Pleasant here as eyes shift to Texas, hurricane
Chicago remains under the influence of a fair-weather high-pressure system at least through Saturday. The air is rather cool, both at the surface and especially aloft. Daytime heating will provide enough instability to generate considerable afternoon cloudiness and the very slight possibility, mainly in the afternoon, of a brief shower or thundershower, especially Sunday.
The attention is on Hurricane Harvey, which is moving slowly northwest toward southern Texas. The storm is forecast to make landfall Saturday, then drift toward the north or northwest on the weekend, but movement will be slow and erratic. The storm is forecast to shift somewhat eastward by Tuesday. Rainfall totals through Tuesday will exceed 20 inches in south Texas, with some locations receiving 35 inches, perhaps more.