Metro Detroit weather: Tracking our first measurable snow of the season

Snow possible this weekend

The Local 4Casters track the latest weather alerts in Metro Detroit and Southeast Michigan. Get the most updated information here:

The weather pattern through Saturday will be one of scattered, very light showers of either rain or snow. But what comes in on Sunday won’t be scattered, and may not be light. I’ll dive into those details in a moment.

But first, if you have Friday afternoon or evening plans, there will be a few light showers around, and any heavier shower will have sleet, too (I’ve already seen some video of sleet falling in Howell). I think the activity will lessen overnight, although some light snow showers may redevelop later at night. Lows in the low-to-mid 30s (0 to 1 degree Celsius), with a southwest wind at 10 to 15 mph.

This evening’s sunset is at 5:14 p.m., and Saturday morning’s sunrise is at 7:22 a.m.


Scattered light snow showers in the morning and light rain showers in the afternoon will dot the area on Saturday. It’ll still be breezy, as well, adding to the chilliness of the day. Temperatures should scrape and claw their way into the low-to-mid 40s (6 degrees Celsius) by early afternoon, with a west wind at 10 to 20 mph.

We may have some partial clearing Saturday evening, but clouds will increase Saturday night and some light snow or snow showers are possible later at night (I think we’ll be dry for our Saturday evening plans). Lows in the low to mid 30s (0 to 1 degree Celsius).

Sunday snow -- what we’re tracking

The upper-level disturbance I discussed yesterday has just moved off the Pacific Ocean and crossed the Pacific northwest coast, and can now be studied by our land-based upper air balloon network (those balloons are called radiosondes, just in case you were wondering). As such, our computer models are developing a better handle on this system.

This disturbance will generate a surface low that will move from Montana Saturday to southern Minnesota Saturday evening and then to near Chicago by Sunday morning. At that point, it’s going to turn east and track pretty close to the Michigan-Indiana-Ohio state line.

The key to determining how much snow we’ll get Sunday is two-fold: \ the thermal structure of the lower atmosphere, and the temperature of the pavement.

Let’s first address the lower atmosphere temperature. Three computer models (IBM GRAF, NAM and GFS) this afternoon suggest that it’ll be cold enough to generate wet snowflakes, with a shallow enough layer of above-freezing temps near the surface to not give the flakes time to melt and turn into raindrops. One model (ECMWF) suggests that we’ll see a mix of precipitation. At this point, especially since the GRAF and NAM are high-resolution models that agree, I’m siding with a mostly snow scenario (perhaps some rain could mix in to the far south).

The next consideration is pavement temperature and, right now, the pavement is above freezing.

So, what I expect Sunday is snow to increase and possibly even become moderate at times. It will start to accumulate on grassy surfaces, as well as on elevated surfaces (picnic tables, patio furniture, barbecues, mailboxes, etc.), since those are not insulated by warmer ground below and will cool to freezing due to the snow.

Pavement, however, will take longer to cool to freezing. Eventually, and especially if the snow becomes moderate, it will, and we’ll see some slush develop on pavement.

All told, I think we’ll see perhaps an inch or two on grassy and elevated surfaces, but less near Lakes Erie, St. Clair and Huron due to it being a little warmer there. Obviously, if the ECMWF model is the one that verifies and we end up with a mix of precipitation, then snow amounts will be less.

Conversely, higher elevation areas, such as the higher terrain in northwest Oakland County, could see a bit more.

**I will have a new high-resolution computer model coming in this evening…I think I’ll have enough of it in to have a complete update to show you on Local 4 News at 11, so make it a point to join me then.**