Carson City area weather: Storms to cause travel disruptions into the holiday weekend

Another round of winter storms will move into the Sierra and Western Nevada beginning late Tuesday into Wednesday, bringing several feet of snow to the Sierra and making travel difficult for Christmas holiday travelers.

For the Sierra and areas above 6,500 feet, there will be periods of significant snowfall starting late Tuesday and continuing through the holiday weekend, according to the National Weather Service. Significant snowpack buildup is probable and major travel delays are likely. Snow will begin on Tuesday, but Thursday and the weekend will be more intense snowfall rates with the worst travel conditions.

The National Weather Service has issued a Winter Storm Warning for the greater Lake Tahoe area from Wednesday 4 p.m. to Sunday 4 p.m.

Also, a Winter Storm Warning is in effect for much of Mono County, the west slope of the Northern Sierra.

For the first storm, the weather service says there could be total snow accumulations of 1 to 3 feet, with 3 to 8 feet above 7,000 feet possible. Winds could gust as high as 40 mph, with 100 mph or more over exposed ridges.

The weather service advises motorists to consider alternate routes or adjusting plans if you are traveling for the holidays. This is especially true if heading into or out of any Sierra locations, where chain controls, long delays, and potential road closures may occur.

Check the latest road conditions with Caltrans and NDOT. For Carson City area updates see CarsonWeather.com. The latest road conditions can be obtained by calling 511 for Nevada and 1-800-427-7623 for California. Monitor the latest weather forecast at weather.gov/reno and check road conditions routinely.

Forecasters advise to prepare an emergency kit for your home and car. If traveling consider alternate plans, remember to carry tire chains, extra food, water and clothing. Once the major storm arrives later Wednesday, travel may be difficult or impossible or an extended period of time.

For Western Nevada, rain/snow spillover likely won't begin until late Tuesday into Wednesday. The heaviest precipitation rates will occur on Thursday and this weekend. Snow levels will fluctuate between 5,000 to 6,000 feet Wednesday and Thursday with snow levels forecast to drop to all valley floors by Friday morning.

There may be accumulating snow in the Reno and Carson City areas. The lowest valleys below 4,500 feet may remain a rain/snow mix, but plan on a breezy and wet/snowy mess on roads region-wide.

Go here or read below the National Weather Service forecast discussion for Wednesday and beyond.

Changes: Focusing in on two primary shortwaves (1) Thursday and (2) the weekend, where conditions may be more impactful and hazardous. General storminess persists in the Sierra from Tuesday afternoon onward. Wind potential increasing for Thursday with GFS showing 700 mb flow 50-65 kts areawide.

Unsettled conditions (wind, rain, and snow, Oh my!) will impact much of the West through the Holiday Weekend. We recommend monitoring the weather, checking your flight status routinely, and keeping an eye on road conditions.

In the Sierra and for passes in northeast, Calif., major travel impacts: very long travel times and possible periodic road closures, especially starting Wednesday night.

For the foothills and lower valleys of western Nevada,rain or a rain/snow mix into Thursday with little to no snow impact. Clear those drains for efficient runoff mitigation! Snow levels drop late Thursday night into Friday (Christmas Eve) with increasing potential for travel disruption due to snow.

A trough will be anchored near the West coast this week allowing for shortwaves to eject inland across California and Nevada. On Wednesday, northeastern California nd the Sierra will be well into the unsettled weather portion of our forecast, but these conditions will only become more intense through the rest of the week, as a notable shortwave barrels through on Thursday and then another one in the queue for the weekend.

Thursday: EPS/GEFS meteograms and ECMWF EFI are still signaling that Thursday afternoon will be quite troublesome for much of the Sierra and western Nevada. Ensemble and deterministic guidance highlight the potential for significant forcing and jet dynamics with a shortwave passage through the region. The shortwave's arrival will enhance the intensity of ongoing snowfall in the Sierra and northeast California, as well as increase the spillover potential into western Nevada.

High confidence for 3 to 5 feet of snow for areas above 6,000 to 7,500 feet from Lassen to Mono County, respectively, with a couple feet possible at Lake Tahoe level. By Thursday night into Friday morning, snow levels will drop down to most valley floors with accumulating snow 'down here" becoming more probable heading into the holiday weekend.

Winds will be quite bullish with the winds for Thursday and the shortwave passage. 50-65 kts at 700mb would be quite significant with the potential for damaging wind gusts. The precipitation should help to temper them, but blowing rain and snow may be a concern Thursday afternoon and evening.

Late Christmas Day into Monday: Another round of snow will be on the table for much of the region. This next system is quite a bit colder than the previous wave, and ensemble cluster analysis signals the unusualness of the lower height anomalies associated with it.

There is a 20% chance that the system`s track will stay north across the Pacific Northwest, but most ensemble guidance and deterministic solutions have it across the Sierra and Basin and Range locations Sunday. Just as a "first look" blended model guidance is showing a 50% of at least 2 inches at KRNO Sunday morning, with around 10-15% chances in the Basin and Range areas. This is additional snowfall, so it doesn`t even account for any snow that may have already occurred before the weekend.

This next storm may catch folks off their game, especially with post-Christmas festivities in full swing and commutes homeward commence. Plan on a broad area of winter driving conditions for western Nevada and over the Sierra this holiday weekend.

Check back for updates.