1%20rk%20banner%20(1)_edited.jpg

A FLAKY FUTURE FOR SOME IN THE MIDWEST...

I ran across an analysis of long-term snowfall trends that finds that snowfall has been decreasing across much of the United States in the spring and fall (“shoulder seasons”) Results from 145 locations show that 116 stations (80%) had decreased snowfall before December, and 96 stations (66%) had decreased snowfall after March 1. Winter snow trends however, were more of a mixed record—with more snow in northern locations and less snow in southern regions of the U.S.

Here's a more specific break-down of city snowfall trends before December. Blue dots represent an increasing trend while pink indicates a decrease. Overall, an 80 percent decrease across the US.

City snow trends after March 1st show a 66 percent decrease.

Winter December 1st-March 1st, actually shows 54 percent of cities increasing their snowfall with the greatest focus across the northern third of the country.

Here's a few select city trends from around my region.


Waterloo

Dubuque

Des Moines

Quad Cities

Another impact of a warming climate is the number of days below 32. From 1980 to 2010 my area averaged roughly 90-110 days below freezing.

By the end of the century climate models estimate that number will drop by 30 days putting the average of below freezing days in the 65-85 day category.

While most of us don't see out first inch of snow until late November or early December, we usually do see our first flakes (a trace) in late October. I haven't seen anything firm to grab onto just yet but the pattern is going to turn cold enough aloft by the end of next week that if precipitation were to occur, it would be in the form of snow. As a rule temperatures at 5,000 feet (850 mb) need to be 0 C. or colder. This is the GFS 850 temps a week from today. Plenty cold enough for the white gold.

By October 20th the EURO is developing another push of cold air sending 850 temps even lower.

For some parts of the upper Midwest snow is forecast. Here's what the EURO depicts for snow totals between now and the period ending October 20th.

The GFS is even further south bringing minor snow accumulations as far south as HWY 20.

Before we go any further I need to make the declarative statement that I'm not forecasting snow yet. All I'm showing is model trends. However, if the cold in the pattern develops as shown, some snow is on the table for somebody in the Midwest. Maybe it's nothing more that a few flurries in my area but its worth watching. Just the steep lapse rates from an air mass this cold aloft would develop instability showers that could draw enough cold air to the surface for our first flakes. Lots of things will have to fall into place but I'm very inspired to even have a small chance this early in the game. For those of you naysayers, it happened last year in October so there is recent precedence. We shall see where the road leads us in the days ahead. Roll weather...TS

ARCHIVED POSTS
RECENT POSTS
1 rk big.png
© 2020 Terry Swails