Crozet Weather Almanac: September 2014



The Old Farmer’s Almanac, Version 223

The difference between modern meteorology and the Farmer’s Almanac is roughly the same as the difference between Astronomy and Astrology.  They have virtually nothing in common (science vs. entertainment) but are both often confused.  Back in the day when Heidi was a young television meteorologist, the best way to get under her skin was to call her a “Weather Girl”.  Now, the way to get her goat is to ask her what the Farmer’s Almanac is forecasting for the winter.  You can try it for fun but I’d stand back a good ten feet.

So what is the Farmer’s Almanac and is it really worthless at forecasting the weather?

The surprise answer is that there are two different “farmer’s almanacs,” both of which trace back almost to the American Revolution.  The oldest is The Old Farmer’s Almanac which has been published continuously since 1792, making it the oldest continuously published periodical in North America.

The other one is the Farmers Almanac, which began in 1818.  The similarity in names obviously predates trademark infringement lawsuits and both have long-term legitimate claim to their names.  Both sell about four million copies a year, both publish detailed long-term weather forecasts and both use “secret forecasting formulas.”

Robert B. Thomas, the founder of The Old Farmer’s Almanac had a philosophy that the almanac ““strives to be useful, but with a pleasant degree of humor.”  This basic philosophy has kept both almanacs going for two centuries.

The roughest time for the almanacs was during the depression and World War II.  Circulation at The Old Farmer’s Almanac had dried up to just 89,000 in 1938 and editor Roger Scaife dropped the weather forecasts. People were furious.  The forecasts were back in 1939.

A German spy was caught in New York City with The Old Farmer’s Almanac in 1942 and the forecasts were again terminated from 1943-1945 to prevent them from falling into enemy use.

The “secret forecasting formulas” aren’t of much scientific interest.  We all realize that basically they just make this stuff up while using a touch of science and clever weaving of normal weather patterns into vague phrasing.  To my surprise, somebody actually bothered to do a real scientific verification.  Dr. John Walsh, meteorologist at the University of Illinois,  found that 50.7% of the monthly temperature forecasts and 51.9% of precipitation forecasts were on the correct side of normal.  In other words, flip a coin.

As Heidi not so elegantly puts it, “If they were actually any good at it then they could make a fortune trading natural gas.  Way more than publishing an Almanac.”  This is true.  Natural gas prices move sharply on weather changes every day and over a billion dollars a day gets traded.  A modest weather edge at the natural gas game could make you “Warren Buffet rich” pretty quickly.

Of course, we meteorologists aren’t much better.  Forecasting skill for less than a week is actually quite high these days but it goes down quickly beyond that.  For some places like the western USA, success at ‘yes/no’ forecasts can exceed 60 percent several months ahead, but for most times in most places, we are just flipping coins beyond two weeks.

Just for fun, this morning I said “So, Heidi, what does the farmers almanac say about this winter?”

“I don’t know and I don’t care.”

I made sure I was standing back at least ten feet.

September Recap

Temperatures for September were almost exactly normal and the weather was generally very calm and pleasant.  Often we pick up lots of rain this time of year from hurricane leftovers, but all was quiet in the Atlantic.  Rainfall at our house was a very dry 0.56”, which isn’t that far from the September minimum record of 0.28”.

Rain Totals

Waynesboro was the driest of the dry.  The McCormick Observatory had nearly 3” of rain, which looks like a data error, but they are an official site so I think it’s legitimate.

  • Crozet Mint Springs 0.56”
  • Old Trail 0.60”
  • Greenwood 0.81”
  • Ivy 1.02”
  • Univ of VA  2.86”   
  • Waynesboro  0.25”
  • White Hall   0.59”
  • CHO Airport  0.86”
  • Nellysford  0.76”


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