000 AXPZ20 KNHC 250319 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 0405 UTC Thu May 25 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 0300 UTC. ...SPECIAL FEATURES... Ashfall Advisory: Popocatepetl Volcano in Mexico near 19N99W has been active, and it continues to emit volcanic ash. The current ash plume is moving SE and approximately 300 nm from the summit likely reaching the offshore waters of Oaxaca. Visibility may be restricted in these areas due to the volcanic ashfall through Thu morning based on the latest forecast from the VAAC, Washington. Mariners should exercise caution. If mariners encounter volcanic ash or floating volcanic debris, you are encouraged to report the observation to the National Weather Service by calling 305-229-4425. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough axis extends westward from northern Colombia near 10N74W to 09N90W to 08N107W. The ITCZ continues from 08N107W to 07N120W to 04N140W. Scattered moderate to isolated strong convection is noted from 04N to 08N between 86W-95W. Similar convective activity is seen from 05N to 12N between 110W-120W, and from 04N to 09N between 120W and 135W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The Popocatepetl Volcano in Mexico near 19N99W has been active during the past few days. An Ashfall Advisory is in effect through Thu morning. Please see the Special Features section for more details. Gentle to moderate NW to N winds are noted across the offshore waters of Baja California. Seas are 4-6 ft in this area, with the exception of higher seas of 5-7 ft seas in N swell north of Punta Eugenia. In the Gulf of California, moderate to locally fresh southerly winds and 2-4 ft seas are present in the northern part of the Gulf while mainly light and variable winds are noted elsewhere with seas in the 1-3 ft range, except for 3- 5 ft seas due to a S swell at the entrance to the Gulf. Otherwise, light to gentle winds and 4-6 ft seas prevail for the offshore waters of central and southern Mexico. For the forecast, a ridge will remain in control of the weather pattern across the offshore waters of Baja California through Fri supporting gentle to moderate NW to N winds. Moderate to locally fresh winds are expected Fri night into Sat. Pulsing fresh to locally strong winds are expected during the overnight and early morning hours near Cabo San Lucas through the end of the week. Moderate, with locally fresh to strong S to SW gap winds will occur in the northern Gulf of California each night. Seas of 5-7 ft due to a NW swell affecting the outer offshore waters north of Cabo San Lazaro will persist on Thu. From tonight through Fri, NW winds offshore Jalisco and Colima should become moderate to locally fresh, with seas reaching the range of 6-7 ft. Reduced visibility due to haze from agricultural fires will persist for the offshore waters of central and southern Mexico tonight and Thu. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Light winds are found offshore Guatemala, El Salvador, Nicaragua and northern Costa Rica. Seas range from 4-6 ft in these waters in S to SW swell. Gentle to moderate S to SW monsoonal winds with 5-7 ft seas in southerly swell prevail across the offshore waters of southern Costa Rica and southward to about 02N. Light southerly winds are over the waters between Ecuador and the Galapagos Islands. For the forecast, light to gentle winds and moderate seas north of the monsoon trough are expected to continue across the central American offshore waters, north of Costa Rica through the rest of the week. Gentle to moderate southwesterly monsoonal winds and 4-6 ft seas are anticipated for the offshore waters of Costa Rica, Panama, Colombia and Ecuador until Fri night. Afterward, monsoonal winds will become mainly gentle, however, seas will build to 7-10 ft in a large southerly swell. Reduced visibility due to haze from agricultural fires will persist across northern central American tonight and Thu. ...REMAINDER OF THE AREA... High pressure of 1030 mb located well northwest of the area near 37N144W dominates the forecast region north of 10N and west of 110W. The related pressure gradient is allowing for a moderate to locally fresh anticyclonic flow, with an area of mostly fresh NE trade winds just north of the ITCZ W of 125W. Seas over this part of the area are 6-8 ft due to a N to NE swell as detected by an altimeter pass. Gentle to moderate southerly winds prevail south of the monsoon trough/ITCZ. Large northerly swell producing seas of 8-9 ft are currently reaching as far south as 27N between 120W-134W, with an area of 8 ft seas from 21N to 26N west of 136W based on altimeter data. For the forecast, the high pressure center will continue to dominate the region N of 10N and W of 110W through Fri. Mostly fresh NE trade winds will continue across the southern periphery of the ridge, especially west of 120W. Seas associated with the northerly swell event across the northern forecast waters will subside to less than 8 ft late tonight into Thu. $$ GR