772 FXUS65 KTFX 160258 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 758 PM MST Tue Jan 15 2019 .UPDATE... Only minor changes needed for the update tonight. Weak wave trying to ride up over the ridge this evening. The result is mainly some low to mid clouds across central portions, with perhaps an isolated flurry or brief light mountain snow shower. Meanwhile low clouds continue to linger across far southwestern MT with some light snow also falling from them. The wave across central portions washes out overnight with clouds also thinning. These thinning clouds may lead to areas of fog developing especially across the Hi-Line. Meanwhile low clouds and snow flurries may linger across the southwest through the night. Wednesday looks to see increasing clouds from the southwest ahead of the next disturbance. A few snow showers are also possible across the southwest, while dry conditions are found elsewhere. Some patchy fog may also linger through the morning across the Hi-Line on Wednesday, with some lower clouds lingering into the afternoon. Anglin && .SYNOPSIS... High pressure ridging aloft over Montana will be broken-down gradually by multiple disturbances through Wednesday. This will be accompanied by increasing clouds, along with a few mainly mountain snow showers. Colder and snowier weather affects the Treasure State Thursday into Friday as additional disturbances overspread the state from the southwest and west. A warming trend commences this weekend as high pressure aloft redevelops over Montana. However, more disturbances traverse this ridge from west to east, resulting in mainly mountain snow. Little or no precipitation should affect the plains and valleys. && .AVIATION... Updated 0000Z. Mainly VFR conditions will be found through the forecast period, with some lower clouds at times for a few sites. A weak disturbance will bring some mid to upper level clouds through this evening from south to north. Other than a few mountain snow showers, no widespread precipitation is expected with this feature. VFR conditions, with light winds, and partly cloudy skies are then expected later tonight into Wednesday morning. An upper level disturbance could then bring increased cloud coverage across the southwest, with some MVFR ceilings possible mainly from KBTM to KBZN and southward. A stall front may also bring some low clouds to KHVR by tomorrow afternoon, perhaps introducing some MVFR to IFR conditions at times. Between these two areas expect to see VFR conditions. Mountain snow showers will also be possible for areas in the southwest by Wednesday afternoon. Anglin && .PREV DISCUSSION... /ISSUED 444 PM MST Tue Jan 15 2019/ Rest of today through Wednesday night...High pressure ridging aloft resides over our CWA through the period. A shortwave trough rounding this ridge crosses our region generally from southwest to northeast and then to the east late this afternoon through Wednesday morning. The main consequence during this period will be an overall increase in cloud cover. However, scattered snow showers should affect the southwest and central Montana mountains and vicinity, and the Rocky Mountain Front, due to a combination of weak upslope flow and the aforementioned shortwave trough passage. Thereafter, periods of light upslope snow persist along and near the Continental Divide through daybreak Thursday. Additionally, light snow showers should begin affecting the Hi-Line late Wednesday evening into early Thursday morning as a reinforcing Canadian cold front moves into that area. Temperatures trend near or slightly above-normal through the period. - Jaszka Thursday and Friday...An upper-level disturbance will move northward through the region while surface winds switch to a more east/northeast direction. This will allow for light upslope snow to develop over the region during the day on Thursday and then continue into Friday night. Overall snow amounts look to be similar to previous forecasts, with 2 to 4 inches possible at lower elevations and 5 to 10 inches in the mountains. Even though snow amounts look light, and spread out over 48 hours, a winter weather advisory might be needed for this event. Temperatures will continue a cooling trend in most areas. Saturday through Monday...Warmer air will try to move into our area fairy quickly behind the upper-level disturbance. Breezy west winds will also develop on Sunday, causing some blowing snow. A few light rain/snow showers will be moving through the region Sunday into Monday. With cold pavement temperatures, some freezing rain is possible. Next Tuesday...A fast moving upper-level disturbance will be moving through the region, bringing with it slightly cooler temperatures and a chance for a passing rain/snow shower. - Brusda && .PRELIMINARY POINT TEMPS/POPS... GTF 20 38 18 27 / 10 10 10 70 CTB 14 31 12 22 / 10 10 20 70 HLN 16 36 17 32 / 10 10 10 60 BZN 16 34 18 37 / 10 10 10 50 WEY 11 29 17 33 / 30 50 50 100 DLN 16 34 21 38 / 10 10 10 40 HVR 13 30 11 24 / 10 10 20 50 LWT 21 40 17 27 / 20 0 10 60 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls