Today’s Wayno/Piraro Bizarro, with weather forecasting in action:
(If you’re puzzled by the odd symbols in the cartoon — Dan Piraro says there are 3 in this strip — see this Page.)
Ah, a bit of word play: a pun on pattern.
From NOAD on the noun pattern:
1 [a] a repeated decorative design: a neat blue herringbone pattern. … [c] a regular and intelligible form or sequence discernible in certain actions or situations. …
weather pattern is a common collocation using sense 1c of pattern. But what the weather map shows is a set of patterns in sense 1a: the fabric patterns polka dot, paisley, check(er(ed)) (possibly its gingham subtype), and an ornate pattern that Wayno assures me is just a random wallpaper pattern, not anything with an actual name.
Ooh, thrilling new visuals for weather reports: a large Rob Roy tartan over rural Tennessee this evening! a Madras mass moving down the California coast! a troublesome triangle of Tie Die in the Texas desert!
These are fabric or wallpaper patterns . There’s an entirely different set of terms for china patterns and silverware patterns. We might want to say that china pattern and silverware pattern involve a specialized sense of pattern. By the time we get to test pattern, we’re clearly in idiom territory, and NOAD has a separate entry for it:
noun test pattern: a geometric design broadcast by a television station so that viewers can adjust the quality of their reception.