The study found that the “accuracy of the surface weather forecast in March-May 2020 decreases markedly” as the flight density decreases due to Covid-19.
The research examined weather forecasts from March 2020 and compared them to the actual weather observed in the same time period.
“It’s the temperature forecast where the accuracy dropped,” says Chen. Hot and cold air patterns are critical in hurricane formation and prediction. If temperatures can’t be tracked accurately, it might be more difficult to identify hot spots from the start.
The forecasts meteorologists create for hurricanes are based in part on computer models. These models are as good as the data put on them.
This data comes from a variety of tools, including planes, cruise ships, satellites, buoys, weather balloons, ground stations, and radars. The Covid-19 outbreak has significantly reduced the amount of data we get from two of those tools: planes and cruises.
More importantly, meteorologists are at a greater disadvantage, especially over water, where these observation tools are already limited. By land, they can launch additional weather balloons or add additional ground stations to help compensate for the loss of flight data.
But they can’t do that on water. The buoys are unevenly distributed and are notorious for data errors. These floating devices alone cannot provide a complete and accurate image of a particular region of the ocean. Meteorologists need the combination of all available tools to accurately understand the state of the atmosphere around the world at any given time.
How Forecasts Affect
One way to compensate for some of that data loss is to have other observing tools collect additional data.
“When the National Weather Service is anticipating high-impact weather events, such as a possible tornado outbreak or a possible hurricane on the ground, it will (usually) launch ‘special’ weather balloon launches to take additional weather measures in the upper levels of the atmosphere , “explains Kyle Theim, a NWS meteorologist in Atlanta. “The accuracy and precision of our weather models are paramount, and these additional observations can help weather models and forecasters predict how extreme weather events will unfold.”
“We found that reconnaissance polls have a significant beneficial impact.” The data collected by hurricane hunter reconnaissance flights is especially effective and can help offset the loss caused by the crash on commercial flights and cruises.
This is especially important for tropical systems where temperature and wind observations are essential to obtain a more accurate forecast.
Forecasts were better and worse in different areas
The study found that the differences vary by location. Remote areas like Greenland and Siberia saw the biggest problems with lower flight numbers.
“This is because the assimilation of aircraft observations provides a much greater improvement in forecasts over regions where very limited conventional observations are available,” the study says. Forecasting is already difficult for these remote regions, so the loss of flight data has a greater impact.
A similar effect hurts forecasts in the southern hemisphere.
“The degradation of the weather forecast is more substantial in the northern hemisphere than in the southern hemisphere,” says Chen. The northern hemisphere has more population and significantly more flights than the southern hemisphere. A drop in flights over the northern hemisphere is, therefore, more striking in the ability to accurately forecast the weather.
Forecasts could worsen
The study results actually run counter to normal predictions of improved precision over time.
“A similar analysis for February 2020 suggests that the accuracy of the surface weather forecast could be expected to improve in 2020 compared to 2017-2019, if aircraft observations were conducted as usual,” the study says. . This blow to precision comes at a time when Covid-19 is exacerbating the effects of severe weather on vulnerable populations.
Research warns that the accuracy problem will only get worse as the Covid-19 pandemic continues.
“You can expect a further worsening of weather forecasts and that the error could be greater for longer-term forecasts,” says Chen. “This could harm early warning of extreme weather and cause additional difficulties for daily life in the near future.”
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