Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Mon Jul 13 2026 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... Offshore of Southwestern Mexico: Low pressure is developing about 240 nm S-SW of Acapulco, Mexico, along a tropical wave. Strong to near-gale force winds, rough seas, and numerous thunderstorms are ongoing off Guerrero and western Oaxaca. The winds and seas were partially sampled by recent scatterometer and altimeter satellite passes. Environmental conditions appear favorable for development, and a tropical depression is expected to form over the next couple of days while the system moves generally west- northwestward, remaining off the coast of mainland Mexico. Expect strong winds and rough seas near the Revillagigedo Islands by Tue night, as the low pressure makes its closest point of approach to the south of the islands. The latest Tropical Weather Outlook gives this system a high chance of tropical cyclone formation in the next 48 hours. Please read the latest Tropical Weather Outlook issued by the National Hurricane Center at www.hurricanes.gov for further details. ...TROPICAL WAVES... The axis of a tropical wave is near 80W, north of 02N, moving westward at around 15 to 20 kt. Any nearby convection is described below in the ITCZ/monsoon trough section. The axis of a tropical wave is near 102W, from 04N northward, moving westward at around 10 to 15 kt. Any nearby convection is described below in the ITCZ/monsoon trough section, with additional details also in the Special Features section regarding the potential for tropical cyclone formation. The axis of a tropical wave is along 133W from 04N to 19N, moving westward at around 5-10 kt. A 1009 mb low pressure is analyzed along the wave axis near 14N133W. Any nearby convection is described below in the ITCZ/monsoon trough section. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N85W to 07N90W. Segments of the ITCZ continues from 07N90W to 09N98W, and from 08N105W to 06N125W to 11N130W. The monsoon trough resumes from 12N133W to beyond 10N140W. Numerous moderate to isolated strong convection is active from 15N to 18N between 100W and 105W. Scattered moderate convection is active from 03N to 13N between 95W and 110W, and from 12N to 25N between 125W and 130W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... In addition to the winds and seas described in the Special Features section off southwest Mexico, a recent scatterometer satellite pass confirmed fresh gap winds across the Gulf of Tehuantepec. Broad ridging is evident elsewhere off Baja California, supporting gentle to moderate breezes and 3-5 ft seas elsewhere, except light breezes and 1-3 ft seas in the Gulf of California. For the forecast, in addition to the impacts of the developing low pressure described in the Special Features section above, the ridge will continue to dominate the offshore forecast waters of Baja California through early Thu, allowing for gentle to moderate NW to N winds to continue along with moderate seas in mixed swell. In the Gulf of California, mainly gentle winds will prevail through Tue night, increasing to moderate to locally fresh in the central and northern portions midweek. Fresh to strong northerly winds will pulse in the Gulf of Tehuantepec during the week, strongest during the late night and early morning hours, with locally rough seas at times. ....OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A recent scatterometer satellite pass confirmed fresh to strong E winds across the Gulf of Papagayo, with moderate to fresh easterly winds elsewhere from 10N to 12N. Winds are light to gentle across the remainder of the waters per overnight scatterometer passes. Moderate seas dominate the waters. Areas of convection associated with the monsoon trough are described above with locally higher winds and seas. For the forecast, fresh to strong gap winds will prevail in the Papagayo region mainly at night through at least Fri night along with moderate to locally rough seas. Fresh to locally strong winds and rough seas are forecast to impact the offshore waters of El Salvador and Guatemala today due to the departing presence of a tropical wave several hundred nautical miles south of the coast of southern Mexico. Moderate or weaker winds and moderate seas in SW swell will prevail elsewhere, except in the lee of the Galapagos Islands where slight seas are expected. ...REMAINDER OF THE AREA... A recent scatterometer satellite pass indicated fresh E to SE winds on the northern end of the tropical wave along 133W. Earlier altimeter satellite data indicated seas to 8 ft in this area, near 15N130W. Gentle to moderate winds 4-6 ft prevail elsewhere, except for fresh SE winds and 5-7 ft seas south of 07N between 95W and 105W. For the forecast, winds and seas associated with the tropical wave near 133W diminish through tonight, and further tropical development is not expected. NE winds will freshen with seas 5-7 ft thereafter north of 15N and west of 125W between broad low pressure along the monsoon trough riding farther north. Elsewhere, the main issue will be the development and track of the low pressure described in the Special Features section above. Expect tropical cyclone development with this low pressure through mid week as it moves northwest of the Revillagigedo Islands. Farther south, moderate to fresh SE winds and 5-7 ft seas will cross the Equator between 100W and 120W and reach as far north as 10N through mid week. Looking ahead, another area of low pressure is expected to form by the middle of the week several hundred miles south of the coast of southern Mexico. Environmental conditions appear conducive for gradual development of this system thereafter, and there is a medium chance tropical depression could form by the end of the weekend while it moves generally west- northwestward well offshore of Mexico.