Area Forecast Discussion
Issued by NWS Missoula, MT
Issued by NWS Missoula, MT
572 FXUS65 KMSO 291925 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 125 PM MDT Sat Jun 29 2024 .DISCUSSION... Showers and thunderstorms are expected to return across the Northern Rockies on Sunday as a Pacific trough moves through the region. Forecast models indicate that precipitation will focus across northwest Montana, with a 40-50% chance of receiving 0.25 inches of rain in Flathead, Lincoln, Lake, and Sanders Counties. A surface low will deepen east of the divide by the afternoon, allowing for atmospheric moisture and instability to increase across southwest Montana and Lemhi County. The Storm Prediction Center has identified this area with a 5% risk for severe thunderstorms capable of producing large hail. High- resolution models suggest storms will develop between 2:00-4:00 PM MDT before moving east of the divide. Elsewhere, the trough`s passage will support the development of showers and thunderstorms, though the risk of stronger storms is lower. Those planning outdoor activities should be prepared for lightning, gusty winds, and small hail. The Northern Rockies will remain on the western periphery of several trough passages from Monday through Thursday next week. This weather pattern will maintain seasonal temperatures, with highs ranging from the 70s to 80s. Daily showers and thunderstorms are expected to develop, with activity focusing along the Continental Divide. By Friday and into the following weekend, more than 80% of ensemble guidance suggests a ridge of high pressure will build across the western US. However, there is significant variation among ensemble clusters regarding the exact placement of the ridge axis and the areas likely to experience the hottest and driest weather. Nevertheless, indications favor above-normal temperatures and below-normal precipitation during this period. /Lukinbeal && .AVIATION... This afternoon, mid and high-level clouds are on the rise over the Northern Rockies airspace as a low-pressure system moves closer to the west coast. Showers are expected to advance into Idaho and reach the Montana border by 30/1200Z as moisture and upward motion accompany the trough. By 30/1800Z, the atmosphere will become increasingly unstable, leading to the development of numerous showers and scattered thunderstorms. /Lukinbeal && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$