870 AXPZ20 KNHC 120315 TWDEP Tropical Weather Discussion NWS National Hurricane Center Miami FL 2205 UTC Thu Jun 12 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 0000 UTC surface analysis and satellite imagery through 0300 UTC. ...SPECIAL FEATURES... South of Southern Mexico (Invest EP93): An area of disorganized showers and thunderstorms located several hundred nautical miles south of the Gulf of Tehuantepec near 10.5N97.5W is associated with a broad area of low pressure. Current associated winds are up to around 20 kt, while seas are building to around 8 ft. Nearby convection is described below. Environmental conditions appear conducive for development of this system, and a tropical depression is expected to form late this week or this weekend while it moves generally west-northwestward just offshore the southwestern coast of Mexico. This system has a medium chance of tropical cyclone formation through the next 48 hours, and a high chance through the next 7 days. Regardless of development, expect increasing winds and seas with this feature. Please refer to the latest NHC Tropical Weather Outlook at www.hurricanes.gov for more details. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... The monsoon trough extends from 10N84W to broad 1011 mb low pressure near 10.5N97.5W to 12N105W, then resumes southwest of the remnant low of Cosme near 13N115W to 10N130W. The ITCZ extends from 10N130W to beyond 06N140W. Scattered moderate convection is noted from 05N to 10N between 85W and 90W, and from 12N to 17N between 90W and 105W. ...OFFSHORE WATERS WITHIN 250 NM OF MEXICO... Please read the Special Features section for information on a broad area of low pressure located several hundred nautical miles south of the Gulf of Tehuantepec near 10.5N97.5W. The remnant low of Cosme is located just southwest of Socorro Island near 17N113W at 1008 mb. No significant convection is present. Remnant winds are estimated to be 20 kt, mainly on the SE side of the center, with seas to 8 ft. Otherwise, weak ridging extends from a 1030 mb high centered well NW of the area near 38N149W to offshore Baja California. Winds are moderate or weaker, including in the Gulf of California, with seas of 5 to 7 ft in the open waters, and 2 to 4 ft in the Gulf of California. For the forecast, other than the broad area of low pressure with tropical cyclone formation possibility mentioned above, the remnant low of Cosme will continue to spin down with associated winds and seas diminishing and subsiding by Thu morning. Elsewhere, little change in winds and seas is forecast, except offshore Baja California Norte where seas may build locally to rough in fresh NW-N swell late in the weekend, along with freshening winds. Moderate to fresh southerly winds will develop in the Gulf of California early next week as troughing deepens over the Baja California Peninsula. ...OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND WITHIN 750 NM OF ECUADOR... Winds are mainly gentle to moderate across the offshore waters. Seas are 5-7 ft in S swell. Widely scattered showers and isolated thunderstorms are across much of the waters from Colombia northward as described above. For the forecast, gentle to moderate winds and moderate seas will persist across the region through tonight. From Thu into Fri night, an enhanced monsoon trough should cause increasing SW winds as well as showers and thunderstorms over the Central American forecast waters. Looking ahead, quiescent conditions are likely for much of the weekend. Winds may increase again south of the monsoon trough offshore southern Colombia and from Ecuador to the Galapagos Islands late in the weekend and into early next week. ...REMAINDER OF THE AREA... Please read the Special Features section for information on a broad area of low pressure located several hundred nautical miles south of the Gulf of Tehuantepec near 10.5N97.5W. Weak ridging dominates the waters north of 15N, and this pattern is supporting mostly gentle to moderate winds west of 120W, with 5 to 7 ft seas in a mix of NW and S swell. S swell of 8 to 10 ft is reaching as far north as the Equator between 105W and 120W. Elsewhere fresh SW winds persist south of the monsoon trough between 90W and 110W, into the area of broad low pressure described in the Special Features section (EP93). Seas may reaching 8 ft near 06N95W south of the broad low. Seas are 4 to 6 ft in SW swell elsewhere east of 120W. In the forecast, other than the broad area of low pressure with tropical cyclone formation possibility mentioned above, the remnant low of Cosme will continue to spin down with associated winds and seas diminishing and subsiding by Thu morning. Little change in winds and seas is expected elsewhere through the weekend, except across the north central waters where freshening winds off southern California will build rough seas into our area. Winds may increase to moderate to fresh across much of the open waters early next week as the pressure gradient between the possible tropical cyclone and building high pressure west of it tightens. $$ Christensen