COLUMBIA, S.C. — It’s the time of year where fantasy snowfall maps are shown on the internet or an ambiguous snowflake shows up on your stock cell phone app. Recently, the internet has been abuzz about arctic air potentially moving south. Some models even showed historic cold in our area Tuesday morning!
However, our mornings this week are not expected to be record cold and these long range forecasts need more context with them.
One way to think of a long range forecast is like a plinko board. A computer model starts off with the current conditions of a region. From there, it takes a path to what it thinks will happen. However, each step depends on the step beforehand, so the farther out you are forecasting, the more error there is likely to be. The closer to the event you are, the less error there will likely be.
This applies to all forecasts, whether that be snow, rain, temperatures, even tropical weather!
When looking at long range forecasts, it’s a lot more important to look at trends. Is the forecast trending cooler or warmer than average? Forecasters also need to look at different models and whether they agree or disagree. Generally, the more agreement you have between models, the more confidence you can have in their solutions.
Despite these limitations, there is no doubt that computer modeling has come a long way. According to a study titled Advances in Weather Prediction published by the American Association for the Advancement of Science, a modern 5-day forecast is as accurate as a 1-day forecast was in 1980.
The United States is also investing into our own long range models to improve their accuracy. In February of last year, NOAA announced the purchase of new supercomputers, which will triple operational weather and climate supercomputing capacity.
Overall, computer models, while important, are still just a tool for meteorologists to use with their own expertise to help create a forecast and not something to be taken to heart. The next time you see a fantasy weather forecast on your phone’s weather app, make sure to check in with us to get the best advice on what’s going to happen.