North Central Plains Snow (Feb 19-20)

[Robert Dewey]

Good links.

Looks like the 12z GFS has trended slightly cooler as well.

Edit: Looks like the HRRR has been trending slightly south as well.

Edit 2: I'm watching KSLE obs (La Crosse). 15z RUC has them straddling the 850mb 0C isotherm with IP/ZR (12z NAM was predicting IP as well), but the station is reporting +SN with 1/4 mile visibility. KAEL also has similar conditions on the forecast soundings, and is currently reporting TSTM +SN with <1/4 visibility.

 

[John Vandehei]

Snowing heavily here east of Kalamazoo. Radar is showing 55dBZ to my north. Some of this might be bright banding, as it's about 35 degrees here. No freezing precipitation or sleet yet. Got about a quick inch of snow in the past 45 minutes.

 

[Robert Dewey]

That bright banding is interesting considering there are snow reports to the south of it. The bright band usually indicates melting aloft, which would imply snow changing to sleet at whatever level above the radar.

 

[John Vandehei]

Snow rapidly changed to all sleet shortly after my last post. Currently a mix of light snow and light sleet.

 

[rdale]

Looks like that's the trend on the backside of the enhanced reflect, Coldwater webcam showing the roads - http://libcam.coldwater.org/view/viewer_index.shtml?id=40855

 

[Mike Kovalchick]

Light snow began here at 1:35 EST and 32F. (ENE of Lansing on the Shiawassee/Ingham County line.) Looks like the 850 0 C line should end up being very close to over head so will prove to be an interesting weather day to be sure. Should end up being mostly a snow event here but any deviations aloft and it will end up with piles of sleet. Thundersleet looks to be a possibility later.

 

[Robert Dewey]

HRRR shows 850mb temps >0C across SW MI, but that quickly cools to <=0C as precip intensity picks up. We'll see how that plays out I suppose.

 

[RMacDonald]

17Z SmartModel is showing DTW around 7" Snow Accumulation for the next 24 hours with around .5" of Freezing Precip embeeded within the snow event, Grand Rapids and Pontiac still locked in around 10-12" of snowfall potential.

 

[Nick Nolte]

Just east of Jackson, MI we've got almost 1" on the ground, it started snowing right about 1:00pm, so it's pretty close 1"/hr right now.

 

[Robert Dewey]

All snow here so far, with about 2 inches in the past 1hr 30m. I'm actually pretty confident now that we'll remain all snow in the northern suburbs of Detroit... 18z NAM does bring temps up to around -1C at 750mb, but the isotherm never crosses 0C. The snow isn't as wet as I had originally thought it would be, it's very difficult to make a snowball. My unscientific guesstimation would say it's probably 10:1 or maybe even 12:1 thus far.

I'm fairly impressed by the 18z NAM, as it keeps us locked under the 100mb deep -10C to -20C DGZ + omega bullseye + RH >90% up through 500mb... until 12z tomorrow morning. Mixing ratios also remain quite moist in the mid levels at 4-5g/kg through the event. QPF creeps up to 1.25 inches, with 1.5 inches over south-central lower MI. Mid-level instability also present, and lightning already occurring over SW MI, northern IL... with a separate area over MN / IA.

Right now, I'm going to say 8-12 inches from Pontiac, MI to Mt. Clemens, MI northward to around Flint, MI. I actually wouldn't be surprised to see more than that... it's still coming down pretty heavily and accumulation quite nicely.

 

[Nick Nolte]

It switched over to all sleet at about 4:45 here and now it's sleet and freezing rain. Stuff is starting to get a little glaze on it. There looks to be a solid area of higher reflectivities about to move over top of me. We ended up with about 4.5" of snow which started at 1pm so it was more than 1in/hr before it changed over. That 0° C 850 line is right at the edge of my county

It's interesting to see the gradient across this zone from south to north, before the changeover the snow here was very wet and snowballs were not a problem

 

[Robert Dewey]

18z GFS even more impressive, at least with the 1.5 inch QPF amounts nudging into my area. In fact, it's showing upwards of 16-19 inches.

 

[Robert Dewey]

It switched over to all sleet at about 4:45 here and now it's sleet and freezing rain. Stuff is starting to get a little glaze on it. There looks to be a solid area of higher reflectivities about to move over top of me. We ended up with about 4.5" of snow which started at 1pm so it was more than 1in/hr before it changed over. That 0° C 850 line is right at the edge of my county.

You can definitely tell by the radar where the snow / sleet line is. The snow appears to be "smoother."

It looks like the 850mb 0C isotherm is a pretty good match for the snow / sleet / freezing rain line right now. Keeping a close eye on it. If we stay all snow here, I think we could end up with a ton.

 

[Robert Dewey]

Up to about 4 inches now. Radar and lightning data lighting up over S WI at the moment. Will be interesting to see how this develops into the colder air, and how far north that 800-700mb warm layer advects.

 

[John Vandehei]

I'm back. Daughter had a gymnastics meet. Been mostly rain/freezing rain for most of the evening here. Luckily, the initial inch and a half of snow soaked up the freezing rain, so roads are quite passible. Trees are definitely glazed in the area. Haven't gone out for a close look, but I'd guess may a 10th of an inch of glaze on trees, signs and other above ground objects.