Arctic front expected to drop wind chills near -50 degrees

Dec. 20—CHEYENNE — "That can't be right, can it?"

Many Cheyenne-area residents have likely had that thought since the National Weather Service first issued a Wind Chill Watch on Sunday.

The statement said that "extremely dangerous and life threatening wind chills" of 50 to 65 degrees below zero Fahrenheit are possible in southeast Wyoming from Wednesday through Friday, with the worst happening Wednesday night through Thursday night.

It went on to say, "Wind chills of this magnitude can cause frostbite in less than 5 minutes if precautions are not taken. Hypothermia and death can also occur due to prolonged exposure to the cold."

Those who have lived through more than one winter in Wyoming's Capital City know that while it's a good idea to be prepared for the worst and hope for the best, sometimes the reality isn't nearly as bad as forecasters warned us to expect.

Sorry, folks, but it doesn't look like we'll be dodging this one. Mother Nature plans to let us know that winter has arrived in no uncertain terms.

Just before noon Tuesday, NWS Cheyenne meteorologist Michael Charnick told the Wyoming Tribune Eagle that the cold front will likely arrive in Laramie County between 2 and 3 p.m. Wednesday, dropping temperatures about 30 degrees in an hour. (For those who enjoy coincidences, the official Winter Solstice in the Northern Hemisphere is at 2:48 p.m. Mountain Time.)

"It's going to be the coldest air mass that people have felt in quite awhile," Charnick said, noting that the expected air temperature of -24 degrees Fahrenheit hasn't been experienced in Cheyenne since 1990.

After an early high temperature of 36 degrees Wednesday, that quick rush of super-chilled air could cause several problems all at once.

"Along and right after the front (arrives) is the best time period for heavy snow," Charnick said. "There could be some snow squalls out there, quick reductions in visibility, perhaps even a flash freeze on some road surfaces, given that we're going to be pretty warm ... ahead of the front."

Wind gusts in the low- to mid-30 mph range should create a wind chill, or "apparent temperature," of -40 to -50 degrees on the edges of Cheyenne, he said, with slightly less severe conditions in the city's interior and the possibility of -55 to -70 degrees in some of the flat, unprotected locations.

The good news is the snow isn't expected to stack up much. Forecasters say most of southeast Wyoming will only see 1 to 3 inches of the white stuff, with up to 6 inches in the higher elevations.

In anticipation of the extreme cold, Laramie County School District 1 officials announced Tuesday afternoon that they would close all schools and other facilities at noon Wednesday. Although students are out on winter break until Jan. 3, "all activities, such as practices, camps and tutoring sessions, are canceled."

The district plans to reopen its facilities on Tuesday.

Also in advance of the cold weather, the Cheyenne Board of Public Utilities offered suggestions for keeping pipes from freezing. They include:

— Keep kitchen and bathroom cabinet doors open to allow for warm air to circulate.

— Locate where water enters the building and open a faucet at the farthest point away just enough to allow a slow drip. This will keep water moving and reduce the chances of freezing pipes. Use a bucket to collect the water for other uses, such as watering plants.

— Insulate pipes that may be vulnerable to the cold or have previously been problematic.

— Use "heat tape" or similar materials on exposed water pipes.

— If you have an attached garage, keep its door shut. Plumbing may be routed through the unheated garage, leaving it more vulnerable to freezing.

— Know the location of your home or business' water shut-off valve and test it regularly.

BOPU officials advises residents to turn the water off at the main valve if they find a pipe starting to leak. For help locating the main water valve, shutting off water to a home or business, or if you have any other water or sewer-related emergency, call 307-637-6471.

While it will be important to stay indoors as much as possible Wednesday night, Thursday and most of the day Friday (which is expected to feature a high temperature of 14 above, but wind chills still in the -15 to -30 range), a warm-up is expected in time for Christmas Day.

Charnick said Saturday's high temperature in Cheyenne is expected to be close to 40 degrees Fahrenheit, with Sunday's high reaching 44. And the reprieve from the severe cold is expected to last into next week, as the Climate Prediction Center says the six- to 10-day outlook calls for above-normal temperatures and near-normal precipitation.

One small silver lining for this week: Although it will be extremely cold, it likely won't tie or break any records. Although the agency doesn't keep records of wind chills, the National Weather Service data shows the record low air temperature for Dec. 22 is -28 degrees, which was set in 1990.

Brian Martin is the Wyoming Tribune Eagle's managing editor. He can be reached by email at bmartin@wyomingnews.com. Follow him on Twitter at @briankmartin.