MOUNT VERNON — To hear “The Old Farmer’s Almanac” tell it, it will be a cold, dry winter in central Ohio this year. But how do they know?
The New Hampshire-based publication claims to have a closely guarded formula dating back to 1792 involving sunspots and phases of the moon, allegedly combined with modern, scientific input.
On the other hand, that could be a bunch of ballyhoo. The traditional method of assembling an almanac forecast is simply this: What is the weather usually like on any given day? Odds are that it will be similar to that most years on the same date. While early January is normally bitter cold, a “January thaw” almost always sets in by the end of the month. Such patterns help forecasters.
Modern scientific weather forecasting takes a similar approach by maintaining past records and using them as the basis of prognostications based on detailed observations, according to Joyce Miller, Mount Vernon Nazarene University professor and meteorology maven. She said that over 2,000 surface weather monitoring stations collect information in the United States, measuring air pressure, temperature, humidity, wind speed and direction. This allows for some forecasting detail, but only on the short term.
“The accuracy of weather prediction declines the further out the prediction is made,” Miller said, because so many variables are involved. But, the more variables that scientists can learn, the better forecasting will get.
“I believe that weather predictions will improve,” Miller said, talking about some of the cutting-edge devices being planned, including microtransmitters so small that they could be dropped from high-altitude airplanes to slowly drift to the ground, transmitting weather data all the while. Miller said the devices are so tiny, they could even be inhaled or swallowed by people without harm.
Data collected from weather balloons helps, too. Last summer Miller participated in a high-altitude balloon workshop at Taylor University in Indiana, sponsored by the National Science Foundation, where she learned how to use balloons to monitor weather conditions as far up as 20 miles in altitude. This spring, Miller will have MVNU meteorology students launching weather balloons to monitor microscale weather systems.
Miller notes that the National Centers for Environmental Prediction has predicted slightly above-average temperatures and average precipitation for the area this winter. Miller said September 2008 was the ninth warmest month for global temperatures since scientists have been monitoring these temperatures. She thinks that fact played a major role in the NCEP’s prediction of a warmer winter for 2009. Thus even global warming is being worked into scientific forecasting.
So does this mean there’s nothing to any of those old folk forecasting methods?
“I don’t think there’s anything to the woolly bear prediction,” Miller said of the popular method of predicting winter based on the color markings on commonplace woolly bear caterpillars. The old method of predicting rain based on the bending of a weather stick might at least reflect the humidity in the air, relating the stick to past rains, Miller said, which is little better than simply assuming that today’s weather will be pretty much like yesterday’s, which it often is.
It’s just those days when it isn’t that can be a problem.
