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  • Writer's pictureMeteorologist Joseph Cooper

Are Meteorologists Really Wrong That Much? The Truth May Be In The Eye of The Beholder

If I’ve heard it once I’ve heard it a million times. “Weatherman: the only profession you can be wrong 50% of the time and still keep your job!”. If I had a dollar for every time I’ve heard this, I would be on a beach in Florida and not writing this article. While most people say this light-heartedly as a joke, others perceive it as the truth. I’ll be the first to admit, that forecasts aren’t perfect and sometimes fall short, but why is that? Why do meteorologists get the forecast wrong? Why do forecasts seem incorrect and what can go wrong in forecasts to significantly alter what was predicted?


First, let’s talk about how often meteorologists are correct. According to the National Oceanic and Atmospheric Administration (NOAA), forecasts are about 80% correct 5 days out with a one-day temperature error of around 2.5°. Accuracy decreases significantly with time, especially after 7-10 days. Short-range forecasts (24 hours or less from the forecast period) are around 90% accurate. But if this is true, why does it seem the forecasts are often incorrect?



The accuracy or inaccuracy of forecasts can often be the perception of the forecasts, not the actual verification itself. After all, truth is in the eye of the beholder, right? This is especially true regarding precipitation. Let’s use rain for example. As meteorologists, we talk about an 80% chance of rain, 50% chance of storms, and so on. However, as we have talked about in prior blogs, this is not the probability of rain in your backyard, but rather the percentage of coverage across the forecast area. While 80% of the forecast area will see rain, 20% will not.



This means while it’s pouring at your friend’s house 14 miles away, it could be bone dry at your place. The perception from your friend is that meteorologists got the forecast right because it rained, but you think it was incorrect because there is 0” of rain in your gauge.

I have personally seen this a lot in instances of severe weather. When the forecast calls for severe weather and watches are being issued, people are preparing for severe storms. But, when there’s no warning or severe storms at their house, the forecast was incorrect. However, 3 counties away 90 mph straight-line winds caused significant damage. The forecast wasn’t incorrect, you were just lucky and were spared the worst of the system.



While perception is big, there is still no doubt that meteorologists sometimes do get the forecast wrong. The atmosphere is very complex and acts as a fluid. Imagine standing downstream in a rapidly flowing river with rocks, twisting currents, eddies, and many other factors. Now put a small boat in miles and miles upstream, then predict exactly where that boat will float and go. This is the kind of challenge meteorologists face every day, but on a much larger scale! Then, add in the fact that very minor changes to the environment can cause significant changes to the forecast!



Moisture is one element that can have a major impact on the forecast, especially in the winter when forecasting snow. Generally, we can expect 10” of snow for every 1” of rain or on a reduced scale, 1” of snow for every 0.10” of rain. While this seems straightforward, if the precipitation forecast changes by 0.10 – 0.20” that translates to 1-2” of snow or possibly more if the ratio is higher (we will touch on that in a moment). Conversely, in the Summer you don’t miss the 0.20” when you get 0.50” of rain versus 0.70” of rain. It’s a different story in Winter when you get 1-2” of snow instead of the predicted 3-4”, or vice versa.


GFS ENSEMBLE PRECIPITATION FORECASTS THROUGH 102 HOURS



Temperatures also make a big difference in Winter. As temperatures cool or warm, the amount of snow per inch of rain will increase or decrease. At 34°F, the snow-to-rain ratio is around 7:1 (7” of snow for every 1” of rain). However, when you cool the temperature a couple of degrees to 32°F the ratio increases to 10:1, and even more dramatically when temperatures fall to 27°F it generates a 15:1 ratio. This means if your forecast is off 3-5°F it can make a big difference in the final amounts of snowfall you receive, especially if this continues over a long period! These are just a couple of factors that go into winter weather forecasting that have major impacts; we won’t even go into jet streaks, dry slots, frontogenesis, or mid-level waves!




So, if the factors of moisture, temperature, and other things are so important, why don’t meteorologists work to generate a more accurate forecast for those variables? While meteorologists can correct the temperature and other forecast variables as the storm is incoming or occurring with live data streaming in, most of the forecasting process is done using complex computer models many hours and days out. These models solve millions of equations to generate a forecast and give us an idea of what the forecast could look like. However, these models are often imperfect and forecast details evolve with time. In some instances, model forecasts can change significantly in a very short period. Weather models rely not only on complex algorithms and physics packages to produce forecasts but “live” data must be input into the models for them to start with the right conditions to generate a forecast. However, the data that is input into the model can sometimes be inaccurate, or in some instances (like over the oceans) there is little to no live data at all, so the model has to generate what it expects conditions to be like in those areas to allow the forecast data to process and generate solutions.



YOU CAN SEE LARGE AMOUNTS OF LIVE READINGS OVER CONTENTS BUT DATA OVER OCEANS RELIES ON PLANES AND SPORADIC OCEAN BUOYS


If the forecast model is not accurately modeling what is occurring in areas where there is no data, it can lead to a significant change in solutions as the incoming system is sampled over land. As live data is entered into the forecast model, the model picks up on where it was incorrect, and the model forecast is altered. These are all things that can significantly impact a forecast.


So, how bad are meteorologists in relation to other professional occupations? As previously stated, meteorologists are about 90% accurate at 24 hours out and 80% accurate 3-5 days out. Taking a look at professional basketball, Michael Jordan was just under 50% accurate, with a field goal percentage of 49.7% over his entire career. His most accurate year was the 1990-1991 season with a field goal percentage of 53.9%. Additionally, Steph Curry is one of the best 3-point shooters of all time. However, his 3-point percentage over his career is only 42.7%. You can also think about filling out your NCAA March Madness bracket, the average bracket is only 66.7% correct. The odds of getting it perfect are about 1 in 120.2 billion and that's if you know more about basketball than the average person!



in conclusion, meteorologists aren’t as inaccurate as they may seem. We are far more reliable than most would think! While forecasts are not perfect, they have come a very long way in the last 5-10 years. As we head into the future with rapidly developing new technologies like AI, there’s no doubt forecasts will continue to significantly improve. Will it ever reach 100% accuracy? Likely not, but perhaps the forecast itself isn’t the problem. A large portion of a meteorologist’s job is to help educate the public and relay the forecast and risks to counter the perception of an incorrect forecast.



 

ABOUT TDS WEATHER


Thermodynamic Solutions (“TDS Weather”) provides professional weather consulting services to a variety of industries including: professional and minor league sports, snow removal and landscaping, golf courses and turf management, colleges and universities, and hospital networks. With nearly two decades of living and forecasting in the Ohio Valley region, our meteorologists provide custom, reliable forecasts that help clients SAVE and MAKE money in their daily operations. Our services include commercial and agricultural forecasting in the short and long ranges, lightning alerts and on-site hazardous weather monitoring, 24/7 on-call decision support services, forensic weather reporting, and more! For weather consulting inquiries, please contact us at info@tdsweather.com. We also provide public weather information multiple times daily on our social media outlets- make sure you’re following us on Facebook, Twitter, and Instagram @tdswx, and TikTok @tdsweather!

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