One Benefit Of Warm Vermont Winter: Ice Jam Flooding Risk So Far Very Low

An ice jam on the Mississquoi River after a thaw in 
January, 2018 diverts water into this Swanton,
Vermont industrial building. 

 If you get a big warm spell accompanied by heavy rain in the late winter or early spring across Vermont, you really run the risk of flooding from ice jams. 

By early February, there should be quite a bit of ice on Vermont rivers, and some of that ice should be pretty thick. 

Not this year. There's hardly any ice on the rivers. 

When a big thaw breaks up the usual river ice, it'll flow downstream until it gets caught on bridge abutments, curves in the river or some other obstruction. 

And, if those chunks of ice are thick, they are not likely to cave under the pressure of more ice and water  coming from  upstream. The collection of ice chunks forms a dam, and flooding results behind this ice dam. 

Just ask anyone who was in downtown Montpelier in March, 1992 what that was like. 

Ice jams like this have historically been a threat almost every winter and spring.

Vermont rivers have remarkably little ice in them at the moment. And the ice that's there is pretty thin, brittle and weak. 

Thick ice on Vermont rivers, ponds and lakes forms when we get a series of cold nights. The near- overcast that has turned us all into tragic victims of Seasonal Affective Disorder has also made our nights incredibly warm. 

January was overall warm, mostly among the top 20 warmest. However, daytime highs in January were generally only sort of milder than average.  Nights were bonkers warm during January, however, among the warmest on record. 

One telling factoid: It got down to 16 degrees in Burlington early this morning, which was the chilliest temperature there since way back on January 22. But this morning's low was still four degrees warmer than normal, but it was still 

As we get into February, temperatures are forecast to be near to above normal maybe all the way to the middle of the month. It looks like we'll have some semi- chilly nights early this week with overnight lows near normal. But another thaw looks like it's coming at the end of the week. 

Clear enough over New England so you can
see snow cover or lack thereof. Lake 
Champlain looks almost entirely free of ice.
Click on pic and zoom in on this view
from this morning. I think the grey, curled
area in middle of lake is a fog bank.

Sure, it could turn really cold in late February and March, and that would certainly increase ice amounts and thickness. But 2024 almost certainly won't be the year of the ice jams. 

LAKE CHAMPLAIN

Meanwhile, much of Lake Champlain remains ice-free.  We haven't been able to get a decent satellite photo of the lake in weeks due to the persistent cloud cover.  So it's been hard to judge how much or how little ice is out there.  

It was better this morning, with mainly clear skies. It looked to me like there was a fog bank in the middle of the lake obscuring some of the view. 

But otherwise, it appears on satellite there is very little ice on the lake, much less than there should be this time of year. 

 Unless it turns intensely cold in late February and we continue to have subzero weather through much of March, Lake Champlain won't entirely freeze. 

 The chances of it being constantly below zero in the first half of March are nil. Which means the lake won't freeze solid again.  

Lake Champlain has only frozen over completely once in the past nine years, though in 2022 it came very close to freezing over, with just one small hole of open water out there in late winter that year.