Warm temperatures will build through Thursday across Billings, south central and southeast Montana, and northern Wyoming before a wetter, cooler pattern arrives for the end of the week. Thunderstorm chances increase Thursday, wi th a few stronger storms possible, followed by a more active period Friday and Saturday.TUESDAY NIGHTIsolated to scattered showers and thunderstorms will continue over the mountains and foothills through the evening before diminishing overnight. Severe weather is not expected. Overnight conditions will be mild with mostly dry weather for lower elevations.WEDNESDAYWarm and mostly dry weather continues across the region as high pressure strengthens aloft. Afternoon highs will reach the 80s to near 90 degrees. A few isolated showers and thunderstorms may develop during the afternoon and evening, mainly near the mountains and foothills.THURSDAYThe warmest day of the week arrives with highs climbing into the lower to middle 90s. Increasing moisture will support more widespread showers and thunderstorms during the afternoon and evening. Some storms could become strong, producing gusty winds, small hail, and locally heavy rainfall.FRIDAYAn approaching Pacific Northwest storm system will bring a more active weather pattern to the region. Scattered to numerous showers and thunderstorms are expected, with rain chances increasing across most of south central and southeast Montana and northern Wyoming. Temperatures will begin to cool.SATURDAYThe unsettled pattern continues with isolated showers and thunderstorms. Moisture levels remain high, keeping precipitation possible. Daytime temperatures will be noticeably cooler, generally ranging from the upper 70s to middle 80s.SUNDAYThe main storm system moves east, but lingering moisture and passing disturbances keeps a slight chance of showers and thunderstorms. Temperatures remain seasonably cool with highs mainly in the upper 70s to mid 80s.MONDAYA few isolated showers or thunderstorms remain possible as weak disturbances move through the region. Otherwise, expect a mix of sun and clouds with temperatures continuing near or slightly below late-August averages. ...read more read less