1/15 – The Chief’s “Winter Weather Advisory” Monday Morning Forecast

A large upper level disturbance encompasses about the northern half of the country, with relatively zonal flow across the southern half of the country. The next in a series of strong disturbances is digging southward out of Canada through Montana early this morning

Obvious forecast problem through Tuesday night is the arctic air and it’s effect on any precipitation that may fall late this afternoon and overnight. There could be as much as a 20 degree spread or more across the area late this morning and early this afternoon, with the potential for that to occur over a rather short distance. The stronger push will occur very late this afternoon and overnight, as northerly winds pick up significantly. Precipitation should break out by mid-afternoon to our west and spread eastward. Fortunately, the moist layer isn’t very deep, only extending up to about 8,000 feet, so precipitation amounts will be rather light, and likely to end around or before sunrise Tuesday. This will make the primary precipitation type in the sub-freezing air freezing rain, with some potential for sleet near the end of the precipitation event. Snow is extremely unlikely in this pattern. The ground is relatively warm in most of the area, so any light ice accumulation that does develop would likely be limited to signs, tree branches, power lines, elevated roadways and bridges.

We should finally see some sunshine by late in the day Tuesday, but temperatures likely to remain in the 30s across most of the area. Bone chilling cold expected Tuesday night under clear skies, with the coldest weather in 5-6 years for Wednesday morning. I have upgraded the Hard Freeze Watch for tonight to a Hard Freeze Warning over northwest portions of the area, and issued a Hard Freeze Warning for the entire area Tuesday night. The Wind Chill Advisory for tonight will remain in place, and another issued for overnight tomorrow night across the northern half of the area.