Research: Pacific storm clouds strengthened 2021 Northwest heat wave

SPOKANE, Wash.– Research from the University of Chicago shows that clouds from a storm off of Alaska contributed to the intensity of the deadly Northwest heat wave last June.  Simulations done during this study showed that without the release of heat from this system, it’s unlikely that the record-setting event would have happened.

Moving water between its three phases, water vapor, cloud droplets, and ice crystals takes a lot of energy. When water vapor rises and turns into clouds, like around a low-pressure system, this releases heat back into the atmosphere.

The amount of energy released during this process, says U of Chicago, helped to strengthen the high pressure that was already forming over the Northwest in June 2021. Simulations that modified this storm to be less of a cloud producer resulted in a heat wave that was less severe too. One feature could not exist without the other.

A NOAA report on the record heat in Washington suggested that a typhoon in the Western Pacific could have led to the intensity of the storm that produced the clouds and heat release mentioned earlier. Another contributing factor that needs more study is the impact of drought and low soil moisture on the intensity of the heat.

Finally, the study suggests that this kind of extreme heat could become more common. Why? As the planet warms, more water vapor content will be available for storms to tap into. Since this kind of setup happens often over the North Pacific, the authors say that the Pacific Northwest is likely going to be at greater risk of dangerous heat in the decades to come.