The biggest newspaper in the Washington, D.C. area asks, "Did global warming intensify the derecho in Washington, D.C.?" It's the same question the Washington Post brought up directly after the derecho thunderstorm struck the Washington area last Friday.
"The amount of energy available to this storm was extreme and , wundergound [sic] weather historian Chris Burt called the number of all-time heat records set around the time 'especially extraordinary,'" writes Jason Samenow of the Post. "But as I wrote the day after the storm, connecting global warming to the derecho is a complicated and controversial question."
Samenow goes on to direct that question to two experts, the first says any role global warming might have played isn't "significant" and the second expert "cringed at the mere question of a global warming link."
Nevertheless, the Post reporter is determined to make the link. He calls the second experts analysis "incomplete and unconvincing." (That weather analyst pointed out that derechos are nothing new, and details the history of the storms.)
"To objectively demonstrate global warming has no role in derecho behavior, it would require analysis of a complete record of derecho frequency and intensity which doesn’t exist," the Post reporter writes, keeping his thesis alive though no experts he quotes agrees with his theory.
Samenow later adds:
The reality seems to be observations and scientific tools necessary to determine any global warming role in the June 29 derecho are either non-existent or limited. But that doesn’t mean we shouldn’t consider the question or attempt to unravel this complex issue the best we can.
While we lack observed data, theory suggests violent non-tornadic thunderstorm winds are likely to increase in a warmer world, says SPC’s Brooks. He told me the following:
“I think it’s quite plausible that we’d expect more non-tornadic wind events in a warmer climate. For starters, in the US, most of the high wind events are in late June-August [when it’s warmest], so climatology tells us that’s when they occur. Whether they occur in the organized fashion of derechos or in less organized storms is a difficult question to answer.”