000 AXPZ20 KNHC 020939 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Thu Feb 02 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 0600 UTC surface analysis and satellite imagery through 0930 UTC. ...SPECIAL FEATURES... Gulf of Tehuantepec Gale Warning: A strong cold front is expected to sweep across the Gulf of Mexico on Fri. Strong high pressure in its wake will build southward along the Sierra Madre mountains of Mexico leading to a significant tightening of the pressure gradient that will induce a strong gale-force gap wind event in the Gulf of Tehuantepec. Gale-force N winds are forecast to begin late Thu night before abruptly increasing to strong gale-force by Fri afternoon, continuing into early on Sat, with possible brief gusts to storm force. Seas will build quickly to near 20 ft Fri night into early Sat. Conditions will improve on Sun with winds diminishing below gale force on Sun and seas subsiding to below 8 ft by late Mon. Please read the latest High Seas Forecast issued by the National Hurricane Center at website https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends from northwest Colombia southwestward to 08N79W to 07N85W and to 04N92W. The ITCZ extends from 04N92W to 02N102W to 06N113W to 06N125W and to 06N140W. Scattered moderate to isolated strong convection is seen within 120 nm N of the ITCZ between 117W-121W. Scattered moderate convection is within 30 nm of the ITCZ between 121W-126W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... High pressure is over the are, with the associated gradient maintaining gentle to moderate northerly winds across the Gulf of California. Seas over the Gulf are 3-5 ft. Moderate to fresh N-NE winds are over the offshore waters of Baja California Sur and southwestern Mexico, while gentle N to NE winds are over the offshore waters of Baja California Norte. Seas over these waters are in the range of 5-7 ft, except 6-8 ft in a long-period NW swell S of Cabo San Lazaro. Strong to near gale-force N winds are in the Gulf of Tehuantepec, with seas of 5-7 ft. Moderate or weaker winds and moderate seas are prevalent elsewhere in the basin. For the forecast, the strong to near gale-force N winds in the Gulf of Tehuantepec will briefly diminish to fresh speeds this afternoon, then pulse back up to strong to near gale-force early this evening and to gale-force late tonight. These winds are forecast to abruptly increase to strong gale-force by Fri afternoon and continue into early Sat, with possible brief gusts to storm force. Along with these winds, seas are expected to build rather quickly to near 20 ft from late Fri into Sat. With strong high pressure N of the area shifting E from late Sat into Sun, this will allow for the gap wind gale conditions to diminish to strong to near gale-force into Mon night. A surge of fresh to strong NW winds will impact the central and southern Gulf of California tonight into early Fri before diminishing Fri afternoon. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Overnight ASCAT data shows fresh to strong NE-E gap winds in the Gulf of Papagayo region and over the Nicaraguan offshore waters region, extending westward to near 90W. Seas are 6-8 ft in the Gulf of Papagayo region and 5-7 ft over the Nicaraguan offshore waters. Fresh to strong N to NE winds are over the Gulf of Panama. They reach southward to near 06N. Seas of 4-6 ft are over these waters. Otherwise, light to gentle winds and moderate seas prevail elsewhere in the basin. For the forecast, fresh to strong trade winds in the Gulf of Papagayo region will prevail into early next week. Seas will be near or to 8 ft in the areas of strongest winds. Large swell generated by an upcoming Gulf of Tehuantepec strong gale force gap wind event is expected to begin to propagate through the Guatemala and El Salvador offshore waters starting Fri night and begin to subside on Sun. REMAINDER OF THE AREA... High pressure of 1025 mb is centered near 32N124W, with a ridge extending southeastward to the vicinity of Cabo Corrientes, Mexico. High pressure covers the area N of 18N. A cold front has moved into the NW part of the area. It extends from near 30N136W to 27N140W. Overnight ASCAT data indicates fresh to strong winds ahead of the front N of 27N and E to near 130W and behind the front N of 29N. Seas with these winds are in the range of 8-10 ft. Satellite imagery shows patches of rain along with scattered showers and isolated thunderstorms N of about 27N and W of 130W. The pressure gradient between the high pressure system and lower pressure in the deep tropics support fresh to strong NE to E trade winds, mainly south of 20N and west of 112W as depicted in overnight ASCAT data passes. In addition, a trough that extends from near 17N117W to 08N120 is assisting with the presence of the fresh to strong NE to E trade winds. Seas are 8-10 ft W of the trough to 122W and from 14N to 17N. Seas elsewhere over these waters are 8-9 ft due to a mix of NE and NW swell. Moderate or weaker winds and moderate seas prevail in the remainder of the basin. For the forecast, fresh to locally strong trade winds and seas of 8-10 ft will change little over most of the area through Fri night. The aforementioned high pressure will slide east- southeastward toward northern Baja California through early Thu in response to the cold front that is presently entering the far NW part of the area. The cold front will begin to weaken later today, then stall as it reaches from near near 30N129W to 28N133W and to 26N140W by late tonight, at which time associated southerly winds ahead of it will have diminished to moderate to fresh speeds, and winds behind will have become light to gentle, N to NE in direction. NW swell producing seas of 8-10 ft will be the main issue for marines by late tonight. These seas will be over the NW and north-central sections of the area, primarily to the NW of a line from 30N127W to 28N133W and to 25N140W. The NW swell will slowly decay by late Fri night allowing for these seas to subside slightly. $$ Aguirre