June 25, 2021 Contact: Rachel Hansen (509) 661-4320
It’s hot but a fire safety outage is not likely – here’s why
LEAVENWORTH – At Chelan PUD, we’ve heard a few questions and concerns from the Upper Valley community about fire safety outages – especially in light of the triple-digit heatwave expected next week. Unprecedented as this weather is, a fire safety outage is unlikely according to the latest forecasts.
A fire safety outage is a proactive power outage designed to prevent catastrophic wildfire ignitions from utility infrastructure. For fire season 2021, this plan is focused on the highest fire risk area — Lake Wenatchee, Plain, and upper Chumstick Highway (from roughly mile marker 7).
We’re constantly watching the weather forecasts using data from the National Weather Service, state Department of Natural Resources and other weather-monitoring services. We’re tracking several factors, including predicted wind gusts, humidity, fuel moisture and potential fire behavior.
Wind speed is one of the most important factors, because wind-blown branches and trees are one of the biggest threats to overhead powerlines. As of Friday, June 25, the wind speeds predicted through July 2 are not expected to exceed 20 miles per hour. The potential for a fire safety outage begins when conditions are dry and predicted wind gusts reach 30-40 mph range.
If we start to see those conditions in the forecast, we have a team of staff at the ready to evaluate the situation holistically and alert our emergency response partners as the weather forecast evolves. If we must use a fire safety outage, we will notify our customer-owners as soon as possible, ideally 48 hours in advance.
Weather data changes hourly, but at this point, all of the factors listed above do not indicate the need for a fire safety outage. In the last decade of historical weather data, the kind of conditions that may lead to a fire safety outage occur about every 3-5 years.
Some of you may have received a red flag alert in the last few days. Red flag warnings are different – the conditions are less severe, they’re expected annually for this area, and they consider a different set of factors. According to the National Weather Service, red flag guidelines for the Upper Valley include: Predicted lightning, dry fuels, temperatures above 70 degrees, sustained surface winds of 15 miles per hour, and humidity less than 20-25 percent.
If you notice your power flicker this summer, it’s probably because we’ve increased the sensitivity of our fault detection system during fire season. This system will tell us if there’s a potential issue we need to investigate, such as a branch or animal contact.
The decision to use a fire safety outage is one we take very seriously. We recognize the devastation that wildfires can have on a community, and we recognize the impact on our customers when power is out. Our first line of defense is to increase tree-trimming, inspect more frequently, fire-hardening our lines, and other preventative actions. A fire safety outage is a rarely used measure of last resort. We hope we never have to use it, but if we do, it’s an occasion when the threat to public safety is greater than the impacts of losing power.
If you’d like to learn more about the fire safety outage plan, please visit chelanpud.org/fsom, where you can sign up for email updates. We’ve also published a frequently asked questions page.