622 FXUS65 KGGW 241017 AFDGGW Area Forecast Discussion National Weather Service Glasgow MT 317 AM MST Sun Dec 24 2017 .DISCUSSION... ...Dangerous wind chills to impact northeast Montana for Christmas holiday travel period... Radar echoes over the region early this morning continue to indicate isolated or widely scattered snow showers moving through, but little or no accumulation is expected. A coating is perhaps possible with some of the steadier activity. The main story will be the Arctic temperatures settling into the region for Christmas Eve and beyond as skies clear. The presence of temperatures well below zero tonight in combination with wind speeds around 10 mph at times justify issuance of a Wind Chill Advisory. For Christmas Day and into the following night, winds will gradually diminish. Very cold overnight lows between 20 and 25 below zero are possible given snow pack, light winds, and clear skies leading to strong radiational cooling. Although exact wind chill criteria may not be met due to the light winds, given holiday travel impacts, and the fact that this is the first prolonged Arctic push of the season, wind chill headlines remain appropriate. To help underline the message, have gone with a long-fused advisory until 19Z Tuesday. Travelers and those with outdoor plans should remember warm layered clothing and it is a good idea to maintain a winter safety kit inside your vehicle. Latest 00Z models continue with a northwest upper flow regime for late this week and next weekend, with periods of snow possible from embedded shortwaves tracking through this flow. It is too soon to speculate on timing and amounts of snow as these shortwaves are hard to detail at such large time scales. The bulk of the activity could just as easily move well to our south and west as it could right over us. Future shifts will be able to get a better handle on this in the coming days as model consensus improves. Right now the focus was on the Christmas holiday impacts from the bitter cold and dangerous wind chills, and the extended period was simply trended to come into agreement with the latest consensus model solutions. Maliawco && .AVIATION... MVFR CIGS are expected across area terminals at times with isolated snow showers, with a return to VFR by tonight as skies clear. West to northwest winds will continue into this evening at 10 to 15 kts. Maliawco && .GLASGOW WATCHES/WARNINGS/ADVISORIES... Wind Chill Advisory from 5 PM this afternoon to noon MST Tuesday for Central and Southeast Phillips...Central and Southern Valley...Daniels...Dawson...Eastern Roosevelt...Garfield... McCone...Northern Phillips...Northern Valley...Petroleum... Prairie...Richland...Sheridan...Southwest Phillips...Western Roosevelt...Wibaux. && $$ weather.gov/glasgow