BILLINGS — Expect scattered showers and isolated thunderstorms to develop over the southwest mountains and foothills Friday morning. By around noon, a strong cold front will push into the northwest, bringing gusty winds reaching 30 to 45 mph, with gusts picking up to 40 to 55 mph along the foothills through Friday night. Rain and mountain snow will start out west this morning before gradually spreading east throughout the day. Falling temperatures could quickly change precipitation over to a rain/snow mix or even straight snow across the higher foothills.
Rainfall projections have dwindled a bit more, with areas along and west of a line from Hysham to Lame Deer to Sheridan, WY, receiving up to a tenth of an inch. Locations west of Yellowstone County will have a better chance of getting meaningful rainfall, with between 0.50-1" possible. Farther east from Rosebud County onward, rainfall will be much lighter, with little to no accumulation expected.
High-elevation snow is still expected across our area mountains. The Beartooths, Absarokas, and Crazies could pick up between 4 to 8 inches in the highest peaks, while the Bighorns and Pryors could get lighter amounts, no more than a few inches. The western foothills can expect a light dusting.
Given the gusty winds and potential for late-afternoon snowfall, a Winter Weather Advisory is in effect for Judith Gap from 3 PM today through 6 AM Saturday. Significant snow accumulations will stay mostly limited to the mountains and higher foothills, though the highest peaks are currently slated to pick up 4 to 8 inches.
Ahead of the cold front, south-to-southwest winds of 20 to 30 mph will develop across north-central Wyoming and southeastern Montana on Friday, then shift to the northwest with gusts up to 45 mph through early Saturday morning behind the front. Very warm daytime highs will range from the mid-70s to mid-80s, about 20 to 30 degrees above normal. Some locations could even see record temperatures. With these warm temperatures, combined with the strong winds and humidity dropping to 14-20%, critical grass fire danger along the MT/WY state line from Sheridan County eastward will be a concern. So, a Red Flag Warning will be in effect from Friday afternoon through midnight for the Sheridan foothills and a large portion of SE Montana.
As we head into Saturday, drier conditions will be taking over, but gusty winds will linger as temperatures turn much cooler, with highs in the 40s and 50s.
Looking ahead to early next week, we are keeping an eye on two active weather systems. The first is an upper-level low moving northeast from the Great Basin that will clip southeastern Montana late Sunday into Monday, bringing a 20 to 50% chance of precipitation. Following right behind, a stronger Pacific storm system is forecast to move in Tuesday and Wednesday, increasing widespread precipitation chances to 30 to 60%. Recent model runs suggest this mid-week system may pull in colder air along with stronger upslope flow into the north-facing mountains and foothills. If this pans out, overall precipitation chances could increase, and we may even see a chance for some lower-elevation snow mixing in by Wednesday. There is still considerable uncertainty with next week's systems, so stay tuned as the models fine-tune the details.
Miller Robson
Q2 Morning Meteorologist
miller.robson@ktvq.com
