Wednesday, March 2, 2016

Winter Weather Advisory Wednesday Night

7:20pm Update: Light snow continues to show up on radar, but likely only just light flurries are actually reaching the surface.  Actually just received a report from down near the Dixon area of very light flurries beginning to fall.

The reason why the radar looks like more snow is falling than what's actually reaching the ground is because a lot of what's being picked up on radar is within the cloud itself.  And with drier air at the surface, a lot of that snow is evaporating before reaching the surface.

This is an atmospheric sounding from the Quad Cities National Weather Service from Wednesday evening.  The green line is the dew point temperature and the red line is the temperature.  The further apart the two lines are, the drier the air is.  So, it's going to take a little while before the atmosphere saturates enough to get the snow to reach the surface.  We'll likely see more snow begin to fill in close to 9pm/10pm.

A Winter Weather Advisory will go into effect for the following counties at 9pm: Carroll, Whiteside, Lee, Ogle and DeKalb.

Clouds will continue to increase through the evening Wednesday with light snow moving in between 10pm and 11pm.  The snow will become a little more steady overnight and early Thursday morning.

Highest snow totals, those close to 3", will found along I-88.  A little further south totals near 4" could be possible for places like Amboy, Mendota and Paw Paw.

With the cooler temperatures it shouldn't take long for the snow to accumulate on the ground and roads.  And with the steadier snow bands, visibility under one mile will be possible during the early morning commute.

For counties within the advisory, snow totals between 2" to 4" will fall.  North of that, including Freeport, Rockford and Belvidere totals between 1" and 2" are likely.  Southern Wisconsin is only expected to receive a dusting, up to half an inch.

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