Counting Some Rays

There’s something shady about the Sunshine Derby. That’s the opinion of Stephen Vermette, professor and coordinator of the meteorology and climatology program in the Geography and Planning Department.

"The Buffalo News publishes a Sunshine Derby on its weather page, as calculated by AccuWeather Inc.” said Vermette (pictured). "The 'Sunshine Derby' shows a running total of the number of Buffalo’s sunny days on a month-to-date and year-to-date basis. This number is compared to four other cities—Rochester, Syracuse, Orlando, and Phoenix. With the exception of Phoenix, Buffalo usually comes out ahead in this count." Fifty percent or greater sunshine is a sunny day, according to the News.

Vermette points out that, as of October 31, 2012, Buffalo’s year-to-date count was 165 sunny days, compared to only 64 days for Rochester.

"There is no weather explanation to account for this scale of difference between the two cities," said Vermette. Working with students in his applied climatology class, and assisted by Jack Kanack, ’83, of Weather Medic Inc., Vermette believes they  have identified the problem.

"Buffalo’s count is based on a measurement of solar energy," he said, “and most National Weather Service stations no longer use that measure, although it’s maintained in Buffalo. That measure makes it easier to achieve a 50 percent sunshine rating than the other system, which is based on cloud cover."

The cloud-cover system is used in the other four cities in the Sunshine Derby. That system records cloud cover in tenths; to achieve a 50 percent sunshine rating, the data has to show a cloud cover of less than five-tenths.

"It’s comparing apples to oranges," said Vermette. "Solar energy provides a more accurate measurement of a sunny day than does cloud cover. But, unless the National Weather Service restores solar-energy measurements in Rochester and the other cities, it’s not accurate to compare solar-energy measurements to cloud-cover measurements."

When all five cities use the cloud-cover system, the year-to-date totals look very different. "Using this measure," said Vermette, "as of October 31, Buffalo had 58 sunny days, as compared to Rochester’s 64 days."

Vermette recommends that, if the Sunshine Derby is to be used as a statistic, all cities should use a common measurement system. The cloud-cover system is available in all five cities—and it shows Buffalo is the cloudiest of the five, according to Vermette.

Thanks to Professor Stephen Vermette, who brought this story to our attention, the Buffalo News announced on Friday, November 30, that it would stop running the Sunshine Derbyon its weather page, according to a story by reporter Mark Sommer.