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Ventilation index isn't readily available

I just spent 40 minutes looking for the ventilation index for Medford and cannot find it on the National Weather Service site, the Weather Channel or Yahoo Weather. I can find a complex formula for computing the number but there is nothing labeled Ventilation Index that I can find on any of those sites. Where, specifically, can I find it?

— Jim P., Central Point

Sometimes the pointy-headed nerds at Since You Asked think they are so smart. But this is one time the answer to a question was less obvious than it first appeared.

Here's how the rigorous intellectual debate took place at SYA headquarters in an effort to answer your question: "Hey, Joe, where can you find that air-quality index thing?" Joe responded, "I dunno, Ed. Isn't it that thing on the back of the Mail Tribune?" Ed looked at the back of the paper and found the air-quality index and smugly thought he had the answer. Wrong.

The air-quality index is a measurement of particulates in the air, not the ventilation index, which measures how well the air is moving through the valley. It used to be that the ventilation index had to be 400 or better to set that pile of brush ablaze. However, if the air-quality index hit 400, you're practically choking to death.

We hate to break it to you, Jim, but the ventilation index that is often mentioned by the weather service and Jackson County is actually a bum steer.

According to Ryan Sandler, warning coordination meteorologist at the Weather Service, the ventilation index number is just not readily available. In fact, it would be misleading to the public because it is one of several factors used to determine whether you can burn. Other factors include wind speed, wind direction and recent rainfall.

Sandler said that he will be informing Jackson County and the Weather Service not to mention the ventilation index in the future.

After a meeting with fire chiefs across the valley about a year ago, it was decided that the ventilation index would be just one of many factors used to determine burn days.

"We wanted to come up with criteria that worked better," Sandler said. "The ventilation number is not the end-all. It is part of the formula, but it is not the formula."

So, Jim, you'll just have to blow that ventilation index number out of your mind.