BATTEN DOWN THE HATCHES–SECURE ANYTHING WHICH CAN GO AIRBORNE–HIGH WINDS THREATEN SATURDAY–GUSTS COULD REACH/EXCEED 60 MPH–STRONG ENOUGH TO PRODUCE DAMAGE

Model forecasts of the developing autumn storm system headed for the Chicago area from north Texas remain consistent. The POTENTIAL FOR HIGH WINDS CAPABLE OF DAMAGE is to grow by and during SATURDAY. Morning showers, and the vertical motions they produce, may interrupt the high winds on occasion–but may also help mix powerful jet stream levels winds down to the surface at other times. That process is to pick up once the showers clear the Chicago area and the area heads into THE STORM’S “DRY SLOT”—the relatively cloud-free indentation in the storm’s cloud mass which lends storms like Saturday’s their characteristic “comma” appearance when viewed from space.

It’s beneath these DRY SLOTS that air sinks, assisting high winds aloft in “mixing down” to the surface. In a sense, the high winds which are to sweep Chicago Saturday are within the “underbelly” of the jet stream.

Downed tree branches capable of taking down some vulnerable power lines appear the greatest threat–though high-profile vehicles may encounter problems, particularly traveling on east/west thoroughfares when powerful south then southwest winds hit the vehicles at a perpendicular angle.In addition, objects not secured–such as lawn furniture, may be vulnerable to the wind as well. It always seems we hear a trampoline among the objects that end up in nearby yard. So, it would be wise to get anything that can go airborne somewhere where they’re NOT subjected to the wind.

EVEN BEFORE SATURDAY peak winds, wind velocities are to be elevated Friday afternoon and Friday night with gusts topping 30 mph at times.The storm is to be a fast mover. Its heaviest rains are to lay out west and north of Chicago. And the precipitation and most clouds are to have exited the area by Sunday giving way to a gorgeous yet windy day.

LONGER RANGE–Winds across the Midwest turn easterly Monday and Tuesday bringing cooler air off Lake Michigan into the area. BUT A NEW WARM SURGE is due Wed and Thursday with winds shifting southerly and allowing temps to warm
DECIDEDLY COOLER PATTERN is modeled as likely to occur beginning by the following weekend and into the next week.