BILLINGS — THROUGH TUESDAY: Monday cranks up the heat even more with readings climbing into the 80s to lower 90s, followed by Tuesday's potential scorcher with upper 80s to mid-90s expected. This will challenge daily temperature records on both Monday and Tuesday, making it feel more like mid-summer than late spring.
Mountain snowpack will begin melting quickly, sending more water rushing down into streams and rivers throughout the week. While major flooding isn't a threat, the combination of higher flows and dangerously cold water temperatures creates hazardous conditions for anyone planning outdoor recreation near waterways. Watch for bank erosion.
Monday, the first signs of instability pop up as scattered showers and isolated weak thunderstorms develop over south-central Montana and northeastern Wyoming during afternoon and evening hours. The main concerns with these storms are sudden wind gusts reaching 45 mph and lightning strikes.
TUESDAY THROUGH THURSDAY: A large low-pressure system drops into the Great Basin and establishes an omega blocking pattern that will dominate our weather story. This system pulls up Gulf moisture northward into eastern Montana and creating daily chances for showers and thunderstorms across much of the region.
The mountains and foothills become the primary target for storms, though the extent and intensity remain somewhat uncertain. The highest moisture will be concentrated over far eastern Montana. However, the low-pressure system's position slightly southwest of our area may limit the atmospheric lift and wind shear needed for severe storm development.
What we can count on is better possibilities for heavy rainfall than we've experienced this spring, thanks to the significantly higher atmospheric moisture. Precipitation amounts will vary dramatically from location to location due to the scattered nature of the thunderstorm activity. Additionally, southeastern Montana will experience breezy conditions with wind gusts ranging from the 20s to 40s mph, likely peaking on Wednesday.
FRIDAY THROUGH SATURDAY: The forecast confidence drops as we head into the weekend. Recent model trends suggest the low-pressure system is expected to eject northward through our region while potentially phasing with a Pacific Northwest trough, maintaining daily shower and thunderstorm chances.
This interaction could enhance the possibility of strong to severe thunderstorms, but this is way too far out for certainty. in any case, the threat of scattered precipitation stays alive through the weekend.
