296 FXUS65 KTFX 040213 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 713 PM MST Thu Jan 3 2019 .UPDATE... Most of our forecast through tomorrow morning remains valid. Only change was to increase low temperatures by several degrees for the north-central MT plains. This was based on latest observed temperature trends and the expectation of limited nocturnal cooling via abundant cloud cover and persistent Chinook winds. - Jaszka && .SYNOPSIS... Strong winds will continue to impact much of northern and central Montana east of the Rockies through Friday with strongest wind gusts likely to occur during a period from late tonight through Friday morning. Dry and mild conditions will prevail for much of the state through Friday while snow and mixed precipitation is possible over the mountains of northwest Montana. Warmest temperatures relative to average will occur over the plains while southwest and western Montana valleys remain near to only slightly above seasonal averages. && .AVIATION... Updated 2258Z. VFR, fast westerly flow aloft, and significant mountain wave turbulence persist next 24-hours. The worst conditions will occur east of the Continental Divide in north-central MT, where southwesterly to westerly surface winds continue. These winds are still expected to be in the 40-60 knot range and gust up to 65-80 knots or so along the immediate Rocky Mountain Front. For the rest of north-central MT, these winds will tend to be in the 20-40 knot range, with gusts up to 50-65 knots at times. Much weaker surface winds grace most of southwest MT, but KEKS will be one exception. Here, a breezy southerly wind will gust up to 30-35 knots at times. Pockets of low-level wind shear are likely over north-central and southwest MT as strong flow aloft persists. Lastly, some mountain- obscuring snow persists along the Rocky Mountain Front portion of the Continental Divide. - Jaszka && .PREV DISCUSSION... /ISSUED 212 PM MST Thu Jan 3 2019/ Strong winds continue to be the major weather impact across the forecast area through Friday as a fast zonal (W-E) flow aloft sags south with embedded shortwave energy ejecting east along the US/Canadian border. While strong winds were not quite as widespread this afternoon, expect another acceleration in wind speeds to occur overnight tonight through Friday morning as the upper level wave moving into SW BC this afternoon moves inland, causing the lee-side trough to strengthen again before moving off to the east on Friday in unison with the shortwave energy aloft. Impacts from blowing and drifting snow should be diminishing along the northern Rocky Mtn Front as temperatures have warmed above freezing to elevations as high as 6000 feet today. Temperatures remain very mild tonight across the plains and in many cases warmer than typical daytime maximum temperatures this time of year, due to the influence of strong winds and cloud-cover. As the surface trough east of the Rockies moves off to the east late tomorrow afternoon and evening the pressure gradient will relax and winds will begin to diminish. A weak ridge of high pressure rebuilds over the region Friday night and Saturday for dry conditions with slightly cooler but still milder than average temperatures. Hoenisch Saturday night through Thursday...a fast progressive pattern will dominate the Northern Rockies over the weekend and into the first half of the upcoming work week. Precipitation, in the form of snow, will primarily impact the mountains along the Idaho/Wyoming borders and the Continental Divide, with dry conditions in most valley/downslope favored locations. Snowfall accumulations over the weekend and into the first half of next week of 3-6" at most mountain locations, with upwards of a foot along the Northern Rocky Mountain Front and in the Centennial/Henry Lakes mountains, are possible. These snowfall accumulations will come over an extended period of time, thus only minor impacts are expected/anticipated over most mountain passes at this time. Temperatures over the plains of North Central Montana are expected to be above normal over the period, with well above normal highs on Tuesday and Wednesday. High temperatures in the valley's of Southwest Montana will be highly dependent on diurnal mixing, with some locations remaining below normal should strong inversions setup over the valley's. Winds will be breezy and gusty from Sunday through Tuesday, especially along the Rocky Mountain Front, plains of North Central Montana, and in the Upper Madison Valley. - Moldan && .PRELIMINARY POINT TEMPS/POPS... GTF 41 52 27 46 / 0 0 0 0 CTB 39 46 24 41 / 0 0 0 0 HLN 27 43 21 39 / 0 0 0 0 BZN 18 40 18 40 / 0 0 0 0 WEY 5 28 9 31 / 10 10 10 0 DLN 19 39 19 39 / 0 0 0 0 HVR 41 52 26 43 / 0 0 0 0 LWT 36 51 26 47 / 0 0 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... High Wind Warning until 5 PM MST Friday Cascade...Eastern Pondera...Eastern Teton...Judith Basin...Liberty...Toole. High Wind Warning until 5 PM MST Friday Northern Rocky Mountain Front...Southern Rocky Mountain Front. High Wind Warning until 5 PM MST Friday Blaine...Chouteau... Fergus...Hill. High Wind Warning until 5 PM MST Friday Eastern Glacier. && $$ http://www.weather.gov/greatfalls