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KEY MESSAGES

- Bitterly cold temperatures continue through this weekend with wind chills dropping as low as 45 below zero in the far NE corner of the state. A Cold Weather Advisory and Extreme Cold Warning remain in effect. - Temperatures warm to near normal early next week along with mostly dry conditions.

DISCUSSION

WEATHER PATTERN OVERVIEW:

An upper trough and arctic surface high pressure system is over the region. The coldest temperatures will continue to be in the northeast, with warmer temperatures in the southwest part of the area. The subzero temperatures will end for most of the area after Monday morning as the upper trough shifts further east. Until then, periods of wind chills around 40 below or colder continue for far northeast Montana through tomorrow morning. The current Extreme Cold Warning area will likely have advisory criteria linger into Sunday. Northwest winds and a weak disturbance over central Montana is allowing for scattered snow showers through tonight across the area, mostly when forced upslope for locales such as the Little Rockies. Most locations will see no more than a dusting of accumulation.

Temperatures will slowly moderate through next week as an upper ridge begins to affect the area, which will also limit chances for precipitation.

FORECAST CONFIDENCE & DEVIATIONS:

Increased chances for snow through tonight, given widespread flurries and periods of measurable amounts, especially near central Montana. Decreased temperatures through this evening to accurately reflect observed trends in temperatures and wind chills.

There is high confidence of the placement of the Cold Weather Advisories and Extreme Cold Warnings and a warmup on Monday. There is high confidence for a very light accumulation from snow showers today for much of NE Montana. There is high confidence in winds through tomorrow.

-JEZ

AVIATION

PATTERN: A cold arctic airmass will remain over the region through Monday morning. Areas of low to mid level clouds will become more scattered overnight, behind a cold front producing periods of MVFR in light snow showers prior to 06Z.

FLIGHT CONDITIONS: Even though MVFR to VFR conditions are expected, cold temperature impacts at all NE MT terminals may cause icing problems and equipment failure due to exposure, especially during the late night through early morning hours until Monday.

GGW WATCHES/WARNINGS/ADVISORIES

Cold Weather Advisory until 1 PM MST Sunday for Central and Southeast Phillips-Central and Southern Valley-Dawson-Garfield- McCone-Northern Phillips-Prairie-Richland-Southwest Phillips- Wibaux.

Extreme Cold Warning until 1 PM MST Sunday for Daniels-Eastern Roosevelt-Northern Valley-Sheridan-Western Roosevelt.