With fewer and fewer flights around the world in the coming days due to COVID-19 what will happen to NWP model accuracy?

Current flights here:

https://www.flightradar24.com/25.84,39.89/3

Model verifications stats here:

https://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/

That’s a good point.  This virus has far reaching effects that most won’t think about.  We can only wait and see. 

https://www.ecmwf.int/en/forecasts/charts/monitoring/dcover?facets=undefined&time=2020031706,0,2020031706&obs=aircraft&Flag=all 

At Christmas all 4 6-hourly intervals have less than 100000 flights.

As noted by someone else in the MO thread here is a piece from ECMWF about this.

Drop in aircraft observations could have impact on weather forecasts

One aspect of the COVID-19 pandemic has been a reduction in aircraft flights and thus of the aircraft-based observations available to weather prediction centres. The observations are used together with many others to help estimate the state of the Earth system at the start of forecasts.

At ECMWF, aircraft reports are second only to satellite data in their impact on forecasts. However, recently added satellite wind observations will help to mitigate the drop in the number of aircraft-based observations.

https://www.ecmwf.int/en/about/media-centre/news/2020/drop-aircraft-observations-could-have-impact-weather-forecasts

This weekends wintry rainbow chase is getting closer than many of our previous chases (144 hours now !)

No doubt as soon as we get to 96 hours HP will settle across and cut off a very unwelcome late March wintry NE'ly. 

Hopefully a fine and sunny weekend will prevail to lift the mood a little.

It was fine and sunny last weekend and hundreds of thousands of people decided to lift the mood a little by all heading to a relatively small number of beauty spots and tourist hotspots. 

We actually could do with the return of the British Monsoon to keep people inside.