Puerto Vallarta, Mexico - Tropical Storm Alvin formed several hundred miles south of southwestern Mexico early this morning, and it has already started to organize into a more coherent system. Satellite imagery shows that thunderstorm activity around the center has increased and become better defined. While the storm is expected to remain small and lose energy quickly, it is expected to bring rains and high seas to the coast of Puerto Vallarta.
Alvin is currently moving toward the northwest at 9 kt (about 10 mph) on a heading of 315°. That motion should continue today as the storm follows the western edge of a broad ridge centered over central Mexico. By tomorrow, Alvin will begin to turn more toward the north-northwest, steering around the same ridge. Late tomorrow night, a mid-level cut-off low to the west is expected to capture Alvin and pull it on a more northerly course. This general track shows Alvin remaining well offshore of southwestern Mexico, then gradually approaching the southern tip of the Baja California Peninsula as a weakening system over the next several days.
Conditions surrounding Alvin should remain favorable for further strengthening through the next 24 hours. Sea surface temperatures in its current location exceed 28 °C, and vertical wind shear is low, allowing thunderstorms to build around the center. The NHC’s forecast calls for Alvin to reach a peak intensity of 50 kt—near the upper end of most model guidance—sometime later today or tonight. After reaching that peak, the storm will encounter steadily increasing shear, drier mid-level air, and cooler waters as it moves northward. Those factors should lead to a gradual weakening trend beginning tomorrow night.
By mid-week, Alvin is likely to degrade to a tropical depression and then to a remnant low before it nears the southern tip of the Baja California Peninsula. High confidence in this wind-down comes from the consensus of forecast models, which show a hostile environment for sustaining tropical-storm-strength winds north of about 20° N. Even as a remnant low, Alvin may bring increased cloudiness and isolated showers to parts of Baja California Sur, but significant impacts appear unlikely.
Mariners in the eastern Pacific should remain aware of Alvin’s evolving winds and seas. Tropical-storm-force gusts may extend outward up to 60 miles from the center at peak strength. Swells generated by Alvin will propagate toward the coast of southwestern Mexico and into the Gulf of California over the next few days. Coastal regions from Manzanillo northward to Cabo Corrientes could see elevated surf and dangerous rip currents, even though Alvin’s center will stay well offshore.
Residents and visitors along the western coast of Mexico and the southern Baja California Peninsula should monitor updates from the NHC and their local meteorological offices. While land impacts remain unlikely at tropical-storm strength, conditions can change if the storm interacts with other weather features. Boaters should prepare to change schedules if gale-force winds develop, and beachgoers should heed warnings about high surf and rip currents.
Tropical Storm Alvin is the first named storm of the 2025 Pacific hurricane season. Forecasters will issue routine advisories every six hours, or more frequently if conditions warrant. The next full advisory, including updates to the forecast track and intensity, is scheduled for later this afternoon.
For detailed forecast discussions, visit the National Hurricane Center’s website and follow their social media feeds. Mariners can check high-resolution sea state forecasts from the Ocean Prediction Center. Stay tuned for the latest Tropical Storm Alvin forecast as this system evolves over the coming days.
