Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Tue May 20 2025 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 0900 UTC. ...TROPICAL WAVES... A tropical wave has been analyzed along 100W from 06N to 13N. Widely scattered moderate convection is occurring from 07N to 12N between 94W and 105W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the border of Costa Rica and Nicaragua near 11N86W to a 1010 mb low near 11N95W to 07N122W. The ITCZ continues from 07N122W to beyond 05N140W. Scattered moderate convection is occurring from 07N to 13N east of 88W, and from 04N to 08N between 132W and 140W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Surface ridging extends through the Mexico offshore waters, anchored by a 1030 mb high centered north of the area near 36N138W. Recent scatterometer satellite data show widespread moderate NW winds occurring across the Baja California waters, with fresh NW winds noted in the bays just offshore of the peninsula. Altimeter satellite data show rough seas of 8 to 9 ft north of 26N in N swell, and seas of 4 to 7 ft across the rest of the Baja offshore waters. Elsewhere, gentle winds and slight seas are noted surrounding a trough in the northern Gulf of California. Otherwise, moderate or weaker winds and seas of 5 to 6 ft prevail offshore of southern Mexico. For the forecast, locally fresh NW winds will pulse just offshore of Baja California, as well as offshore of southwestern Mexico, this morning before diminishing. Elsewhere, pulsing fresh NW winds are expected each night and morning north of Punta Eugenia this week. Large NW swell over the Baja California Norte waters will lead to rough seas across this region this week. Otherwise, moderate or weaker winds and moderate seas are expected across the remainder of the waters into this weekend. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Gentle to moderate S to SE winds prevail north of the monsoon trough, with gentle to moderate S to SW winds occurring to the south. Seas of 4 to 6 ft dominate the waters offshore of Central and South America. For the forecast, gentle to moderate SE to E winds will occur north of the monsoon trough through midweek, with gentle to moderate SE to SW winds occurring to the south, from Costa Rica through Ecuador. By Thu, pulsing moderate to fresh E to NE winds are expected to develop in the Gulf of Papagayo, with winds likely continuing through this weekend. Elsewhere, a Southern Hemisphere swell will promote rough seas across the equatorial waters near the Galapagos Islands by midweek, with rough seas expanding farther north and east this weekend. ...REMAINDER OF THE AREA.... Surface ridging extends over much of the eastern Pacific waters, anchored by a 1030 mb high centered north of the area near 36N138W. Recent scatterometer data show pockets of strong NE winds occurring north of 20N, and widespread moderate to fresh NE winds north of the monsoon trough and ITCZ. Large N to NE swell is promoting rough seas of 8 to 10 ft north of 20N between 120W and 140W, as seen from SOFAR buoy data and altimeter data. Farther south, wind-generated rough seas of 8 to 9 ft prevail from 05N to 15N west of 125W. South of the monsoon trough and ITCZ, gentle to moderate S to SE winds and seas of 5 to 7 ft are noted. For the forecast, locally strong NE winds will pulse north of 20N through early Wed as a strong pressure gradient prevails between ridging to the north and the monsoon trough/ITCZ. Widespread moderate to fresh NE winds will also continue north of the monsoon trough through Wed, with winds diminishing for the second half of the week as high pressure to the north weakens. Large N to NE swell will support rough seas north of 15N through Wed, and offshore of Baja California Norte into this weekend. Farther south, wind-generated rough seas will continue from 05N to 15N west of 125W through late week. Elsewhere, a long-period S to SW swell will promote rough seas across the equatorial waters Tue into this weekend.