Small Storm Thursday Night. Bigger One Sunday?

Not much has changed since this time yesterday. SE Michigan is still looking at a weaker clipper system moving through the area Thursday Night, followed by a much stronger, but much more unpredictable storm on Sunday.

First I will mention the clipper. Earlier in the week, I was thinking that advisory level snows were possible with this storm system, but unfortunately for SE Michigan it has continued to trend further and further north on the forecast models, and it's just not looking like this will provide much more than 1-2" of snow on Thursday Night. To be honest, it's barely worth mentioning now, because although it's going to be the first snow SE Michigan will receive from an actual storm system as opposed to lake effect snow, it's not like it's going to give SE Michigan much more snow than some of the lake effect events you guys have received so far this year. I'll probably continue to update the forecast with this storm just for the heck of it, but really the main thing to focus on is a potentially significant storm on Sunday, which is what the next portion of this post will cover.

Again, over the past day the main medium-range forecast models (the GFS and ECMWF) have all continued to favor a strong low-pressure system affecting the Eastern U.S. around next Sunday. There is now enough consistency for me to fully believe that there will be a significant snow storm somewhere in the Eastern U.S. this Sunday. Obviously, the million-dollar question now becomes: Where will this storm track? The answer to this question will adversely affect what SE Michigan sees from this system.

As far as I see it, there are three main possibilities for where this storm will track. Option one has this storm bombing out near the East Coast, providing a nice snow storm for areas east of MI but leaving SE Michigan largely dry. Option two has the primary low pressure system moving to the east through Illinois, Indiana, Ohio, etc...with the primary low eventually occluding and transferring energy to a secondary low, which would move up through Central PA & NY. This is the scenario to hope for if you want a snow day. This scenario would likely give SE Michigan at least several inches of snow, with Winter Storm Warning criteria snowfalls entirely possible. In addition, as the secondary low rapidly intensifies, high wind & blowing/drifting snow would certainly become an issue. Option three has the primary low becoming stronger, which would result in a further west track with the likely result in SE Michigan being a sloppy mix of rain/snow.

At this time I believe it's prudent to look at some forecast models & at least try to get an idea of which track I might favor.

First, I'll start off by looking at the 12z GFS. The 12z GFS has some energy diving SE from the Dakotas. This energy eventually phases with the digging polar jet, with the result being a primary low pressure system that gets to around Cincinnati before transferring its energy to a secondary low pressure system which tracks from SE VA to Central NY. Yes, this is a rather complicated storm system with the transfer of energy...so I understand if it's tough to follow. The result is a very good storm system for the I-80 corridor of Northern IL, IN, and OH, with MI missing out on the best snows, but still getting several inches. In addition, winds would get very strong at the end of this storm and in the following days if this solution verified. Some images showing what happens are below:

1 a.m. Sunday

7 a.m. Sunday

1 p.m. Sunday

7 p.m. Sunday


The next model to look at is the 12z ECMWF. Although I do have access to images from this model I can't repost them, but I will describe what it shows. Essentially, the main difference between the ECMWF and GFS is that the ECMWF has the primary low pressure system moving much further north than the GFS, and it also does not feature an energy transfer. The result is a low pressure system that tracks from Iowa to Chicago to Central MI, and while SE Michigan would see a lot of precipitation from this track, a lot of it would fall as rain. I doubt there would be much accumulating snow, and what would accumulate would likely be washed away as precipitation changes over to rain.

So, obviously there is a significant amount of disagreement among the forecast models. At this time I would favor the GFS track as the GFS has been outperforming the ECMWF w/ regards to accuracy in recent weeks. However, this by no means is equal to me calling for a guaranteed snowstorm for SE Michigan on Sunday & Sunday Night. If things work out correctly, there could definitely be a big snowstorm for SE Michigan, with a snow day being possible next Monday, but there's still a lot of uncertainty. I will probably have another post up tomorrow night.