I think I have the same problem (but I can't see your picture to verify that).
It's a "hashed lines" colour display, rather than full colour. Doesn't happen that often.

Windows 10, latest Chrome (Version 75.0.3770.142 (Official Build) (64-bit)). Turning off all Chrome extensions has no effect. Web site refresh does not correct the problem. Internet connection is good. Couldn't find anything in Windy's FAQ about this. It went away before I could try Windy's error console.

Here's two images, the second is zoomed in:

In addition to my last post, here's another "hashed lines" with the Error Report showing "no errors":

@idefix37 Thank you, though I was looking for some kind of legend or reference on this site that would contain that sort of info (not just this info in particular).

@TomSlavkovsky Thanks for the explanation. Is there a legend somewhere that explains all the symbols used? For example, "black spots show previous lightning strikes"; I can guess that, but I don't know if there's any representation of the frequency or the duration of the strikes. Or if the ring emanating from a strike has a numeric meaning.

In addition to my last post, here's another "hashed lines" with the Error Report showing "no errors":

I think I have the same problem (but I can't see your picture to verify that).
It's a "hashed lines" colour display, rather than full colour. Doesn't happen that often.

Windows 10, latest Chrome (Version 75.0.3770.142 (Official Build) (64-bit)). Turning off all Chrome extensions has no effect. Web site refresh does not correct the problem. Internet connection is good. Couldn't find anything in Windy's FAQ about this. It went away before I could try Windy's error console.

Here's two images, the second is zoomed in: