818 FXUS65 KTFX 141953 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 153 PM MDT Mon Jul 14 2025 .KEY MESSAGES... - Widespread rain and isolated thunderstorms develop tonight over North Central MT. - Scattered thunderstorms this evening over Southwest MT. - Cool and rainy day over North Central MT on Tue. - Scattered afternoon thunderstorms on Thursday. - Mostly dry and warm this weekend. && .DISCUSSION... - Meteorological Overview: The summer storm is on track to affect much of CWA starting tonight. Ahead of the storm, showers/thunderstorms are developing over Southwest MT. These storms could produce some strong wind gusts. As of 130 PM, the cold front is generally along a line from Lincoln to Lewistown, and slowly moving southward. This front should move down to the I-90 corridor from Butte to Bozeman this evening, before stalling out once again. The precip develops this evening near the Canadian border and gradually moves southward overnight. Expect a rainy/cool day over North Central MT on Tue. Temperatures will not rise much from the overnight lows on Tue over North Central MT. Wednesday and Thursday...much of the precipitation will exit the area by Wednesday morning, with just a few showers left over the eastern portions of the CWA by Wednesday afternoon. On Thursday, warmer air pushes back into the CWA, but a weak upper level disturbance also moves southeast through the CWA as well. This will result in a few afternoon showers/thunderstorms. Friday through Monday...Generally warm and mostly dry conditions are expected through the weekend and into early next week. The GFS model does have a few isolated thunderstorms during the evening hours Sat thru Mon over the eastern portions of the CWA though. - Forecast Confidence & Scenarios: The main concern is rainfall potential tonight through Tuesday. Widespread rainfall of about 1/2 to 1 inch is expected over North Central MT with this summer storm. Areas in Glacier Park could get a bit more, generally in the 1 to 3 inch range. Snowfall looks to mainly affect areas above 8500 feet in Glacier Park, with an inch or two possible at ridge tops above 9000 feet. The total rainfall over Southwest MT still looks to be on the light side with most areas just averaging about 1/4 to 1/2 inch over the next few days. Confidence is low for thunderstorm activity Saturday thru Monday over the eastern portions of the CWA. The upper level support for the storms is low, thus confidence in timing for any storms is also low. Brusda && .AVIATION... 14/18Z TAF Period A cold front continues to push southward through North Central MT. This front will be through Great Falls by 18z. Low ceilings are developing on the north side of the front. Expect showers/thunderstorms to develop this evening along the Canadian border, and transition to more of a stratiform rain by Tuesday morning over North Central MT. Expect the precipitation to become more scatter by Tuesday evening. Mountains/passes will become obscured by this evening, and remain obscured through Tuesday across the CWA. Brusda Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 52 56 49 69 / 70 100 60 20 CTB 48 54 43 66 / 80 90 30 10 HLN 55 62 49 76 / 30 90 70 20 BZN 54 72 48 75 / 30 90 80 30 WYS 44 78 41 73 / 30 70 70 20 DLN 51 74 47 75 / 20 80 50 10 HVR 52 62 46 70 / 90 90 40 20 LWT 50 56 45 62 / 70 100 90 50 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls