Dense Fog, Heavy Rainfall Set to Bring Messy Travel Tuesday Morning

Winter Weather Advisory:

Earlier this morning, the National Weather Service added a few more counties have been added to the WINTER WEATHER ADVISORY. This includes Winnebago, Boone, and McHenry Counties and this portion of the advisory will run from 8AM this morning to 4PM this afternoon. This is mainly due to the chance for freezing rain early on, which may lead to a few icy spots on the roadways.

Flash Flood Watch:

Although nothing has changed with the FLOOD WATCH that's in place this morning, Winnebago, Boone, Ogle, Lee, DeKalb, and McHenry counties remain under the FLOOD WATCH until mid-day today. Heavier rainfall rates, especially those produced by any thunderstorm that develops, could result in flooding issues in low-lying and flood-prone areas. We also have to take into account the runoff produced by this morning's rainfall. This will likely cause some of the local rivers, streams and creeks to rise.

Dense Fog Advisory:

In addition to the Winter Weather Advisory and the Flood Watch, Ogle, Lee, and Dekalb Counties are also under a DENSE FOG ADVISORY until 10AM this morning. Visibility values could be lower than a mile at times until the expiration of the advisory. And due to showers and thunderstorms passing over the area during the early morning hours, visibility may fluctuate while traveling over short distances. 

What to Expect:

A frontal boundary draped over the Stateline Tuesday morning is the main culprit behind this morning's messy weather. This potent boundary is acting as a divider between the cold air to the north and the warmer air-mass to the south. 

Areas north of the frontal boundary, those that live along and north of highway 20, will be more susceptible to the potential for mixed precipitation. Hence why areas hugging the Wisconsin/Illinois border are placed under the Winter Weather Advisory. Ice accumulations of a tenth of an inch, to at the highest two tenths of an inch. Rainfall-wise, amounts will range from a quarter of an inch, all the way to three quarters of an inch, especially those that encounter this morning's thunderstorm potential.

The chance for heavy rain continues into the late-morning/mid-day hours, with showers slowly tapering off by mid-afternoon. On the backside of this complex storm system, a light and scattered mix of rain and snow will be possible before we dry out by this evening. 

Even with the precipitation coming to an end, I still urge you to take extra caution if you plan to travel prior to the evening commute. Conditions remain dry overnight, with skies remaining mostly cloudy into the early stages of Wednesday. As an area of high pressure takes control of the Upper Midwest, tomorrow morning's clouds will give way to some afternoon sunshine. Despite that, a northerly to northwesterly wind will limit highs to the 20s, which is more than ten degrees below normal.