As the calendar moves into the month of December, forecast models are indicating an active weather pattern ahead. In particular, one particular weather system, which is schedule to develop two weeks from now, brought haunting memories of a severe weather outbreak that took place in December 2000.
Looking Back: December 16, 2000
In 2000, the set up consisted of a large area of low pressure centered over the tri-state area of Missouri, Illinois and Iowa.
Near the surface of the ground (roughly half a mile up), VERY strong winds were blowing from the south into Alabama, and the map below shows winds as high as 40-50 knots (46-58 mph) measured in Birmingham. These winds were ushering in warm, moist air into the Southeast, which served as the “fuel” for the resulting severe thunderstorms that developed throughout Alabama. In fact, the image below is an archived radar image depicting supercell thunderstorms that produced a deadly tornado in Alabama.
All in all, a total of 20 tornadoes and another 47 reports of wind damage were reported during the December 16, 2000 severe weather outbreak.
Looking Ahead: December 16, 2015
In the world of social media, it is very common for a “doom and gloom” weather model to make its way onto the internet. In fact, when we saw the model imagery below, the first thought that came into our heads was “this is very similar to a past event, on this date, what a coincidence!” We are not placing a whole lot of stock into the forecast model output at this time, because it would be unrealistic to do so.
Why is it unrealistic? Simply put, the outlook below is a model solution for a potential weather event that is more than two weeks away. Accuracy within weather forecast models is limited to the first five to seven days, so anything beyond this time frame has the potential to change drastically between “now and then.”
In fact, it is just as likely that December 16, 2015 would go down in history as a pleasant, sunny day in the Tennessee Valley. It all depends on the timing of individual — and highly variable — atmospheric elements that determines whether sunshine or a severe weather event develops two weeks from now.
With that said, here is what one particular forecast model is indicating for December 16, 2015.
According to this model, a very strong low pressure system is forecast to develop in central Illinois, producing a broad swath of heavy rain as well as very strong winds, as indicated by the tightly packed amount of lines surrounding the low (these lines are called isobars, and they illustrate lines of equal pressure).
While the location of this low pressure system is further east compared to the 2000 event, it would still be able to pull warm, moist air into the region. Coupled with the indication for strong winds, this model output is signaling bad news on December 16. The good news, though, is that since this particular date is still over two weeks away, the actual weather that may develop could widely change compared to what’s shown below.
Below is the wind forecast for a level roughly half a mile above the ground. Notice that the peak winds are further west compared to 15 years ago; again, model output variability is still high this far away from the date in question, so while the severe weather event has a possibility of developing… It is just as possible for this set up to develop way too far west, east, or not at all.
Bottom line, while a lot can change between now and December 16, it is important to be weather aware and vigilant in case a severe weather set up does develop during the next few weeks. Whether this event materializes or not, December is part of the secondary tornado season in the South (including the Tennessee Valley), and so it is always a great idea to be prepared.
Be sure to review emergency preparedness plans for at work, at school, and at home. Double check that you have enough supplies for everyone in your family, including your pets, in the event that a severe weather outbreak damages or cuts off access to nearby stores.
During the event, stay ahead of the storms by watching WHNT News 19 on your TV or streaming online via your cellphone or tablet. You can also get the latest weather updates via the LiveAlert19 app.
– Meteorologist Christina Edwards