Potentially Epic Snowstorm To Affect SE Michigan Tomorrow Night and Friday

Wow. That's all I have to say about the potential this system has. This should easily be our biggest snowstorm since the New Year's Day 2008 Blizzard (12" of snow at my house), and it has the potential to be even bigger than that. A snow day is extremely likely on Friday, and I have no qualms about raising the alert level to very high.

Here's what's going to go down:

Right now, the low pressure system that will affect us is over Los Angeles. It is so strong that snow is being reported in the hills of Southern California. From Los Angeles, this system will race to the ENE, eventually tracking from Northern Illinois to Northern Indiana to Northern Ohio on Friday. This forecasted track is further south than what was forecast this morning, so a lot more snow and a lot less ice is now expected. In fact, the ice storm threat for Lake Orion is nearly nil. The snowstorm threat however, is stronger than ever.

As the storm tracks ENE, it will run into a moist and unstable airmass over the Great Lakes. This will result in a favorable environment for heavy snow to occur in SE Michigan after about Midnight tomorrow. The snow will fall at a rate in excess of 1" per hour for much of Friday Morning, before tapering off Friday Afternoon and ending completely Friday Evening. When all is said and done, Lake Orion (and much of SE Michigan) will likely have in excess of 8" of snow.

Now, while only 2-5" of snow will be on the ground by 6:00 a.m. Friday Morning, there will be near-whiteout to whiteout conditions making driving nearly impossible. Also, there will be wind gusts of up to 30 mph, meaning that snow will be blowing across the main roads that are plowed, and drifting on the back roads that aren't plowed. Therefore, I feel confident that a snow day will occur on Friday.

There are only two possibilities in which I can't see a snow day occurring, and in my opinion the chances of each possibility are low.

Possibility One: The storm track moves further south, in fact, too far south. It would take a huge shift to the south, but it theoretically could happen. In this case, we would only get 4-8" of snow, with only 1-3" of snow falling before 6:00 a.m. Friday because the main precipitation shield would be too far to our south. However, I can't see such a huge shift occurring.

Possibility Two: The storm slows down more than expected. The snow starts at around 4:00 a.m. Friday, and only 1-2" of snow is on the ground by 6:00 a.m. In this case we could have school, because our school got burned the last time they called a snow day on the expectation that significant snow accumulations would occur during the day. (That occurred on February 1st, 2008, when we were supposed to get 4-7" during the day and ended up only getting 3" of snow total.) If this possibility becomes reality, get ready for a long, long, long commute home Friday, as the bust potential on this storm is extremely low. However, I just don't think I can see our school not realizing that it would be extremely dangerous to send all students to school in near-whiteout conditions Friday Morning.

So, all in all, we should have an extended Christmas Break due to a likely snow day on Friday.

Here's my snow map for SE Michigan. Note that there will likely be some 12+" totals where convective banding of snow occurs. Where convective banding of snow occurs, there will be thundersnow and the potential of snowfall rates in excess of 2" per hour.