Residents of central Montana planning outdoor events Monday and Tuesday should spend some time consulting their local forecasts before heading out.
The National Weather Service has issued a Hazardous Weather Outlook, warning lightning, thunder and rain is expected early in the week.
A surge of monsoonal and plains moisture will push into the Billings area Monday which could increase the likelihood of showers and thunderstorms, the warning said. People who live in low-lying areas or near recent burn scars should keep a look out for flash flooding associated with heavy rains.
As Monday wears on, the chance for a thunderstorm will become more likely. Skies will be partly sunny and highs will reach 87. Northwest winds 5 to 9 mph will switch to the southeast in the afternoon.
By evening, the chance for a shower or thunderstorm will be 50 percent. The storms are expected to produce the heaviest rainfall will form in a line from Roundup through Billings to Sheridan, Wyo., according to the NWS. Skies will be mostly cloudy and lows will bottom out near 62.
The slow-moving thunderstorms, which could materialize Monday night, will likely continue into Tuesday. The chance for a shower or thunderstorm will hold at 50 percent. Skies will be mostly cloudy and highs won't break out of the low 80s. A Northeast wind between 6 and 10 mph is expected.
The likelihood of a storm will decline to 40 percent Tuesday night. Skies will be mostly cloudy, and lows will fall to 59. Northeast winds 6 to 11 mph will blow out after midnight.