Snow Expected Mother's Day Weekend in West, Plains

Linda Lam
Published: May 6,2015



 
Thoughts of Mother's Day typically include flowers and warm temperatures. That will not be the vision for many in parts of the West and Plains this year.
A significant late-season snowstorm is setting up in the central and northern Rockies for Mother's Day weekend. This could impact travel in the region.
(MORE: America's Worst and Best Winter Cities 2014-15)
A closed upper-level area of low pressure will move into California late this week and then will slide eastward this weekend, producing significant mountain snows across the northern and central Rockies. The Sierra should also see at least some beneficial snowfall.
(MORE: Record Low Snowpack in the Sierra)
Cooler temperatures will develop in the Southwest late this week and then in the Rockies and portions of the northern Plains this weekend. High temperatures will be up to 25 degrees below average. Rapid City may only reach the 40s for highs this weekend. Low temperatures will be near to slightly below average, with temperatures dipping into the 20s and 30s for much of the Rockies.
The colder temperatures will set the stage some wintry precipitation, but the question is whether there will be enough cold air in lower elevations of the High Plains to produce significant snow.

When, Where and How Much

Saturday Night's Forecast

Sunday's Forecast

Sunday Night's Forecast

Snowfall Forecast

Late week: Cooler conditions will move into parts of California Thursday and Friday as an upper-level low digs southward into California from the Pacific Northwest. This is also known as an "inside slider". Snow will fall in the higher elevations, especially over 6,000 feet, beginning early Thursday with locally heavy snowfall possible. A few inches of snow, however, are possible down to 5,500 feet in the Sierra. This system will also bring showers and thunderstorms to the lower elevations.
If you are traveling through the Sierra expect slippery roads. Chains and a winter survival kit are recommended from the National Weather Service office in Hanford. There may even be a chain requirement on Interstate 80 and U.S. 50.
(FORECAST: Lake Tahoe, California | Sequoia National Park)
Saturday: The upper-level low will slide east this weekend, and the rain and snow will end in California. The chance for significant snow in parts of the Rockies will increase. The best chance for heavy snow will be in the higher elevations in central and eastern Wyoming and Colorado. Snow levels are expected to lower Saturday night, with the Black Hills in South Dakota also seeing snow pick up, then.
Prepare for wintry travel conditions along parts of Interstates 80 and 25 in Wyoming and Interstate 70 in Colorado high country.
(FORECAST: Aspen, Colorado | Yellowstone National Park | Casper, Wyoming)
Sunday: Colder temperatures will spread from central Wyoming and Colorado into far western Nebraska and western South Dakota. This may allow some of the rain to change to wet snow in lower elevations. There are some differences in the computer forecast models, but it could be cold enough for snow in parts of the Denver metro (particularly the foothills) into eastern Wyoming, the panhandle of Nebraska and western South Dakota. This snow could be heavy, at times.
Slippery travel conditions are likely to spread into sections of Interstate 80 in the Nebraska panhandle, Interstate 90 in far western South Dakota and northeast Wyoming and Interstate 25 in Wyoming. Travel may remain difficult along Interstate 70 in Colorado and Interstate 80 in Wyoming.
(FORECAST: Denver | Cheyenne, Wyoming | Rapid City, South Dakota)
Rain and snow should slowly diminish Sunday night, and will likely clear the region by Monday morning. Snowy travel may linger into early Monday in these areas.
Snowfall in the Sierra is likely to be generally less than 6 inches, although up to a foot of snow is possible in the highest elevations.
The mountains in Colorado and Wyoming and the Black Hills of South Dakota may see total snowfall amounts of 1 to 2 feet. Some lower elevations of Wyoming, the Nebraska panhandle, and far western South Dakota may see 6 inches of wet snow or more.
(MAPS: Weekly Planner)
Mother's Day weekend is still a few days away and given the differences in the computer forecast models, the forecast details will be updated as the week progresses.

Are May Snow Storms Unusual?

Spring and winter collide as a Winter Storm Zephyr hit Colorado on Mothers day 2014 covering blooms and blossoms and tulips. (Photo By Steve Nehf / The Denver Post)

Winter storms do still occur in May, especially in the West. Just last year Winter Storm Zephyr impacted the Rockies from May 10-13, Mother's Day weekend, with 43 inches of snow at Divide Peak in the Sierra Madre range of Wyoming.
(MORE: Winter Storm Zephyr Recap)
The average date for the last measurable snowfall (0.1 inches of snow or greater) in Cheyenne, Wyoming, is May 9, so this is not that unusual for the area. Casper, Wyoming, sees almost 3 inches of snow on average during the month of May.
In the Denver area, the average date for last measurable snowfall is April 27, so this is a little later than average. However, Denver has seen snow as late as June.
In Scottsbluff, Nebraska, an average of half an inch of snow falls in May. Rapid City, South Dakota averages 1.1 inches of snow in May and has received snow in June, with the latest date of measurable snowfall being June 13, 1969.
MORE: Best Winter Photos 2014-2015