000 AXPZ20 KNHC 040731 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Mar 4 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 0710 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A surface trough extends from the border of Colombia and Panama near 07N78W to 08N90W to 00N105W. The ITCZ extends from 00N113W to 03N140W. A second ITCZ is south of 03.4S between 106W and beyond 120W. Scattered moderate convection is noted from 03.5N to 06.5N between 82W and 88W, and from 06N to 10N between 133W and 140W. Of note, during March and April of each year, a second ITCZ is present in the southern hemisphere of the eastern Pacific basin, especially during La Nina events when the cold equatorial sea surface temperatures are stronger. This rather special situation is currently analyzed on the surface map. Forecast models continue to show a well defined second ITCZ south of the equator through at least Sun. OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A ridge dominates the offshore forecast waters of Mexico, with a weak trough along the mainland coast of the central and southern Gulf of California. Recent ASCAT scatterometer data showed mainly moderate NW to N winds offshore Baja California, locally fresh between Cabo San Lazaro and Punta Eugenia. Moderate NW winds were sampled in the central and southern Gulf of California to near Cabo Corrientes. Winds are mainly gentle elsewhere, including in the northern Gulf of California. NW swell offshore Baja California has been decaying with remnant 5 to 8 ft seas present. Seas are 4 to 7 ft elsewhere offshore Mexico in mainly NW swell, except mixed with SW swell offshore Oaxaca and Chiapas. In the Gulf of California, seas are 1 to 2 ft in the northern Gulf, 2 to 4 ft in the central Gulf, and 3 to 5 ft in the southern Gulf. Areas of light smoke and haze due to agricultural fires are likely over the offshore waters of SE Mexico. For the forecast, winds will be moderate or weaker across the offshores of Mexico by sunrise today, then will increase to moderate to fresh offshore Baja California Norte this evening, then increase to fresh to strong there Sun night as the pressure gradient tightens, reaching to near Cabo San Lazaro by early Mon. Moderate to fresh NW to N winds will develop and spread from the northern to the central Gulf of California Tue until Tue night. Fresh to strong winds may develop in the far northern Gulf of California late Wed night. A new NW swell set will spread offshore Baja California Norte this afternoon, building seas to 7 to 9 ft from Cabo San Lazaro northward through Sun afternoon, with yet another NW swell set early next week pushing seas of 8 ft or greater to 110W by mid-week. Winds in the Gulf of Tehuantepec may pulse to moderate to fresh Sat night into early Sun. OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh NE to E offshore winds are in the Gulf of Papagayo and just north of there, with mainly light to gentle winds elsewhere per earlier ASCAT scatterometer data. Seas are 3 to 5 ft in S to SW swell offshore Ecuador to the Galapagos Islands, and 2 to 4 ft elsewhere. Areas of light smoke and haze due to agricultural fires are over the offshore waters of El Salvador and Guatemala. For the forecast, moderate to fresh winds will pulse offshore Nicaragua including the Gulf of Papagayo through today, then pulse to fresh to strong thereafter. Seas will build to 5 to 7 ft during the pulsing fresh to strong winds. Winds will pulse to moderate in the Gulf of Panama to south of the Azuero Peninsula through the next several days, with light to gentle winds across the remainder of the offshore waters. Seas will be mainly 3 to 5 ft in S to SW swell, except building to 4 to 6 ft offshore Ecuador to the Galapagos Islands tonight through Mon. REMAINDER OF THE AREA... A ridge dominates the waters north of the ITCZ. Moderate to locally fresh trades prevail north of about 07N and west of 115W, with mainly light to gentle winds elsewhere. Seas are mainly 6 to 9 ft in NW to N swell across the area of moderate to locally fresh trades, and 4 to 7 ft in in mixed SW and NW swell elsewhere. For the forecast, a system west of 140W may spread associated fresh to strong E to SE winds and seas of 8 ft or greater across the NW waters early Mon through early Wed. Little change in winds is forecast elsewhere. Meanwhile the existing area of NW to N swell will subside through the weekend. A new set of NW swell will push south of 30N this morning with seas of 8 ft or greater reaching to near 24N by early Sun. Another set of NW swell will push south of 30N Sun, with seas of 8 ft or greater covering most of the waters north of 15N and west of 115W by Mon evening, then gradually decaying through mid-week. Seas of 12 ft or greater will spread south of 30N by Sun evening, reaching to near 28N before subsiding to less than 12 ft by early Mon. $$ Lewitsky