The overall health and performance of WMO coordinated Global Observing System is under continued monitoring during the current COVID-19 outbreak. Large parts of the system, for instance its satellite components and many ground-based observing networks, are either partly or fully automated, and are therefore expected to continue functioning without significant degradation for several weeks, and in some cases even longer. However, if the outbreak lasts more than a few weeks, missing redeployments, repair, maintenance and supply work, etc. will negatively impact the performance of some systems.
The significant decrease air traffic caused by the outbreak has had a clear impact. In-flight measurements of ambient temperature and wind speed and direction made by commercial airliners are a very important source of information for both weather prediction and climate monitoring. In some parts of the world, in particular over Europe, the decrease in the number of in-flight measurements over the last couple of weeks has been dramatic (see chart top right provided by EUMETNET). The countries affiliated with EUMETNET, a collaboration between the 31 national weather services in Europe, are currently discussing ways to boost the short-term capabilities of other parts of their observing networks in order to partly mitigate this loss of aircraft observations.
The COVID-19 outbreak may also be impacting other types of weather observations. In most developed countries, surface-based weather observations are now almost fully automated. However, in many developing countries, the transition to automated observations is still in progress, and the meteorological community still relies on observations taken manually by weather observers and transmitted into the international networks for use in global weather and climate models. WMO has seen a significant decrease in the availability of this type of manual observations over the last two weeks. Some of this may well be attributable to the current coronavirus situation, but it is not yet clear whether other factors may play a role as well. WMO is currently investigating this. In the map below, countries shown in darker colours provided fewer observations over the last week than averaged for the month of January (pre-COVID-19). Countries shown in black are currently not sending any data at all).
At present, the adverse impact of the loss of observations on the quality of weather forecast products is still expected to be relatively modest. However, as the decrease in availability of aircraft weather observations continues and expands into areas of the world where it cannot easily be mitigated, we may expect a gradual decrease in reliability of the forecasts. The same is true if the decrease in surface-based weather observations continues, in particular if the COVID-19 outbreak starts to more widely impact the ability of observers to do their job in large parts of the developing world. WMO will continue to monitor the situation. The organization is working with its Members to mitigate the impact. The WMO Global Observing System serves as a backbone for all weather and climate services and products provided by the 193 WMO Member states and territories to their citizens.
