Posted: Mar 18, 2013 8:50 AM by Meteorologist Matt Elwell
Updated: Mar 18, 2013 8:50 AM
With the official start of spring on Wednesday, we are looking at a fairly active weather pattern over the next several days. It has been a quiet and very warm pattern over the last several weeks, but the current weather models indicate we are going to see more of a ‘spring' pattern emerging for the near-to-mid range forecast.
A weak disturbance looks to bring light snow accumulation for Monday afternoon and evening both east and west of the divide. Most areas are likely to pick up less than an inch of new snow by Tuesday morning, with the vast majority of the area picking up a half inch or less.
What interests me is a Pacific storm that looks to mature as it hits the west coast and transition to a weakening system by the time it hits Alberta, Canada. What sticks out to me on this system is that it will draw warmer air and moisture out ahead of it on Tuesday and Wednesday and then drop much cooler Canadian air into the mix for Wednesday evening and Thursday for southwest Montana.
The accumulated snowfall forecast is all over the board as far as the models are concerned. This has been the case for most of the winter season. I have tended to stay on the lower side of the models as the result, and it has worked out pretty well for us so far. I believe that this system is much the same, but the set-up has put this storm more in the middle of the road for me this time.
In Butte, the model runs are more compact as far as the model spread is concerned. Most of the models are coming in with an inch or less for Monday and Tuesday with the model average around a half inch. The incoming system on Wednesday night and Thursday seems to range between 1-2 inches with the highs near 3 inches. These numbers seem about right.
Bozeman's forecast shows a little more spread. The Monday and early Tuesday spread seems to be around an inch to an inch and a half, though there are a couple of outliers that are pushing 3 inches. Despite the difference in the models, I think that less than one inch is probably in line. The real difference comes in the Wednesday and Thursday timeframe. The models are anywhere between one inch to over eight inches. The model average is around 5 inches.
The system is tricky, but it seems that a 5 inch snow will be a little hard to come by in the valleys. The dynamics at this point aren't there to see a sustained snow capable of 5 to 8 inches. In actuality, the snowfall will likely be between 1 to 4 additional inches of snow with the majority of it hitting early on Thursday.
We will continue to track this storm and bring you the very latest and the latest data pours into the STORMTracker weather center.