Tornadoes in area possible but rare

Tornadoes have been in the news lately. Not the ones that ravage the Plains states in tornado alley, but right here in Idaho of all places. Just 10 days ago, in a rare event, several tornadoes were seen across Shoshone in Southern Idaho’s Lincoln County. The twister was caught on video, and luckily there was only minor damage reported and no injuries. Just this past June, a stronger tornado tore through the community of Bear, Idaho, in Adams County, damaging homes, forests and injuring one person.

Tornadic storms probably don’t top the worry list of most folks around here, and rightly so. Idaho sees an average of only three tornadoes per year, ranking 36th in the nation for tornado frequency. Our neighbors in Washington and Oregon average only two tornadoes per year, while Montana sees an average of 11. Closer to home, across the Idaho Panhandle, you have to go back a couple of years for the most recent tornado. Back in June 2004, a tornado formed in Bonner County over Priest Lake. It moved onshore and passed through the town of Coolin before dissipating south of the town. Eight homes and businesses were damaged, and the roof of a fire station was peeled off. Even so, the tornado went on the record books as an F0 on the Fujita tornado damage scale, the weakest rating.

A stronger tornado struck Bonner County in May of 1994, but mainly damaged trees in a sparsely populated area just south of Priest Lake. Farther back, in April of 1991, an F2 tornado (which can have wind speeds up to 157 mph) did an estimated $250,000 worth of property damage.

The most recent tornado occurring in Kootenai County happened back in May of 1997, when an F2 tornado struck near Athol, damaging mainly old-growth trees. A weak tornado rated F0 was reported just south of Stateline in September of 1994.

Peering further into the record books, Shoshone County had one weak tornado back in 1987 which did some minor property damage but also injured three people. In records dating back to 1950, there were no tornado incidences listed for Boundary County.

Obviously, tornadoes are possible across the Inland Northwest, but they are an infrequent occurrence. Why? Well, in order to get tornadoes, you need to have thunderstorms. Coeur d’Alene averages only 13 days of thunderstorms per year with the peak activity in June. Of the thunderstorms that do occur, few are classified as severe, which requires winds greater than 57 mph, hail larger than 3/4 inches in diameter, or a tornado. The key fuel for thunderstorms, and more particularly severe thunderstorms, is warm, moist air. Here, we get the warm air in the summer, but it’s usually quite dry. We get the moist air in the winter, but then it’s too cold. So the ingredients don’t often come together in this part of the country to produce tornadoes.

Don’t think, though, that you’ve found a safe haven from the hazards of Mother Nature in the Inland Northwest. Wind storms, ice storms, flash floods, landslides, wildfires and even earthquakes are potential hazards around here. The risk of those particular events though, will make for an interesting topic in a future column.

Of more pressing concern are the record dry conditions across the area. We are nearly halfway through the month and have only received .03 inches of rain. The normal for October is 1.93 inches. From mid-June to the present, we’re experiencing the driest period since 1895. It does look like we could see some rain tomorrow and into Monday, but it’s not looking particularly wet for the rest of next week.