Tropical Weather Discussion

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Tropical Weather Discussion NWS National Hurricane Center Miami FL 1005 UTC Sat Oct 18 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 0835 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Panama near 08N78W to a 1008 mb low pres near 14N98W to 10N117W and beyond 08N140W. Scattered moderate to isolated strong convection is observed from 07N to 16N and between 85W and 105W. Similar convection is noted from 07N to 11N and west of 125W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... A broad area of low pressure located south of southern Mexico is producing a large area of showers and thunderstorms, especially north of 07N and between 91W and 105W. A recent scatterometer satellite pass indicate that moderate to fresh winds are occurring in these waters. Seas in the area described are 5-7 ft. In the remainder of the Mexican offshore waters, a weak pressure gradient dominates, supporting moderate or weaker winds and slight to moderate seas. For the forecast, moderate or weaker winds will prevail across the offshore waters of Baja California through early next week. A NW swell will bring rough seas to the N Baja California waters Sun through early Mon, while another long-period swell will reach the area late Mon. Winds will freshen up and seas build to rough midweek through late next week. Moderate NW winds are forecast in the central and southern Gulf of California this evening through Mon. At the same time, fresh NW winds will pulse across the waters of Cabo Corrientes. Looking ahead, strong to near gale-force N gap winds and rough seas are expected in the Gulf of Tehuantepec Mon through late next week. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... A line of showers and isolated thunderstorms over the offshore waters of Central America is producing heavy downpours, gusty winds and higher seas. A recent scatterometer satellite pass captured gentle to moderate southerly winds south of the monsoon trough. MOderate seas are noted in these waters. Elsewhere, light to gentle winds and moderate seas prevail. For the forecast, moderate SW winds and moderate seas will occur south of the monsoon trough into early next week, with gentle winds and moderate seas prevailing to the north. ...REMAINDER OF THE AREA... Latest satellite-derived wind data indicate that the subtropical ridge positioned well northwest of the region supports moderate to fresh NE winds north of 10N and west of 130W. Seas in these waters are 7-10 ft. Meanwhile, moderate to locally fresh southerly winds and moderate seas are occurring south of the monsoon trough. Elsewhere, moderate or lighter winds and moderate seas are prevalent. For the forecast, moderate to locally fresh NE winds and rough seas will occur north of the monsoon trough into this weekend as high pressure prevails to the north. Winds will diminish slightly for the second half of the weekend. A new NW swell will support rough seas north of 25N through Sun. A tightening pressure gradient will support fresh to locally strong winds and rough seas near westward-moving low pressure along the monsoon trough Sun through late next week. Moreover, increasing winds and building seas are expected over the northern waters early next week as a weakening cold front moves southward along the California coast.