First Snowfall Imminent
Wednesday, November 21st, 2007Yes, the snow is coming! The combination of warm surface temperatures and a pocket of warmth aloft have so far kept the precipitation in the form of rain all day, but after 6:00 PM a few changes are going to take place. As the surface low over southern Illinois begins to move east of the area, winds will back to the north and cool down the air aloft as surface temperatures begin to drop after sunset. This will begin the transition to snow, starting over northwest and north central Illinois, moving slowly but steadily eastward. Anytime after about 7:30 PM (or a touch earlier) is fair game to start seeing a little bit of mixed precipitation, but the major switch won’t occur here in Lake County until later in the evening, probably around 10:00 PM or so.
So, the big question that’s on everyone’s mind - just how much snow are we going to get out of this? Well, that all depends on just how long we maintain that period of mixed rain/snow. The sooner we switch to snow, the more we get and vice versa. On an average across the county, I would say 1-3″ total. Areas in the far northwest portion of the county and along the McHenry County border will see the highest totals, hitting a bit under 3″ to possible (but unlikely) isolated 4″ totals. The total accumulation will decrease steadily as you move eastward, with areas directly along the lakeshore possibly not even breaking 1″. Here’s a map of probable snowfall totals:
So, when you wake up tomorrow morning, there’s a very good chance you’ll be greeted with a White Thanksgiving!
A reminder, a Snow Advisory is in effect until 3:00 AM Thursday morning. Please drive carefully!
