Chicagoans enjoy six hours more daylight Friday than the little over 9 hours per day which occurred just six months ago as winter began. With nearly five times the energy of that winter sunshine and the sun now high in the sky as it passes overhead, delivering more direct sunlight, it’s more difficult for NE winds off Lake Michigan, such as those predicted Friday, to produce the level of cooling which occurred only months ago. The solar heating produced by the added daylight threatens to destabilize the atmosphere Friday—i.e. increasing the rate at which temperatures decline with height. That leads to the formation of towering cumulus clouds in the afternoon, any of which could produce isolated gusty thunderstorms. Inland areas are at greatest risk for precipitation and nearby jet stream winds threaten to impart energy to these storms which could lead to strong wind gusts.
-Tom Skilling
WGN-TV Chief Meteorologist Tom Skilling and the WGN Weather Center staff provide daily coverage of weather in the Chicago area.
