Fire Triggered PyroCB Storms are Yet Another Weather Risk
The California wildfire problem has brought to light yet another weather risk for the utilities in the region – something known as Pyrocumulonimbus (pyroCB) storms. This is a little-known phenomenon whereby smoke and heat from forest fires accumulate in the atmosphere and trigger the creation of thunderstorms. The volatile and unpredictable nature of pyroCB storms is what makes this type of event worth knowing about.
How a PyroCB Storm is Created
These fire-triggered thunderstorms can occur when an intense wildfire sends a super-heated updraft of smoke, ash, and water vapor into the air (the smoke particles provide a surface for the water droplets to attach to). Once in the atmosphere, this mix of particles and water vapor cools, forming large and dark cloud columns.
One of the main differences between a pyroCB storm and a typical thunderstorm is that it produces much less precipitation. What remains is essentially a dry lightning storm that can generate lightning strikes that trigger additional fire activity, which can rapidly spread due to potential tornado-like winds, making a bad situation even worse. And these lightning strikes are unpredictable, which can compromise worker safety.
The phenomenon is not yet well understood, as it is a new, emerging threat that is expected to increase in frequency as climate change progresses. Scientists have just recently started studying and tracking this type of weather activity. Simply put, no good came come from them – in addition to increasing power outages, these weather events can hurt the environment in the same way as volcanic eruptions.
I think – for utility companies located in wildfire-prone areas – pyroCB storms should be mentioned in training regimens as well as exercises and drills. They are happening more frequently, will likely cause additional outages from time to time, and are extremely dangerous. There is little doubt, these storms are no joke.
