Changes in nonextreme precipitation may have not-so-subtle consequences

Changes in nonextreme precipitation may have not-so-subtle consequences

SOURCE: Illinois News Bureau DATE: September 18, 2017 SNIP: Major floods and droughts receive a lot of attention in the context of climate change, but University of Illinois researchers analyzed over five decades of precipitation data from North America to find that changes in nonextreme precipitation are more significant than previously realized and larger than those in extreme precipitation. These changes can have a strong effect on ecosystems, agriculture, infrastructure design and resource management, and point to a need to examine precipitation in a more nuanced, multifaceted way. “This study articulates how everyday precipitation events – not just the extremes that have been the focus of most studies – are changing,” said Illinois civil and environmental engineering professor and lead author Praveen Kumar. “It’s not just the amount of rainfall that is important; it’s the duration of that rainfall and the amount of time between rainfalls and dry...
Stunning new analysis reveals just how unprecedented Harvey was

Stunning new analysis reveals just how unprecedented Harvey was

SOURCE: Think Progress DATE: September 14, 2017 SNIP: Hurricane Harvey’s landfall in Texas was “unprecedented” and “beyond anything experienced,” as the National Weather Service described it late last month. Now scientists are beginning to quantify just how unprecedented it was. A study released Friday by Metstat, a weather-analysis company specializing in “detailed precipitation analysis” and “weather frequency analysis,” found that Harvey delivered a stunning once-in-25,000-year deluge over much of southeast Texas. Some places saw an unimaginable once-in-500,000-year deluge, which translates to a 0.0002 percent chance of this deluge occurring in any given year. Since global warming has been making extreme precipitation events more likely, however, the U.S. won’t have to wait 25,000 years to witness the next event of Harvey’s proportion. As climatologist Michael Mann explained during the storm, “the kind of stalled weather pattern that is drenching Houston is precisely the sort of pattern we expect because of climate change.” Climate science predicted a weaker jet stream, and Harvey stalled because of a weakened jet...
Extreme rainfall risks could triple in the U.S. under climate change, scientists warn

Extreme rainfall risks could triple in the U.S. under climate change, scientists warn

SOURCE: Washington Post, Nature DATE: December 5, 2016 SNIP: U.S. residents may want to start preparing for a stormier future, scientists say. According to a new study, future climate change could cause an increase in extreme precipitation events throughout much of the country — in fact, these events could become up to five times more frequent in some areas. It’s an outcome many climate scientists have already predicted for the planet as a whole, according to Andreas Prein, a scientist at the National Center for Atmospheric Research and the new study’s lead author. “We expect that intense rainfall extremes will get more frequent and more intense in the future climate because if we warm up the atmosphere, air can hold more moisture,” he said. In fact, he added, records from the past few decades indicate that we’re already seeing this effect in the warming United...