A Meteorologist Explores Survival Skills and Climate Change as a ‘Heat Dome’ Sears the Southwest
On Monday, the first day of summer, it was hard not to focus on the scorching Southwest, where 110-degree-plus temperatures spilled far outside their typical geographic range for this time of year, in part thanks to an atmospheric feature called a “heat dome.” (Back in 2011, this phrase had an earlier headline moment, deconstructed at the time by Erik Eckholm for The Times.)
This Twitter item from Ryan M. Maue says much about the heat, centered in Arizona but spreading far and wide:
A Twitter item from meteorologist Ryan Maue at the peak of the heat spike in the Southwest on Monday, June 20. Credit Ryan Maue
Maue, a meteorologist for Weatherbell Analytics, a company doing advanced analysis of storm and temperature probabilities for a variety of clients, predicted the extreme heat in the Southwest more than a week ago. Read more from Andrew Freedman at Mashable from back on June 14.
Even before the heat hit a peak on Monday, at least four hikers in Arizona died from heat-related ailments, officials reported over the weekend. The high temperatures have contributed to the outbreak of wildfires around the region. What’s particularly unnerving about the Southwest passing old heat records is that demographic shifts are adding enormously to the amount of societal exposure to dangerously high temperatures. In a warming world, expect more risk.
Last year, I wrote about an important analysis of the two drivers of heat risk in the United States, summarizing the findings this way:
[E]xtreme heat in the United States is likely to rise enormously by mid century, driven equally by demographic shifts boosting Sun Belt populations and projected changes in heat waves in a warming climate.
Given Maue’s long lead time in predicting today’s heat blast, I reached out to him Monday afternoon for a chat on the role of human-driven climate change and the urbanization of the region in raising thermometers to new heights.
Here are a few snippets transcribed from the interview (with some light editing for comprehension), along with a link to the recording:
Maue said studies point to a substantial rise in chances of having hotter peaks in summer temperatures, but the the change remains subtle in the grand scheme of things:
Global warming or even natural variability in the warming direction would tend to shift your odds slightly better – so instead of maybe 1 in 100 it may be 1 in 50. So instead of a 1 percent chance of breaking a record, now you have a 2 percent chance. So depending on how you want to frame that you could say the chances improved by 50 percent or the odds doubled, but you’re still talking about a very small chance to begin with.
He described how, in the Southwest particularly, the geography and urbanizing landscape contribute substantially to the extent of heat events:
The trick here is that we’re talking about a desert. A desert, particularly one that’s urbanized, has an enormous heat-island effect…. Your overnight lows generally are starting out from a higher point. Yuma, Needles, Phoenix, sometimes don’t even get below 90 at night. So by the time it’s 10 or 11 in the morning, it’s already 105, 110 degrees. So it just takes a little bit of sunshine to heat that column of air right back up.
That demographic shift has also brought hundreds of thousands of relative newcomers to a region where long stretches of days over 100 degrees are the norm, he said, exacerbating the health threat unless people learn how to cope, and particularly drink far more water they might think necessary.
Maue explained the atmospheric dynamics within a “heat dome” that amplify temperatures well beyond the heating impact of southern sunshine. He added that his review of data in recent decades shows such events has been developing more frequently:
Instead of a few times every other decade now it’s a few times a decade. So we have the large-scale pattern now favors higher temperatures itself. The question, from an attribution point of view is, how do we get those large-scale patterns? Is that something that’s human influence? Are we going to see more of these long-wave or upper-level patterns that favor these strong ridges? That’s what the literature that uses climate simulations tends to agree on. We’re going to have these longer-lasting ridges and blocks.
Maue discussed how “two camps” of researchers claim to have increased predictability of such weather events over periods of a month or more by using clues either in the Arctic, related to the extent of sea ice and snow cover, or in the temperature of surface waters across the Pacific Ocean. He explained how any improvement in such forecasts would have substantial benefits for commodities markets and improving management of water and energy supplies.
Maue is one of a host of communicative weather and climate experts who’ve made Twitter an invaluable portal for journalists and others eager to dive deeper into the forces driving consequential weather. (The National Weather Service has developed great social media skills, as well.) On a tough issue like clarifying and responding to climate change, there’s no single go-to expert. Reality emerges through networked discourse. Sample the stream here.
For more on the impact of global warming on such events, read the helpful Washington Post overview filed a few days ago by Jason Samenow and Angela Fritz.
For a broader assessment of hot summers in a warming world, and the long-term benefits of cutting carbon dioxide emissions, explore this relevant new study in the journal Climatic Change: “Future risk of record-breaking summer temperatures and its mitigation,” by a team at the National Center for Atmospheric Research.
And of course there’s plenty to review on Dot Earth:
– “Study Finds Sun Belt Population Growth and Warming Climate Could Quadruple Exposure to Extreme Heat” (May, 2015)
– “Extreme Weather in a Warming World” (September, 2010)
– “Hot Weather in a Warming Climate” (July 2010)
– “More Record Highs and Far Fewer Lows” (November, 2009)