Western Winter Storm Brings Heavy Snow, Upslope Flow
Winter Storm Warning. We’re watching a winter storm brewing out west that could pack up to a foot of snow and gusty winds. It’s already snowing in Banff, Alberta, which is exciting news for ski & snowboard enthusiasts. (Image above courtesy http://banffnorquay.com/)
Winter Weather Headlines. Warnings and advisories are already in place across Montana, Idaho, and Wyoming. Foothills and mountains can likely expect 12″+ of snow thanks to upslope flow that will ramp up in the next 24-48 hours.
Howling Winds. The jet stream forecast above shows a large jet streak diving southward along the Pacific Northwest coast. Wind speeds in this region of the jet stream top out around 150 mph. (Image: UCAR)
Tracking the Storm. The map above shows the vorticity forecast as the storm begins to intensify. This region in red represents an area of vertical motion (or rising air), which in turn often leads to enhanced precipitation. (Image: UCAR)
So Where’s The Snow? Most of the snow will likely fall on the eastern side of the mountains across Montana thanks to strong upslope flow (east winds pushing up against the mountain slopes). Some pockets of 12″+ are likely in the higher elevations, but overall most lower elevations will see 6″ or less. (Image: WSI RPM)
Big Sky, Big Snow. Montana will take the brunt of the snowfall, making for treacherous travel conditions along I-90 and I-15. The map above shows totals ending midday Tuesday, but there will be additional snow to the south and east after that.
A Wet Week Ahead. In addition to the snow storm for the Northwest, another area of low pressure is set to develop near Colorado and kick up some significant rain for the Central and Southern Plains. This next storm will have a multi-day severe weather threat across the Southern states in addition to heavy rain.
Southern Soaking. At least a few inches of rain are likely to accumulate from Missouri southward. This forecast from the Weather Prediction Center highlights rain through our Halloween holiday, which for some will unfortunately be soggy.
We’ve got a lot more to talk about this Sunday on WeatherNation — tune in on TV or on your mobile device. And have a great week ahead! -Meteorologist Miranda Hilgers