This must be a new definition of the word is, with which I am unfamiliar.
The Weather Channel this morning, in the "Local on the 8s" forecast, informs me in the narration that "a weather advisory is in effect for our area." Emphasis mine. But the screen tells me that there's a "winter weather advisory in effect from 4 a.m. to 7 p.m. CDT Tuesday." Which is tomorrow. So to say that an advisory is in effect some 22 hours before it actually goes into effect is to utilize the verb is in a new an unexpected way, no?