Smoke hangs on a little longer, but a major pattern change is on the way as cooler temperatures, widespread rain, and thunderstorms bring welcome relief to south central and southeast Montana and northern Wyoming later this week .TUESDAY EVENINGIn far southeast Montana, including Carter and Fallon Counties, a few afternoon thunderstorms have developed. Any storm that forms may become strong to severe with damaging wind gusts up to 70 mph, torrential rain, and isolated large hail. Smoke lingers overnight while mild temperatures hold across the area. Most communities remain dry with lows mainly in the 60s, though some western valleys may cool into the 50s.WEDNESDAYThunderstorms increase across south central and southeast Montana and northern Wyoming as a stronger disturbance moves into the region. A few stronger storms remain possible over southeast Montana. Many locations have a chance of showers and thunderstorms during the afternoon and evening, with localized downpours capable of producing minor flooding issues. Smoke should begin to gradually improve as increasing moisture and precipitation help clear the air.THURSDAYRich monsoonal moisture combines with cooler air to produce widespread showers and thunderstorms. Rain chances range from 40 to nearly 100 percent, and periods of heavy rainfall are increasingly likely. Flash flooding becomes a concern, especially from the Billings area eastward through eastern Montana. High temperatures fall sharply into the 70s. Air quality improves as rain and northerly winds help disperse wildfire smoke.FRIDAYNumerous showers and thunderstorms remain likely across south central and southeast Montana and northern Wyoming, with additional heavy rain possible. This may be one of the wetter periods of the summer, especially east of Billings. Temperatures remain well below normal, with afternoon highs generally staying in the 70s. Severe weather is not expected, but locally heavy downpours could lead to isolated flooding concerns.SATURDAYConfidence decreases somewhat, but the forecast remains on the cool and unsettled side. Scattered showers and thunderstorms may continue as lingering moisture remains in place.SUNDAYConditions begin to improve as high pressure strengthens along the Rockies. Temperatures recover toward more typical August levels, and rain chances become more isolated. However, lingering ground moisture from the previous days could still fuel scattered afternoon and evening thunderstorms.MONDAYA warmer pattern settles over Montana and northern Wyoming. High temperatures return to near seasonal averages, though enough moisture may remain in place for another round of isolated to scattered afternoon and evening thunderstorms. ...read more read less