Rain and snow showers possible Friday

 

The last several days have been rather rainy, adding up to just under one inch of precipitation since Tuesday in Rockford.  Scattered light rain showers and drizzle will continue through the evening Thursday as low pressure slowly rotates away from the Stateline.  North winds have kept temperatures in the low 40s, well below the average high of 50 degrees.  As temperatures continue to cool through the evening, there may be a few snowflakes that mix in before Midnight.

There isn't much of a break between the departing low pressure system Thursday night and the next low slated to move in Friday afternoon.  West winds Friday will bring temperatures slightly closer to average, but highs are expected to remain in the mid 40s.  The day will likely start with some cloud cover before a little dry air works in around Noon.  This could bring some breaks in the clouds, and finally give us a little sunshine.  But the added sunshine could help build instability ahead of a rather strong cold front and low pressure system currently near the Canadian Rockies.  This low will quickly dive southeast through Minnesota and into southern Wisconsin and northern Illinois Friday evening, pulling a cold front through as it does so.

Scattered rain showers are likely to develop, some possibly more convective in nature with small graupel occurring with some of the heavier showers.  Winds will be strong from the west/northwest during the afternoon with gusts near 30 mph.  As the colder air arrives Friday evening, wind gusts to 40-45 mph may occur.

During the evening snow will be possible, driven by the strong cold front and upper level low.  Like the rain showers, these too could be convectively driven and develop into snow squalls that move across the region.  The best time frame for these snow squalls would be roughly between 6pm and 12am.

Snow squalls are nothing new, but aren't too common for us in the Stateline.  A couple months ago there were numerous 'snow squall warnings' that were issued on a Friday evening as heavy snow moved across the area.  This intense burst of snow reduced visibility quite a bit and caused road conditions to deteriorate for a time during the evening.  Snow squalls usually occur fairly quickly and are defined as an intense burst of snow and wind.  They can produce near whiteout conditions with a sharp drop in visibility, causing rapidly deteriorating road conditions.  Snow squalls do not last long and are usually out of the area within an hour or two.