The "Big Blow"
Posted by JAC on 10/13/2009, 7:41 am
Buzz Bernard, Senior Meteorologist
The anniversary of one of the most intense storms in U.S. history is approaching, that of the Columbus Day "Big Blow" that savaged the Pacific Northwest, western Oregon in particular, in 1962. Because the "Big Blow" slammed into a relatively low-population -- and in the eyes of many people 47 years ago, remote -- portion of the country, it's perhaps never gained the notoriety of other historic storms.

But to this day, it ranks among the most violent non-tropical cyclones in U.S. history. The Big Blow is important for another reason, too. It serves as an anecdotal base line for measuring how far weather prediction capabilities have advanced over the past half century.

The morning of October 12, 1962, was the start of just another typical autumn day in Portland, Oregon, with the weather forecast calling for "cloudy with showers," and people preparing for weekend trips and football games. Even though forecasters were aware that a healthy Pacific storm lurked several hundred miles west of San Francisco, there was no sense of danger in Portland.

But the ocean cyclone veered northeastward, strengthened and launched a devastating surprise attack. By dinnertime, winds in excess of 100 mph had ripped through the Rose City and indeed all of northwest Oregon. Gusts reached 179 mph at Cape Blanco on the coast, carrying away the anemometer -- or whatever was left of it. A wind that violent is typically reserved for Category 4 or 5 hurricanes The Oregon toll: 24 dead; almost $200 million in property damage (1962 dollars).

These days, such fury rarely catches us off guard. The entire weather prediction process from analysis to forecast is handled quite ably by computers. Modern forecasters are basically tasked with cleaning up any messes the automated procedures leave behind. That's not to say computers get it wrong a lot. They don't. In fact, the models are very good. A stunning change from 1962.

Here's an example: During December 1-3, 2007, another immensely powerful windstorm pummeled the Pacific Northwest coast. The "storm" was actually a series of formidable systems that peaked on Monday, December 3, when wind gusts of over 100 mph battered towns all along the northwest Oregon and southwest Washington coasts. Winds peaked at 147 mph in southwest Washington.

A short distance east of Cannon Beach, Oregon, the brutal winds destroyed a 700-year-old Sitka spruce, once considered the world's largest, snapping it in two 75 feet above the ground. Nearby, thousands of spruce and Douglas firs were felled. Entire tracts of forest looked as though they'd been harvested by a monster threshing machine (see photograph below).







Compared to the 1962 storm, however, the violence took no one by surprise. As early as Wednesday, November 28, the Portland National Weather Service office issued a statement warning of the possibility of strong, damaging winds by the weekend. Later, the office put out the first ever hurricane-force wind warning for coastal waters.
We've come a long way since the Big Blow.


Note: Senior meteorologist Buzz Bernard is recently retired.

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Isn't it ironic? - dixieagle, 10/12/2009, 12:15 pm
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