Spring Flood Outlook

Published 03/06 2014 10:34PM

Updated 03/06 2014 11:13PM

SOUTH BURLINGTON, Vt. - It might not feel like it, but spring is less than two weeks away. March through April is prime time for flooding as snow and ice melt. This year the threat may be later than past springs since it's been so cold.

Temperatures stayed below freezing Thursday, but strong March sun still did some melting.

"If we have just warm temperatures during the day the snow goes out slowly and that's what we look for for a nice easy thaw," says Greg Hanson.

Hanson is the Hydrologist at the National Weather Service in Burlington. He keeps an eye on our lakes and rivers. He says the flood threat is low over the next few weeks as temperatures stay at or below average.

"We're not really expecting to melt any snow over the next couple weeks, so that will hold that off a little bit,” he said.

But with sixty-three inches of snow sitting atop Mount Mansfield, holding up to eight inches of water, a sudden rain storm could change that.

“If we got an inch or two of rain on top of that, that's where the problems come from," he says.

From mid March to early April Hanson says the flood threat increases, mostly from huge chunks of melting river ice.

"I think the bigger concern would be for ice jams moving forward. We still have plenty of ice covering the rivers. Some of it's a foot to a foot and a half thick."

Predicting where and when ice jam flooding will occur is one of the most challenging parts of a spring flood outlook. Along North Williston Road in Essex along the Winooski River, ice jams are always a problem. A jam caused flooding there during a January thaw.

"But on the Lamoille and the Missisquoi in Vermont, that ice really stayed put for the most part and in Northern New York the Saranac, the Great Chazy, a lot of the northern rivers that flow into the Saint Lawrence, the Salmon River that goes through Malone and Fort Covington. That ice has stayed put," Hanson says.

Jams are most likely there, but not impossible elsewhere.

"Ice jams, they always give us surprises and so I expect we'll see some further south too," Hanson said.

The longer the cold hangs around, the greater the risk of a quick melt, and flooding, later in the spring once temperatures inevitably warm up.

Copyright 2016 Nexstar Broadcasting, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.