File Photo | Photo: Dave Briggs / Flickr (Creative Commons)

The National Weather Service has issued a winter storm watch for McHenry County and said snowfall in excess of six inches is possible on Wednesday and Thursday.

The National Weather Service (NWS) issued the watch Tuesday afternoon.

The watch, which goes into effect late Wednesday evening, includes McHenry, Boone, Ogle and Winnebago counties.

The recent tranquil weather pattern will become “more active” as a storm system lifts through the upper Midwest through early Wednesday, the NWS said.

Strong gusty winds are developing Tuesday afternoon into Wednesday.

A period of rain showers is expected from Tuesday afternoon through the evening.

Another storm system will impact the region later Wednesday night into Thursday with a wintry mix of snow, sleet and rain eventually changing over to snow.

The NWS said heavy snow is possible, with total accumulations in excess of six inches possible.

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Minor ice accumulations are also possible and winds could gust as high as 35 mph.

“Plan on slick, snow covered roads. The hazardous conditions are likely to impact both the morning and evening commutes on Thursday,” the watch said.

The snow is expected to end Thursday evening.

The latest road conditions for Illinois are published online by the Illinois Department of Transportation at