Posted: Nov 5, 2012 4:08 PM by Meteorologist Mike Rawlins
Updated: Nov 5, 2012 4:08 PM
UPDATE - 4:08pm Monday
Well in advance of this week's major winter storm, the National Weather Service has issued a Winter Storm Watch for most of central and northern Montana.
6-12" of snow are expected at lower elevations across the plains, including Great Falls.
Up in the mountains, up to 2 feet of snow is expected through Saturday.
Hazardous travel conditions are likely later this week, and travelers should be prepared for extreme driving conditions.
With temperatures near 70 degrees across Montana this afternoon, it's hard to believe a major winter storm is on the way.
Since last week, computer forecast models have been extremely consistent in showing a powerful storm system moving into the Northern Rockies by the end of this week.
With good run-to-run consistency, meaning the models show the same solution time after time, we have high confidence in our forecast for this event.
A strong Canadian cold front will push across Montana late Wednesday night and early Thursday morning.
Winds will shift to the north and much colder air will dive south out of Canada.
High temperatures will drop from the 50s/60s into the 20s/30s for the second half of the work week.
As the surface low moves southeast of Montana, a east to northeast wind will develop.
This wind flow creates upslope, meaning winds are forced up the mountains and precipitation amounts become enhanced.
For north central Montana, this is perfect for accumulating snow.
In the upper atmosphere, the jet stream will dig south, creating a trough of low pressure in the West.
A southwest flow will develop aloft, carrying moisture off the Pacific Ocean and northeastward into the Treasure State.
This will help fuel the storm system with moist air aloft.
At the same time, an area of high pressure will slide south through central Canada.
This dome of high pressure will force very cold air down into Montana.
Daytime highs will dip below freezing and nighttime lows will dive into the single digits for the end of the week.
Right now, we're still days away from this event occurring, so we have plenty of time to nail down the fine details of the forecast.
I expect the snow to begin falling early Thursday morning and continue off and on through late Friday.
This will be a prolonged event, and anyone traveling during this time should stay weather aware.
It's still too early to throw out specific snowfall amounts for the region, but I will say there is high likelihood that some areas will see over 8" of snow.
As the storm begins to move away on Friday, some forecast models develop strong winds across central Montana.
This could create blizzard-like conditions for many areas, making travel very hazardous.
Stay with STORMTracker Weather for continuous coverage of this potential winter storm.