Winter weather to return for weekend

May 20—CHEYENNE — A return to winter weather is forecast through Saturday morning.

"An unusually strong weather system coming through" will begin as a cold front and may ultimately turn into several inches of snowfall, said Brandon Wills, a meteorologist with the National Weather Service's Cheyenne office.

Wills said temperatures into Saturday morning are expected to primarily be in the low- to mid-20s Fahrenheit, and potentially into the teens for overnight lows.

"So, it's a pretty bitter cold for this time of year, and most people are not going to like it," he said. "This isn't a surprise — we do have snowfall this late into the season," and, some years, even into June.

The low temps will mean a chance of snow accumulation, likely the heaviest around the Wyoming-Colorado border and farther to the west. "The southern foothills of Laramie County, they're going to get a fair amount of snow. Right now, we're forecasting four to 10 inches," and potentially up to a foot in the higher elevations, Wills said.

Because recent temperatures locally have been warm, "it's going to take a little bit of time for it to start accumulating," Wills said. With the sharp drop in temperatures overnight, and snowfall possibly beginning around then, it's a possibility, he said.

"It's just a matter of the snowfall intensity. If we have just light snow showers, it's going to limit snow accumulation," Wills said.

There is a winter storm watch for Laramie County until noon Saturday.

A hard freeze watch is also planned in southeast Wyoming for Friday evening through Saturday morning. According to a NWS alert, "frost and freeze conditions could kill crops, other sensitive vegetation and possibly damage unprotected outdoor plumbing."

The snow is expected to be wet and heavy. This is good in the sense that it will blow around less, but it also means it could weigh down tree branches, Wills said.

Laramie County is on the "very northern fringe" of this weather system, he said, with heavier snowfall expected in Colorado.

Friday afternoon, the city may see some periods of a rain and snow mix, before switching back to all snow Friday night. Snow showers will stick around until mid- to late Saturday morning, Wills said, when the storm is expected to start leaving the area.

Cool temperatures will persist, with highs on Saturday between 35 and 40 degrees in Cheyenne. Wills said temperatures will begin "creeping back up toward normal temperatures by Sunday," with highs around 50. On Monday, highs will be in the low 50s for Cheyenne, and on Tuesday, temperatures will begin to get back up to around 60.

While the cold weather and snowfall may not be welcome this time of year, it's not necessarily an anomaly.

"It's not unheard of. In the office, we typically say between Mother's Day and Memorial Day, usually we'll get hit with some type of snowfall accumulation before we can kind of expect the warmer temperatures to stick around," said the meteorologist.

Wills recommended people who need to travel Friday and early Saturday carry an emergency bag with things like extra layers of clothing, blankets, flashlights, water, food, and any other supplies that may be useful in the case of weather delays or highway closures.

"We have had the windiest season so far of the last approximately 20 years" of NWS data gathered for Wyoming, Wills said. "We have issued 111 high wind warnings ... from the fall of last year to presently," which is at least 20 high wind warnings more than a previous record, he added.

Wills said sustained winds of 15 to 20 mph are expected Friday, with gusts up to 25 to 30 mph.

Protecting plants

Nettie Hardy, horticulture and operations supervisor at the Cheyenne Botanic Gardens, offered some advice for those with outdoor plants they're hoping to protect as temperatures plummet.

One of the main things, Hardy said, is to water your plants, saturating the ground, before the cold hits.

"(This) helps plants to not be quite as stressed, and then also insulates them, as well, prior to temperatures dropping," she said.

Annuals, such as marigolds, should be moved inside, as should plants like peppers and tomatoes.

As for perennials, Hardy recommended they be covered in frost cloth or a bedsheet. Things like five-gallon buckets or plastic can also be used, but Hardy said something breathable — like the frost cloth or a sheet — is better. With non-breathable materials, plants risk getting too warm once temperatures come back up, or may suffocate.

Unfortunately, not much can be done for trees, unless they're very small, Hardy said. In that case, they can be covered in frost cloth or a sheet.

Depending on how cold it gets this weekend, any plants outside are susceptible to possible damage, although things can be done to help mitigate that damage.

"We live in Wyoming, and it's sort of the risk we all run trying to grow plants here," Hardy said.

Hannah Black is the Wyoming Tribune Eagle's criminal justice reporter. She can be reached at hblack@wyomingnews.com or 307-633-3128. Follow her on Twitter at @hannahcblack.