Wednesday, November 25, 2020

History of Snow Between Thanksgiving and Christmas: Are Our Chances Higher This Year?

In late October, we issued our WINTER WEATHER OUTLOOK for 2020-2021.  The general idea is for a backloaded winter with shorter "teaser" periods of cold and snow in December.  So far (as of this writing before Thanksgiving, we've had under an inch of snow). 

Sledding with my kids when they were much younger!

How much snow do we typically get between Thanksgiving and New Years' Eve? We average around 10" over the last 10 years although the trend for early season snow has dropped over the last 15 years.

How about actual snowfalls?  We average around 4 one-inch snowfalls during the holidays.


Snowfall is one thing. But snow on the ground during the holidays is entirely different. More days with snow on the ground, the better chance we will remember it as a "snowy" holiday. We average around 8 days with snow on the ground over the last 10-15 years. 


As of this writing we are watching for changes in the pattern that strongly show more cold.

* Ridge developing across central Asia
* Jet stream across the North Pacific changing
* More frequent lows across Northern Pacific

All of this is resulting in the high pressure across the western US/North America with low pressure across eastern US. We call this a +PNA pattern (Pacific North American)




The super-long range model output into Christmas week is also strongly hinting at this eastern TROUGH/COLD lasting beyond December 20th. While I think this is probable, my confidence is high ONLY through the first two weeks of the month.

Animation from Thanksgiving to December 21st

Historically we average 15 days with temperatures in the 30s or COLDER over the last 10-15 years. Last winter we had 14 days in the 30s or COLDER before December 31st



Either way, cold and BELOW NORMAL temperatures are coming the first week of December with good chances of accumulating snow along with lake effect multiple times! Winter is coming everyone...





Wednesday, November 11, 2020

What Period Of Time Had The Most Lake Erie Ice Cover?

Lake Erie ice coverage - Photo Courtesy: Scott Sabol, January 2011

High Resolution Satellite - March 8,2019

It took a while but I finally finished plotting the daily Lake Erie ice coverage for each season since 1972. I separated this into month periods starting with November and ending with May.  This is all color coded. 
  • Light blue blocks indicates ice coverage under 1%
  • Bright blue is 2% to 10%
  • Dark Blue is 11% to 25%
  • Purple is 26% to 50%
  • Pink is 51% to 74%
  • White indicates at least 75% coverage

You'll notice several things here:
  1. Significant ice typically doesn't develop until late December.
  2. Mid/late 1970s AND the early 2000s stand out as the most significant ice coverage period in  January and early Februar
  3. First half of February is typically the peak for ice coverage
  4. November 23, 2014 was the earliest ice cover
  5. May 17, 1982 was the latest ice cover 

NOVEMBER


DECEMBER


JANUARY


FEBRUARY


MARCH



APRIL

MAY

The entire graphic assembled through winter of 2018-19



Monday, November 02, 2020

Monstrously HUGE Winter Scorecard. It's All Here!

The entire winter scorecard for each winter since the snowiest winter on record (2004-05) in northern Ohio.

I included these parameters:

* AVERAGE TEMPS (DEC-FEB)

* DEC-FEB TEMPERATURE RANKS

* AVERAGE TEMPS VS NORMAL (15 YEAR AVERAGE)

* AVERAGE TEMPS (THANKSGIVING TO MARCH 20)

* LIQUID PRECIP

* DAYS WITH SNOW ON THE GROUND (ONE INCH)

* PERCENTAGE OF TOTAL DAYS (WINTER) WITH ONE INCH

* TOTAL DAYS BETWEEN FIRST AND LAST SNOWFALL

* TOTAL DAYS WITH 3" SNOWFALLS

* MAX 3 DAY SNOWFALL

* MAX ONE DAY SNOWFALL

* SEASONAL SNOW TOTAL

* NUMBER OF DAYS ABOVE NORMAL

* DAYS ABOVE 60

* DAYS ABOVE 40

* NIGHTS BELOW 20

* NIGHTS BELOW ZERO


The scorecard is uploaded in two parts. If you want something else added to this list, let me know.






Thursday, October 29, 2020

Recent Seasonal Snowfall Totals - Northern Ohio/Midwest/US - Part II

We start the snowfall retrospective with last winter's (2019-2020) snow totals in northern Ohio.

Last year was the 5th straight year with below normal snowfall. The longest stretch of below normal seasonal snowfall was 9 winters between 1963 to 1972. 

Here are the average snowfall totals for northern Ohio. (Color contours are different than the image above)

How about the last 10 winters?  Here are the local snowfall amounts. Colors might be different year to year.













Last year's running snowfall accumulations really tell the story when compared to other years.  (Hat tip to Jared Rennie for supplying these snowfall graphics below)


CLEVELAND


AKRON-CANTON AIRPORT

MANSFIELD

CHARDON

NORWALK

OBERLIN

Snowfall history since 1900. Black line is the 10 years running average.

Snowfall history since 1940

Snowfall history since 1960


Snowfall history since 2000


Snowfall departures since 2000 (red are years below normal. Blue above normal)


Number of days with at least ONE INCH of snow on the ground each winter


Number of days with at least ONE INCH of snowfall


What are the winter with the MOST/LEAST one inch+ snows?
What are the winters with the MOST/LEAST DAYS with at least 1" snow on the ground?


What has been the snowiest decade in Cleveland?


Ohio, Indiana and portions of Michigan saw below normal snowfall last winter. Yet snow was above normal snowfall across Illinois and the upper midwest.

Notice the high snow numbers across the Upper Peninsula of Michigan.


Overall snowfall departures last winter across midwest/Great Lakes. 
The last 5 winters (2014-15 to 2018-19) snowfall vs normal below. Last time Ohio had above normal snowfall was 2014-15.





How about the rest of the country? US snowfall vs normal over the last 6 winters. Purple is above normal snowfall. Tan/brown colors are below normal. (Thanks goes out to Jared Rennie for the images)  Last image is the winter of 2014-15.








Part III of the 3 part series will highlight Lake Erie Ice History...