It may be the middle of May, but winter isn’t done with Wyoming yet.
Another wave of wet weather from the Pacific Ocean will reach Wyoming on Sunday night, which will mean more snow in mountain ranges across the state. The system also might have enough strength for a rain-snow mix to fall into the lower elevations.
“I'm not expecting accumulating snow on the plains, but some folks may experience snow on Monday morning,” said Cowboy State Daily meteorologist Don Day. “Central Wyoming could see some wet snow.”
Most Wyomingites don’t want to wake up to that in late May, but Day thinks this spell of wintry weather is worth celebrating. It means moisture on Monday and better weather for the Memorial Day weekend.
“A lot of people aren't going to like the weather for a few days, but the timing is good for this to clear out and get warm again for Memorial Day weekend,” he said. “That’s how I’m spinning it.”
Wet Weather
The latest Pacific weather system will reach Wyoming on Sunday evening. The greatest impact will be at elevations above 7,000 feet.
“Most of the snow is going to fall above 8,000 feet but could drop as low as 7,000 feet by Monday,” said meteorologist Celia Hensley with the National Weather Service office in Riverton. “There could be some brief snow showers in Jackson, Star Valley, and Pinedale that morning.”
Overnight temperatures across Wyoming could drop below freezing between Sunday night and Monday morning. Daytime highs on Monday will range from the 40s to mid-50s.
Day believes it could still be cold enough Monday morning for Casper, Lusk and Lander to experience a final gasp of winter in the form of wet snow.
“The heaviest moisture looks to be in the northeast and the east central parts of the state,” he said. “The heaviest snow may end up in the Bighorns, the eastern side of the Wind River Range could do well with this system, we’re going to see more snow in the Absarokas and the Beartooths, and it’s going to be cold and wet in Yellowstone.”
That could be enough to postpone the opening of the Beartooth Highway.
The National Park Service and the Montana Department of Transportation are working to have the entirety of U.S. Highway 212 open by Memorial Day weekend, but another snowstorm could delay the intended day.
Hensley believes most of Wyoming won’t see snow, but there will be widespread moisture and cooler temperatures on Monday and Tuesday.
“There are still quite a few uncertainties with this system,” she said. “The biggest threat is that it will be cooler and wetter for the Monday morning commute.”
Beneficial Moisture
With a little over a month until the start of summer, many people will grumble about another cold spell. However, Hensley said this Pacific system will bring a lot of beneficial moisture to Wyoming.
“There could be upwards of an inch or more of rainfall between Saturday night and Tuesday morning,” Hensley said. “That's definitely going to be beneficial for eastern Wyoming, where the worst drought conditions are.”
Central Wyoming could see up to an inch of additional moisture from this system. Temperatures will be cooler, but Hensley said we’re too close to summer to worry about winter temperatures.
“We're definitely not looking at January, February or March cold,” she said. “We’re into the latter half of May. It’ll be a fairly cool system, but it's not a cold system by any measure.”
The biggest question is whether this weather will be enough to reach the region with the worst drought conditions. Despite the abundance of moisture across most of the state, southeast Wyoming is still experiencing “extreme” drought, according to the U.S. Drought Monitor.
“Platte, Goshen and Laramie counties have not gotten spring moisture while everywhere else has,” Day said. “This storm system is important because it has a chance to bring some moisture to those areas.”
Based on the current modelling and projections, Day said this Pacific system “has a chance” to reach Cheyenne with enough moisture to produce some precipitation. But we won’t know until it’s come and gone.
“Cheyenne’s got a chance, but it's not a slam dunk,” he said. “We’ll have to assess the situation after the storm moves out to see how well they did.”
Memorial Mayday
Sunday and Monday will be cool and wet across most of Wyoming, but warmer temperatures and sunnier skies will return by Tuesday. If that pattern holds, Day believes it bodes well for anyone planning an outdoor excursion for Memorial Day.
“We should have a warning trend going into Memorial Day,” he said. “The timing is good for everything to clear out in time for the three-day weekend.”
Day believes Memorial Day is often “disappointing” for many Wyomingites. Although it’s seen as the first weekend of summer, many people who run off into the mountains find themselves cold and miserable rather than basking in the warm summer sun.
“Memorial Day always gives me a little pause,” he said. “A lot of people get the camper and fishing poles out, head into the hills, and then they go up and sit in rain and snow for three days. In my experience, it can be a disappointing weekend.”
Hensley said it’s still too early for a firm Memorial Day forecast, but agreed that the prognosis is positive. You might need a jacket, but the parka and heavy socks can probably be stowed away for a few months.
“Indications are that it could stay on the warmer side, or at least seasonally warm into Memorial Day weekend,” she said. “We don’t know for sure, but it is trending more on the warmer side than the colder side.”
Andrew Rossi can be reached at arossi@cowboystatedaily.com.
