Winter storm watch issued for Metro Detroit

Major winter storm headed for southeastern Michigan

DETROIT – As you may recall, I've been highlighting since last week the potential for a winter storm in the Tuesday night / Wednesday timeframe (and those of you who follow me on Twitter at @PaulGrossLocal4 received an update over the weekend). Now that the upper level trough of low pressure has moved onshore out west, our computer models are starting to converge on a forecast…although there are still some differences.

No worries Monday night or Tuesday during the day, though. Skies will be clear to partly cloudy overnight with lows in the low to mid-30s. It will start getting cloudy on Tuesday, with highs in the low 40s.

It gets interesting on Tuesday night. Rain showers will develop early in the evening and then gradually turn into some wet snow as colder air works its way in, but I don't expect much accumulation Tuesday evening. Sometime after midnight, the snow will pick up in intensity and it should be snowing pretty heavily by dawn Wednesday (potentially more thundersnow?).

Your Wednesday morning rush hour is going to be a mess, and school closings are a possibility. By the time the snow tapers off Wednesday afternoon, the heart of the metro area should see an average of 4 to 6 inches of dense, heavy snow (by the way, our record snowfall for Wednesday is 2.4 inches, and I think that record is in serious jeopardy).

Less will fall north of I-69, as you'll be farther away from the storm. It's the areas south of Detroit, especially Lenawee and Monroe counties, that I'm really focusing on because the amount of snow in these areas will be highly dependent on the timing of the changeover from rain to snow. In fact, some of my computer models actually show a rain/snow mix well into the night in these places, which would easily knock at least a couple of inches off of the total accumulation.

I hope to have more specifics about this tomorrow.

Wednesday will also be quite windy; with temperatures steady to falling through the 20s, it's going to be a raw day, as well.

After a sunny start on Thursday, clouds will increase, but that's not the issue. Rather, Thursday is going to start off with temperatures barely above zero (the record low is 5 degrees, so that record is in jeopardy, too), and only rise into the low 20s. And you thought we were done with this stuff!

Temperatures will rebound back to near 40 on a windy Friday with a few light rain or snow showers possible.

The weekend looks mostly cloudy right now, with a potential light snow shower either day.  Highs should reach the upper 30s on Saturday, and near 30 on Sunday.  By Monday, we're back into the 20s for highs.