BOZEMAN – A beautiful weather day across SW Montana with the only exception near the Idaho/Wyoming state line.
Isolated thunderstorms are possible from Big Sky to West Yellowstone this afternoon and early evening. Thunderstorms are likely to develop over southern Beaverhead county and then track toward the ENE this afternoon and evening.
Thunderstorms should be on the weaker side or non-severe, but a few storms could produce brief heavy rain, small hail, strong outflow wind gusts, and frequent lightning.
River levels across SW Montana continue to run very high and near bank-full for a few rivers. Right now the two rivers to watch are the Gallatin and Yellowstone.
Flood Advisory for the Gallatin River has been extended through Thursday. The river continues to oscillate near minor flood stage in the late afternoon to early evening hours. So far, the river hasn’t crested above minor flood stage. Minor lowland flooding is likely along the Gallatin River this week.
Flood WARNING continues until further notice for the Yellowstone River. River levels near Livingston Tuesday afternoon showed levels around 9.5’ with a flood stage at 10’. The Yellowstone will also oscillate up and down for the rest of the week and could come close to flood stage at times.
The other big weather news is a pattern change coming this weekend into next week. Forecast models show a deep trough digging into the Pacific NW and sliding over into the central and northern Rockies beginning Saturday.
Unseasonably cool air with widespread rain is likely and higher mountain snow is also possible Sunday into Monday. Forecast highs will fall down into the 50s with 30s at night for lower valleys and below freezing temperatures for higher elevations. I will update the extended forecast for you tonight at 5:30 pm and 10 pm on KXLF and KBZK.