Micro

My Montana

As Seen by Martha Hendrickson

Microburst

July 21, 1997

What is a Microburst? - A microburst is a severe downdraft from a thunderstorm with an outward spread of damaging winds extending 2.5 miles or less. An intense microburst can produce wind speeds as high as 150 mph. Microburst winds may rotate, but differ from a tornado in the respect that microbursts descend and spread outward. Tornado winds converge and rise. For the first 5 minutes of a microburst, winds will intensify until reaching their peak. They sustain this peak for 2-4 minutes and gradually subside. The microburst generally does not last longer than 15 minutes. -- Infomation from the National Audubon Society Field Guide to North American Weather, and the Aeronautical Information Manual (AIM).

Winds in the Libby Microburst were clocked unofficially at 72 mph, near the edge of the storm, by the Forest Service. The National Weather Service toured the damages and based on their knowledge and experience estimated winds in the heaviest damaged areas may have reached as high as 114 mph.

With the roar of the wind, the hammering of hail, a torrential downpour, and falling branches hammering roofs, many residents reported they did not hear the tree fall on their house. Others reported they heard the terrifying boom and crash.

This house was totaled. It was moved on the foundation and interior walls were damaged. However, it is in the process of being remodeled and is looking like new again.

This house was across the alley from the totaled house shown above. It was really hammered! It has since been repaired and improvements added. The yard has been nicely re-landscaped.

Damage to the home is unknown. It looks well covered in a blanket of ponderosa pines.

Here's a nice home "Lost in Spruce". Damages are unknown. Access to the front door is completely blocked by this prickly tree.

This one is mine. The 3-foot overhang was crushed and two rafters were broken. Even though the tree impacted directly above the bedroom window, the glass wasn't even cracked. Sheet rock nails were popped out and perf-a-tape was wrinkled. Three branches penetrated the roof into the attic. I was one of those who did not hear the tree hit the house through the deafening noise of the storm.

Bam! A lot of vehicles received direct hits by falling trees. This hit was a little hard on the engine hood of this nice car.

Wham! Here's another direct hit to this pickup. The cab is nearly smashed flat.

Double Wham!! This pickup received a tree across the enginehood ahead of the windshield and another across the box over the rear axle.

Missoula - Western Montana and Northern Idaho	Glasgow - Northeastern Montana
Great Falls - Central Montana	Billings - South Central Montana

U-PICK - Any where in the United States

This page created by Martha Hendrickson. E-mail your comments.