


Tropical Weather Discussion
Issued by NWS
Issued by NWS
717 AXPZ20 KNHC 302205 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Wed Jul 30 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 1800 UTC surface analysis and satellite imagery through 2130 UTC. ...SPECIAL FEATURES... South of Southwestern Mexico (EP99): Shower activity associated with a trough of low pressure located several hundred miles southwest of the southwestern coast of Mexico has become a little better organized since yesterday. Environmental conditions appear conducive for additional development, and a tropical depression is likely to form during the next day or two while the system moves west-northwestward around 15 mph, remaining well offshore of the southwestern coast of Mexico. There is a high chance of tropical development within the next 48 hours. Refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details about these invest areas. Tsunami Threat: A powerful 8.8 magnitude earthquake occurred at 2325 UTC July 29 off the east coast of Kamchatka, Russia. Tsunami waves have been observed, and waves reaching more than 3 M above the tide level are possible along some coasts of Ecuador. Tsunami waves reaching 1 to 3 M above the tide level are possible along some coasts of Costa Rica. Tsunami waves reaching 0.3 to 1 M above the tide level are possible along some coasts in Central and South America. Mariners and coastal interests should consult local authorities and visit www.tsunami.gov for the latest information and guidance. ...TROPICAL WAVES... A tropical wave axis is along 84W, from 04N northward through central Costa Rica and eastern Nicaragua into the western Caribbean, moving to the west around 10 kt. Scattered moderate to strong convection is occurring from 04N to 10N east of 87W. A tropical wave axis is along 93W, from 03N northward into southeastern Mexico, moving to the west around 10 kt. Scattered moderate to strong convection is occurring from 05N to 14N between 90W and 98W. A tropical wave axis is along 126.5W, from 04N to 17N, moving to the west around 5 to 10 kt. Scattered moderate convection is occurring from 09N to 14N between 119W and 127W. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 09N84W to a 1008 mb low near 12N112W to 09N123W. The ITCZ extends from 09N124W to beyond 11N140W. Widespread moderate to locally strong convection is noted from 07N to 19N between 100W and 120W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Fresh to strong N to NE winds and 6 to 7 ft seas are occurring in the Gulf of Tehuantepec as high pressure prevails over the northwestern Gulf of America. Farther west, scatterometer satellite data show moderate to fresh SE to NE winds, with localized strong winds, are occurring well offshore of Jalisco through Michoacan as EP99 strengthens to the southwest. Altimeter satellite data show 6 to 8 ft seas in this area. Elsewhere, a 1009 mb low centered near 30.5N114W extends a trough southeastward through the Gulf of California into Baja California Sur. The pressure gradient between these features and ridging to the west is leading to moderate to fresh NW winds and moderate seas offshore of Baja north of Cabo San Lazaro, as noted on recent scatterometer data. Gentle to locally moderate SE winds and slight seas prevail in the Gulf of California. For the forecast, a trough of low pressure, EP99, is located several hundred miles southwest of the southwestern coast of Mexico. Environmental conditions appear conducive for additional development, and a tropical depression is likely to form during the next day or two while the system moves west-northwestward around 15 mph, remaining well offshore of the southwestern coast of Mexico. There is a high chance of tropical development within the next 48 hours. Elsewhere, fresh to strong N to NE winds will pulse in the Gulf of Tehuantepec through this weekend, with the strongest winds occurring each night and early morning. Winds will diminish in this region by early next week. Elsewhere, moderate to fresh NW winds, with locally strong winds, will occur offshore of Baja California through this weekend. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Moderate to fresh E to NE winds and moderate seas are noted in the Gulf of Papagayo as low pressure prevails in the south-central Caribbean, and a tropical wave moves westward through Central America. Generally moderate S winds are ongoing south of the monsoon trough, with mainly gentle winds noted to the north. Seas of 4 to 6 ft in S swell dominate the regional waters, as noted on altimeter data. For the forecast, fresh to occasionally strong E to NE gap winds will occur in the Gulf of Papagayo into this weekend as low pressure dominates the south-central Caribbean. Moderate to occasionally fresh E winds will extend beyond the Papagayo region through the waters offshore of El Salvador and Guatemala into Sat. Looking ahead, fresh S winds are expected offshore of Ecuador and southern Colombia on Fri. A long-period S to SW swell will move through the South American waters Fri into this weekend, leading to rough seas between Ecuador and the Galapagos Islands. Seas will slowly subside by Sun. ...REMAINDER OF THE AREA... See the Special Features section above for information on Invest area EP99. Recent scatterometer satellite data show strong to locally near- gale force winds and rough seas of 8 to 10 ft are occurring near EP99, centered near 12N112W. Farther west, widespread fresh to locally strong NE winds and 8 to 10 ft seas are noted from 10N to 20N west of 135W, to the east of EP98, centered west of the area near 12N143W. The rest of the eastern Pacific north of the monsoon trough and ITCZ is dominated by ridging, stemming from a 1027 mb high centered near 32N139W. Gentle to moderate NE winds are noted north of 25N and west of 130W, near the center of the high pressure, while moderate to fresh N to NE winds and 4 to 7 ft seas are noted over the rest of the region. South of the monsoon trough and ITCZ, away from EP98 and EP99, moderate to locally fresh SE winds and moderate seas prevail. For the forecast, a trough of low pressure, EP99, is located several hundred miles southwest of the southwestern coast of Mexico. Environmental conditions appear conducive for additional development, and a tropical depression is likely to form during the next day or two while the system moves west-northwestward around 15 mph, remaining well offshore of the southwestern coast of Mexico. There is a high chance of tropical development within the next 48 hours. Elsewhere, fresh to locally strong NE winds occurring east of EP98, centered west of 140W, will diminish through Thu morning. Rough seas in this region will continue through Thu and expand farther east toward 130W on Fri and Sat. Widespread moderate to fresh N to NE winds will prevail north of the monsoon trough and ITCZ into this weekend as high pressure persists north of the region. $$ ADAMS