Bundle up, Boise. A near-record big chill is coming. | Idaho Statesman

Getting out for Idaho Potato Drop festivities on New Year’s Eve in Downtown Boise the past few years has meant bundling up for polar bear weather — and this year will be no exception.

National Weather Service forecasters say it will be in the mid-teens Saturday night and get even colder after midnight. But that may actually feel warm compared to the sub-zero temperatures we’re expected to get next week.

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We’ve had some light snow Friday morning. The next chance of snow is Sunday morning — and 1 to 2 inches are expected to accumulate by Monday afternoon.

Here are the near-record lows we’re looking at next week at the Boise Airport. Temperatures should be even colder on the west side of the city and Treasure Valley.

▪  Tuesday: 1

The record low for Jan. 3 is -6, set in 1910.

▪  Wednesday: -6

The record low for Jan. 4 is -9, set in 1991.

▪  Thursday: -9

The record for Jan. 5 is -12, set in 1991.

▪  Friday: The record for Jan. 6 is -10, set in 1982. It’s a little too far out to forecast, but it could be as low as -10 this year. That presumes it’s mostly cloudy. If the clouds clear, it could be even colder.

This is way below normal for Boise. The normal high for Dec. 30 is 36, and the normal low is 23.

Why is this happening?

Normally, our weather comes from the west off the Pacific Ocean, but a high-pressure system in the Gulf of Alaska will cause a northerly flow of arctic air to knock down temperatures, said Joel Tannenholz, a meteorologist at the Weather Service.

The Treasure Valley already has inversion conditions, with cold air trapped near the valley floor that make it colder in Boise than at Bogus Basin.

“We have a lot of snow on the ground and that creates radiational cooling,” meteorologist Korri Anderson said. That essentially means the sun’s heat is reflected back into space. It also enhances cooling overnight.

Outdoor burning and use of wood stoves and fireplaces will not be permitted in the cities and unincorporated areas of Ada and Canyon counties Friday because the Idaho Department of Environmental Quality forecasts yellow/moderate air quality.

When was the coldest day ever in Boise?

We have had some wicked cold stretches in recent years, including the opening and close of 2013. The year started with four days of sub-zero temperatures (January 19-22) and ended with two days of sub-zero temperatures (Dec. 8-9).

There was a six-day stretch of sub-zero temperatures in December 1990. Temperatures ranged between -18 and -23 on Dec. 20-25 that year.

The coldest day in Boise history was Jan. 16, 1888, when a temperature of -28 was recorded, according to National Weather Service data. It’s been almost that cold in modern times — temperatures dropped to -25 on Dec. 22, 1990. That was the fourth-coldest temperature on record for Boise.

What should you do to prepare?

This weather can be dangerous if you have an emergency on the road and aren’t prepared for it, or if the power goes out at your house for an extended time.

Check out the Weather Service’s checklist of things to keep in your car, such as blankets, water/snacks, extra hats/gloves/boots, snow shovel, flashlight, first aid kit and flares. The American Red Cross has tips on what to have on hand in case of a power outage, such as bottled water, easy-to-prepare food, flashlights and extra batteries.

If you’re worried about keeping your pipes from freezing, Suez has a “big chill” checklist that includes tips such as keeping a trickle of water running from the highest faucet in your house. Note: The trickle should be the size of a pencil point.