


Area Forecast Discussion
Issued by NWS Great Falls, MT
Issued by NWS Great Falls, MT
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836 FXUS65 KTFX 301125 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 525 AM MDT Mon Jun 30 2025 Aviation Section Updated. .KEY MESSAGES... - Dry conditions start out the week, with daily chances for showers and thunderstorms moving in region wide starting Wednesday. - Hotter temperatures settle in for the week, with a cool down starting on Friday. && .DISCUSSION... /Issued 216 AM MDT Mon Jun 30 2025/ - Meteorological Overview: The upper-level ridge building in and surface high pressure will allow for mostly sunny skies tomorrow besides cumulus clouds across higher terrain. Subsidence in place will keep the region dry for Monday. The increased thickness in heights aloft will allow for the heat to start building in for the week. Wednesday looks to be the hottest day, as southwest flow aloft will advect in warm and moister air. Starting on Tuesday, an upper closed low will start to advect in monsoon moisture from the Southwest U.S. This will begin daily chances for showers and thunderstorms through the forecast period as a series of disturbances move through. Tuesday`s precipitation chances will mainly be along and south of the I-90 corridor, with the rest of the week having at least a slight chances for precipitation through the week. Hot temperatures and drier low levels of the atmosphere can allow for a few strong wind gusts with thunderstorms. Though, chances for severe storms remain isolated at this moment. Increased PWATs to 0.75-1" at times will bring brief heavy downpours with storms as well. Towards the end of the week, a cold frontal passage Thursday through Friday morning will bring a relief to the hot temperatures Friday and Saturday. Temperatures look to moderate out to near seasonable for the beginning of next week. - Forecast Confidence & Scenarios: Moisture advection is trending earlier, with it arriving by Tuesday. There is an increasing signal for isolated showers and thunderstorms Tuesday afternoon and evening mainly along and south of the I-90 corridor as a result. Convection this week doesn`t look robust overall with weaker shear and CAPE in place. Hot temperatures Wednesday will create deep inverted V profile soundings. This and DCAPE at 1,000+ will create an environment for a few strong wind gusts with collapsing thunderstorms. Thursday is looking similar across Southwest MT. There is good confidence for 90 degree temperatures this week at lower elevations. There`s a 80-100% chance for 90 degree temperatures Tuesday afternoon for the lower elevated Southwest valleys and along the Missouri and Milk River valleys. Wednesday, there`s a 80-100% chance for 90 degrees in the same areas, including most of the North-Central MT plains. The thermal belt region in the Bear Paws is currently forecasted to have minimum temperatures at the low to mid 60s Wednesday and Thursday, which can elevate the heat impact. -Wilson && .AVIATION... 30/12Z TAF Period Ridging aloft will maintain widespread VFR conditions for the duration of the TAF period. Winds will generally be light and variable in the southwest and will develop an easterly component over the plains. - RCG Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .PRELIMINARY POINT TEMPS/POPS... GTF 88 56 91 58 / 0 0 0 0 CTB 84 52 87 55 / 0 0 0 0 HLN 89 58 92 59 / 0 0 0 10 BZN 90 53 94 55 / 0 0 10 20 WYS 80 41 83 44 / 0 0 20 20 DLN 86 52 88 53 / 0 0 20 20 HVR 87 54 93 58 / 0 0 0 0 LWT 80 54 86 58 / 0 0 0 10 && .TFX WATCHES/WARNINGS/ADVISORIES... None. && $$ http://www.weather.gov/greatfalls