New to this site - the multiple layered UI presentation and analysis is very good, but couldn't see a North Atlantic and European jetstream layer or separate model?
Jet-streams are high speed winds which are observed in the high troposphere.
So in Windy, if you select the Wind layer and move the altitude slider to an altitude corresponding to 300 or 250 hPa, you get a « jetstream layer »
For example today, the ECMWF shows this wind field at 250 hPa. (here with customized colors)
In addition You can display Geopotential isolines.
Click on More layers... in the right menu