Tropical Storm Mario Forms Off Southern Mexico; Forecasters Warn of Northward Threat
National Hurricane Center labels the 13th named Pacific storm a 'mini' system as watches are issued in Michoacán and agencies say Mario could strengthen toward Baja and send moisture into the U.S. Southwest
Tropical Storm Mario formed Friday morning off the coast of southern Mexico, bringing the 2025 Pacific hurricane season its 13th named storm and prompting warnings for dangerous winds, heavy rain and flooding as it moves northward toward the U.S. border.
The National Hurricane Center described Mario as a "mini" tropical storm with sustained winds near 40 mph as of Friday. A tropical storm watch was issued for a stretch of Mexico's Michoacán state from Lázaro Cárdenas to Punta San Telmo, where officials warned of potential coastal impacts, flash flooding and wind damage through the weekend as the system approaches.
Forecasters expect Mario to track northwest along the Pacific coast, affecting southern Mexico over the weekend before continuing closer to the Baja California Peninsula and the U.S. southwest. Public and private forecast agencies said the storm could strengthen as it moves over warmer waters; AccuWeather senior meteorologist Heather Zehr said Mario has the potential to become a hurricane before reaching the Baja California Peninsula.
"Some moisture may begin to show up in the form of clouds and spotty showers as early as Tuesday in parts of Southern California, Arizona and southern Nevada, but it is more likely from Wednesday on," Zehr said. Officials cautioned that even if Mario does not reach hurricane strength, its rainbands could produce localized flooding, mudslides in steep terrain and hazardous surf along affected coastlines.
The National Hurricane Center continues to monitor Mario's intensity and track, issuing updates as the system evolves. Emergency managers along the Pacific coast of Mexico and municipal authorities in vulnerable coastal and inland communities have been advised to prepare for periods of heavy rain, gusty winds and the possibility of flash flooding.
Mario's emergence comes amid an active eastern Pacific hurricane season. Forecasters said exact impacts to the southwestern United States will depend on the storm's track and rate of intensification over the coming days. Residents in potentially affected areas were urged to follow official local advisories and to prepare for quick changes in weather conditions.
The situation remained fluid late Friday, and agencies warned of further updates as Mario moves closer to land and environmental conditions change.