000 AXPZ20 KNHC 031644 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Fri Nov 3 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 1530 UTC. ...SPECIAL FEATURES... Tropical Storm Pilar is centered near 10.2N 103.0W at 03/1500 UTC, moving west-southwest at 18 kt. Estimated minimum central pressure is 1000 mb. Maximum sustained wind speed is 45 kt with gusts to 55 kt. Numerous moderate to isolated strong convection is noted from 09N to 12N between 101W and 105W. Peak seas are around 16 ft. Pilar is expected to turn toward the west and a decrease in forward speed during the next couple of days. A slower west-northwestward motion is forecast by early next week. Little change in strength is forecast during the next few days. 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 Gale Warning: Gale force winds continue across the Gulf of Tehuantepec with peak seas estimated to be around 14 ft. These winds are due to a very tight pressure gradient across the region in the wake of a cold front that moved across the Gulf of Mexico and southern Mexico a couple of days ago. Gales are expected to persist through Sun night. Very large and dangerous seas of 10-14 ft will merge with swells generated by Pilar located well to the southeast of the area and moving farther westward into the open Pacific. This is 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. Potential for heavy rainfall over Central America: A disturbance (Invest 97L) is currently in the central Caribbean Sea. Plenty of tropical moisture and an unstable atmosphere is forecast to produce heavy rains Friday through the weekend across Central America. This rainfall is likely to result in flash flooding and possible landslides. Please refer to the local weather services for more information. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends off the coast of Nicaragua near 12N87W to 12N98W, then SW of Pilar from 08N104W to 05N111W. The ITCZ extends from 05N111W to 09N130W to beyond 07N140W. Scattered moderate to isolated strong convection is noted from 04N to 12N between 77W and 90W and from 05N to 13N between 124W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section above for details on the Gulf of Tehuantepec Gale Warning. Outside of those two events, surface ridging extends across the Baja California offshore waters anchored by a 1021 mb high pres near 33N130W. The pressure gradient from this high pressure and lower pressure over Mexico is leading to moderate to locally fresh NW to N winds in the Gulf of California, with 2 to 4 ft seas. Meanwhile, light to gentle winds are noted across the rest of the Mexico offshore waters. Seas range 4-5 ft in mixed NW and S swell. For the forecast, Tropical Storm Pilar will continue to move farther away from the Mexico offshore waters during the next few days. A gale warning is in effect across the Gulf of Tehuantepec through Sun night. The combination of the gale warning and Pilar is resulting in large and confused seas off Oaxaca. Winds and seas will diminish through Mon. Meanwhile, moderate to fresh winds in the Gulf of California will diminish by the end of the weekend. 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... Gentle to moderate S-SW monsoonal winds prevail across the offshore waters with seas 4 to 6 ft. Seas range 8 to 9 ft across the offshore waters of Guatemala due to the Tehuantepec gap wind event, west of 94W. Seas are within mixed swell across the Central American and South American offshore waters. Scattered showers and thunderstorms are across the waters from Costa Rica southeastward to southern Colombia as described above. For the forecast, expect large seas off Guatemala through Sun due to swell generated off southern Mexico from gale force winds in the Gulf of Tehuantepec. Gentle to moderate winds and slight to moderate seas will persist elsewhere. ...REMAINDER OF THE AREA... Please refer to the Special Features section above for details on Tropical Storm Pilar. A few showers and thunderstorms are active near a trough with an axis along 120W from 12N to 15N between 119W and 122W. Moderate to locally fresh winds with seas to 6 ft. Surface ridging extends across the region anchored by a 1021 mb high pressure near 32N130W. Moderate to fresh winds are noted N of the ITCZ to 20N and W of 120W. From 20N to 31N, winds are gentle to moderate. Seas range 5 to 7 ft in this area. South of the ITCZ and monsoon trough, gentle winds prevail with seas to 7 ft. For the forecast, Pilar will move to 9.9N 105.4W this evening, 9.8N 108.6W Sat morning, 10.0N 111.0W Sat evening, 10.4N 113.4W Sun morning, 11.1N 115.0W Sun evening, and 11.8N 116.2W Mon morning. Pilar will change little in intensity as it moves near 13.5N 118.5W early Tue. Mainly moderate to fresh winds will prevail N of the ITCZ and monsoon trough through early next week. Seas will be mainly 5-7 ft through the next several days, locally to 8 ft across the trade wind zone. A weak cold front is expected to push across the NW portion of the forecast waters which is expected to bring seas 8 to 9 ft by early next week. $$ AReinhart/Mora