DETROIT -

Snow will develop this evening, but not until later due to a very dry atmosphere overhead (you’ll read more about this below).

Increasing snow overnight will continue at least into Wednesday morning. The heaviest total snow amounts will be south and east of a line from just south of Detroit to Adrian. Those areas could receive up to 6 inches of snow.

More: Winter Weather Advisories issued across SE Michigan
More: Communities under snow emergencies

Farther north and west, amounts will taper off, with 3 to 5 inches between I-94 and M-59, and 2 to 4 inches north of M-59. It's going to be a breezy day, with highs near 24. Skies become partly cloudy Wednesday night, with lows near 6.

Then expect a couple of partly cloudy, dry days on Thursday and Friday, with highs in the mid to upper teens.

Meridian Winter Blast begins on Friday, so come on down and have some fun!

Mostly cloudy on Saturday, with highs around 19. There’s a chance for snow on Sunday, but it appears that the brunt of this system will miss us. Highs in the low 20s.

And now, here’s something really cool I want to show you.

Watch: Wednesday afternoon radar loop

Take a look at this radar loop from late this afternoon, and notice the “holes” filling in around Indianapolis, northern Indiana and Chicago. Radar obviously tells us where precipitation is, but it can also be useful in many other ways to us meteorologists. What’s happening here is that the air in the region where you see the “holes” was very dry, and the snow you see on the radar was being detected aloft by the radar, but was sublimating and not reaching the ground.

So why the “holes?”

Keep in mind that the radar beam originating from those radars travel out at an angle. So, near the radar, the beam is close to the ground. But go out 50 miles from the radar and the center of the beam is 4,460 feet above the ground, and is detecting the snowflakes falling from the clouds before they disappear in the dry air.

But why are the “holes” getting smaller?

As the falling snow sublimates, it gradually starts moistening the atmosphere. As that happens, the snowflakes fall farther and farther before disappearing. The farther they fall, the closer to the radar we start to see there, so the “holes” steadily get smaller.

How does this help my forecast?

By seeing this I knew that the snow we were seeing moving our way on radar was going to take longer to arrive than at first glance.

Chuck Gaidica, Ben Bailey and I had our “geek moment of the day” when we all saw this!

Don’t forget to follow me on Twitter at @PaulGrossLocal4!