Alright, the long awaited update...

My apologies for not getting this out earlier, but here it is. First, let's take a look at the current radar trends:



As you can see, Lake Orion is just starting to get the prefrontal precipitation. It is falling as rain; however, forecast models support this changing over to snow by daybreak tomorrow morning. The next feature you will see is the massive hole of precipitation over Indiana & Illinois, and if you're like most people, you are probably freaking out thinking that you're going to miss out on a lot of the best snows. However, fear not. The low pressure system is forecast to move ESE over the next 12-18 hours, and as it does, the hole of precipitation, known scientifically as the "dry slot" of the storm, will also move ESE. Essentially, where it is right now is about as far north as I think it's going to get. I will say that if I have any viewers south of about I-696...you may have some trouble with the dry slot tomorrow, but I don't believe it will be for an extended period of time.

The main fun that's going to unfold for you guys tomorrow is from the band of heavy snow on the backside of the low pressure system that is currently falling in Wisconsin & Iowa. This is known as the "deformation band" or "trowal" in the meteorology world, and it is forecast to slide ESE into the Lake Orion area tomorrow. The further north you are, the more likely you are to catch the brunt of this band, so, for example, people in Saginaw are more likely to stay in this heavy snow axis for a longer period of time than people in Lake Orion, but people in Lake Orion will fare slightly better with this band of snow than people in, say, Canton (I think I have some readers in the Plymouth-Canton area ;).

So essentially, what I believe is going to happen is that in Lake Orion, precipitation will change over from rain to snow around daybreak as temperatures start to fall. In the early-mid morning hours, the snow may get a little lighter, and in areas to the south, the snow may stop falling completely for a few hours. However, around midday, I expect the snow to pick back up with a vengeance again, and to fall at a quick rate, until finally tapering off in the mid-late evening hours.

Snowfall Map:

At this time, I won't bother to post images of what all of the forecast models show, because they all show something similar. Essentially, all of the models show around .5-.8" of liquid equivalent falling in the Lake Orion area after the changeover to snow tomorrow. Using normal 10:1 snow-to-water ratios, this would equate to 5-8" of snow tomorrow. However, with the way that I believe temperatures will crash as this storm unfolds, I think the average ratios will be above 10:1, more like 12:1. This would equate to about 6-10" of snow for the Lake Orion area. However, the wettest model by far is the NAM, and it tends to overdo precipitation a little bit. As this is the only one that I feel would support 10" of snow falling, I'm going to try to trim accumulations to a range of 6-9". South of around I-696, I feel that the dry-slot will be a little more of an issue, and in addition to that, I feel that you make take a little longer to changeover from rain to snow. Due to this, I will cut accumulations down an inch there to 5-8". On the other hand, north of around I-69, I feel you'll have less trouble with the dryslot and a quicker changeover to snow, so I'll add an inch onto accumulations there, for a forecast of 7-10". The resulting map:



Impacts From This Storm:

I really don't have any other way to say it except to say that this storm will be an absolute nightmare for travel. Firstly, the rain you guys are currently getting will freeze under the snow on untreated roads such as dirt roads & subdivision streets. Obviously, the main roads will probably have more slush than anything on them because of salt & plows, but I still wouldn't advise anyone to travel anywhere unless absolutely necessary tomorrow, because the roads are going to be terrible. Secondly, the 6-9" of snow means it will be very difficult to get around after the storm is over on any unplowed roads. In addition, winds will gust to 30 mph near the end of the storm, and after the storm is over, causing very poor visibility as the freshly fallen snow is whipped up and blown all over the place. This will also cause drifts of over 1'. Finally, these winds combined with the temperature plunge will cause wind chills to drop well below zero on Sunday Night & Monday Morning.

Snow Day Chances:

In my opinion, if you guys want to throw any accomplishments my way on this storm (and really, you don't have to lol), it should be moreso for sniffing out the possibility of a storm in this timeframe over a week ago and then keeping you guys informed step-by-step as the storm became more and more likely to affect Lake Orion (of course, with many twists and turns in this case). I do not feel the actual snow day prediction will be very hard. Unless an absolute disaster happens w/ regards to accumulations, I feel you guys have a great shot at a snow day on Monday. Everything from the large amount of snow that will fall, to the sheet of ice on the back roads & subdivision roads due to the rain freezing over, to the poor visibility, to the extremely low wind chills all support a snow day. I will therefore give Monday a snow day grade of "A".

Once again, I'm very sorry I didn't get this up earlier. As always, feel free to leave questions/comments in the comment box below. The upside of this post getting posted later than expected is that I used the extra time to study more for my exams, meaning that I may put out an extra update tomorrow afternoon before my final snow day prediction which will be posted exactly at 7:30 p.m. Eastern Time (and that may be coming in video form if I feel that ambitious).