000 AXPZ20 KNHC 250945 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Wed Oct 25 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 0600 UTC surface analysis and satellite imagery through 0930 UTC. ...SPECIAL FEATURES... Category 4 Hurricane Otis is just inland Mexico near 17.2N 100.1W, or about 20 nm northwest to north of Acapulco at 25/0900 UTC, moving north-northwest at 9 kt. Estimated minimum central pressure is 948 mb. Maximum sustained wind speed has diminished to 115 kt with gusts to 140 kt. Peak seas are to around 32 ft. Satellite imagery still shows a well symmetrical configuration to the overall cloud pattern structure. Numerous moderate to strong convection is noted within 90 of the enter, except within 120 in the NE quadrant. Otis is expected to maintain its current motion through early tonight .On the forecast track, the center of Otis will move farther inland over southern Mexico through tonight. Rapid weakening is expected as Otis moves inland over the higher terrain of Mexico. Otis will likely dissipate over southern Mexico tonight. Damaging hurricane-force winds will spread inland over southern Mexico this morning with extremely destructive winds near the core during the next few hours. Wind speeds atop and on the windward sides of hills and mountains are often up to 30 percent stronger than the near-surface winds indicated in this advisory, and in some elevated locations could be even greater. Otis is expected to produce rainfall totals of 8 to 16 inches with maximum amounts of 20 inches through Thursday 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 affect portions of the southern coast of Mexico during the next day or so. These swells are likely to cause life-threatening surf and rip current conditions. Please consult products from your local weather office, and please refer to the 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 low pressure in northwest Colombia to across southern Costa Rica and to 12N93W. It resumes at 10N103W to low pressure near 07N121W 1010 mb to low pressure near 07N135W 1010 mb and to 07N140W. Numerous strong convection is seen from 09N to 14N between 87W-91W, and within 60 nm south of the trough between 87W-90W. Scattered moderate to isolated strong convection is within 120 nm south of the trough between 84W-87W. Scattered moderate convection is within 120 nm south of the trough between 103W-108W and between 117W-122W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the SPECIAL FEATURES section above for more details on Hurricane Otis. 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 6-9 ft with these winds due to long-period northwest swell. Over the Gulf of California, moderate southwest to west winds are present along with seas of 2-4 ft. The remainder of the southwestern Mexican offshore waters outside of Otis are under generally gentle to moderate northwest winds and seas 5-6 ft in mixed swell. For the forecast, Otis will continue inland Mexico weakening to a tropical storm near 18.2N 100.5W this afternoon and to a tropical depression near 19.2N 101.0W Thu morning and dissipate Thu afternoon. Seas of 8 to 9 ft in long period northwest swell offshore central and northern Baja California will subside by late this afternoon. Looking ahead, fresh north winds along with renewed long period northwest swell may develop over the weekend to the west of Baja California. A Gulf of Tehuantepec fresh to strong gap wind event is likely to begin late Thu night into Fri. ...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 5-7 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 today. Winds become moderate to fresh over the weekend. Westerly wind speeds are likely to increase to fresh to strong north of the Equator by early Thu into Fri as broad low pressure 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 8-10 ft near the aforementioned fresh westerly winds and broad low pressure. ...REMAINDER OF THE AREA... A north-south oriented surface ridge extends across the waters between 130W-140W. A 1021 mb high center is analyzed near 28N134W. 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. Moderate northwest swell continues to propagate across most of the waters between 92W-120W. Seas are 6-8 ft due to mixed long-period southwest and northwest swell are west of the Galapagos Islands to 114W and mainly south of about 07N. For the forecast long-period northwest swell over the far NE part of the area will continue to spread seas of 8-9 ft north of 26N and east of 130W through early this evening. $$ Aguirre