Published: April 15,2016
(MORE: How Winter Storms Are Named)
As much as 19 inches of snow has already been reported near Bynum, Montana as of Friday night with 4.5 inches near Skyway, Colorado.
Winter storm warnings have been issued by the National Weather Service for parts of Utah, Colorado and southern Wyoming, including most of the high country of Colorado, the Front Range foothills and, starting Saturday morning, the Front Range Urban Corridor including Denver and Boulder. Warnings have also been posted for the cities of Cheyenne and Laramie, Wyoming.
Winter Weather Alerts
The atmospheric ingredients for the weekend Rockies snowstorm. That moist air flowing up the slope of the High Plains will pass over a pool of cold air, the "cold conveyor belt", pulled southward down the Front Range and High Plains.
This will provide a soaking in lower elevations of the Plains. But as the precipitation gains elevation in the High Plains and Front Range of the Rockies, it will become a wet, heavy snowstorm.
(FORECASTS: Flash Flood Threat | Severe Threat)
Winter Vexo Timing
Before the upper low stalls and becomes cut off from the jet stream, it is sweeping through the Great Basin, generating some modest mountain snow totals in the northern Rockies and Wasatch. This snow may continue in spots through the beginning of the weekend.(INTERACTIVE RADAR: Where the Snow is Now)
Current Radar and Conditions
- Saturday: Changeover to snow progresses farther into the plains of northeast Colorado, and the Nebraska panhandle; Heavy snow in the mountains, foothills, and Front Range along and west of I-25 in southeast Wyoming, Colorado; Snow in the mountains of Utah and northern New Mexico.
- Sunday: Heavy, wet snow may continue in parts of the same areas of the High Plains as on Saturday, particularly in the Nebraska panhandle and southeast Wyoming; mountain snow continues in Wyoming, Colorado, northern New Mexico.
- Monday: Snow, possibly still heavy, may spread a bit farther north into northern, central and southeast Wyoming, far southwest South Dakota, and may linger in the Nebraska panhandle. Snow may also persist in parts of the high country of Colorado and northern New Mexico.
- Tuesday: Snow ends in most low elevations, but still may linger in the mountains of Colorado and northern New Mexico.
Saturday Night's Forecast
Winter Storm Vexo Snowfall Forecast
Since some of these locations may see snow fall for four to five days, totals could become impressive, by April standards.- Highest confidence of at least 1 foot of snow: Foothills west and southwest of Denver, Palmer Divide between Denver and Colorado Springs, southeast Wyoming, most of the Nebraska panhandle, mountains of southwest Colorado. Some locations above 7,000 feet in Colorado and southern Wyoming could pick up several feet of snow.
- At least 6 inches of snow possible: Plains of south-central and central Wyoming, parts of the northeast Plains of Colorado, including the Denver-Boulder-Ft. Collins I-25 Front Range corridor, Sangre de Cristo Mountains of northern New Mexico, parts of north-central and northwest Montana.
Snowfall Forecast Through Early Next Week
A portion of Interstate 70 westbound had to be closed to the west of Denver on Friday due to heavy snowfall, which temporarily stranded some motorists.
You may have to alter your travel plans in these areas. In this scenario, the following stretches of interstates may be closed for a period of time:
- Interstate 80 from southern Wyoming into the Nebraska panhandle
- Interstate 25 in southeast Wyoming and also in the foothills south of Denver to Monument Hill.
- Interstate 70 both in the foothills west of Denver and also, possibly in parts of the Plains east of Denver
- Interstate 76 in parts of the Plains northeast of Denver
This may sound familiar. Roughly three weeks ago, Winter Storm Selene hammered parts of the Front Range and High Plains, crippling travel in both Cheyenne, Wyoming, and Denver.
Locations in the U.S. where April is the snowiest month of the year, on average.Where April Snowstorms Are Typical
December, January or February may come to mind first, but in parts of the Rockies and High Plains, April is a month rife with snowstorms.Alaska-based climatologist, Dr. Brian Brettschneider found 34 locations in the Rockies and High Plains where April is the snowiest month including:
- Breckenridge, Colorado (26.5 inches)
- Casper, Wyoming (11.6 inches)
- Mt. Rushmore, South Dakota (11.3 inches)
Let's consider another example, the state capital of Wyoming, Cheyenne.
In over 100 years of records dating to 1915, nine of the top 20 snowstorms of record (using non-overlapping three-day snow totals) in Cheyenne have occurred entirely, or in part, during the month of April.
Number of Top 20 Cheyenne, Wyoming, Snowstorms By Month
Number of Top 20 Cheyenne, Wyoming, Snowstorms By Month
Number of Top 20 Snowstorms
Data: ACIS/NOAA Regional
Climate Centers (Note: One snowstorm, Apr. 30 - May 2,1942 occurred in
two different months, and, therefore, was counted in both April and May
in the historgram above.)
And it's not just about April.
Cheyenne has also had seven separate May days with at least 10 inches of snow and two June days with at least 7 inches of snow, according to National Weather Service records dating to 1883.
(INTERACTIVE: When Spring's Last Snow Typically Happens)
Winter Storm Zephyr dumped a foot of snow in Cheyenne over Mother's Day and the following Monday, 2014, the heaviest calendar-day snow so late in the season by a narrow margin.
This Mother's Day winter storm snarled traffic, downed trees and triggered power outages.
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