Locally dense fog likely Thursday evening, snow remains in focus Friday
Overall impacts from both expected to be brief
ROCKFORD, Ill. (WIFR) - While we were able to squeeze out a bonus mild day Thursday, allowing our January thaw to extend into a third day, our fortunes are about to change. In fact, in some locations, our fortunes already are changing.
Over the past several days, the “warmth” has allowed for quite a bit of snowmelt to take place, sending an additional amount of moisture into the lower levels of the atmosphere. Combine that with the fact that the winds are very, very light this Thursday evening, we lack a mechanism to stir up the atmosphere in any meaningful way.
That’s a prime recipe for fog development, and that’s exactly what has happened across parts of the area Thursday evening. Early on, visibility had already come down to as low as a quarter mile or less, especially across the I-88 corridor.
As a result of the fog development, and the likelihood that more fog is likely to develop in the hours ahead, the National Weather Service has issued a Dense Fog Advisory for Stephenson, Carroll, Whiteside, Ogle, Lee, and DeKalb Counties through midnight. Given some model projections, I would not be entirely surprised to see Winnebago and/or Boone Counties added to this advisory, but that remains to be seen.
We are expecting visibility to drop to a quarter mile or less across much of the area through mid to late evening. After that time, there will be rather quick improvements funneling in from north to south. That’s because winds will be shifting to the northeast, ushering in drier air to the region. Furthermore, they’ll be picking up in intensity, further enabling the atmosphere to become better mixed. By the time the midnight hour rolls around, visibilities will have improved drastically.
Now to our next big story, and that’s the winter storm system that’s likely to impact the Midwest over the course of the next 24 to 36 hours.
Our expectation remains that we will get some snow in and around the Stateline, though it’s quite apparent that the heaviest of the snow is almost certain to bypass our immediate area.
Winter Weather Advisories have been issued for counties touching up to the Mississippi River in Iowa, while Winter Storm Warnings are in effect for a good chunk of the interior portions of Iowa, southern Minnesota and northern Missouri.
It will be in those areas where anywhere between 5 and 12 inches of snow may occur. Locally speaking, we’ll get a few inches in a spot or two, while others will get nothing or next to nothing.
Our latest computer forecast models puts the Rockford area right around an inch or potentially a little bit less. There could be closer to two inches as you head well to the west of Rockford toward the Mississippi River. West of the Mississippi River, that’s where the better chances of seeing two to locally five inches of snowfall.
As far as the timing of the snow goes, it’s the period spanning roughly 7:00pm Friday and 1:00am Saturday during which some minor travel impacts may occur.
Once again, as has been the case often this winter, it’s likely to be another near miss for northern Illinois and southern Wisconsin. With that in consideration, the snowfall deficit, which has now reached close to nine inches for the season, is likely to continue to grow, especially considering that snow chances over the next 10 days are few and far between.
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