000 AXPZ20 KNHC 020254 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 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 0000 UTC surface analysis and satellite imagery through 0100 UTC. ...SPECIAL FEATURES... Tropical Storm Pilar is centered near 12.4N 92.6W at 02/0300 UTC, moving west at 10 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Peak seas are currently around 18 ft. Deep convection has diminished in the past several hours with scattered moderate present from 11N to 14N between 90W and 95W. A faster westward to west-southwestward motion is expected over the next few days. Some additional weakening is possible during the next couple of days. The combination of previous heavy rainfall and any additional rainfall from Pilar may produce flash and urban flooding, along with mudslides in areas of higher terrain of the Pacific coast from El Salvador into southern Guatemala overnight. Swells generated by Pilar and strong winds near the Gulf of Tehuantepec are expected to continue affecting the Pacific coast of Central America during the next day or two. 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: Storm force N winds continue across the Gulf of Tehuantepec this evening and are expected to remain at minimal storm force through early Thu due to a very tight pressure gradient across the region in the wake of a cold front NE of the area. A recent altimeter pass showed large seas, potentially missing the peak area which are believed to be around 23 ft. Gales will then continue for the remainder of Thu through early Sun. Continued very large and dangerous seas of 12-24 ft will merge with swells generated by Pilar located just 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 06N97W to low pressure, Invest EP93, near 13N116W, to 09N121W. The ITCZ extends from 09N121W to beyond 09N140W. Numerous moderate isolated strong convection is noted from 05N to 11N between 77W and 89W. Scattered moderate isolated strong convection is noted from 11N to 14N between 113W and 116W associated with Invest EP93, and from 09N to 11N between 120W and 123W. Scattered moderate convection is noted from 08N to 10N between 138W and 140W. ...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 moderate to fresh NW-N winds in the central and southern Gulf there. Seas are 3-5 ft across the Gulf of California. Light to gentle winds dominate the remainder of the open waters away from the Tehuantepec region, along 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 to 11.7N 94.8W Thu morning, 10.8N 97.8W Thu evening, 9.9N 101.0W Fri morning, 9.4N 104.1W Fri evening, 9.5N 106.8W Sat morning, and 9.7N 109.2W Sat evening. Pilar will weaken to a tropical depression over 10.5N 113.1W late Sun. As Pilar moves into this area gales occurring downwind of the Gulf of Tehuantepec may briefly spread all the way to the NW quadrant of Pilar. By Thu, a slow and gradual weakening trend is expected into the weekend. Meanwhile, moderate to fresh winds in the central and southern Gulf of California will diminish through the end of the week. NW-N winds may increase to fresh to strong offshore Baja California Norte 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, gentle to moderate S-SW monsoonal winds prevail across the offshore waters with seas of 4-6 ft, except 6-7 ft offshore Ecuador to the Galapagos Islands. Scattered showers and thunderstorms are across the waters from Costa Rica southeastward as described above. For the forecast, Pilar will move to 11.7N 94.8W Thu morning, 10.8N 97.8W Thu evening, 9.9N 101.0W Fri morning, 9.4N 104.1W Fri evening, 9.5N 106.8W Sat morning, and 9.7N 109.2W Sat evening. Pilar will weaken to a tropical depression over 10.5N 113.1W late Sun. 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. ...REMAINDER OF THE AREA... Please refer to the Special Features section above for details on Tropical Storm Pilar. Invest EP93 at 1007 mb is centered near 12.5N116W with associated convection as described above. Associated winds have likely diminish to 20 kt at most, with seas of 5-6 ft. Otherwise, high pressure prevails N of the monsoon trough and ITCZ. Winds are moderate or weaker except locally fresh from 08N to 20N and W of 130W. Seas are 4-6 across the remainder of the open waters, locally 7 ft across the trade wind zone of locally fresh winds. For the forecast, Pilar will move to 11.7N 94.8W Thu morning, 10.8N 97.8W Thu evening, 9.9N 101.0W Fri morning, 9.4N 104.1W Fri evening, 9.5N 106.8W Sat morning, and 9.7N 109.2W Sat evening. Pilar will weaken to a tropical depression over 10.5N 113.1W late Sun. Meanwhile, Invest EP93 no longer is being forecast for any probability of tropical cyclone formation. Mainly moderate winds will prevail, except locally fresh continuing across the central portion. Seas will be mainly 5-7 ft through the next several days, locally to 8 ft across the trade wind zone and also in the NW waters this weekend as a weak cold front dies just NW of the area. $$ Lewitsky