First the Snow, Then the Cold
December 06, 2012 8:01 PM
Snow is an almost certainty heading through Friday, Saturday, and Sunday, but still plenty of details to hammer out. As I showed you in the previous blog, a band of 1 to 3 inches looks pretty likely from I-90 through the highway 14 corridor. But completed computer models that have run today are now sliding the snow just a little further north and are also slowing it down. Looks like many in the east could get through their morning commute with little trouble, but snow should be flying by noon. A much different story in the west with snow coming in early and exiting early. More snow is likely for some on Saturday. Once that is over, then the frigid cold shows up. Saturdays storm will drag down some Arctic air from Canada which would make this the first real shot of Arctic air this winter. Temperatures will fall through the day Sunday with wind chills likely below zero through the day and right into early Monday.
Lets start with the snow first. Here are some updated maps showing you now where that first band of snow Friday will end up.
Compared to yesterday, the band is generally 25 miles further north. But remember that things can still shift. I’ve seen similar scenarios like this where the heaviest snow band was actually almost 50 miles different then what the forecasting models showed just a day before, so a lot can happen as the snow develops. But this gives you a pretty good idea of where the highest likelihood is where that band will develop.
This is how much the National Weather Service is forecasting for this Friday storm.
Taking that one step further, new storm rolls in Saturday and Saturday night. This storm will also bring some snow. Now lets show you what these same computer models have for total snowfall between both storms.
You can see by these two images that the picture becomes far less clear once you get into that second storm. Snowfall totals couldn’t be farther apart between the two images with the first one only giving snow to the far northeast with this second storm. Meanwhile the second image shows more widespread snow falling with the second storm then the first. Some areas even end up over 6 inches for the weekend.
The snow totals may not be a guarantee but the cold air is. Check out just how cold it’s going to be by comparing 5000-foot temperatures from Saturday afternoon to Sunday afternoon.
Shown on these images is a temperatures drop of some 20°C, which is about 35°F. That is a crazy drop in temperatures at that level. Meanwhile, since cold dense air sinks, its likely quite a bit colder at the surface then at this level. This gives you an idea of just how cold things will get this weekend. Add some wind to those temperatures, and we are looking at wind chills 10 to 20 degrees below zero. Yikes! Stay warm!!