724 FXUS65 KTFX 161800 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1050 AM MST Wed Dec 16 2020 Aviation Section Updated. .UPDATE... Light snow continues this morning over the Northern Rockies, producing minor impacts to travel over Marias, Rogers, and MacDonald passes. This activity is expected to continue, but gradually decrease in coverage through the day. After a brief lull this evening, attention turns to the next round of snow developing tonight along the Continental Divide including the Southwest MT ranges. Overall forecast describes the situation well, so an update will not be posted at this time. && .SYNOPSIS... Periods of light mountain snow can be expected, with generally breezy to gusty winds. A period of stronger winds is expected this weekend. Please, keep this in mind if planning any outdoor activities. && .AVIATION... 1050 AM MST Wed Dec 16 2020 (16/18Z TAF period) VFR conditions prevail. A band of mid-level clouds is presently obscuring mountains on approaches to KHLN/KBZN/KEKS with likely in- cloud icing. Cloud cover becomes more widespread overnight through Thursday. Increasing winds aloft may introduce low level wind shear at KCTB/KHVR/KLWT, along with associated mountain wave turbulence. Snow develops over most mountain areas, with a possibility for temporary reduction to MVFR/IFR conditions at KBZN/KEKS through mid- day Thursday. Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PREV DISCUSSION... /ISSUED 522 AM MST Wed Dec 16 2020/ Today... Ripples in the flow aloft pass to the east and ridging builds into the area again, while mountain showers gradually end. Breezy to gusty winds are forecast across much of central and northern Montana, with unseasonably warm highs and dry conditions. Thursday... We begin to feel the effects of the next upper level trof approaching from the west. Expect gusty winds to continue. Most snow will fall and accumulate along the mountains of The Divide and those of southwest Montana. Widespread gusty winds will favor evaporating moisture that tries to fall to lower elevations; however, a few passing light snow showers are possible across the plains overnight, with a brief rain shower or two at lower elevations during the day. Highs from the upper-30s to mid-40s are forecast. Friday through next Tuesday... Ridging dominates the overhead weather pattern on Friday. Expect a mild day in terms of temperatures and moisture. With a trof located over The Canadian Hudson Bay, and another trof upstream and high pressure dominant off of the west coast of California, a strong zonal flow sets-up across The Great Divide, and winds begin to gust Friday afternoon. Expect strong westerly gusty winds to become widespread throughout the weekend, with generally gusty winds continuing through Tuesday. Perturbations in the flow aloft favor mountain showers that will begin Saturday, increase in areal coverage across southwest Montana on Sunday, and become more widespread northward into central Montana on Monday and Tuesday. Next Wednesday... Numerical model solutions are quite divergent at the end of this forecast period; however, at this time, it looks like we will see a dry day with cooler highs ranging in the 30s, and gradually decreasing winds. - Fogleman && .PRELIMINARY POINT TEMPS/POPS... GTF 43 30 45 24 / 10 10 10 10 CTB 40 25 41 18 / 0 10 10 10 HLN 42 27 43 26 / 10 10 10 0 BZN 39 21 41 20 / 10 10 40 10 WYS 26 15 31 7 / 60 70 80 30 DLN 36 22 38 17 / 10 10 30 0 HVR 39 23 43 17 / 0 0 10 10 LWT 39 25 43 22 / 10 0 10 10 && .TFX WATCHES/WARNINGS/ADVISORIES... High Wind Watch from Friday evening through Saturday morning Cascade...Central and Southern Lewis and Clark...Chouteau... Eastern Pondera...Eastern Teton...Fergus...Judith Basin... Meagher...Toole. High Wind Watch from Friday afternoon through late Friday night Eastern Glacier...Northern Rocky Mountain Front...Southern Rocky Mountain Front. && $$ http://www.weather.gov/greatfalls