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The Spokesman-Review Newspaper
Spokane, Washington  Est. May 19, 1883

Iceland’s volcanic ash clouds can affect growing season

Randy Mann

There has been a lot of interest in volcanic eruptions, especially the one over Iceland. Many of us saw the huge volcanic ash cloud that forced the closure of a large region of European air space. Thousands of flights were canceled that affected at least 10 million passengers.

Scientists in Iceland are now reporting that the eruptions “appear to be calming down.” The ash cloud that has been threatening the continent’s airspace is dissipating.

However, the volcano in southern Iceland’s Eyjafjallajoekull glacier, is still rumbling and could erupt again. There is also a larger volcano nearby that could also erupt at any time.

These ash clouds, which float miles above Earth, are capable of knocking out jet engines. On June 24, 1982, British Airways Flight 9 flew into a cloud of volcanic ash thrown up by the eruption of Mount Galunggung (near Indonesia) that resulted in the failure of all four engines. The aircraft was able to glide through the ash cloud and the pilots were then able to restart the engines. Fortunately, the jet landed safely.

Not only is airline traffic affected by the volcanic eruptions, but agriculture could suffer as well. It’s possible that this region may have an unusually cool summer produced by the enormous ash clouds blocking out some of the sun’s normal warmth.

It’s happened before. During the summer of 1992, a year after the massive eruption of Mount Pinatubo in the Philippines, the Maritime Polar Jet Stream from the Gulf of Alaska pushed much farther south than normal into areas east of the Rockies in Canada and the northern U.S. weather patterns looked more like spring than summer.

Last week, I talked about tornado outbreaks in parts of the central U.S. According to the National Weather Service, on May 19, 2010, a small tornado classified as an F0 on the Enhanced Fujita Scale caused damage to farm buildings 5 miles northeast of Moses Lake. Winds were estimated to be near 80 mph.

As of early Tuesday, the average temperature for May at the Spokane International Airport was at 50.9 degrees, which is 2.6 degrees below normal. Rainfall is about .80 inches below normal as only .46 inches has fallen as of early this week. But, that figure should go up before the month ends.

Longer term, I’m still forecasting a hotter and drier than normal summer across the Inland Northwest. There may be as many as 25 to 30 days this summer at or above 90 degrees.

Contact meteorologist Randy Mann at randy@longrangeweather.com.