Wait, it's May! Highways closed in Sierra, chains required for mountain travel because of snow

Caltrans ended up closing several highways and requiring chains on several routes in the mountain areas on Thursday, which wouldn’t be that unusual, except it’s not December – it’s May.

KCRA reported that because of a steady snowfall in Nyack along Interstate 80 near Emigrant Gap, chain controls were required from Kingvale to Donner Lake. 

Caltrans also closed State Route 89 in the Sierra Nevada on Wednesday night based on the winter storm warning at high elevations. It remained closed Thursday morning because of snow.

A couple of storm systems will bring moderate to heavy snowfall to the Sierra Cascade range over the next several days, according to the National Weather Service, and travel impacts over the passes are likely.

San Francisco State Univeristy professor of meteorology John P Monteverdi said having wet weather in May is not unprecedented.

And the reason it's happening now, he said, is because California is still experiencing an El Nino season, and the warm waters in the tropics are causing precipitation for coastal cities along the Pacific Ocean.

Plus, this year, Monteverdi said there is a phenomenon in the Indian Ocean where clouds and thunderstorms are moving along the jet stream headed toward the West Coast.

Another big storm is expected for Saturday. For more road closure information, click here.