Update After a Quick Look at a Couple New Models

Had a chance to quickly look at a couple new models lat this evening and the trend appears to be heading a bit further south with the main system and a bit colder , too. So what does this all mean? Well, during the past day or so the trend had been moving a bit further north with the low moving out of Louisiana to near the I-20 corridor in Alabama and then eastward into Georgia. That meant the likelihood that it would try to remain mainly rain from northern Mississippi into northern Alabama and Georgia during the heaviest precipitation. Now during this same time, the ECMWF (Euro) model had been a bit of an outlier with the track hugging the northern Gulf coast and indicating the potential for more frozen precip further south to near the Tennessee River.

Here are images from the NAM Model at 6 AM, Noon and 6 PM Friday. Notice that the freeze line has sunk south of the southern Tennessee border. In addition, the NAM onset precipitation in Northwest Alabama around Noon and spreads it eastward through the afternoon, likely as freezing rain.;

Now, here is the high resolution BAMS model for the Tennessee Valley, exclusive to WAAY-TV. This is the most recent run available at press time. The images are at 3, 6 and 8 PM. Notice the freezing precipitation line makes it to the Tennessee river by 3 PM and then tries to migrate northward into the evening. Also note, the very heavy snowfall being indicated by the model from the Shoals through Huntsville. This run actually has the heaviest snow from US 72 northward to about US 412 just south of Nashville.

A few things of note, this model has been quite consistent for the past several days and this is just slightly a bit further south and colder. It also increased precipitation amounts. Now my gut feeling is that US 72 may be a good demarcation line for the Tennessee Valley. I also still have my doubts that once temperatures reach freezing or below and precipitation starts that the temperature rises much more than a degree or two. When you are just at freezing a degree is HUGE. But if you are a couple below one won't make a big difference.

Unfortunately, nothing is still for sure. Heck the National Weather Service is still in doubt. Look at the differences in opinion between two neighboring NWS offices, Nashville and Huntsville. The counties in southern-middle Tennessee overseen by the Huntsville WFO are in a Winter Storm Warning while those next door and under the direction of the Nashville WFO are just under a Winter Weather Advisory.

I love my job! :)