A tornado warning was issued Thursday evening for parts of Fresno and Madera counties as an unusually volatile spring storm moved through the Central Valley, bringing the threat of damaging winds, hail and a possible tornado.
The National Weather Service said the warning was set to remain in effect until 6:15 p.m. Forecasters said “a severe thunderstorm capable of producing a tornado” was located near South Dos Palos, about 25 miles west of Madera, and moving northeast at 15 mph.
The storm was expected to affect mainly rural parts of southwestern Madera and western Fresno counties.
In a separate severe thunderstorm warning, the weather service said the same system was capable of producing 70 mph wind gusts and quarter-size hail.
“Flying debris will be dangerous to those caught without shelter,” the weather service said in its warning. “Damage to roofs, windows, and vehicles will occur. Tree damage is likely.”
The warning was based on radar-indicated rotation, meaning forecasters detected wind patterns that can signal a tornado may develop. That does not necessarily mean a tornado has touched down. A tornado is considered confirmed only when it reaches the ground.
The warning came as a broader storm system began creating conditions more favorable for thunderstorms across California.
Such storms are relatively uncommon in much of the state, but meteorologists have warned that this pattern could produce lightning, hail, strong wind gusts and isolated funnel clouds or tornadoes through the weekend.
Residents in the warning area were urged to take shelter immediately.
The weather service advised people to move to a basement, if available, or to an interior room on the lowest floor of a sturdy building and to stay away from windows. People outdoors, in vehicles or in mobile homes were told to get to substantial shelter and protect themselves from flying debris.
Forecasters also warned that heavy rain could lead to localized flash flooding. Drivers were urged not to travel through flooded roadways.
Officials said residents should continue monitoring alerts from the National Weather Service, local media and emergency notifications as conditions change.