Winter weather advisories posted for Tuesday night through late Wednesday
By Bob Berwyn
SUMMIT COUNTY — A classic spring storm is rolling across the West, marked by a deep trough of low pressure extending down into the desert Southwest. As an “inside slider,” the low will move east of the Continental Divide and set up a deep, moist northeast flow that could produce significant snowfall on the east slope of the Front Range under upslope conditions.
A winter weather advisory from 12 p.m. Tuesday night to 6 p.m. Wednesday (May 11), with 4 to 8 inches of snow possible above 7,000 feet along the Front Range. The winter weather advisory extends to the higher terrain of Summit County, where the National Weather forecast also calls for the chance of 4 to 8 inches of snow across the higher terrain. A-Basin could pick up some decent snow once the weather system moves east of the area Wednesday and the flow switches around to the north.
Farther west and south, around Vail, Aspen and Crested Butte, a winter storm warning is in effect, with heavier snow expected across south-facing slopes Tuesday night, shifting to north-facing slopes Wednesday.
Unsettled weather will continue into Thursday when high pressure builds back into the area for an extended warmup that could bring the first sustained surge of runoff. The southern mountains could start seeing some thunderstorms setting up late in the week, especially Saturday, when an almost summer-like pattern brings a disturbance north from the Baja area.
Wednesday’s high will be in the mid-30s under snowy skies, with a low around 20 early Thursday morning. Friday and Saturday, temperatures will climb back up into the mid-50s with nighttime lows in the mid-20s. The average May 11 high in Frisco is 55 degrees, the average low is 26 degrees. The record reading for the date is 71 degrees, set in 1961 and the record low is 6 degrees, set in 1955.
On the plains, spring is in full swing, as highs reached the mid to upper 80s, with Lamar recording the statewide high at 88 degrees. Wolf Creek Pass was the cold spot, at 21 degrees. Around the country, Laredo, Texas was the hotspot, registering 100 degrees, while Berthoud Pass reported the coldest reading in the country, with 18 degrees.
The variable spring weather has set up a mixed bag for backcountry skiers, who could encounter a fresh layer of windslab Wednesday and Thursday while in search of fresh powder. That slab will be resting atop layers water-soaked snow that may not handle the load very well. The recent warmup triggered a spate of impressive wet snow avalanches around Colorado.
The new snow could add weight to existing massive cornices, where backcountry travelers need to exercise special caution. Check the Colorado Avalanche Information Center website for a late-season bulletin.