1. 2. 3. Northern Wisconsin Weather: Numbers from the last LES and sub-zero temps. 4. 12. 15. 16. 17. 18. 19. 20. 23. 24.

25. 26. Numbers from the last LES and sub-zero temps. 27. 28.

Up to 2 feet of snow fell from the last lake effect snow event (Wednesday & Thursday).

I pulled together all the snow reports from NWS offices in Marquette (MI), Green Bay, and Duluth (MN) from the two-day event and listed them in this spreadsheet screenshot (to the right).

The left column lists totals from Wisconsin while the right from the UP of Michigan.
The highest totals I found were 25" in Luce County, MI and 13" in Vilas County, WI.

I received only three days' worth of flurries from the event.

To better answer Derek's question, the winds were very favorable for a few locations but never veered (turned clock-wise) northerly enough to bring heavy snow across the entire south shore of Lake Superior.

With winds staying northwest, a small section of the western south shore received some heavier snow (6-13"), and the eastern south shore was hammered (25"). For the Wisconsin shoreline to actually see some high snowfall amounts from the Lake, the wind needs to turn to the north or northeast.

The forecast for the last event called for some northerly winds but they didn't materialize.
I threw the map together (above) to give a rough idea of the most favorable directions for certain locations to see the highest amounts. I've never spent time in the Keweenaw Peninsula, but I'd image that any wind direction - except due southwest - would bring lake-enhanced snowfall.

Many things go into making lake-effect snowfall, several that are beyond me, the ones I do understand: the difference (delta T) between lake surface temperatures (warm) and air temperatures in the lower few thousand feet (cold but not dry) need to be greater than 13 C, an inversion helps avoid atmospheric mixing - but too low squashes the convection, and the winds need to stay blowing but not above 20 or 25 mph. The last several events were forecast to be better than they actually turned out, not all of the variables always come together perfectly.

After the clipper and cold front, some cold air settled in Saturday morning.

This morning I measured a low temperature of 4.8 degrees just after 7:00. The last time our low temperature dipped below 5 degrees was on 8 March, 2008, 260 days ago.

The NWS forecast called for most of northern Wisconsin to be at or near zero by dawn, but several places fell lower than expected.

With the help of GRlevel3, Paint, and MesoWest, I put together this map (to the right) of measured low temperatures across the region.

The coldest area was centered on the Saxon and Montreal river valleys: -12 in Upson, -14 in Wakefied, and -18 at Saxon Harbor. In fact, for 10 hours overnight (from 20:00 until 5:00) Ironwood, MI was the coldest official reporting location (ASOS) in the continental US. Then Eagle River, WI took over until 8:00.

Labels: , ,

30. 31.