


Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
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963 FXUS65 KTFX 150543 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1143 PM MDT Mon Jul 14 2025 Aviation Section Updated. .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. && .UPDATE... /Issued 831 PM MDT Mon Jul 14 2025/ A few thunderstorms continue to track across southwest MT this evening, mainly south of a Dillon to Bozeman line where a very warm and dry airmass is still in place, maintaining a risk for gusty winds. A much cooler airmass is surging south into central MT this evening as precipitation intensifies ahead the of the incoming upper level trough, currently rotating through far southern BC. Shower and thunderstorm coverage has begun to increase across north- central MT over the last hour with sufficient elevated CAPE and wind shear to support the risk for isolated strong to severe thunderstorms over mainly eastern portions of central MT through midnight. Large scale lift ahead of the trough will increase overnight with an area of widespread precipitation sagging south from Alberta into north-central MT later in the overnight period. Pops and winds were updated to reflect latest observed trends and incorporate incoming hi- resolution model data, but overall forecast remains on track. Hoenisch && .DISCUSSION... /Issued 831 PM MDT Mon Jul 14 2025/ - 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... 15/06Z TAF Period Widespread rain with embedded thunderstorms will be the main concern over the next 24 hours across the region with the potential prevailing MVFR and IFR ceilings and visibility, especially along the Rocky Mountain Front and across central Montana. Showers will start to become more scattered towards the end of the TAF period and are expected to diminish overnight into Wednesday morning. Mountain obscuration will remain a concern throughout the entire TAF period. -thor Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 53 56 49 69 / 80 100 60 20 CTB 50 54 43 66 / 100 90 30 10 HLN 56 62 49 76 / 30 90 70 20 BZN 53 72 48 75 / 30 90 80 30 WYS 43 78 41 73 / 40 70 70 20 DLN 51 74 47 75 / 20 80 50 10 HVR 55 62 46 70 / 80 90 40 20 LWT 50 56 45 62 / 70 100 90 50 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls