Rare cold snap possible for Inland NW as December closes
As Christmas weekend winds down, unusually cold air will begin sneaking into the Inland Northwest. While the holiday weekend won’t feel substantially different than a typical December day, by New Year’s Eve, Spokane and the rest of the region will be in the grip of a rare cold air mass that may bring the lowest daily high temperatures the Inland Northwest has seen in a decade.
The air mass has the potential to send temperatures across the region plummeting fifteen to 25 degrees below seasonal averages, according to Andrew Brown, Warning Coordination Meteorologist for the National Weather Service’s Spokane office.
And while there is some uncertainty about the precise high and low temperatures that will manifest, particularly toward the latter half of next week, Brown said Wednesday forecasters have high confidence in the general outlook for brutally cold weather.
Current computer model forecasts call for highs close to 10 degrees in Spokane December 29-31. It’s coldest air that has parked over the Inland Northwest since 2011. An extended period of highs at or near 10 degrees hasn’t happened since 2009, according to Weather Service records.
“That’s where we think this is kind of a rare event,” Brown said. “This has the potential to last a little bit longer than the typical Arctic outbreak, and we have not seen that very regularly.”
Potential effects from the frigid air include pipes that freeze and burst, threats to pets and hypothermia among people without adequate indoor heat or those who venture outside. The National Weather Service offers tips for preparing for cold weather on its website.
The area’s cold-temperature records are not in danger of falling, Brown said. The coldest daily high temperature recorded in Spokane for December 29 is -9. December 30’s record is -8. Both were set during a cold snap in 1968. Spokane’s chilliest New Year’s Eve came on the final day of 1884, when the temperature rose only to -6.
Predicting low temperatures next week is much more challenging, the Weather Service said. Many small-scale factors, such as cloud cover, fog and local terrain make it harder to say with certainty how far temperatures will fall overnight. Inland Northwesterners are advised to check the forecast closely each day for updates.