COVID‐19 Pandemic Imperils Weather Forecast

Who would guess that a virus could reduce the accuracy of weather forecasts? Nevertheless, because of knock-on effects from a reduction in aircraft traffic it appears to be true.

Weather forecasts play essential parts in daily life, agriculture and industrial activities, and have great economic value. Meteorological observations on commercial aircraft help improve the forecast. However, the global lockdown during the COVID‐19 pandemic (March‐May 2020) chops off 50‐75% of aircraft observations. Here, we verify global weather forecasts (1‐8 days ahead) against the best estimates of atmospheric state, and quantify the impact of the pandemic on forecast accuracy. We find large impacts over remote (e.g., Greenland, Siberia, Antartica and the Sahara Desert) and busy air‐flight regions (e.g., North America, southeast China and Australia). We see deterioration in the forecasts of surface meteorology and atmospheric stratification, and larger deterioration in longer‐term forecasts. This could handicap early warning of extreme weather and cause additional economic damage on the top of that from the pandemic itself. The impacts over Western Europe are small due to the high density of conventional observations, suggesting that introduction of new observations would be needed to minimize the impact of global emergencies on weather forecasts in future.

From Ying Chen, COVID‐19 Pandemic Imperils Weather Forecast.

Hat tip: Kevin Lewis. Yes, the excellent one.