Frontal passage this afternoon and evening. Much cooler and cloudier weather on the way.

current surface map

Today, a cold front is expected to pass through most of the area before 6 p.m.  With this cold front, I don't expect ANY shower or thunderstorm activity before it passes through, mainly because of limited moisture (upper 50's dew points) not much lifting from the cold front, and the weakening of the strong cyclone over extreme Southern Canada. Some areas east of Defiance may receive a shower or thunderstorm just before the cold front mainly because of better moisture available to lift.  Tonight, the clouds are expected to thicken and increase in coverage as the cyclone continues to occlude.  Along with increasing wind, I do expect lows to fall into the lower to middle 50's.  But the low dew points (dew points are expected to be in the low to middle 40's), the low could fall below this value, maybe as cold as 47 or 48, especially if cloud cover is not as much as expected.  Later, this week, the strong upper level low that is causing this strong system over Canada will develop into a large trough over a large portion of the Upper Midwest and Great Lakes regions, later becoming a rather large cut-off low.  This will cause the weather to stagnate and could become rather cloudy, wet, and chilly for a few days, especially Friday through Sunday, with the pattern continuing into next week.  Due to cold air aloft, any afternoon heating next week could cause daily afternoon showers and thunderstorms, especially since this cut off low is expected to draw in more moisture.  After this, according to the GFSx model, the cut-off low will finally be absorbed into the upper level flow, and the pattern should shift, allowing the ridge over the western ridge to finally move eastward, bringing much warmer weather to the East.

GFS model forecasts