Summer offers plenty of heat, hail and wind
The lazy days of summer haven’t been so lazy when it comes to the weather. In the last 10 days North Idaho has experienced record heat, severe hail, and winds over 50 miles per hour.
The latest triple-digit heat wave during the weekend of July 13 saw records fall in Kamiah (103 degrees), Bonners Ferry (100 degrees), and Kellogg (101 degrees). Though records were not broken in Coeur d’Alene, the heat was nothing to sneeze at. Coeur d’Alene has had four days of 100-plus degree heat so far. The year with the most 100-plus degree days was 1975, when there were six. We still have plenty of summer left to go, and some of the hottest temperatures can occur during the end of July and the beginning of August.
Friday the 13th was the day for strong winds across the Panhandle. Winds topped out at 40 mph at the Coeur d’Alene airport, but weather spotters in Rathdrum reported winds of 53 mph, while a spotter in Hauser reported winds of 41 mph. In Spokane, the airport also recorded a wind gust of 53 mph while Felts Field in the Spokane Valley recorded a 45-mph gust.
I have often noticed in many National Weather Service storm reports that wind speeds are estimated. Not everyone has an anemometer (an instrument that measures wind speed) in their backyard. I recently installed a weather station in my backyard which includes an anemometer, and I have to admit I am surprised at what the actual wind speeds are in comparison to what I have perceived them to be. Recently, hearing the wind howling through my evergreens, I was sure they were near tropical storm force (39-73 mph). As I rushed to my weather station console, I was disappointed to find a maximum measurement of only 31 mph.
If you ever find yourself in the thick of some intense winds and you don’t have an anemometer handy, there is a way to make a reasonably good estimate of wind speed based on the observation of trees. The Beaufort scale was developed in 1805 by Sir Francis Beaufort, a British admiral. In those days, when naval officers reported estimated wind speeds, their descriptions were often subjective and open to interpretation. Beaufort came up with a scale from zero to 12, which did not use numbers to refer to wind speed directly, but categorized the force of the winds based on its visible effects on a ship’s sails. In the 1850s, the scale was adopted for non-naval use, and in the 1900s, the descriptions were extended to include land observations as well. The table contains some examples, using tree motions based on the Beaufort scale, of how wind can be estimated.
The complete Beaufort scale can be found online at www.fi.edu/tfi/units/energy/ table1.html
Of significant importance to the National Weather Service are wind speeds measured or estimated at 58 mph or greater. These kinds of winds would either verify a severe thunderstorm or result in a severe thunderstorm warning being issued. Weather-spotter reports of winds, even if they are just estimates, can be very valuable.
Wildfire report
Hot and dry summer weather continues to intensify the wildfire situation. As of July 17, 13 large wildfires were burning across Idaho, affecting more than 156,000 acres. Though none wasoccurring in the immediate Coeur d’Alene area or North Idaho, drifting smoke from the fire-ravaged areas in other parts of Idaho, Washington, or Oregon can still affect air quality and sky conditions locally.