000 AXPZ20 KNHC 030406 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... Tropical Storm Pilar is centered near 10.7N 99.2W at 03/0300 UTC, moving west-southwest at 19 kt. Estimated minimum central pressure is 998 mb. Maximum sustained wind speed is 50 kt with gusts to 60 kt. Peak seas are currently around 20 ft. Convection has recently been weakening, with scattered moderate to isolated strong convection within 75 nm of the center. Pilar has been moving radpidly over the past several hours, but is expected to become slower as it continues to move west- southwestward over the next couple of days. 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: Recent ship observations and an earlier scatterometer satellite pass confirmed gale force N winds across the Gulf of Tehuantepec as far south as 14N. Peak seas are around 14 ft. These winds are due to a very tight pressure gradient across the region in the wake of a cold front NE of the area. Gales are expected to persist through Sun. Very large and dangerous seas of 10-14 ft will merge with swells generated by Pilar located SE of the area and moving across the outer portion of the Tehuantepec offshore zone. 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... Segments of the monsoon trough extends from 11N86W to 11N88W, and from 07N110W to 06N105W to 1007 mb low pressure near 14N118W to 10N125W. The ITCZ extends from 10N125W to 07N140W. Scattered moderate convection is noted from 08N to 10N east of 85W, from 11N to 13N between 100W and 102W, and from 09N to 11N between 124W and 126W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please refer to the Special Features section above for details on Tropical Storm Pilar and the Gulf of Tehuantepec Gale Warning. Outside of those two events, surface ridging extends across the Baja California offshore waters anchored by a 1022 mb high pres near 32N129W. 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, gentle to moderate 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 move to 10.0N 101.8W Fri morning, then change little in intensity as it moves farther west through early Mon. In addition to Pilar, a gale warning is in effect across the Gulf of Tehuantepec. 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 5 to 7 ft. Seas range 8 to 10 ft ft across the offshore waters of Guatemala near Pilar, west of 93W. Seas along the Central American offshore waters are in mixed swell, while the South American offshore waters are within S swell. 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 Sat due to swell generated off southern Mexico from gale force winds in the Gulf of Tehuantepec, and the effects of Tropical Storm Pilar centered farther west of the area, moving westward. 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. Invest EP93 is centered near 14N118W with associated convection as described above with a central pressure of 1007 mb. Scatterometer winds are 15 to 20kt with locally 25 kt, and seas of 5-6 ft. Otherwise, a 1021 mb high pressure prevails N of the monsoon trough and ITCZ near 32N129W. Scatterometer showed winds are moderate to fresh from the ITCZ to 17N. Light to gentle winds are noted N of 17N and W of W of 120W. Winds south of the ITCZ and monsoon trough are moderate to locally fresh. 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 10.9N 99.4W Fri morning, 10.4N 102.6W Fri afternoon, 10.3N 105.5W Sat morning, 10.5N 108.1W Sat afternoon, 10.7N 110.5W Sun morning, and 11.2N 112.3W Sun afternoon. Pilar will change little in intensity as it moves near 12.3N 114.9W by Mon afternoon. Meanwhile, some slight development of Invest EP93 is possible today while it moves slowly northwestward over the central portion of the eastern Pacific basin. By Friday, upper- level winds are expected to become increasingly unfavorable for further development. There is a low chance of development for this system in 48 hours and 7 days. Mainly moderate to fresh winds will prevail N of the ITCZ and monsoon trough and around EP93 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. $$ Christensen