000 AXPZ20 KNHC 191555 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Fri Nov 19 2021 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 1545 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A cold front over the NW Gulf of Mexico will reach the southeast part of that Gulf late today. High pressure will build behind the front. The pressure gradient between this building high pressure and lower pressure within the eastern north Pacific monsoon trough will support a gale- force gap wind event from today into late Sat morning. Seas will build to around 12 ft during this upcoming event. Please see the latest NWS High Seas Forecast issued by the National Hurricane Center at website://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more information. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from northwestern Colombia to a 1010 mb low that is located near Panama at 10N78W, then to over southern Costa Rica, to the coast at 10N84W and continues to 07N90W to 08N100W and to 09N106W. The ITCZ continues from 09N106W to 08N120W to 10N128W, where it pauses just to the east of a trough. It resumes to the west of the trough from 10N131W to 09N136W, where it pauses just to the east of another trough. It resumes again from 08N138W to beyond the area at 08N140W. Scattered moderate convection is within 120 nm north of the ITCZ between 115W-120W, and within 30 nm of the ITCZ between 109W- 115W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO Please see the Special Features section above for details on a recently started Gulf of Tehuantepec gale-force gap wind event. As mentioned above gale force north to northeast winds have begun across the Gulf of Tehuantepec region. As for the synoptic pattern outside the Gulf of Tehuantepec region, a ridge extends from high pressure of 1022 mb centered near 29N129W southeastward across the offshore waters west of the Baja California peninsula. The pressure gradient across the area is supporting mainly gentle to moderate winds across the open waters outside of the Tehuantepec region. Seas are in the 4-6 ft range across these open waters. Over the Gulf of California, light to gentle winds prevail. Seas are in the 2-4 ft in the southern Gulf of California, and 3 ft or less in the central and northern Gulf of California. For the forecast, the gale-force winds across the Gulf of Tehuantepec region will continue through late morning on Sat. Gap winds may once again approach gale-force again in the Gulf of Tehuantepec region early next week as strong high pressure surges southward over eastern Mexico. Fresh to strong northwest to north winds may develop in the northern Gulf of California early next week. Fairly tranquil conditions are forecast elsewhere through the upcoming weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, and WITHIN 750 NM OF ECUADOR The earlier moderate to fresh northeast to east winds across the Papagayo region have increased to fresh to strong speeds as of this morning. Otherwise, light to gentle winds are noted north of the monsoon trough. Gentle to moderate southerly winds prevail south of the monsoon trough. Seas are in the 4-7 ft range across the majority of the offshore waters, highest south of Panama and west of Colombia and Ecuador. For the forecast, the fresh to strong northeast to east winds in the Papagayo region will diminish to moderate to fresh speeds by early this afternoon, then pulse back up to fresh to strong speeds late tonight into early on Sat, and diminish once again to moderate to fresh speeds during Sat afternoon. These winds may pulse again to fresh to strong for a brief period early on Sun, then remain at moderate to fresh speeds thereafter. Gentle to moderate winds will prevail across the rest of the area the next several days. REMAINDER OF THE AREA... A 1022 mb high pressure center is located near 29N129W. A trough extends from 14N126W to 09N131W. A second trough is to the west along a position from near 12N135W to 07N138W. Satellite imagery shows scattered moderate to strong convection from 10N to 15N between 125W-131W. The pressure gradient between the area of high pressure and the surface troughs is supporting moderate to fresh winds from 10N to 20N between 120W and 140W. Light to gentle winds are in the vicinity of the high center. Gentle to moderate winds are elsewhere north of the ITCZ. Gentle to moderate southerly winds are south of the monsoon trough and ITCZ. Seas of 5-7 ft are observed over the waters within the moderate to fresh winds. Elsewhere, seas of 4-6 ft prevail. For the forecast, a dissipating stationary front over the far NW corner of the area will transition to a trough that will move across the far northern waters through the weekend. It will be followed by moderate to fresh north to northeast winds as high pressure builds in behind it. Seas of 5-6 ft will follow in wake of the cold front. An area of fresh to strong east winds between the first trough mentioned above and the aforementioned high pressure has developed from 13N to 15N between 127W-129W. Seas with these winds are about 8-9 ft. These winds are forecast to diminish to mainly fresh speeds during Sat afternoon, with seas to 8 ft due to mixed swell. $$ Aguirre