When two curves bend downward and a weather symbol bends upward, what do the three curves mean?

If all three curves have arrows, it is the symbol of "wind" (the symbol of weather forecast is sometimes confusing, but now it is basically in the form of "tree" with three vertical lines to represent the symbol of wind! ), if there is no arrow, it is a sign of "fog". If the curvature is large and the surrounding black spots are yellow, it is a sign of sandstorm!