Snow Amounts Expected for Weekend Blizzard
by Cody Matz
February 08, 2013 8:20 PM
For those of you looking for some much-needed moisture, I’d say you can rejoice as the largest winter storm of the season will move through the area as we go through the weekend. Areas of rain and snow can be expected with more than a foot of snow possible in some areas. This is not expected to be a drought buster by any means, but it will hopefully put a small dent in the epic drought we have been experiencing since last summer. I won’t to remind you though that the exact track of this storm is still undetermined, however we do have a pretty good idea of where it will land and what most of us will experience.
Here is where the storm is as of Friday evening. It’s spinning about across the Desert Southwest and rolling eastward. Notice the Nor’easter running through New England and dropping 2+ feet of snow in spots. We are not expecting that much snow around here, but it doesn’t take that much snow to cause major travel headaches and for a storm to be down right dangerous.
We continue to fine tune our forecast as the storm gets closer. The track of this storm Thursday was still very much in question with so many potential solutions as you can see below.
But Friday we got a much better idea of what will likely occur now that the we are much closer to pinning down the track of this storm.
Compare the two images and notice that the solutions are starting to look very similar, even though they are still in slightly different areas… well with the exception of the furthest north one. This one is very unlikely and my guess is that the storm will end up tracking somewhere in between those 5 more southerly lines. This would give the southeast a little bit more snow if temperatures can fall fast enough Sunday morning to bring a period of heavy snow into the picture. Below is an image of what you can expect across the area Saturday night through Monday morning.
So the west and north are very easy (in terms of precipitation type) because temperatures will stay cold enough for all snow. It’s the pink shaded areas that are the tricky spots. The precipitation in these areas will start as rain, but switch over to snow at some point during the storm. The times at which this will occur varies drastically. This is where the extreme difficulty comes into play. For example, lets say we are forecasting this storm for Brookings. If the precipitation starts out as rain and then switches over to snow Sunday morning at midnight then they could end up with say a foot of snow. But now lets say temperatures stay just warm enough for rain through 6am. Now, those 6 hours that you were getting snowfall accumulation are history. So instead of getting a foot of snow, you end up with a half-inch of rain and say 6 inches of snow. Do you see the difficulty??
So here is the current snowfall forecast…
The heaviest snow by far will be across the north and west with potentially widespread amounts of 10 to 15 inches about Redfield, to Watertown, Sisseton, Milbank, and Ortonville. There is a little more uncertainty with just how much will fall across central and southern South Dakota which is why Valentine, Winner, Pierre, Huron, Chamberlain, and Mitchell are all in the 6-12 inch category. Some signs are suggesting though that there could be pockets of 14 or 15 inches of accumulation for some in that band, but its just impossible to know for sure. The southeast though is the most complicated with a very large snowfall gradient over a very short distance. For example, this storm could bring an inch of snow to Beresford but 8 to Sioux Falls. Literally 25 miles could mean the difference in 6 or even 8 inches of snow. But its impossible to know where this gradient will set up for sure, so I broad brushed the area with a less steep gradient, but something that is still possible. I would just say that the southeast should be prepared, and should not be shocked by anything that occurs cause it literally could be all rain or a little rain and a lot of snow. I don’t mean to be wishy washy, but I just want to be honest and say there is really no way of knowing for sure.
Here is something that we are a little more confident about is the amount of liquid that will fall out of the sky. Remember that this includes all of the snowfall expected if you melt it into water.
Notice that much of the area can expect a half-inch or more with some local areas picking up an inch and a quarter of liquid. That’s not all that impressive if it were happening with a storm in June, but considering that the winter months are far dryer, this is a pretty potent storm.
After a lot of the snow has stopped falling, the winds really start to pick up. Not that they wont be blustery while the snow is falling, but the core of the strongest winds wont occur until Sunday night and the first half of Monday. This is when the snow will really begin to blow around. Check out the sustained wind speeds possible Sunday night at midnight.
The red shows winds sustained of at least 30mph and that doesn’t even include the 40 to 50mph gusts that are expected. This will be a one two punch. So even if the snow begins to wind down in your area Sunday afternoon, doesn’t mean its over yet because the blowing snow is just beginning. Check back here during the weekend for updates on the winter weather as well as snow and rain totals early next week. Stay safe!!