000 AXPZ20 KNHC 212038 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 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 1800 UTC surface analysis and satellite imagery through 1900 UTC. ...SPECIAL FEATURES... Pacific Gale Warning for far northern waters behind a cold front: A cold front extends from the coast of Orange County, California through 30N119W to 22N130W to 19.5N140W. 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 28N west of the front to around 136W, 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 is large NW swell following the front, with seas reaching up to around 19 ft tonight 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 building shorter-period waves associated with northeast trade winds, with combined significant wave heights reaching 12 ft mainly from 07N to 19N and west of 120W. These seas of around 12 ft may continue through Sat night before decaying for the end of the upcoming weekend. 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 07.5N78W to 04N91W. The ITCZ extends from 04N91W to 01N101W to 03N115W to beyond 00N124W. Scattered moderate isolated strong convection is noted from 00N to 03N between 88W and 92W, from 00N to 03N between 95W and 103W, and from 01N to 09N between 112W and 132W. Scattered moderate convection is noted from 01S to 02S between Ecuador and 83W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A cold front is nearing the Baja California Norte waters with fresh to strong SW winds ahead of it pushing into those waters. 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. Fresh to strong N winds are in the Gulf of Tehuantepec due to high pressure N of the area, with seas of 5 to 8 ft there. 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 except building to 4 to 6 ft in NW swell offshore Baja California Norte. For the forecast, fresh to strong N winds in the Gulf of Tehuantepec will diminish shortly, with another pulse late tonight into early Wed. A cold front entering offshore Baja California Norte 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 remainder of the forecast period. 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 per recent ASCAT scatterometer data 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. Some haze is being reported at coastal locations due to ongoing agricultural fires. For the forecast, fresh to strong gap winds will pulse across the Gulf of Papagayo and the coast of Nicaragua through the next several days. Moderate to fresh N to NE winds can be expected over the Gulf of Panama through Fri morning, locally strong Wed night through Thu. 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 tonight into early Wed, as well as significant seas over the northern waters continuing into mid-week. A cold front extends from the coast of Orange County, California through 30N119W to 22N130W to 19.5N140W. 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 N of about 24N. 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 14N between 90W and 106W 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 25N W of 110W, supporting fresh to strong speeds for the latter half of the week through Sat, then diminishing somewhat for the end of the upcoming weekend. Mainly gentle to moderate winds and slight to moderate seas will prevail elsewhere. $$ Lewitsky