We Will NOT See 20.5 Inches of Snow By Christmas

Check the Source Before you Hit the Share Button

Throughout the last couple of hours I’ve been answering questions about a claim that a local Facebook page has made saying that we will see nearly 21 inches of snow by Christmas Day. Is it true? Absolutely not. While it is likely that we will see a White Christmas, the likelihood of receiving 20.5 inches of snow by that date is highly unlikely.

It is posts like these that ruin the credibility of meteorologists across the country who actually went to college and studied the science and have a degree to prove it.

Making a forecast for 15 days out and saying that it’s going to be accurate is kind of like trying to predict who will win the Super Bowl a year from now, by what score and who wins the MVP, basically impossible.

In their post they show a single run of the Global Forecast System computer model, known as the GFS. They chose ONE single run from Tuesday afternoon/evening which shows that we will see somewhere from 20 to 30 inches of snow from Sioux Falls into southeastern Minnesota. What they aren’t showing you is that the exact same model from just one day before, projecting 0.0 inches of snow for the greater Sioux Falls area. You can see the two models compared below.


Click on picture to enlarge

Which one is correct? Neither of them. But it just shows how much things can change with the weather in such little time.

As meteorologists, it would be irresponsible for us to base our forecast off of one singular model run. Instead we look at numerous models, not just the GFS, taking them into consideration and comparing them against each other, as well as comparing different runs of the same model to each other, before finally making our own forecast. Models are a tool for the meteorologist, but not the end all be all.

Am I trying to make a claim that we meteorologists are correct all the time? No. We are human and of course we make mistakes. But we learn from these mistakes to try and make sure they don’t happen again.

All I ask is that next time you look for a weather forecast, please turn to someone who is a professional meteorologist who has a degree/certificate in meteorology or atmospheric science like your local television meteorologists or the National Weather Service rather than sharing a fear mongering post from an uncertified source. I can’t speak for the rest of the television stations in the area, but I can say that all three meteorologists at KDLT have a four year degree in meteorology and we would be happy to answer any questions you have.

-Brandon Spinner
Chief Meteorologist
Twitter: @wxspinner89
Facebook: Meteorologist Brandon Spinner