The 12z GFS model data is in. The GFS seems to be locking in on a solution for the track of the storm that could affect southeast Missouri, southern Illinois, western Kentucky, and central/southern Indiana.
For the fifth consecutive run, the GFS is taking a "warm" track. Meaning the surface low is tracking further north and bringing up warm air ahead of the storm. This would equate to rain for southeast Missouri, southern Illinois, western Kentucky, and central/southern Indiana.
Here is a look at the surface chart with precipitation for 6pm CT Thursday (Christmas Eve).
The surface low tracks right from central Arkansas northeast over southeast Missouri and then it turns almost due north. Usually you would expect for the low to keep tracking east/east-northeast but that doesn't seem to be the case. I am not 100% sure why the model is tracking the storm this direction although I have a sneaking suspicion it is taking in to account the Greenland blocking pattern I talked about last week.
The model is generating quite a bit of rain for southeast Missouri, southern Illinois, western Kentucky, and extreme southern Indiana. Take a look at the jet stream forecast for 12pm CT Thursday. Look at how the jet dives all the way down to the gulf and then turns sharply north. The jet will act as a conveyor belt to draw up the moisture.
Not all of the 12z rainfall totals are in just yet, but the 6z run puts down around 2.5" of rain for Cape Girardeau Wednesday-Thursday night.
I am also starting to turn down my "winter storm mode" and turn up the "severe weather mode". There will be plenty of warm air and moisture pumping up from the Gulf of Mexico. There will be a lot of wind as the low moves closer and through the area. There will also be spin in the atmosphere due to the closeness of the low. Energy in the upper level moves through the area around 6pm CT Thursday. Here is the 500mb vorticity chart.
There are a few things still missing for me to be really concerned for severe weather around the area. It would be good if we could get a dry slot to develop to allow the atmosphere to destabilize a bit.
The severe weather threat isn't anything to get worked up about yet. This storm is still 4-5 days away and a lot of things can (and probably will) change. The energy that will make all of this happen is just now coming onshore over northwest US.
Keep checking the forecast on KFVS12, kfvs12.com, and I will continue to post updates here on the blog and on Twitter.