000 AXPZ20 KNHC 280349 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Tue Feb 28 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 0000 UTC surface analysis and satellite imagery through 0350 UTC. ...SPECIAL FEATURES... Eastern Pacific Swell Event: The leading edge of a new set of long-period NW swell will begin to propagate into the NE part of the area starting Tue afternoon in the wake of a weak cold front expected to move across the waters N of of Punta Eugenia Tue morning before dissipating shortly thereafter. This swell will be reinforced by another set of NW swell that will approach these same waters W of Baja California beginning on Wed as a strong cold front moves across the region. The swell will spread southward, with the leading edge of the 8 ft seas reaching near 18N between 110W-136W by Thu morning. Maximum seas generated by this swell event are expected to be in the range of 10-17 ft at a period of 10-14 seconds, with the highest of the seas expected N of about 27N between Baja California Norte and 128W on Wed evening. The swell will begin to decay late on Thu. Please read the latest High Seas Forecast at https://www.nhc.noaa.gov/text/MIAHSFEP2.shtml for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...Updated A surface trough extends from northwest Colombia SW to 03N78W. The ITCZ extends from 04S92W to 03S112W to 01S128W. A second ITCZ extends from 02N132W to 05N140W. Scattered moderate convection is from 04N to 16N W of 123W. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please see the Special Features section above for more details on an upcoming northerly swell event. Very strong high pressure of 1038 mb is centered well to the NW of the discussion area. Associated ridging extends southeastward from this high center to across the Baja California peninsula and offshore waters. The gradient between the ridge and lower pressure across Mexico is supporting moderate to fresh N to NE winds across the Baja California and Jalisco offshore waters, and the entrance of the Gulf of California where seas are 5-8 ft in NW swell. Moderate NW winds are in the southern Gulf of California with seas to 5 ft. Light to gentle variable winds are elsewhere along with seas to 4 ft. For the forecast, the fresh NW winds offshore Baja California will continue through Thu night, then diminish as strong high pressure W of Baja California weakens. A weakening cold front will move across the waters W of Baja California Norte tonight, then dissipate Tue as it moves across the central peninsula and Gulf of California. A stronger cold front is forecast to approach the waters W of Baja California Norte N of 29N late Wed afternoon, then quickly move across the remainder of the waters W of Baja California and the entire Gulf of California through Thu evening while it weakens. This front will be preceded by strong to near gale-force SW to W winds in the northern Gulf of California Wed with seas building to 9 ft. Fresh to near gale force W to NW winds will also affect the offshore waters N of Punta Eugenia Wed evening with fresh to strong winds extending southward to Cabo San Lucas through Thu. Decaying swell of 8 to 10 ft in the wake of the front will subside Fri. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh NE to E winds are over the Gulf of Papagayo with seas to 4 ft. Moderate to fresh northerly winds are also in the Gulf of Panama extending past the Azuero Peninsula with seas to 4 ft. Winds are light to gentle elsewhere, with seas of 3-4 ft in SW swell. For the forecast, with little overall change expected in the present synoptic pattern, winds offshore southern Nicaragua including the Gulf of Papagayo will pulse at fresh to strong speeds at night and into the mornings through Thu, with peak seas to around 7 ft. Moderate to fresh N to NE winds will pulse in the Gulf of Panama at night and into the mornings through Thu. Winds will remain light to gentle elsewhere during the forecast period. REMAINDER OF THE AREA... Please see the Special Features section above for more details on the upcoming northerly swell event. Latest ASCAT data passes reveal fresh to locally strong NE to E trade winds just north of the ITCZ extending to near 21N and W of about 112W. The locally strong winds are confined to the western part of the area. These winds are the result of the pressure gradient between strong high pressure N of the forecast waters and lower pressure in the vicinity of the ITCZ. Seas within this area of trade winds are in the 8-11 ft range. A cold front extends from near 30N124W southwestward to 28N130W, where it begins to dissipate to near 27N139W. Latest ASCAT data passes indicate fresh to locally strong NE winds behind the front. Seas with these winds are in the 8-10 ft range. These seas are spreading out ahead of the front for 120 nm W of 135W. The ASCAT data also suggests that winds are moderate or weaker elsewhere. For the forecast, the fresh to strong trades will continue over the same area through Fri. Northerly swell will begin to decay tonight. A reinforcing set of long-period northerly swell is forecast to arrive into the north-central waters Tue and linger through the rest of the week while it slowly decays. A surface trough may form over the far western part of the tropical region near 140W by late Wed night. If this does occur, expect for trade winds in that part of the area to possibly increase to strong to near-gale force speeds, and for seas to build significantly. $$ Ramos