Major Thanksgiving Storm Likely For Midwest, Great Lakes

I am making the call for a major Thanksgiving storm system (likely with snow) to hit the Midwest, Great Lakes, and possibly the Plains and Northeast. Let's take a look at why I am now making this call.

This is a 500mb height anomaly forecast, valid a few days out. As you can see, there isn't much going on in the United States, so why am I showing you this? Well, we have to go to East Asia for that answer. If you look in the top left corner of the image, you will see a strong trough present in East Asia. It has been shown that there is a 6-10 day gap between what happens in East Asia and what happens in the East US. So, if we use this forecast (valid November 13) and apply the 6-10 day gap to it, we end up at November 22, or a day or two from Turkey Day.

We can also use the Lezak Recurring Cycle (LRC), which is, in the simplest of simple explanations, a repeating pattern that forms every fall and cycles through the winter. This pattern first forms in September-October. A strong storm system hit the Plains, Midwest and Great Lakes on October 2. If we use the expected 51 day gap between each cycle and add on a day or two to give the forecast a little wiggle room, we find this strong storm system hitting the Midwest/Great Lakes on November 21-23, which falls right on Thanksgiving!

I think it's time we turn to the models to see what they're saying. This is the morning forecast from the GFS model for Thanksgiving. This image shows precipitation over a 12 hour period, as well as MSLP lines. The pink line is the rain/snow line. Any precipitation above that line would be snow, and precip. below the line is likely to be rain. The GFS is forecasting a pretty strong storm system to be present across the Midwest/Great Lakes on the morning of Turkey Day. While the GFS has been juggling the position of this storm system, it has been forecasting a strong storm system in the general East US on Thanksgiving.

As you can see in the above forecast, there is a lot of color above the pink line. Yes, this would mean snow. However, because all I am confident in is the presence of a storm in the mentioned regions, I don't think now is the appropriate time to make calls on precipitation. However, if there is to be precipitation, it will most likely focus in on the Upper Midwest and Great Lakes.

This is likely to be the most accurate forecast for this system if we rely on the LRC, but any East US forecast with a strong storm system could verify if we use only the East Asian theory. Personally, I think it's a good idea to combine the two and use the GFS forecast above (which will definitely change in coming days).

Let's sum this all up:
•I am making a call for a storm system on Thanksgiving Day.
•This system will hit the Midwest, Great Lakes, and Northeast.
•Snow is likely, possibly heavy in some areas.
•Cold weather will follow the system.

Andrew