Powerful Storm Arrives This Week

Posted at 11:55 PM, Dec 17, 2012
and last updated 2012-12-18 05:02:45-05

As I outlined in detail with a post on Sunday, a rather powerful low pressure system will be pressing into the Great Lakes Wednesday night bringing wind and rain with it.

That rain will continue through most of Thursday before mixing with and changing to snow Thursday evening. Accumulations are likely through the first half of Friday.

The last few computer forecast model runs (there are several of them per day) are still showing a strong, developing, and deepening low pressure system coming out of the southern Rockies and Southern Plains. The exact track of this system has been changing from model run to model run.

The attached photo is a snapshot of our in-house forecast model we call FutureTrack HD. It’s very reliable and has proven to be accurate on previous occasions from severe weather to big snowstorms.

A low pressure system will develop well south and west of Michigan and begin moving our way Wednesday night. Clouds and rain will overspread the area Wednesday night into Thursday. The low will actually strengthen (or deepen) as it tracks into the Upper Midwest and Great Lakes Thursday and Friday.

The exact track will play a major role in the type of precipitation we see:

  • A track further north and west of the Great Lakes (as our model shows) will mean more warm air, a slower changeover to snow, and perhaps northwest to west-northwest winds on the backside of the system Thursday and Friday for some lake-enhanced and lake-effect snow. This wind field will drag the snow further inland, so we all see accumulations.
  • Other models show this track just south of Michigan. That would mean we stay north of the low with cooler air, a quicker changeover to snow, and a north-northwest wind behind the system would give appreciable snow only areas along and west of U.S. 131.
  • If our northern counties stay mainly in snow through this event, then could be looking at more significant accumulations versus areas from Grand Rapids south that see more rain or a mix.

What we know for sure is the wind with this low will be quite strong, probably on the order of at least 20 to 30 miles per hour  with gusts of 40 to 50 mph possible.

Last Tuesday I stated on our 5:00 PM and 6:00 PM newscasts that it looked as if we may not see a white Christmas (according to our forecast models). This storm looks to be our only real chance for one.

The models do agree that a ridge of high pressure, cool temps, and somewhat uneventful weather will settle into the Great Lakes behind this system for the weekend before Christmas.

For those of you that would like to see what these forecast models look like and what I see as a meteorologist, click hereto see where this low is on Wednesday evening. Notice the location of the “L” south/west of Michigan over southeast Kansas.

  • Click hereto see the location of the “L” by Thursday morning over northern Illinois around Rockford. All the purple on the map is potential precipitation. The white/gray lines around the low represent sea level pressure lines (isobars). The closer together they are, the windier and stronger the storm.
  • Click hereto see the location of the “L” by Thursday evening…over northern lower Michigan around Traverse City. To see the difference in model tracks, take a look here. This model has the low over St. Louis on Thursday morning. Quite the difference.

Get your cameras ready: the winds and sharply colder air will likely generate some impressive waves on Lake Michigan Thursday and Friday, but please stay off the piers, Snap all your photos from shore and email them to us at They can also posted on our FOX 17 Facebook page. I’ll say thanks in advance.

Get the complete West Michigan forecast updated several times daily at Have a pleasant and safe week.