After Vermont Storms, Chances Of Renewed Flooding Not Worrisome. At Least For Now

Flooding in Winooski, Vermont on December 19, 2023,
The National Weather Service in South Burlington releases
bi-weekly flood outlooks in the winter and early spring. Today's
updated outlook offer not much to worry about. 

 Those bi-weekly flood outlooks the National Weather Service office in South Burlington puts out every other Thursday take on an added importance after all the extreme weather we'v'e had.  

I think a lot of us Vermonters are still feeling pretty raw after the epic floods last summer and the renewed, destructive floods in December. 

The latest flood outlook came out today and continues to show near normal flood potential for the next two weeks. That really means that we won't have any flooding, unless an unusually heavy rain storm wanders through. 

These bi-weekly flood outlooks take into consideration snowpack, soil moisture, water levels and weather forecasts. 

Opposing factors - some that enhance flood potential, others that diminish the chances - are competing against each other. 

We've had a wicked stormy weather pattern for weeks, months, really. So the ground is saturated, and stream flows are running a little high. 

But it's also been warm. That means there's not much river ice that could eventually cause ice jams.  Mountain snow cover and the amount of water in that snow is below normal.  Which reduces the chances that a lot of melting snow would add to runoff if we had a big rain storm. 

It's going to be cold the next few days, which means river ice will increase. But not all that much, because the cold weather doesn't look like it will last long. The deepest cold should just run from today through Sunday before an another warmup starts. 

We've also started a rather dry weather pattern yesterday, but forecasters think it will start to get a little wetter next week. Light snows are hitting some northern areas today, and more very light snow might fall Saturday. But that will add very little to the snow cover and potential runoff in the mountains. 

However, that warmer weather pattern expected to begin next week will be fairly active once again.  That means frequent chances of precipitation. The good news is at this point at least, I don't see signs of any kind of mega-storm sweeping through Vermont. So that will be a welcome break. 

There is, however, an elevated chance of flooding in southeastern New England, mostly because they have been even wetter than Vermont has over the past couple of weeks. 

There's also a somewhat higher than average chance of flooding out by Buffalo, New York and surrounding areas. They've been getting buried in lake effect snow this week. When it warms up, rain and thawing could produce flooding out there.  

Lake Champlain Lake Level Might Peak Early This Year, No Significant Flooding Expected

Relatively high lake levels on April 25, 2019, invading
wetlands near Alburgh, Vermont, as the lake should do
every spring. The cycle of high water each spring 
helps the ecosystem. 

 Lake Champlain might be nearing its peak level earlier than usual this year, depending, of course on whether the rest of this month proves unusually wet or not. 

Many of of us watch the Lake Champlain level each spring.  On the negative side, if the water gets too high, we have to worry about flooding. If it doesn't rise much, it could hurt the ecosystem in and around the lake, as many plants and animals depend upon natural high and low water cycles. 

As of yesterday, the lake level stood at 98.2 feet above sea level. As WPTZ meteorologist Ben Frechette pointed out today, that's actually a little higher than normal for this date. The lake on average peaks in the final days of April at around 98.5 feet. Flood stage is 100 feet.

If you look at the chart Frechette helpfully provided on Twitter today, the lake started rising sooner in the spring than normal, but at about the same rate at usually does. 

That reflects the early onset of mountain snow melt during our warmer than normal March. Much of the snow melted off the hills prematurely, so the lake level went up early.  The lake might start to recede early, too, if weather for the rest of the month is either normal or drier than average.

How high the lake gets this year depends on how much rain we receive.  Snow melt will soon start to s  get less and less important as there's just not all that much snow in the mountains left to melt.

The lake appeared to reach an early peak of 98.26 feet on Saturday, and then started a slight decline. That still seems high enough to keep the ecosystem happy. 

There's a good chance the lake will have at least one more burst of rising levels toward this weekend if current weather forecasts pan out. 

We have the potential for some fairly heavy rain on Thursday. Forecasters say the rain could be heavy enough to cause sharp rises on rivers, possibly even with some minor flooding. Since so many rivers feet into Lake Champlain, that storm, if it comes will lead to higher lake levels. It could even come close to 99 feet if there's a lot of rain late this week.

From there, the lake will start to recede again late next week, unless more wet storms arrive. 

Even if that storm hits Thursday, I don't think Lake Champlain will hit flood stage this year, unless we have some very heavy rain storms between now and mid-May.

At 100 feet, you start to see erosion problems on the shore, some roads covered in water, and maybe a few very low lying camps see flooding. At 101 feet, the flooding gets pretty serious, but I really doubt that will be a problem this year. 

You don't want the lake to get too high, though. Photo that
I took in 2011 shows record high Lake Champlain levels
destroying camps in Burlington, Vermont.  

The relatively high water we are seeing is a good thing, and it's even better if lake rises even a bit more this month. 

The ecosystem of Lake Champlain really depends on higher water each spring. 

The rise and fall of Lake Champlain in the spring helps ensure healthy wetlands which all kinds of plants and animals depend upon. 

The federal Environmental Protection Agency calls wetlands "biological supermarkets," which provide food for a wide variety of animal species. Lake Champlain has tons of wetlands along its edges, which helps the ecosystem throughout the Champlain Valley and beyond. So you want those wetlands to work the way they're supposed to.  

Of course, as we learned in 2011, too much water and snow melt are a really bad thing. That year, the lake shattered the record for its highest level ever seen, at 103.2 feet. The lake level in 2011 stayed above 102 feet for more than a month. 

The flood easily caused more than $6 million in damage. 

There is of course no way that flood will repeat itself this year. Instead, we should just enjoy the natural lake cycle, even if it is happening a little earlier than average.