropical Storm Otis. The area of winds over 20 kt and/or seas over 8 ft associated with Otis currently covers the waters from 12N to 17N between 96.5W and 100.5W. The pressure gradient between the subtropical ridge to the west of the Baja California Peninsula and relatively broad lower pressure in northwest Mexico is supporting moderate to fresh northwest to north-northwest winds to the west of Baja California. Seas are 6-10 ft with these winds, in NW swell. Over the Gulf of California, moderate to fresh southwest to west winds are present along with seas of 3-5 ft. The remainder of the southwestern Mexican offshore waters outside of Otis are under generally gentle northwest winds and seas 5-6 ft in mixed swell. For the forecast, Tropical Storm Otis will strengthen to a hurricane by this evening near 15.5N 99.5W, then move to near 16.5N100W early Wed before moving inland by Wed evening near 17N100.5W. Otis will weaken to a tropical storm inland near 18N101.5W Thu morning, and to a remnant low near 18.5N102W Thu evening before dissipating later Thu night. Fresh west winds in the central Gulf of California will diminish by early this afternoon. Elsewhere, fresh northwest winds across the Baja California offshore waters will diminish to moderate this afternoon. Seas of 8-10 ft in long-period northwest swell offshore central and northern Baja California will subside Wed. Looking ahead, fresh N winds along with renewed NW swell may develop over the weekend to the west of Baja California. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Generally gentle winds persist north of the monsoon trough. South of the monsoon trough, mainly moderate south to southwest winds prevail. Seas are 6-8 ft between Ecuador and the Galapagos Islands in mixed southwest and northwest swell. Seas are 5-8 ft elsewhere. For the forecast, moderate southerly winds will continue across the South America and Galapagos Islands offshore waters through Wed. Westerly wind speeds are likely to increase to fresh north of the Equator by early Thu into early on Fri as broad low pressure likely forms over the far eastern Pacific waters. Mixed swell will maintain seas in the 6-8 ft range across most of the waters through the rest of the week, except 7 to 9 ft near the aforementioned fresh westerly winds. ...REMAINDER OF THE AREA... A north-south oriented surface ridge extends across the waters between 130W-140W. The gradient resulting from this synoptic set-up is favorable in supporting mainly moderate anticyclonic winds between 130W-140W, and moderate to locally fresh north winds east of 130W and north of 25N. Moderate or weaker winds prevail elsewhere north of the monsoon trough. Moderate south to southwest winds are south of the monsoon trough as seen in overnight ASCAT data passes across that part of the area. Moderate northwest swell continues to propagate across most of the waters between 92W-120W. 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 north of 25N and east of 130W will diminish this afternoon. Meanwhile, long- period northwest swell over the far NE part of the area is forecast to continue spreading seas of 8 to 10 ft north of 26N and east of 130W through late tonight before subsiding Wed. $$ Hagen