The mild conditions this winter have not been conductive to ice skating on our local waterways, but on Wednesday morning many Addison County residents took unplanned trips across ice - when traveling across driveways and parking lots!
The culprit? A warm front bringing unseasonable rain, followed by a cold front and plummeting temperatures - an effect some meteorologists call a “flash freeze”.
This winter has been milder than average, but temperatures have also fluctuated dramatically. This weather station on Upper Plains Road in Salisbury recorded roller-coaster weather this week - temperatures below zero on Sunday and Monday mornings, followed by a warming that resulted in 40 degree temperatures and rain on Tuesday night. The below zero temperatures early in the week cooled surfaces and allowed ice to form when the rain started. A brief, relatively warm downpour on Tuesday night turned any remaining snow to slush and ice, and the cold front passage froze the water in place before daybreak on Wednesday. The result was dramatic - any surface not heavily treated with salt was immediately iced over. Even wooded areas became ice slicks (see above), because the frozen soil prevented water from soaking in to the ground. Temperatures remained below freezing, and in fact plunged back into the single digits early Thursday morning, so none of the ice melted, unless it was smothered in road salt.
The effects on the local rivers were rather dramatic. After the frigid temperatures early in the week caused thick ice to form, the warmer temperatures and rain caused rivers to rise a bit, ripping apart and repositioning much of the ice. By Thursday, the ice had repositioned itself in dramatic, jagged formations.
This flash freeze was at least the third this year; similar events contributed to the post-Christmas pileup on Highway 89 and also led to slick roads last Friday. The next few days offer the potential for a few inches of snow in some areas, but unfortunately next Monday and Tuesday may bring yet another rain followed by a similar freeze. Any snow we get over the next few days will probably also be converted to ice.
It seems a waste to have to deal with dangerous roads without piles of snow to play in, but as always it is possible to find an upside. At least there’s not a lot of snow shoveling to do - and the ice formations that form on the Bristol Cliffs are especially spectacular this year.
Charlie Hohn is a recent graduate of the UVM Field Naturalist graduate program. He has been closely watching the weather ever since he was a child in southern California. Charlie will be posting occasional blog posts here about Addison County weather. He also maintains a blog about water at slowwatermovement.blogspot.com.