Weekend snow: Saturday update

UPDATE: The Winter Storm Warning continues for the entire Stateline area through midnight Sunday night. The snow will continue to fall through Sunday evening. Snow totals look to be at least 6 inches area wide but larger amounts are becoming more likely. Generally 6" near the Wisconsin border. Closer to Rockford totals look to be greater, near 8 inches. South is where you will find the highest totals, 10 inches or more closer to Chicago.

Main impacts will be to travel. Snow covered roads will be a concern tonight and tomorrow as the snow continues to fall. Tonight the snow will be slushy in nature, while tomorrow the snow will be lighter. But with gusty winds from the north east and the fluffy snow in place, blowing snow will be a big concern tomorrow and tomorrow afternoon. Blowing and drifting snow could great reduce visibilities and make driving dangerous.


3PM UPDATE: The Winter Weather Advisory for southern Wisconsin has now been replaced with a Winter Storm Warning beginning Saturday night, which now puts the entire Stateline area under the Winter Storm Warning. The timing of the winter storm still looks to be on track for this evening. Rain is currently south of I-88 but will switch over to all snow by 6pm.



Good Morning!  Everyone ready for the biggest snow to come this winter?? 

A Winter Storm Warning is in effect for all of northern Illinois and a Winter Weather Advisory for southern Wisconsin all beginning Saturday night and lasting through Sunday evening.  If you still have some shopping or errands to do, I would suggest getting everything done now so once the snow does begin, you're not out driving around Sunday. 

Snow totals still look on track with most areas in northern Illinois likely receiving over six inches of snow, isolated amounts near eight or even nine inches could be very common.  Temperatures now are in the upper 20's and will rise into the low 30's during the afternoon.  A rain/sleet mix may occur south of Rockford, south of I-88, with the onset of precipitation this afternoon before switching over to all snow after sunset. 

Timing:  Dry and partly sunny through mid-afternoon Saturday.  A mix develops south of Rockford as early as 3pm and then switches over to all snow by 6pm.  Moderate snow continues through the night Saturday into Sunday. 

Winds:  Northeast winds will increase Sunday morning dropping visibility down to under a mile at times and making it difficult to travel. The snow will lighten up, but the wind stays strong causing the snow to drift and blow through the evening Sunday.

Amounts:  Snow totals over 6 inches will be very common through the area, with locally higher amounts.  Still appears the highest totals will be south of the area with lake effect snow pushing some totals in northeast Illinois and out towards Chicago close to 10 inches to maybe even 12 inches!  The snow at onset will be heavier with snow to liquid ratios likely closer to the average of 10 to 12:1.  By Sunday morning, the snow should turn a little more light with temperatures in the 20's.  Area wide between 6" to 10" of snow is possible.  Good news, it's coming down over a 12 hour period, so that should help some.


Weather Discussion:
A cold front will slide through northern Illinois later today and it's this front combined with warm, moist air moving in from the south that will bring rapid upward air movement through the atmosphere.  While the forcing in the atmosphere isn't overly strong, the quick rise in air is what is going to be responsible for the heavier snowfall tonight and Sunday morning.  It still appears likely that the cold front will settle very close to the I-88 corridor.  Wherever that front lies is where the heavier snow will fall.  By Sunday late morning and afternoon, colder air from the north will push the front further south with low pressure moving through central Illinois.  Winds will increase during the morning Sunday sustained around 20-25 mph and gusting 30-35mph.  The heaviest snow bands will shift slightly further south, however, light to even moderate snow will continue to fall during the day Sunday.  Overnight Saturday, there may already be 3" to 4" of snow on the ground with an additional 3" to 4" coming during the day Sunday.  The snow will lighten up Sunday evening, but will continue to fall into the night with little accumulation occurring overnight Sunday.