


Tropical Weather Discussion
Issued by NWS
Issued by NWS
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085 AXPZ20 KNHC 181522 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 1605 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 1200 UTC surface analysis and satellite imagery through 1500 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from the coast of Panama near 09N84W to a 1008 mb low pres near 13N99W to 09N135W. ITCZ continues from that point to beyond 08N140W. Scattered moderate to isolated strong convection is noted N of 09N between 87W and 105W. Similar convection is noted from 07N to 12N and west of 125W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... The combination of the proximity of the monsoon trough and a broad area of low pressure located south of southern Mexico is producing scattered showers and thunderstorms, especially north of 08N and between 90W and 106W. A recent scatterometer satellite pass indicate that moderate to fresh winds are occurring in these waters. Moderate seas prevail in this area. 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 SW 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. Strong to near gale-force NE gap winds and rough seas are expected in the Gulf of Tehuantepec Mon and continue pulsing through next week. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Scattered showers and thunderstorms along the monsoon trough prevail over the offshore waters of Central America 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 in the rough range. Meanwhile, moderate to 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 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 SW swell will support rough seas north of 25N through Sun. A tightening pressure gradient will support fresh to 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 Mexican coast. $$ ERA