000 AXPZ20 KNHC 011618 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Wed Nov 1 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 1510 UTC. ...SPECIAL FEATURES... Tropical Storm Pilar is centered near 12.5N 90.5W at 1500 UTC, moving west at 6 kt. Estimated minimum central pressure is 996 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Peak seas are currently around 20 ft. Scattered to numerous moderate to strong convection is noted within 240 nm across the W semicircle, while scattered moderate isolated strong convection is within 210 nm across the E semicircle. On the forecast track, Pilar will begin to move away from the coast of Central America through this afternoon, but the core of the storm is expected to remain offshore, reaching near 12.2N 91.8W this evening, and near 10.6N 97.3W Thu evening. Some gradual weakening is forecast during the next couple of days and Pilar moves west- southwestward and into the open Pacific waters through the weekend. Heavy rains from Pilar will produce flash and urban flooding, along with mudslides in areas of higher terrain of the Pacific coast of Central America from southern El Salvador, across southern Honduras, western Nicaragua into northern Costa Rica through today. Swells generated by Pilar are expected to continue affecting the Pacific coast of Central America during the next couple of days. These swells are likely to cause life- threatening surf and rip current conditions. Please consult products from your local weather office. 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 Pilar NHC Forecast/Advisory and Public Advisory at www.hurricanes.gov for more details. Gulf of Tehuantepec Storm Warning: Strong gale force N winds observed across the Gulf of Tehuantepec overnight have increased to storm-force winds this morning, and are expected to remain at minimal storm force for the rest of tonight through early Thu due to a very tight pressure gradient across the region in the wake of a cold front N of the area. Winds may fluctuate to just below storm force to minimal storm force at times, but the difference will be negligible. Gales will then continue for the remainder of Thu through early Sun. Very large and dangerous seas of 12-24 ft have built with these winds, and are merging with swells generated by Pilar located SE of the area, resulting in confused and hazardous seas where they interact. Please read the latest NHC High Seas forecast at www.hurricanes.gov/marine for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from well SW of Pilar near 07.5N93W to low pressure, Invest EP93, near 12.5N115.5W to 06N136W. The ITCZ extends from 06N136W to beyond 05.5N140W. Scattered moderate to strong convection is noted from 00.5N to 08.5N E of 81W, from 04N to 08N between 82W and 100W, and within 120 nm either side of trough between 114W and 130W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section above for details on Tropical Storm Pilar, and on a Gulf of Tehuantepec Storm Warning. A moderate pressure gradient continues over the Gulf of California region, producing fresh to strong NW-N winds in the central and northern Gulf, with moderate to fresh winds in the southern Gulf. Seas are 4-6 ft across most of the Gulf of California. Elsewhere across the Baja California offshore waters, a weak ridge prevails across the region, producing mainly light to gentle winds with 4-5 ft seas in mixed SW and NW swell. For the forecast, other than the Gulf of Tehuantepec Storm Warning, Pilar will move west-southwestward this afternoon through Fri, and pass through the southern portion of the strong winds blasting out of Tehuantepec. Pilar is expected to reach near 12.2N 91.8W this evening, near 11.6N 94.2W Thu morning, near 10.6N 97.3W Thu evening, near 9.4N 103.3W Fri evening, and continue west-southwestward through the weekend. Little change in intensity is expected. Meanwhile, fresh to strong winds in the northern and central Gulf of California will diminish later today with subsiding seas. Mainly gentle to moderate winds will prevail elsewhere, possibly increasing to fresh to strong from Punta Eugenia northward by early next week. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Please refer to the Special Features section above for details on Tropical Storm Pilar. Aside from Pilar, mainly moderate S-SW monsoonal winds prevail across the offshore waters with seas of 4-6 ft, except 5-7 ft offshore Ecuador. Scattered showers and thunderstorms are across the waters from Panama southward as described above. For the forecast, Pilar is expected to reach near 12.2N 91.8W this evening, near 11.6N 94.2W Thu morning, near 10.6N 97.3W Thu evening, near 9.4N 103.3W Fri evening, and continue west- southwestward through the weekend. Little change in intensity is expected. In addition to high and confused seas interacting between Pilar and seas generated across Tehuantepec, large and dangerous surf will continue along the coastlines of El Salvador and Guatemala through Fri. Elsewhere, mainly moderate monsoonal winds will prevail through the forecast period, locally fresh to strong in the Gulf of Panama by the end of the week. ...REMAINDER OF THE AREA... Please refer to the Special Features section above for details on Tropical Storm Pilar. High pressure is centered W of southern California along 129W with a ridge extending south and southwestward across the waters N of the monsoon trough and ITCZ. Fresh winds to 20-25 kt surround a 1007 mb low pressure, Invest EP93, near 12.5N115.5W, where seas are 6-8 ft. Winds are moderate or weaker elsewhere, along with seas of 5-7 ft. For the forecast, high pressure N of the area will shift slightly SE through the next few days and act to freshen the winds S of 24N and W of 120W through the weekend, which will build seas to around 8 ft in that area. Little change in seas is forecast elsewhere, except in the far NW waters where seas may build to around 8 ft late in the weekend in new NW swell. Pilar will move west-southwestward through the weekend and pass along and S of 10N through Sun, before beginning to turn west-northwestward. Meanwhile, the organization of Invest EP93 has not improved since yesterday, and the environmental conditions are forecast to become increasingly unfavorable for development during the next day or two while the low meanders over the central portion of the eastern Pacific basin. Looking ahead, a larger pulse of NW swell may arrive and push SE of 30N140W early next week. $$ Stripling