000 AXPZ20 KNHC 312225 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Tue Oct 31 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 2100 UTC. ...SPECIAL FEATURES... Tropical Storm Pilar is centered near 11.4N 89.5W at 2100 UTC, moving east-northeast at 3 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Peak seas are currently around 17 ft. Numerous strong convection is from 10N to 12.5N between 89W and 91.5W. Scattered moderate isolated strong convection is elsewhere from 09.5N to 14N between 87W and 94W. Pilar is move very little overnight, then begin to move west-southwestward Wed through Thu and away from land. Pilar could intensify slightly over the next day or two before. 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 El Salvador southward to Costa Rica through Wednesday. Swells generated by Pilar are expected to continue affecting the Pacific coast of Central America during the next few days. These swells are likely to cause large and dangerous surf and life-threatening 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: Gale force N winds continue across the Gulf of Tehuantepec, and extend southward to near 13.5N, as strong high pressure is building across eastern Mexico behind a cold front in the Gulf of Mexico. Winds will increase to minimal storm force tonight through early Thu. Winds may fluctuate to just below storm force to minimal storm force at times, but the difference will be negligible. Gales will continue after Thu and gradually diminish below gale-force through Sat evening. Very large and dangerous seas of 12-24 ft will build with these winds, and also mix with swells generated by Pilar located SE of the area, resulting in confused and hazardous seas where they merge. 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 SW of Pilar near 07.5N91W to 06N103W to low pressure, EP93, near 12N116.5W, to 10N121W. The ITCZ extends from 10N121W to beyond 07N140W. Scattered to locally numerous moderate to strong convection is noted from 01.5N to 10N E of 88W, and within 120 nm either side of the trough between 113.5W and 118W. Scattered moderate isolated strong convection is noted elsewhere within 180 nm S of the trough between 91W and 95W, and within 150 nm S of both boundaries W of 118W. ...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 very tight pressure gradient continues over the Gulf of California region, producing fresh to strong NW-N winds in the central and northern Gulf. Afternoon ASCAT scatterometer data showed these winds still to around 30 kt across NW portions. Seas are 6-8 ft across the northern Gulf of California, and 4 to 7 ft across southern portions. Elsewhere across the Baja offshore waters N of Punta Eugenia, gentle to moderate N to NE winds prevail, with some narrow zones of stronger NE winds filtering through passages through Sebastian Vizcaino Bay to around Punta Eugenia. Mainly light to gentle winds are across the remainder of the offshore waters, locally moderate near Cabo Corrientes. Seas are 4 to 6 ft across these offshore waters. For the forecast, other than the Gulf of Tehuantepec Storm Warning, Pilar will stall tonight, then move west-southwest Wed through Fri and away from land. Large northerly swell that will be generated by this Tehuantepec wind event will merge with swell from Pilar to produce confused and dangerous seas across these southeast Mexican waters through Thu. Meanwhile, fresh to strong winds in the northern and central Gulf of California will diminish Wed while seas subside. Mainly gentle to moderate winds will prevail elsewhere, along with 4-6 ft seas. ...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 5-7 ft in southerly swell, except 4-6 ft offshore Colombia. Scattered showers and thunderstorms are across the waters from Costa Rica westward as described above. For the forecast, Pilar will move very little overnight, then turn west-southwestward and move to 11.5N 90.5W midday Wed, reach near 10.7N 94.5W midday Thu, near 9.6N 100W midday Fri, then continue west-southwestward through the weekend. Some very minor strengthening is possible over the next 48 hours. Elsewhere, mainly gentle to moderate monsoonal winds will prevail through the forecast period. A storm-force gap wind event in the Gulf of Tehuantepec will generate very large NW swell moving into the offshore waters of Guatemala tonight through the end of the week. These large seas from the NW will combine with sea propagating away from Pilar to create very confused and hazardous boating conditions. ...REMAINDER OF THE AREA... Please refer to the Special Features section above for details on Tropical Storm Pilar. High pressure is centered offshore of southern California and extends a ridge south and southwestward across the waters N of the monsoon trough. Fresh winds to near 25 kt surround a 1008 mb low pressure, Invest EP93, near 12N116.5W, where seas are 8 to 10 ft. Moderate trade winds are found elsewhere W of 125W between the ITCZ and 20N, with 6-7 ft seas. Gentle winds within the ridge are elsewhere N of 20N, while moderate SE winds prevail S of the ITCZ. For the forecast, Pilar will begin to move west-southwestward and away from land Wed through Thu, reaching near 9.6N 100W midday Fri, near 9.5N 105.3W midday Sat, and near 10.1N 109.3W midday Sun. Little change in strength is expected. Invest EP93 has not become better organized since yesterday, and environmental conditions are forecast to become increasingly unfavorable for development during the next couple of days while the low drifts generally northeastward. Elsewhere, gentle to moderate winds will prevail, increasing to moderate to fresh from 09N to 21N W of 110W by the end of the week into the weekend, which will build seas to around 8 ft in that area. Little change in seas is forecast elsewhere. $$ Stripling