707 FXUS65 KTFX 090457 AFDTFX Area Forecast Discussion National Weather Service Great Falls MT 1057 PM MDT Tue Jul 8 2025 Aviation Section Updated. .KEY MESSAGES... - Heat continues through Wednesday, along with a few gusty showers and thunderstorms each afternoon. - Cold front pushes through Thursday, bringing a few showers along with cooler temperatures. - Seasonable temperatures this weekend along with dry conditions, before another cold front pushes through early next week. && .UPDATE... /Issued 759 PM MDT Tue Jul 8 2025/ Updated forecast is out. Just adjusted grids towards current trends. Isolated showers/thunderstorms continue to affect Southwest MT. Not much measurable rainfall occurring, but some wind gusts of 35 to 45 mph and lightning. Most of these storms should diminish between Midnight and 2 AM. Overnight lows look on track, but note it will take most of the night of cooling before we reach the overnight lows, and just for a short time around day break. For Wednesday, it will be another very warm afternoon, with afternoon temperatures of 95 to 100 common over the area. The heat advisory continues for portions of North Central MT. The other main concern will be the fire weather and thunderstorm potential. It will be very close to fire weather statements for Wednesday, but my current thinking is we have just enough greenness at lower elevations to hold off for one more day, but with windy conditions and humidity below 20 percent, any new fire starts will not be easy to contain during peak heating. The mountains seem green enough that they should be ok for this event. In terms of thunderstorms, the HREF continues to prog numerous cells moving from southwest to northeast through the CWA during the late afternoon and evening hours, with gusty winds/lightning the main impact. There will be the potential that some of these storms could be severe. A short cool snap is then expected for just Thursday and Friday. Brusda && .DISCUSSION... /Issued 759 PM MDT Tue Jul 8 2025/ Upper level ridging currently entrenched over the Western US has brought a warm air mass into North Central and Southwestern Montana, with many lower elevation locations reaching into the 90s this afternoon. While skies have been clear so far today, we have noticed a few puffy cumulus clouds start to develop across the higher terrain of Southwestern Montana. A few of these may eventually grow into some virga showers or even dry thunderstorms this afternoon, potentially producing lightning strikes and gusty winds. Wednesday will be another warm day across North Central and Southwestern Montana, with highs once again reaching the 90s for most lower elevation locations. With this said, the ridge will begin to break down during the afternoon, which will result in gusty winds and increased shower and thunderstorm activity across the area, mostly across the Plains. A few of the showers and thunderstorms could produce some strong, gusty winds due to the very dry air near the surface, and overall synoptic winds and low RH values could lead to increased fire growth and spread. Please see the Fire section below for more information. Beyond tomorrow, a cooler air mass will push into the area, bringing another chance for some showers on Thursday but then drier air follows for the weekend. Temperatures will rise a bit over the weekend, but another cold front will push through the area on Monday, keeping the mercury from getting quite as high next week. - Forecast Confidence & Scenarios: Overall forecast confidence remains high through the next few days, with shower and thunderstorm activity on Wednesday being the biggest impactful question mark. Most mesoscale models show at least some shower and thunderstorm development during the afternoon, though there remains some uncertainty to the coverage and organization of the storms. Regardless of the organization of the storms, even a weak shower will be capable of producing gusty outflows due to the dry air mass in place. Ludwig && .AVIATION... 09/06Z TAF Period A few lingering showers across Southwest Montana will maintain a low-end threat for a gust of wind through 09Z or so. Otherwise, attention turns to daytime hours Wednesday, when a myriad of impacts develops. Initial concerns will be for gusty surface winds developing mainly over the western plains. Low-level turbulence will be possible in these areas. Progressing further into the day, hot temperatures and deep mixing will result in very high based showers and thunderstorms in the afternoon and evening across the region. These showers and thunderstorms will be capable of producing strong and erratic wind gusts, with little in way of precipitation. -AM Refer to weather.gov/zlc for more detailed regional aviation weather and hazard information. && .FIRE WEATHER... Hot, dry, and windy conditions are expected on Wednesday as an upper level ridge breaks down across the area. While later in the year this would necessitate a fire weather statement, current fuel moisture and ERC values remain relatively low across the area, which will help reduce the overall fire danger tomorrow. Additionally, a few gusty showers and thunderstorms will be possible tomorrow afternoon, which could cause any fires that do get started to exhibit erratic fire behavior around any showers or thunderstorms. Ludwig/Brusda && .PRELIMINARY POINT TEMPS/POPS... GTF 61 98 59 78 / 0 10 20 30 CTB 58 91 56 66 / 0 0 20 60 HLN 60 94 59 81 / 10 10 20 20 BZN 55 95 52 85 / 20 10 20 10 WYS 48 83 43 77 / 10 10 20 20 DLN 52 90 48 82 / 10 20 20 10 HVR 61 100 58 77 / 0 10 20 30 LWT 59 92 55 77 / 0 20 20 30 && .TFX WATCHES/WARNINGS/ADVISORIES... Heat Advisory until 8 PM MDT Wednesday for Cascade County below 5000ft-Hill County-Northern Blaine County-Western and Central Chouteau County. && $$ http://www.weather.gov/greatfalls |