[sunshinesnacks]

This NOAA National Blend of Models (NBM) viewer lets you enable observations and then roll back the forecast initialization date to see forecasts and observations at the same time.

It’s experimental, and selecting weather stations is a little clunky, but it has some really cool info that’s hard to find other places.

https://apps.gsl.noaa.gov/nbmviewer/?col=2&hgt=1&obs=true&fo...

Edit:

This GEFS plume viewer is cool, too.

https://www.emc.ncep.noaa.gov/users/meg/gefs_plumes/index.ht...

You can check a box to plot observations and then pick an older “cycle”.

Both are limited to the US.