A powerful winter storm will drop California’s heaviest snowfall this year

(CNN) — A very dangerous winter storm has arrived in California and will dump meters of snow, powerful winds and rare blizzard conditions in the mountains over the weekend.

The storm brings California’s biggest snowfall of the year, which poses a significant risk to tourists but will provide a major boost to the state’s water supply and tourism.

“There are a number of ways we can say that traveling the roads or even leaving your home during this (storm) can be dangerous,” the National Weather Service office in Reno, Nevada, warned Wednesday. “The circumstances will be very messy, so this is not the time to gamble with your life or the life of your family.”

Snow began falling in the Pacific Northwest late Wednesday night and spread to California’s North Coast Range, Klamath Mountains and Sierra Nevada by early Thursday morning. As snow continues to spread across California, so will strong wind and blizzard conditions.

Snowfall is expected to reach extremes of 7 to 12 centimeters per hour Friday through Saturday, especially along the Sierra Nevada.

Extreme and prolonged snowfall means that 1.8 to 3 meters of snow can “bury” parts of the Sierra in just two or three days.

The most extreme conditions will develop at the highest elevations, with winds in excess of 160 km/h on the highest peaks of the Sierra, in addition to meters of snow. Winds are expected to be so strong that accurately measuring snow may be difficult, as large snow drifts are likely.

Heavy snow and strong winds are expected to produce rare and prolonged snow conditions across much of the Sierra and parts of the Northern Range. Visibility can drop to almost zero, meaning that it is impossible to see more than a few meters (or none at all) in the most intense snowstorms.

Given these conditions, “there is a high potential for significant and lasting disruptions to daily life in the highest elevations of the Sierra Nevada from Friday through Saturday,” the Weather Forecast Center warned.

Around 30 centimeters of snow is forecast over the weekend in areas above 1,500 meters above sea level. A few centimeters are also possible for lower elevations, including Reno, Nevada. In lower areas, winds will gust to 96 kmph with snow.

Extreme conditions in low-lying areas increase the risk of road hazards.

The weather service has warned that travel through the Sierra will be “extremely hazardous or impossible” through the weekend. Portions of major highways such as I-80 may be closed for long stretches.

Strong winds will spread to where the snow falls. By Sunday, gusts in excess of 88 km/h are likely across much of the west, including the Rocky Mountains.

Prolonged high winds can bring down trees and power lines, causing property damage and power outages.

The heaviest snow and strongest winds from this major storm are expected to gradually subside in California on Sunday.

However, another quick burst of less intense snow could occur across Northern California on Monday.

The storm will give the snowpack a much-needed boost

California’s Sierra Nevada snowpack is off to a slow start this winter.

“We’re definitely playing catch-up (with snowpack in the Sierra),” Aidan Lindaman, senior meteorologist with the National Weather Service in Reno, told CNN.

But recent storms have helped make a difference. According to Lindaman, parts of the Sierra are getting close to erasing the snowpack deficit.

Given the enormous amount of snow forecast to cover the Sierra over the weekend, there’s a “good chance” the snowpack will close the gap or exceed typical, Lindaman added.

Snowpack is an important source of water, and surveys conducted by the California Department of Water Resources help the state predict how much water will be available for the rest of the year.

According to the US Environmental Protection Agency, millions of people in the West rely on snowmelt in warmer months for hydroelectric power, irrigation and drinking water.