Friday, January 8, 2016

January 9-11 Potentially Significant Winter Storm

A potentially-significant winter storm appears to be unfolding in the January 9-11 timeframe.

Before we even dive into this storm, it's crucial to acknowledge that there are two model guidance 'camps' for this storm. As a result, there is unusually high uncertainty, so keep that in mind while reading this post.

Tropical Tidbits
The first solution we'll look at is the east-and-weaker idea. This is the latest GFS model's projected snowfall accumulation through Sunday morning. In this forecast, we see a swath of about 4-8" from southwest Missouri into extreme southwest Illinois, with a stripe of 2-4" on a northeast path until about Gary, Indiana. From that point, amounts on the order of 4-8" are outlooked for much of Michigan, particularly from the extreme southwest part of the state into the northeast part of the state.

This solution has been gaining ground in the last few model cycles, especially against the second model solution, which we'll analyze next.

Tropical Tidbits
The other solution being analyzed is a further northwest and stronger storm track. This is the 12z RGEM model, and it shows a solid 4-8" across much of the southern half of Missouri, with a small jackpot zone of 12-16" from extreme southwest Illinois into central Illinois. A zone of about 5-10" is outlooked for the Chicagoland area into the western half of Michigan.

This solution would appease many in the Midwest and Great Lakes regions looking for snowfall, but this particular solution is been losing traction to the weaker/southeast track in the last few model cycles.

Despite high model uncertainty, and the fact that I've seen stranger things happen, I'm expecting that weaker & southeast track to win out.

To summarize:

- A potentially significant winter storm is expected in the January 9-11 timeframe.
- High model uncertainty exists.
- A 2-6" snowfall swath could impact a southwest-to-northeast line from southwest Missouri to northeast Michigan.