A powerhouse low pressure system is spinning just off of the Pacific Northwest coast at midday today. Snow has already broken out and is becoming widespread across the Northern Rockies, including much of Montana:
As of 11 am CST, 3 inches of snow had fallen in Buffalo, MT, and it's just getting started. Here is what it looked like along Highway 12 North of Bozeman just a short while ago (via twitter):
Winter Storm Warnings are in effect across much of this region, as shown in pink on the image below. Blizzard Warnings are in effect for the areas shaded in orange:
Within the Winter Storm and Blizzard Warning areas, widespread snowfall of 6-12 inches can be expected, with 12-18 inches and locally higher amounts in northern Montana and northwestern North Dakota. Coupled with strong, gusty winds, white out to near white out conditions can be expected, and travel is highly discouraged.
Meanwhile, further to the South and East, moisture is slowly beginning to return back North from the Gulf of Mexico ahead of this system. As the associated cold front and surface dryline move into the central Plains this weekend, a threat of severe weather will be on the rise.
Below is the latest severe weather outlook for Saturday afternoon and evening from the Storm Prediction Center (SPC) in Norman, OK:
Severe storms are possible within the brown shaded area on the image, with the highest likelihood in the yellow shaded area. Strong, damaging wind gusts and hail are possible, as well as a few tornadoes, especially as the activity initially develops by mid to late afternoon on Saturday.
The threat of severe weather will spread Southeastward on Sunday, as indicated by the area outlined in red on this computer model forecast image valid at 6pm CST on Sunday afternoon:
By Sunday, the main threat will become damaging wind gusts and hail, as low level wind profiles will be less favorable for tornado development, and widespread cloud cover ahead of the system will keep the atmosphere from becoming as unstable as it will be to the West on Saturday.
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