000 AXPZ20 KNHC 040249 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Sat Nov 4 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 0240 UTC. ...SPECIAL FEATURES... Tropical Storm Pilar is centered near 9.9N 106.2W at 04/0300 UTC, moving west at 15 kt. Estimated minimum central pressure is 1002 mb. Maximum sustained wind speed is 40 kt with gusts to 50 kt. Numerous moderate to scattered strong convection is noted from 120 nm to 180 nm from the center in the northwest quadrant of Pilar, and scattered moderate convection is noted within 60 nm of the center. Peak seas are currently around 16 ft. Pilar will continue moving toward the west during the next couple of days. By early next week, a slower west- northwestward motion is forecast. 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 13 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 continues to interact 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. Strong winds will diminish by Tue as well as seas subsiding below 8 ft. 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 moving across the northwest Caribbean Sea into Honduras. Plenty of tropical moisture and an unstable atmosphere is forecast to produce heavy rains 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 from 12N87W to 07N100W. The ITCZ extends from 06N110W to 10N125W to 07N140W. Scattered moderate convection is noted from 10N to 12N east of 88W, and from 06N to 08N west of 135W. ...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 the Gulf of Tehuantepec gap wind event, surface ridging extends across the Baja California offshore waters anchored by a 1023 mb high pres near 31N130W. The pressure gradient from this high pressure and lower pressure over Mexico is leading to moderate to 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 to 6 ft in mixed 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 will remain 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, although the effects of Pilar will diminish as the storm moves farther west, leaving mostly wind waves and shorter-period swell associated from the Tehuantepec gap wind event. The gale force winds will end by Sun night with the strong winds diminishing by Tue. Seas will also subside across the Oaxaca offshore waters by Tue. Looking ahead farther north, the moderate to fresh winds in the Gulf of California will diminish by Sun, but NW-N winds may increase to fresh to strong offshore Baja California Norte early next week as a high pressure builds west of the region following a frontal boundary that will approach the area and stall early in the 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 93W. Mixed swell will persist 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 night 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 may be ongoing near a trough near 120W from 12N to 25N. The trough had previously been a well developed low pressure area, but has since weakened. Winds have subsequently diminished as well, but a recent altimeter satellite pass indicated combined seas up to 7 ft were lingering near the trough. Surface ridging extends across the region elsewhere north of 20N anchored by a 1022 mb high pressure near 31N130W, supporting mostly moderate trade winds mainly from 10N to 20N. Earlier scatterometer and altimeter satellite pass indicated fresh trade winds with combined seas to 8 ft from 08N to 15N west of 135W. For the forecast, Pilar will move to 9.7N 108.3W Sat morning, 9.9N 111.0W Sat evening, 10.5N 113.2W Sun morning, 11.1N 114.9W Sun evening, 11.8N 116.5W Mon morning, and weaken to a remnant low near 12.4N 117.6W Mon evening. Pilar will change little in intensity as it moves to near 14N 120W late Tue. Otherwise, mainly moderate to fresh winds will prevail north of the ITCZ and monsoon trough through early next week. Seas will be mainly 5-7 ft through the next several days, with seas to 8 ft across the trade wind zone. A weak cold front is expected to push across the waters north of 25N through Mon, accompanied by seas 8 to 9 ft which will cover most of the area north of 10N and west of 120W by mid week. $$ Christensen