Here it comes: Treasure Valley’s first big inversion of the winter

The Treasure Valley is bracing for its first inversion of the winter, as cold temperatures become trapped on the valley floor. And right behind it will come bone-chilling below-zero temperatures as part of an Arctic blast next week.

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 as the Idaho Department of Environmental Quality forecasts yellow/moderate air quality.

During an inversion, colder temperatures stay near the valley floor and temperatures rise as the elevation increases. Boise is expected to have a midday temperature of 24 Friday, but Idaho City, at a higher altitude, will reach 30 degrees, according to the National Weather Service.

Frigid temperatures are expected to hit the Treasure Valley Sunday, with snow in the morning accumulating to one to two inches. Monday night temperatures will drop to - 2 degrees. Tuesday will be a high of 10. Long range forecasts call for a continuing drop in night time temperatures to -14 degrees on Friday. But that may seem warm compared to Fairfield, where the National Weather Services is predicting a -33 degrees on Friday night.

This story was originally published December 29, 2016 at 4:30 PM with the headline "Here it comes: Treasure Valley’s first big inversion of the winter."