Lack of Snow Along the LakeshoreDecember 20th, 2012 at 7:35 pm by Patrick Powell under Weather
I am sorry that it took a while to get this to social media but my television responsibilities come first. We have been numerous comments on my snow forecast from yesterday. Basically everyone away from Lake Michigan thinks we did an excellent job, while the people right along the Lakeshore think we were pretty bad. Before I try to explain what was good and bad, let me say that the Lakeshore counties will be getting snow overnight.
I have dropped the amounts I am forecasting, but there should be accumulation as the wind direction changes and the temperature drops a little. The temperature drop will also help lead to more blowing snow overnight. Most of the area will continue with accumulating snow and strong winds that will gust over 40 mph through about 1 AM for central sections and through 4 AM along the Lakeshore. This is the updated forecast for total snowfall.
I am expecting snow to continue early tonight and most of the area will get 2-4 additional inches after 7 PM tonight. Including the lakeshore, due to falling temps and changing wind direction. What had hurt the snowfall totals within a few miles of Lake Michigan was a combination of wind direction, warm lake waters, and temperatures that were close for snow already. With the storm center passing to our south, we had Northeast winds off the lake for much of the day. Lake Michigan is at roughly 44 degrees right now and with the winds over the lake it helps warm the lowest levels of the atmosphere a few degrees. From what I saw, temperatures along the lakeshore where about 2 degrees warmer than the rest of the area all day long. That 2 degrees was enough to keep the precipitation as a rainy mix. While it was heavy snow in Fond du Lac at 34 degrees, there was a rainy mix in Manitowoc at 36 degrees and a snowy mix in Sturgeon Bay and Marinette at 35 degrees. If the lowest few hundred feet of the atmosphere had not been slightly warmed by Lake Michigan, Manitowoc would have around 11 inches of snow. Obviously, Manitowoc doesn’t have much in the way of snow at all.
This is the temperature profile from this afternoon in Green Bay…..
I highlighted the Freezing line in blue, the temperature profile of the atmosphere is in red. You can easily tell that it was snow falling, but the snow was melting in the final few hundred feet along the lakeshore, below the black line I drew in. I thought that the lakeshore would mix at the start, at least the first few hours, then switch over as the intensity of the snow increased. This happens often enough that I was expecting it. Reality is that the warm lake waters kept the lakeshore as a mix, and that will not change until the wind direction turns to the north or northwest. That wind shift is already occuring, so please have a little patience. You will get some snow tonight, but more than half of my forecasted snow fell as a 35 degree rainy mix today.