From the SoMAS weather desk: Bad storms coming

Heavy weather: Tropical Storm Cristobal churns through the Gulf of Mexico on June 5.
By GREGORY ZELLER //

From the Never Rains But It Pours file comes this grim long-range forecast, courtesy of Stony Brook University: It’s gonna rain, hard.

Like, biblical hard.

So says SBU’s School of Marine and Atmospheric Sciences, which has used global climate modeling to determine that future tropical cyclones – you know them as hurricanes – will produce more intense rains than ever before.

The project, detailed in a scientific paper published last month by the online journal Geophysical Research Letters, predicts that the number of Atlantic Ocean hurricanes making U.S. landfall will decrease in coming years – but those that do will “create dangerous conditions for U.S. residents in eastern coastal states through heavy rainfall, strong winds and storm surge.”

Those are concerns in any coastal storm, of course. But the SoMAS study – which used a variable-resolution version of the National Center for Atmospheric Research’s Community Atmospheric Model 5, a computer model of North Atlantic tropical cyclone climatology that factors in climate change – suggests “the prospects of storms that carry intense rain patterns over short periods of time” is rising fast, and with it, increased storm-surge threats.

Coastal concern: Fewer storms, more damage, warns budding scientist Alyssa Stansfield.

“Essentially, our work with climate and storm modeling provides evidence that hurricanes will produce more precipitation per hour of impact in the future,” noted SoMAS Associate Professor Kevin Reed. “This finding is consistent and adds to our (previous) work using models of Hurricane Florence and tracking extreme amounts of rainfall.”

That previous study, and the work detailed May 30 in Geophysical Research Letters, is part of ongoing SoMAS research funded by the U.S. Department of Energy’s Office of Science, focused on how hurricane-induced hazards may change in future climates.

The team, including PhD student and paper lead author Alyssa Stansfield, ran CAM5 simulations specifically to study changes in the number, intensity and sizes of future storms. Overall findings suggested decreases in the total number of Atlantic cyclones and the number of storms making U.S. landfall, as well as an overall decrease in rainfall totals – over years – from those fewer landfalls.

But as anyone who was on Long Island in October 2012 can tell you, just a single landfall – just one hundred-year storm – can be catastrophic enough. And those future landfalls, however many there are, will be treacherous indeed, according to Stansfield.

“Predicting how rainfall from hurricanes will be impacted (by climate change) is especially important,” according to the third-year atmospheric sciences student, now the author of two published scientific papers. “Flooding is a very dangerous hazard associated with hurricane landfalls.”