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By the Numbers, Weather or not

Bill Meredith

"Rain is grace; rain is the sky condescending to the earth;
without rain there would be no life."
             John Updike.

(June, 2011) I typically have breakfast with the Washington Post spread out on the table before me, while my wife sits nearby in her rocker scanning the shopping ads in the Frederick Post. At some point she will hand me the sports section. This is partly because the Frederick paper has better sports coverage; Washington is always a day late in reporting on games played after 6:00 pm, which is most of them, and it often completely ignores the Orioles. But the main reason I want the Frederick sports section is because the weather report is on the back page of it.

Since I grew up on a farm and have raised gardens throughout my life, I always have been interested in the weather. This interest was amplified when I was in graduate school learning to be an ecologist; one of the leading textbooks at that time taught that weather was one of the four most important factors that control animal populations. So I used to maintain a small array of weather-recording instruments on the roof of the science building to generate data for my ecology class; this provided a supply of first-hand examples that the students could use in lab studies. Since retiring, I no longer need such information; but I still find it interesting, so each day I enter it on a spreadsheet in my computer. I have trained the spreadsheet to draw graphs that compare daily temperature and rainfall with long-term averages, in an array of different colors. My wife regularly questions the value, and sometimes even the sanity, of this activity, but I justify it on the grounds that I enjoy it and it does no harm to society at large.

One of the first weather stations in the country was established at Mount St. Mary’s College in 1869, so, except for a few gaps during the war years, we have a continuous record of rainfall for this area over the past 142 years. The average for that period is 45.37 inches per year, which is just what the textbooks say is needed to maintain the deciduous forest that originally grew here. Individual years vary, of course, but over that time the annual rainfall was less than 30 inches only three times, most recently in 2001, and more than 70 inches only once, in 1996.

The National Weather Bureau has always hoped to find a way to predict rainfall, and several years ago they did a study of the effect of the sunspots on weather. The number of sunspots reaches a maximum approximately every 11 years, and the Bureau found evidence of a 22-year cycle in rainfall. This seemed interesting, so by a combination of coaxing and threatening I persuaded my computer to draw a graph of the whole 142 year rainfall record for Emmitsburg. At first it appears to be a random sequence of peaks and valleys, but if you stare at it for a few hours you can make out a more or less regular pattern of wet and dry years which conforms roughly to a 22-year cycle. However, I am not able to see any relation between the peak years of rainfall and the sunspot maxima. Also, I was surprised by the amount of local variation that the graph revealed. Frederick, only 25 miles from us, receives an annual average of almost five inches less rain than Emmitsburg; and during the Dust Bowl years of the 1930s, when the Midwestern states were in extreme drought, rainfall in Emmitsburg was actually above average. Since the sunspot cycle is the same whether you are in Emmitsburg, Frederick or Kansas, I am forced to conclude that for now, we aren’t able to predict long-term rainfall patterns much better than groundhogs or wooly bears.

So far, 2011 has added to my uncertainty. In the past month, national news has covered wars in Afghanistan and Pakistan, governments being overthrown in the Middle East, nuclear meltdowns in Japan, precarious economies in Europe and at home, and congressional deadlock over how to deal with the national debt; but in the face of all these things, the headlines have been dominated by the weather. Record numbers of tornadoes have occurred in the southern states, and as I write, the flood crest in the Mississippi River is approaching New Orleans. All of those other problems in the news could possibly be solved by people of good will, if they could put self-interest aside. But rainfall remains impossible to control.

By comparison to the rest of the country, here in Emmitsburg things aren’t so bad. We have had some storms which flooded basements and temporarily submerged roads in low places, but nothing like those in the southern states. The year is off to a wetter start than usual; with May just past half gone, the rain gauge in my garden has recorded 25.62 inches. This would project out to about 68 inches for the year if things continue as they are now… wetter than usual, but not a record. But nothing is constant; chances are that things will change. The first two months of this year were actually below average, and my records include several cases where wet springs were followed by droughts in summer or fall.

Farmers and gardeners have learned from experience that there is no place for pessimists in this business. Anyone who plants a seed must be an optimist; you have to believe that things will grow and survive. My garden was too wet to plow in March, but the ritual potato that I planted on St. Patrick’s Day has come up and appears to be happy, insofar as it is possible for a potato to be. Last week we had a few days without rain, and I got the garden plowed; a gentle drizzle began before I finished, but I was able to get a row of potatoes and a few tomato plants into the ground. It has rained every day since then, but instead of stewing about it I have decided to accept John Updike’s wisdom that rain is grace. I recall a verse somewhere in the Bible... in the Sermon on the Mount, if memory serves… that says the rain falls equally on the just and the unjust; and I imagine it says the same about dry seasons somewhere in there too, although I haven’t bothered to look it up.

After you retire, there is less need to worry about some things. Sooner or later, the rest of the garden will get planted. In the meanwhile, there is the prospect of sitting on the porch, watching the wrens in the birdhouse my grandson made some 20 years ago, and receiving unexpected visits from children. Evenings on the porch will be enhanced by the birthday presents friends recently gave me… a pack of cigars and a bottle of that "liquid sunshine, garnered on faraway southern hillsides" like they had in The Wind in the Willows. Rain, or the lack of it, can’t compete with that.

Read other articles by Bill Meredith