520 AXPZ20 KNHC 172205 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Fri Nov 17 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 2145 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from northern Colombia to across the far southwestern Caribbean Sea to across the central part of Costa Rica to 07N100W to low pressure near 09N114W 1011 mb to 11N123W to 09N140W. Scattered moderate to isolated strong convection is within 120 nm south of the trough between 85W-95W, and within 60 nm south of the trough between 106W-111W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh to strong NW to N winds are in the Gulf of Tehuantepec north of 15N. A 1016 mb high pressure is centered offshore central Baja California near 25N116W. A rather weak gradient in place is allowing for generally light to gentle winds to exist offshore offshore Baja California, to the north of Cabo San Lazaro, underneath the high pressure center. Gentle to moderate NW to N winds are within about 60 nm offshore southern Baja California, to the south of Cabo San Lazaro. Seas of 5-8 ft prevail west of Baja California in a NW swell. In the southern section of the Gulf of California moderate to fresh NW winds are present there, while fresh to strong NW winds are in the central part of the Gulf. Seas are 4-6 ft over these sections of the Gulf. Gentle NW winds are over the northern Gulf of California with 1-2 ft seas. Gentle W to NW winds prevail elsewhere offshore between Jalisco and Guerrero, where seas are 4-6 ft. For the forecast, the fresh to strong N winds will continue in the Gulf of Tehuantepec through Sat night before diminishing early Sun. NW swell across the Baja California offshore waters will gradually subside through Sat. The pressure gradient between high pressure just west of Baja California and lower pressure over northern Mexico will support moderate to fresh NW winds across central and southern portions of the Gulf of California through Sun, except for fresh to strong tonight. These winds will then expand into northern portions of the Gulf of California and increase to fresh to strong Sun night through Tue and diminish moderate speeds Wed and Wed night in the central and southern portions and to fresh speeds in the northern portion. West of Baja California, NW to N winds will increase to fresh Sat afternoon, then increase to fresh to strong Sun through Sun night. Looking ahead, the next gale-force gap wind event in the Gulf of Tehuantepec is possible during the middle of next week. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Scattered to numerous showers continue offshore Costa Rica from 07N to 10N between 83.5W-90W. Fresh SW winds are occurring within this area of showers and thunderstorms. Seas are in the range of 6-8 ft in this area. Elsewhere south of the monsoon trough, moderate SW winds are ongoing with seas of 5-7 ft. Gentle winds prevail N of 09N, along with seas of 5-7 ft in mixed swell. For the forecast, light to gentle winds will prevail N of 09N through the forecast period. Moderate to fresh SW winds will continue offshore Panama and Costa Rica through Sat, with seas to 8 ft offshore Costa Rica tonight. Winds will diminish thereafter under a weak pressure pattern. ...REMAINDER OF THE AREA... A 1011 mb low along the monsoon trough is centered near 11N115W. Scattered moderate isolated strong convection is noted from 09N to 11N between 113W-116W. A recent ASCAT pass shows strong SW to W winds from 08N to 10N along with seas of 9-10 ft. Development, if any, of this system is expected to be slow to occur over the next day or two as the disturbance moves generally westward. After that time, environmental conditions are forecast to become less conducive for further development. There is a low chance of tropical cyclone development within the next 48 hours. A series of surface troughs are analyzed on the 18 UTC surface map. The first one extends southward from a large low pressure system north of the area to 30N122W to 24N130W and to 22N140W. The second one extends from near 30N126W to 25N140W and the third one from near 30N129W to 28N139W. Recent ASCAT data shows mostly fresh southwest winds north of 28N between 123W and the second trough. The ASCAT data also shows fresh W to NW winds west of the second trough. Large seas of 8-10 ft in NW to N swell are ongoing over the open waters N of about 05N and W of 110W. Elsewhere, a surface trough extends from near 23N120W to 14N123W. Scattered moderate to isolated strong convection is noted within 120 nm east of the trough from 18N to 22N and within 60 nm west of the trough from 14N to 17N. Moderate to fresh N winds are W of the trough to near 128W. Seas are 9-10 ft in the vicinity of the through due to long-period NW swell. South of the monsoon trough and E of 120W, moderate to fresh S to SW winds prevail with seas 7-9 ft in mixed SE and NW swell. For the forecast, the large NW to N swell covering the area from 02N to 30N between 110W-140W will gradually subside through Sat night as it continues to spread southward, bringing seas of 8-10 ft tonight between the Equator and 16N west of 110W. The fresh winds associated to the troughs over the northern part of the area will shift to N of 30N on Sat. NE trade winds will increase a bit to fresh late Sat through Sun night across most of the area north of the monsoon trough/ITCZ as high pressure builds back across the region. $$ Aguirre