FXUS65 KMSO 190719 AFDMSO Area Forecast Discussion National Weather Service Missoula MT 119 AM MDT Sun May 19 2024 .DISCUSSION...Precipitation has begun to increase across north central Idaho and western Montana very early this morning. Dewpoint spreads are still significant enough in portions of western Montana to keep rainfall from hitting the ground just yet, but light rain has been reported in central Idaho. As the atmosphere moistens and destabilizes through this afternoon, the probability for widespread thundershowers will increase. As the trough moves further south on Monday, central Idaho and western Montana will have continued below-average high temperatures and another round of showers and isolated thunderstorms by Monday afternoon. During this period, snow levels are expected to drop to around 5,000 feet, with light accumulations mainly occurring above around 6,000 feet. Model clusters and ensemble mean guidance show good agreement for the Northern Rockies to be between weather systems on Tuesday, indicating near-normal temperatures and isolated afternoon showers. The forecast for Wednesday to Friday (22nd-24th) is trending wetter, dominated by a broad trough. Eighty percent of model clusters maintain a closed low weather pattern with cool temperatures and widespread precipitation. However, there are still timing and strength differences regarding the potential low- pressure system, making it difficult to pinpoint specific details. && .AVIATION...Shower activity has begun to increase across western Montana and north central Idaho early this morning. As the atmosphere destabilizes through the day, the probability for thunderstorms will increase, impacting most terminals through roughly 20/0200Z. Snow levels will begin to lower, causing snow in terrain above 6000 feet, with mountain obscurations becoming more prevalent late this evening and overnight. && .MSO WATCHES/WARNINGS/ADVISORIES... MT...None. ID...None. && $$