Come on, trusty pedants. Help me on this one...

[clam]

Before I get myself too cross about this, I need to know if I'm right.
Weather forecasters: "wrap up warm."
Yes or no? Should it not be "Wrap up warmLY?"

Yes, you are right.

Ye-es, technically but "wrap up warm" is a vernacular phrase these days so I think that exempts it to some extent.

"Snow event" on the other hand - WTF??

OK, and what about "wintery weather" as seen on my LEA's web-site, as opposed to "wintry."
Pah!

wintry weather? Are they really using that phrase? I have to wonder what they expect in the middle of winter if not wintry weather. The adjective seems a bit superfluous to me.