Subject(s): YellowStone National Park, fires of 1988
Title: Black Saturday
Hi, I'm Dave Thurlow from the Mount Washington Observatory and this is The Weather Notebook. Fires began burning in Yellowstone National Park in June of 1988 and they didn't go out until they were finally extinguished by snows in November of that year, 10 years ago. In all, 800,000 acres of park burned, but fire fighters will always remember August 20, now known as Black Saturday:
Phil Perkins: "On that single day we burned 165,000 acres in the park."
That's Phil Perkins, the Fire Management Officer at Yellowstone National. More forest burned on that one day than during any other entire decade in the Park's history thanks to weather conditions that were ripe for fires.
Phil: "The fire perimeter was very large so we had many miles of open flame and that's preheating the vegetation, any moisture that the vegetation had, it was drying it out in front of it and we had low humidities and then we had winds that, for about 6 hours that day, blew from 40 to 60 mph and for a period of about 2 hours blew from 60-80mph."
Besides the strong winds and the dryness of the brush, what really helped sustain the fires were the fire produced convection columns, firestorms, which are huge columns of flames sucked upwards by the rapidly rising hot air.
Phil: "The convection columns were going up well over 20-25 thousand feet in the air, generating so much energy with the wind...it was just lofting pine cones and other branches and needles very long distances so we were having spot fires two and three miles ahead of the main fire front."
Eventually the winds slowed down and firefighters gained some control over the blaze, but August 20th, 1988 will always be remembered as Black Saturday. Our show is underwritten by Subaru and the National Science Foundation.