BILLINGS — A ridge to the east and a large low to the west are driving our weather pattern. As the western low approaches through Thursday, expect increasing moisture at all levels of the atmosphere to act as fuel for showers and thunderstorms.
A series of disturbances moving along this pattern will bring periods of rain, with the best chance Thursday through Friday and another round of showers Friday through early Saturday. A Pacific cold front Thursday night into Friday will help trigger more organized thunderstorms and cooler temperatures.
An upper low settles in for the weekend, keeping things cooler and wetter into early next week. Highs will be the warmest through Thursday.
Tonight:
- Isolated to scattered showers and thunderstorms are possible this afternoon and evening.
- Things are less active east of Billings, but if storms do form, gusty winds will be the main threat.
- Showers could linger overnight in eastern Montana but very sparse.
Thursday:
- The main round of precipitation looks likely, with more widespread showers and storms as the upper-level support strengthens and the Pacific front approaches.
- Severe thunderstorms are possible, especially in the plains of Montana and Wyoming, with main threats being strong winds and hail. Winds could be gusty near storms.
- Temperatures will reach the upper 70s to lower 90s, with the warmest in eastern Montana.
- Overnight into Thursday night: some clearing or lingering showers possible as the front moves through.
Friday through Tuesday:
- A strong trough and developing upper low move into the region, bringing cooler and wetter conditions.
- An upper low will move along the Montana/Canadian border. Showers will generally be light.
- Friday: precipitation chances are roughly 50% to 80%) across much of the area.
- Friday into Saturday: a broad shield of showers/thunderstorms remains possible, with storms totals showing 0.1 to 1 inch possible overall. The best chances for more than 0.25" tend to east of Billings; the best chance for around 0.50" or more is east of Rosebud County.
- Precipitation chances taper off over the weekend.
- Temperatures on Friday will warm into the 70s to low 80s, then cooler air with upper 60s to 70s Saturday; a gradual climb back into the 70s–80s Sunday and Monday.
