Sheridan broke a nearly century-old temperature record Thursday, reaching minus 27. On Sunday, the high in Sheridan was 58 degrees.
That’s an 85-degree swing in four days. The National Weather Service doesn’t track this kind of record, but it’s a tremendous swing.
The heavy snow and ice that fell during last week’s winter storm is rapidly melting. That can cause tremendous issues for home and business owners as they learn how well everything holds up under such extreme conditions.
“Freezing and thawing is a real challenge in Wyoming,” said retired insurance agent Dave Bell. “I don’t know if I’ve ever seen these issues anywhere else but in Wyoming.”
Up And Down
The polar vortex that smothered Wyoming with subzero temperatures and heavy snow has moved on. There’s a season for these incredible fluctuations, and this is it.
“The impressive swing is a testament to how extreme that cold wave was,” said Cowboy State Daily meteorologist Don Day. “When we get into this time of year, from mid-February to late March, you get longer days and bigger warm-ups.”
Day cited Sheridan as a prime example of the extent of the extreme swing. From Feb. 19 to Feb. 20, the temperature swung 43 degrees upward from the record-low minus 27 to 36.
Bell said the experience was similar in Pinedale on Monday.
“We were around zero this morning, and it was 38 degrees by the afternoon,” he said. “A 50-degree switch isn’t uncommon up here.”
Nevertheless, Day categorized this as “a natural response” to Arctic outbreaks. More importantly, the swing shouldn’t make much difference in the areas where Wyomingites want things to stay cold.
“This is not going to be a problem for the state’s snowpack,” he said. “Runoff tends to start when you have a warm spell that lasts for a couple of weeks in late March and April. This warm-up is expending a lot of energy causing ice jams and leaks in the lower elevations. It’ll settle the snow in the mountains, but we’re not going to see a big erosion of the snowpack.”
Ice Jams
There was a lot of moisture across Wyoming over the weekend as ice and snow rapidly started melting. This can pose a problem for a lot of infrastructure across the state.
“Anecdotally, when you get a big warm-up like this, you can get a lot of street flooding and water leaks, especially on flat roofs,” Day said. “Ice and snow block gutters and grates, and water starts to pool. That’s a common byproduct of a big warm-up after a lot of snow and severe cold.”
In his 30 years in the insurance industry, Bell said there was always an influx of water-related claims caused by “ice jams.” The extreme temperature swing over the last week could wreak havoc across the Cowboy State.
“I didn’t pay a lot of claims from the weight of ice and snow causing problems,” he said. “Most of the claims were from the slow migration of water as it freezes and thaws.”
Water is an unusual substance, elementally. While most substances become denser when transitioned from liquid to solid, water expands and becomes less dense, causing cracks in pipes, roofs, and roads.
Day cited a policy in Pinedale where residents are asked to leave “bleeders” on all winter to ensure their pipes don’t completely freeze. And science sometimes defies logic when it comes to wintertime plumbing problems.
“I don’t know the science behind it, but hot water lines freeze faster than cold water lines,” he said. “You might have a pipe running into your bathroom that’s not used in winter, and all of a sudden, you’ve got a flood because that pipe finally unfroze and cracked.”
“Bleeders” ensure that nobody’s pipes freeze entirely. While this is not a foolproof way to prevent problems, it does give everyone a better chance of avoiding these weather-related issues.
“If your bleeder keeps enough water running from your house, that ensures that the frost gets driven down the line and keeps that line running down the street,” Day said. “If it freezes solid, you’ll have a real mess on your hands.”
Falling Flat
Pooling water and ice jams are particularly problematic for anyone with a flat roof, which is why Wyoming insurance agencies tend to deny coverage for flat-topped structures.
“Having a flat roof in Wyoming isn’t smart from the get-go,” said Issac Miller, a sales producer for AllState Insurance in Cheyenne. “You won’t see any of those claims at AllState, because they’re pretty careful about who they insure for reasons like these.”
Miller said he’s heard of small leaks leading to the complete collapse of flat-roofed structures. Gutters could usually prevent water from pooling on the top of structures, but if those gutters get frozen, the water has nowhere to go.
“The strength of a roof comes to how much of a load they can bear,” he said. “In Wyoming, there’s a much heavier load with all the snow and ice. Allstate is very careful about who they insure when it comes to this.”
Blowhards
When the heavy snow and subzero temperatures moved out of Wyoming, a classic Chinook wind moved in. Chinook winds are prevailing warm, westerly winds generated by the warming of air that has lost most of its moisture.
Across the mountainous terrain of Wyoming Chinook winds can be incredibly powerful and destructive. Miller said that’s covering most of the claims he’s been receiving in Cheyenne.
“Most of the claims we’ve gotten recently have been wind-related,” he said. “Trees falling on houses, structural damage from wind, things like that. In fact, it’s been pretty quiet on claims except for wind.”
As warmer temperatures persist, Wyoming will be wet and sloppy for the next several days. Daytime high temperatures could creep into the 60s by Friday and will stay in the high 50s for most of the state over the weekend.
But this isn’t the first salvo of spring. Day said there’s strong potential for more winter weather, even if the extended periods of extremely low temperatures are over.
“Once we go through a week of these warmer temperatures, we will go back into a colder pattern that lends itself to a return to snow and colder weather,” he said. “We could very well have cold nights with single-digit or subzero temperatures, but the prolonged strings of several subzero days are probably over.”
Andrew Rossi can be reached at arossi@cowboystatedaily.com.
