390 FXUS65 KMSO 100706 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 106 AM MDT Tue Jun 10 2025 .DISCUSSION... KEY MESSAGES: - Near-record daytime high temperatures today. - A few strong storms this afternoon and again Wednesday afternoon and evening. - Cooler late this week with daily afternoon showers and thunderstorms. Hot temperatures will continue across the Northern Rockies today, with many locations approaching daily record highs. The ridge axis does shift eastward today, allowing southwesterly flow to develop over the region. This pattern will support the formation of scattered afternoon/evening showers and thunderstorms. Model guidance highlights the most likely areas for storm development along the Divide and into southwest Montana. Any storms that form this afternoon could produce gusty, erratic winds, with stronger cells generating gusts up to 50 mph. This southwesterly flow continues into Wednesday as two weak disturbances move through the area. The first is expected to pass from southern Idaho County into Lemhi County and southwest Montana during the morning, bringing scattered showers and possibly an isolated thunderstorm. A second disturbance will follow a similar path in the afternoon and may trigger additional thunderstorms. These storms could produce locally heavy rainfall, small hail, and gusty winds. Looking ahead to Thursday and into the weekend, the southwest flow aloft persists. While temperatures will ease compared to earlier in the week, highs will still reach the mid-70s to 80s or around 10 degrees above normal for this time of year. Daily afternoon and evening showers and thunderstorms remain likely, especially along the Continental Divide extending into Lemhi County. && .AVIATION...Hot temperatures continue today but the ridge of high pressure will begin to shift east this afternoon, opening the door for a developing southwesterly flow pattern. This shift will bring modest mid-level moisture and instability, supporting the development of afternoon showers and thunderstorms along the Continental Divide. Activity may impact terminals such as KSMN and KBTM between approximately 10/2000Z and 11/0200Z with vicinity shower potential at remaining terminals. Watch for gusty outflow winds to near 40 kts near stronger showers and thunderstorms. Thunderstorms dissipate this evening but showers and isolated thunderstorms return Wednesday morning, especially from I-90 southward as a weak disturbance pushes through. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...Heat Advisory until 9 PM PDT Tuesday for Lower Hells Canyon/Salmon River Region...Orofino/Grangeville Region. && $$