Thursday, November 11, 2010

Armistace Day blizzard improved weather forecasting--a little

Anyone who lives in the Seattle area knows that local weather forecasting `seems to be done by alchemy, astrology or just plain guessing. Five-day forecasts are simply not to be believed, especially during winter; on occasion you will see weather forecasts that “predict” rain, hail, sleet, showers, snow, thunderstorms and sunshine all in the same day—and none of the above occurs. There was a time, of course, when weather forecasting was much worse. Back in the “good old days” weather patterns were little understood, and the jet stream—whose fast speeds and warped patterns frequently result in serious weather disturbances—was not discovered until World War II. I bring this up because while I was checking-up on the latest news on the Vikings saga on the Minneapolis Star-Tribune website (doesn’t anybody like Brad Childress?), there was a story about the “famous” Armistice Day (now Veterans Day) blizzard of 1940. Even the second week of November is early for major snow fall in the Midwest, and people were caught completely off-guard by the storm that raged for three days. Although the "forecast" for November 11 called for cooler temperatures and snow flurries, it in fact began with unseasonably high temperatures reaching the mid-60s in some areas, but by evening winds were roaring—the same winds that took down the Tacoma Narrows Bridge a few days earlier—bringing with it rain followed by heavy snow as a low pressure system combined moist southern air with arctic air. But this is in hindsight; weather forecasters had little idea that this was about to occur. Residents in the Midwest, fooled by the initial warm temperatures, found themselves ill-equipped to cope with the storm, especially those caught in the countryside and on waterways. As much as 27 inches of snow fell, with snow drifts—whipped-up by winds of up to 80 mph—as high as 20 feet. People who were forced to venture outside were literally blown against buildings or forced to crawl. Over 150 people would eventually be killed as a direct result of the storm, as communications and transport were at a standstill for days.

The ensuing outrage over the failure of weather forecasters to accurately predict the storm led to the creation of more localized weather stations that updated conditions hourly instead of daily. World War II brought additional technology to enhance forecasting, including the discovery that radar could detect moisture patterns in the atmosphere. The least we can say is that meteorologists are better guessers now.

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