000 AXPZ20 KNHC 211511 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 UTC Tue Mar 21 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 1200 UTC surface analysis and satellite imagery through 1300 UTC. ...SPECIAL FEATURES... Pacific Gale Warning for far northern waters behind a cold front: A cold front analyzed from near Point Conception, California through 30N123W to 25N130W to 21N140W. Strong high pressure building in behind the front with cold-air advection is supporting strong to gale-force W to NW winds north of about 29N west of the front to around 137W, with strong to near-gale force winds north of 25N. As the front moves E away from the area, winds will diminish below gale force late tonight into early Wed. Pacific Significant Swell Event: The other hazard from the aforementioned cold front will be large NW swell following the front, with seas reaching up to around 19 ft this afternoon into early Wed along and north of 30N. Wave heights in excess of 12 ft will reach as far south as 23N Wed before subsiding. Looking ahead, even as the NW swell decays Thu into Fri, it will mix with increasing shorter-period waves associated with northeast trade winds along with combined significant wave heights reaching 12 ft mainly from 05N to 25N and west of 110W. These seas of around 12 ft may continue through Sat night before decaying somewhat. Please read the latest High Seas Forecast at https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml and Offshore Waters Forecast at www.nhc.noaa.gov/marine/offshores.php for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from 08.5N78W to 05N90W. The ITCZ extends from 05N90W to 00N98W to 03S101W to 03S120W. Scattered moderate isolated strong convection is noted from 01N to 03N between 88W and 90W, and from 01N to 07N between 115W and 137W. Scattered moderate convection is noted from 01N to 04N between 94W and 96W, and from 01N to 03N between 105W and 110W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh to near gale-force N winds are in the Gulf of Tehuantepec due to high pressure building N of the area, with seas of 5 to 8 ft there. A cold front is just NW of the area. Fresh to strong SW to W gap winds are in the northern Gulf of California N of 30N ahead of the front along with 3 to 6 ft seas, with similar winds just beyond 60 nm offshore Baja California Norte. Mainly gentle anticyclonic winds around a ridge ahead of the front are across the remainder of the offshore waters of Mexico, along with seas of 2 to 4 ft which are starting to build in NW swell offshore Baja California Norte. For the forecast, fresh to strong N winds in the Gulf of Tehuantepec will diminish by late afternoon, with another pulse late tonight. The cold front just NW of the area will cross the Baja California Peninsula and Gulf of California tonight through Wed night. Fresh to strong SW to W gap winds will be in the northern Gulf of California ahead of this cold front with similar winds offshore Baja California Norte, and fresh to strong W to NW winds will occur offshore Baja California behind the front through the end of the week. Fresh to strong winds will develop behind the front in the central and southern Gulf of California to near Cabo Corrientes Thu night through early Sat. Meanwhile, large NW swell of 8 to 12 ft will arrive behind the front offshore Baja California tonight through the end of the week, with a reinforcing set this weekend. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Fresh to locally gap winds are occurring across the Gulf of Papagayo due to high pressure north of the area, with seas of 5 to 7 ft there. Moderate to fresh gap winds are ongoing in the Gulf of Panama. Elsewhere, light to gentle variable winds prevail over the offshore waters of Central America and northern South America, along with seas of 3 to 5 ft mainly due to a long- period south to southwest swell. For the forecast, fresh to locally strong gap winds will prevail across the Gulf of Papagayo and the coast of Nicaragua through Fri night, then again Sat night. Moderate to fresh N to NE winds can be expected over the Gulf of Panama through Fri morning. Gentle to moderate winds and slight seas will prevail elsewhere through the period. REMAINDER OF THE AREA... Please see Special Features section above for details on a Gale Warning in effect for the waters well W of Baja California Norte through tonight into early Wed, as well as significant seas over the northern waters continuing into mid-week. A cold front extends from near Point Conception, California through 30N123W to 25N130W to 21N140W. Ahead of the front, fresh to strong SW winds are N of about 27N. Behind the front, fresh to strong NW winds are occurring around the above mentioned area of strong to gale-force winds, and associated seas are 8 ft or greater. Weak high pressure ridging is the main feature over the area to the south of the front. Moderate to locally fresh trade winds mainly from near 03N to 20N west of 130W are supporting combined seas of 5 to 7 ft in that area. Mainly gentle to moderate winds and slight seas are noted elsewhere, except seas to around 7 ft from 03N to 15N between 90W and 105W due to an earlier Gulf of Tehuantepec gale event. For the forecast, the cold front will move east across the northern and central waters through Wed as its southern part weakens and dissipates. As high pressure builds in behind this front, trade winds will increase from around 03N to 24N W of 110W, supporting fresh to strong speeds for the latter half of the week into the upcoming weekend. Mainly gentle to moderate winds and slight to moderate seas will prevail elsewhere. $$ Lewitsky