690 FXUS65 KTFX 100011 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 611 PM MDT Mon Jun 9 2025 Forecast and Aviation Section Updated. .KEY MESSAGES... - There will be daily chances for showers and thunderstorms Tuesday through Sunday with some storms being strong to severe. && .UPDATE... Updated forecast is out for this evening. No significant changes, just to align grids with neighbors. Main concern is the potential for thunderstorms develop late Tue afternoon into Tuesday evening. The HRRR has a few strong storms over North Central MT. The main impact looks to be strong wind gusts, but some hail is also possible. Thunderstorm activity becomes a bit more widespread for Wednesday. Brusda && .DISCUSSION... /Issued 228 PM MDT Mon Jun 9 2025/ - Meteorological Overview: An upper-level ridge is over North-central, Central, and Southwestern Montana today. This will bring clear skies and hot temperatures to the area this afternoon. Due to northwest flow aloft there will be hazy skies across much of North-central, Central, and Southwestern Montana this afternoon. They will gradually clear by this evening due to westerly flowing aloft moving over the area. On Tuesday the upper ridge begins to flatten. On Tuesday afternoon a cold front will move southwest from Canada and bring cooler temperatures, and showers and strong to severe thunderstorms to North-central, Central, and Southwestern Montana Tuesday afternoon and evening. On Tuesday along the Hi-line there will be hazy skies at times. On Wednesday a shortwave trough will move over Southwestern and Central Montana. This will bring showers and thunderstorms to Southwestern and Central Montana Wednesday afternoon and evening. Rain showers will then spread northward to North-central Montana Wednesday evening. Thursday through Sunday a series of upper-level shortwaves move through the upper-level flow. This combined with southwest flow aloft will bring a round of showers and thunderstorms to North-central, Central, and Southwestern Montana each day Thursday through Sunday. - Forecast Confidence & Scenarios: The Storm Prediction Center (SPC) has issued a Marginal Risk (5% chance for wind gusts of 58 mph or greater and a 5% chance for hail 1 inch in diameter or greater) for severe thunderstorms on Tuesday for Glacier County down to extreme eastern Fergus County over to northern Gallatin County. The SPC has issued a Marginal Risk (5% chance for wind gusts of 58 mph or greater and a 5% chance for hail 1 inch in diameter or greater) for severe thunderstorms on Wednesday from Southwestern Montana up to the Montana 200/US Highway 87 Corridor between Great Falls and Lewistown. On Thursday there is a 35 - 65% chance for thunderstorms across North-central, Central, and Southwestern Montana. On Friday there is a 25 - 55% chance for thunderstorms across North-central, Central, and Southwestern Montana. On Tuesday there is a 10 - 40% chance for a tenth of an inch of rain or greater across North-central, Central, and Southwestern Montana. On Wednesday there is a 30 - 60% chance for a quarter inch of rain or greater. On Tuesday across North-central Montana there is a 40 - 60% chance for a tenth of an inch of rain or greater. On Thursday there is a 30 - 70% chance for a quarter inch of rain or greater across North-central and Central Montana. On Thursday there is a 30 - 60% chance for a tenth of an inch of rain or greater across Southwestern Montana. -IG && .AVIATION... 10/00Z TAF Period Overall, VFR conditions will prevail across the CWA through the period. Wildfire smoke generally is thinning out, but a new wildfire has developed north of Helena, which is introducing new smoke issues. Otherwise main concern will be thunderstorm potential developing mostly after 21z Tue. For now kept the TS out of TAF sites, but is possible some storms could develop by 23z Tue, so updates will be issued for this in later packages. Some distant mountain ranges continue to be obscured by smoke, and that trend likely to continue overnight. Brusda Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 55 84 54 81 / 0 30 40 40 CTB 51 80 49 77 / 0 20 40 40 HLN 59 90 56 80 / 0 40 30 50 BZN 52 86 51 78 / 0 20 40 60 WYS 40 78 41 72 / 0 40 30 80 DLN 51 84 49 73 / 0 40 20 80 HVR 52 85 54 81 / 0 10 70 40 LWT 54 80 50 76 / 0 20 50 50 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls