Monday, September 23, 2013

Lies ... and (weather) statistics

I'm sure you've heard the old saying about the three kinds of lies, in which the third "kind of lie" is statistics.

That bit of wisdom played out during the weekend with Charlotte's weather.

If you look at the monthly statistics from Charlotte Douglas International Airport, we've had above-average rainfall for the month. The official rainfall total is 2.89 inches, and that is nearly a half-inch above average for this time in September.

As we all know, that's a deceptive number. If you look at that total, you'd think September has been a relatively wet month.

In fact, measurable rain has fallen only three days. And 2.74 inches of that 2.89-inch total came Saturday night, with the passage of a cold front. There also was .14 of an inch Sept. 1, and .01 of an inch the next day.

It has been, in short, a dry month -- despite what the numbers say.  Certainly, the heavy rain Saturday night will help bring a little life to growing things in the region, and it will give a boost to the water table.  But it hasn't been a wet month.

John Tomko, who does the number-crunching at the National Weather Service's office in Greer, S.C., is fond of saying that meteorological averages are merely the result of extremes. In other words, our annual Charlotte snowfall of about 5 inches really comes from some winters with 8 or 10 inches, averaged out with winters with an inch or less.

Incidentally, Charlotte is now 7.25 inches above average at this point of the year, with 38.21 inches. We already have received 5 inches more precipitation than all of last year, and we're approaching the average number for the whole year.


Anonymous said...

And you're saying what?

Anonymous said...

He is saying, "I have very little to say."

And you should be careful of what you write. Steve has a very sensitive following of groupies here who will hurl all sorts of insults in his defense.

Anonymous said...