Time For Those “Almanac” Forecasts

August 30, 2018

6pm Thursday

Do you ever feel the urge to pick up one of those “Farmer’s Almanacs” just to see “what’s going to happen this winter”?  Or maybe you’ve seen some forecasts floating around online?  Apparently a lot of people do!  Here’s the Old Farmer’s Almanac forecast for this coming winter

Farmers Almanac Forecast Is Crap 2a.png

Warm and wet, but mild and snowy eastside…okay…

Now the Farmer’s Almanac forecast.  Yes the apostrophe is in the correct place on this one.

Farmers Almanac Forecast Is Crap 2b

I wonder what the difference is between TEETH-CHATTERING COLD vs. BITING COLD vs. STINGING COLD?  Hmmm…

But how accurate are these forecasts?  Well, it’s not too hard to find opinions, for example:  “…IT NAILED THE SNOWSTORM ON CHRISTMAS EVE LAST YEAR!”.  But there are very few studies looking at its accuracy.  They claim 80% accuracy…wait, I just choked up laughing…

Jan Null at Golden Gate Weather Services here has checked the Old Farmer’s Almanac accuracy in the past, rarely does it do well.

Brian Macmillan and I put together a presentation several years ago based on 4 winters of Old Farmer’s Almanac forecasts.

Farmers Almanac Forecast Is Crap 1

We didn’t analyze any sort of “snow/cold” forecasts because those are quite subjective; just how the temp and precipitation forecasts compared to reality here in Portland.

MarkOldFarmersAlmanac2

The Old Farmer’s Almanac was correct on precipitation anomaly (month-wise) only 50% of the time during the 16 months we analyzed.  As you can see the temperature forecasts (below) were even worse…OFA is wrong far more often than right.

MarkOldFarmersAlmanac1

The conclusion?  These forecasts are often terrible.  I’m quite confident no one is able to forecast daily, weekly, or monthly…many months ahead of time.

Chief Meteorologist Mark Nelsen