Lake Effect Advisory - UPDATE

Hello.

The NWS has issued a Lake Effect Snow Advisory until midnight for pretty much all of the western chunk of the blog.  Let's dive into that.

A great question was posed by a Facebook follower, asking why that advisory is up for Lansing and Ingham/Eaton counties, with no snow showing on the radar?  Here's what I see.

The National Weather Service just put the advisory out shortly before 2 PM EST.  It looked like everything would stay confined to US 131 and west, as I stated in the forecast discussion earlier today.  Between this morning and now, conditions have changed to support more widespread snowfall.

Taking a look at the forecast models and some current conditions, I talked about Alberta Clippers, which is a nickname for an upper air disturbance embedded in the larger flow.  You may also hear or see the term Jet Streak or Jet Core.  Whatever the name, this small pocket of really fast moving air acts as a trigger, and destabilizes the atmosphere on a more localized basis than your garden variety front..  We have one sitting near us right now, and it won't move a lot between now and midnight according to the RAP forecast model.

It will enhance the lake-effect snow that has been falling the last couple of days by the lake shore, and the strong winds aloft will help push those bands further inland.  Hence, the advisory, and along with it, since this is a banded snow event, the amounts of snow any one spot picks up will vary significantly.

Here's the NWS forecast for snow through late tonight...

Snow Forecast, National Weather Service Grand Rapids, updated during lunchtime.

I hope this helps clarify why we have that in place!