Today is April Fools Day, but this is no April Fool. The number of aircraft groundings across the globe is making weather forecasts less accurate. This is because when the aircraft are grounded, they are not up in the skies providing vital insight to meteorologists.Believe it or not, aircraft actually play a huge role in weather prediction. It is one of the many components that come together to create the world's weather forecasting system. As such, the World Meteorological Organization (WMO) today issued a warning about the impact of the current aviation situation on global weather forecasting. Let's take a look at the details.

Why are planes needed?

According to the World Meteorological Organization, commercial aircraft contribute to something known as the Aircraft Meteorological Data Relay program. Aircraft capture a huge number of data points each second. In many cases, this data is used for diagnostics, such as in a crash, or feeding back to control rooms constantly monitoring for problems.

However, this data can also be useful for the purposes of weather observation and forecast. Specifically, aircraft are harvesting data on atmospheric conditions while flying. Examples include ambient temperature and wind speed. The aircraft can measure these at the source.

Aviation, Grounded, Weather Forecasts
Weather reporting dropped significantly in March. Image: EUMETNET via WMO

Typically, the aviation reporting system provides in excess of 700,000 measurements each day, but right now, airlines are providing fewer data points. Let us take easyJet as an example. On the 1st of March, the airline contributed 17,000 observations. However, by the 24th of March, this had fallen to almost zero. Now the airline's fleet is grounded until June at the earliest.

Lars Peter Riishojgaard, Director of the Earth System Branch in WMO’s Infrastructure Department commented on the loss of data. He mentioned that the impact is still relatively modest, however, he added:

"as the decrease in availability of aircraft weather observations continues and expands, we may expect a gradual decrease in reliability of the forecasts"

Fewer planes are flying

As alluded to above, the cause of this huge fall in measurements is due to a global grounding of the world's commercial aircraft. This is being felt hardest in Europe, the current epicenter of the coronacrisis.

Many airlines on the continent have been forced to ground most, if not all of their flights. For example, easyJet and Ryanair have stopped all scheduled flights for the time being. Meanwhile, yesterday we explored how Norwegian appears to have grounded its entire fleet of Boeing 787s.

Even major flag carriers are feeling the impact, however. German Flag carrier Lufthansa has a fleet of just under 200 Airbus A320 family aircraft. Of these, only 20 have flown in the past three days.

What do you make of this news? Will it really have a significant impact on weather forecasts? Let us know your thoughts in the comments!