By Joe Romm / Climate Progress: Earlier this month, Chris Mooney moderated a terrific Climate Desk event featuring top climate researcher Jennifer Francis along with senior Weather Channel meteorologist (and former skeptic) Stu Ostro.

Climate Desk summarizes their findings:

Ostro’s observations suggest that global warming is increasing the atmosphere’s thickness, leading to stronger and more persistent ridges of high pressure, which in turn are a key to temperature, rainfall, and snowfall extremes and topsy-turvy weather patterns like we’ve had in recent years.

Francis’s scientific story is complementary. She sees the rapid warming of the Arctic weakening the northern hemisphere jet stream, and thus, once again, slowing down the weather, leaving a given pattern stuck in place for longer (making any event potentially more disruptive and extreme).

As Climate Desk explains:

Stu Ostro is a senior meteorologist at the Weather Channel, and was a longtime climate change skeptic—until the devastating 2005 Atlantic hurricane season, when he started documenting hundreds of cases of extreme and unusual weather and the patterns associated with them, and became convinced that something is very off about the atmosphere.

For more on Ostro’s work and amazing story, see:

• One Meteorologist’s Come-to-Jesus Moment on Climate Change (by Chris Mooney): Like many TV weathermen, Stu Ostro didn’t believe in climate change—until extreme weather and scientific evidence changed his mind.
• Weather Channel expert on Georgia’s record-smashing global-warming-type deluge

Jennifer Francis is “a top climate researcher focused on the Arctic, whose work has drawn dramatic attention in the context of the very warm U.S. winter of 2012 (and attendant droughts and wildfires), the Russian heat wave and Pakistan floods of 2010, and other extreme weather events.”

For more detail on Francis’s research

• Arctic Warming Favors Extreme, Prolonged Weather Events ‘Such As Drought, Flooding, Cold Spells And Heat Waves’
• NOAA Bombshell: Warming-Driven Arctic Ice Loss Is Boosting Chance of Extreme U.S. Weather
• How Arctic Ice Loss Amplified Superstorm Sandy — Oceanography Journal