June was a month of extremes across the U.S. Record heat dominated the West, where all time record June temperatures were being set in multiple states. Meanwhile, the same weather pattern that supported the prolonged, intense heat across the West, locked in an extremely wet set up across the East. Not only were numerous daily rainfall records set, but both Philadelphia, PA and Macon, GA, ended up with their wettest June ever.
Heat waves are one of the most well-understood consequences of climate change. Data already suggests that heat waves are becoming more common and more intense. As global average surface temperatures continue to rise, the probability of extreme heat events is expected to dramatically increase. One study, published in the Proceedings of the National Academy of Sciences in 2012, found that the odds of extremely hot summers worldwide were about 1-in-300 during the 1951-1980 timeframe, but had increased to nearly 1-in-10 by 1981-2010.
Heavy rain events are another likely consequence of climate change. As the atmsophere warms, it is able to hold more moisture. So, when that moisture comes back down in the form of rain (or snow), there is more of it to fall. Although there is a large amount of regional variability, heavy precipitation events in particular have been on the rise in parts of the U.S. - as described in the draft of the National Climate Assessment.
In this graphic, we highlighted the June daily high temperature records in red and the daily rainfall records in green. Where you see states with a blend in colors, there was a mix of both heat and rain records. Notice how the division between heat and rain lines up with the overall jet stream set up that dominated most of the month. Some scientists think that blocking weather patterns, like the one we saw in June, are becoming more common due in part to climate change. Jennifer Francis of Rutgers University has been studying the effects of Arctic ice melt on the Northern Hemisphere jet stream. She believes that as the Arctic warms faster than the tropics, the pole-to-equator temperature difference will diminish and the jet stream will slow down and become more amplified - keeping weather patterns in place for longer stretches of time. This is an active area of research, with more studies likely to be published soon.
Climate change is influencing the growing number and size of wildfires across the West. Warming temperatures and changing snowpack trends since the 1970s have made the Western U.S. more vulnerable to wildfires. As temperatures rise, mountain snowpack is shrinking and melting earlier in the spring. This leaves forests drier and more likely to burn. Last summer, a Climate Central analysis showed that the number of larger fires burning on federal land in the West has doubled since 1970, and in some states, including Arizona and Idaho, have tripled or even quadrupled.
We have listed a variety of multimedia content below for you to explore.
1) Interactive Wildfire Map Tracks Blazes in Real-Time:
2) Latest Wildfire Stories:
3) High-Resolution Graphic:
4) Climate Central Research Report:
5) NASA's "MODIS" Instrument Onboard the AQUA Satellite Sees Smoke from Yarnell Hill Fire