The United States is being invaded by a threat to our people, plants, pets, and pipes. No it’s not some kind of biochemical warfare, it’s just a little gift from the season many of us forgot existed this year, winter! One of the largest blasts of cold air this season is currently affecting temperatures across the United States. After a winter that bottled most of the cold air up north of the United States and Canadian Border, this blast will bring freezing temperatures all the way to the Gulf of Mexico and Mexican border in spots. The current surface analysis shows the big picture with a large cold front now off of the east coast and a secondary cold front trailing this just across the Appalachian Mountains.



Strong north and northwest winds are helping aid in pushing this cold air south and creating for some stinging wind chills, especially later tonight. Current air temperatures as of 18Z show a 31°F reading at Little Rock, 16°F in Chicago, and just 5°F at Bemidji, MN all of which will be dropping much lower tonight. Many areas across the south are under frost advisories and freeze warnings for tonight as cold air like this has not really penetrated into these areas this year. Additionally, the strong winds behind the reinforcing cold front have prompted wind advisories and even a few high wind warnings with gusts up to 60mph in a few areas this evening and tonight in the Appalachians.



Taking a look at the NAM model below, depicting temperatures for 12Z tomorrow morning, one can see the 0°C line sinking all the way into northern Florida, just a little north of the Gulf of Mexico, and even dipping down to the Texas/Mexican border in parts of west Texas. In fact, most of the United States will see temperatures at or below freezing tonight! That is certainly something we have not been able to say this winter.

Taking a look at the 850mb level at 0Z this evening, the NAM model shows the strong cold air advection that is occurring behind the cold front, aiding in dropping those low temperatures tonight.
As mentioned above, wind chills will also be a factor tonight. Below is the apparent temperatures for tomorrow morning as predicted by the National Weather Service. It will feel like it is in the teens for parts of northern Florida, Georgia, Alabama, Mississippi, and Louisiana tomorrow morning. Many of these areas are not well prepared for temperatures of this nature and precautions will need to be taken in order to protect the life of plants and infrastructure such as water pipes. Farther north, temperatures will feel like they are below zero in many spots as far south as northern Texas across to Missouri and in the Appalachians down into northern Georgia and western North Carolina. Not to be outdone though, the typical cold spot up in International Falls, MN will expect to see an apparent temperature of -29°F on Sunday morning.
With all this talk of cold air, snow chances are probably one of the first things everyone is thinking about. As a low pressure system continues to develop over the Rockies, some areas could pick up a few inches of snow as well as some ice accumulations. Considering many areas at risk for this snow and ice have received little, if any winter weather precipitation this season, this could create for some travel issues. This situation will have to be monitored carefully over the next few hours as Winter Storm Watches are just beginning to be issued for parts of Texas, New Mexico, and Arkansas. Stay tuned for future blog posts on this topic!
So will there be more cold air outbreaks for the lower 48 states in the near future. Taking a look at the models, it does not appear we should expect anything of this magnitude at least for the next 10 days which would bring us into mid to late February. However, it does appear there is a lot of cold air bottled up in the polar regions so it will definitely be something to continue to monitor.