FXUS65 KTFX 201955 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 155 PM MDT Sun Sep 20 2026 .KEY MESSAGES... - Above average temperatures return this week. - Patchy fog early Monday morning. - Next system arrives late week bringing wind and rain. && .DISCUSSION... - Meteorological Overview: Southwesterly upper level flow will be the predominant weather pattern this week as upper level ridging stalls out over the center of the North American Continent this week, keeping us generally warm and dry for most of this week. Expect temperatures to generally be either side of 80 along the Missouri River corridor, with temperatures not as warm in the higher terrain and along the Rocky Mountain Front. Winds will also be uncharacteristically light for much of the week, with winds generally struggling to gust over 20 mph through Thursday. Our next weather system will arrive Friday or Saturday, which will bring cooler temperatures, gusty winds, and the possibility for some widespread precipitation, though the amount of rainfall remains fairly uncertain at this point in time. - Forecast Confidence & Scenarios: Friday/Saturday system: an upper level trough and associated surface front embedded in the upper level flow are expected to arrive in the Northern Rockies Friday or Saturday. Current model forecasts suggest that this setup will bring some widespread precipitation, with the potential for many areas to receive over a quarter inch of liquid equivalent. The other concern will be the wind, as the strengthening trough may produce a bit of a sting jet on its southwest side, which would produce some gusty westerly winds thanks to the sinking air behind a cold front. As of Sunday afternoon, probabilities for 60 mph wind gusts appear low (generally under 20 percent), but this event will need to be watched in case probabilities increase. Ludwig && .AVIATION... 20/18Z TAF Period Scattered to broken MVFR/low-VFR conditions will prevail through 00z Monday along and east of a KWYS, to KLWT, to KHVR line; with increasing CIGS thereafter. The potential for fog development then becomes the next concern, most notably over the plains terminals of KHVR and KCTB where MVFR/low-VFR VIS is expected to develop between 10-14z Monday. Additional fog development is possible across Southwest Montana during this timeframe; however, confidence was not high enough to prevail at this time. - Moldan && .PRELIMINARY POINT TEMPS/POPS... GTF 46 79 49 80 / 0 0 0 0 CTB 44 76 45 77 / 0 0 0 0 HLN 44 76 45 77 / 0 0 0 0 BZN 39 73 41 75 / 0 0 0 0 WYS 27 67 28 69 / 0 0 0 0 DLN 39 72 40 74 / 0 0 0 0 HVR 45 79 47 81 / 0 0 0 0 LWT 42 75 46 79 / 0 0 0 0 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls