Tuesday Evening Flood Forecast Update

The flooding Lamoille River crashes its way through trees
in Jeffersonville, Vermont amid snow showers on
December 19, 2023. We might see similar scenes
by Thursday, though the flooding is not expected
to be quite as bad as last December. 

The first shower of our very wet New England storm were headed into the region late Tuesday afternoon as we brace for our latest flood event. 

Thankfully, fingers crossed anyway, this still doesn't look as bad as the floods in the Julys of 2023 and 2024 or even the one in December, 2023.  But I do expect at least a little damage out of this one.

The National Weather Service office in South Burlington tells us an initial wave or rather heavy rain will come through tomorrow morning, both before and after dawn.

 That could be enough to touch off some minor flooding, and ponding of water on roads, which would be a hazard on the highways.

During the morning commute that heavy rain will make the highways a bit of a hydroplane hell, so you'll want to slow it down yet again as you head to work.

By mid-morning or so, you'll think we're getting a nice break from the threatening weather forecast. The rain will noticeably lighten up, even stop at times. It won't be over, though. 

That will last until mid to late afternoon as temperatures keep warming up and melting that snow from the mid and high elevations. 

Then it will pour again, which is when we'll have to start worrying about the flooding. The drive home will be another hydroplane hell, with the added bonus of rising small creeks and streams, perhaps some washouts starting on the edges of the dirt roads, that kind of thing.

I suspect some gravel roads might be more susceptible to damage than you'd expect from the size storm we're about to get. The soil is probably still a bit soft and loose on roads that were just repaired after the floods we had just five months ago. So erosion could be a problem on steep hills.

Almost all the downpours in the second round of rain will come after dark, when it's hard to see flooding ahead of you. This type of storm tends to send marshy areas alongside low spots on Vermont roads and highways expanding onto the pavement. Hit the water in those instances and  you can wreck

Or stall in the water.

Overnight the main rivers will start to rise quickly. Most rivers in Vermont will reach at least minor flood stage or come close to it. That's especially true in southern and central Vermont. But it will happen everywhere.

Overall, the amount of rain we're expecting and the amount of snow melt that will occur is still pretty much in line with earlier forecasts

RIVER CRESTS 

Following is a sampling of the latest flood crest predictions on several rivers in Vermont.

 Note the forecasts are subject to change now through the time flooding  There's a possibility - but no guarantee - this could still get a little worse yet. 

Passumpsic River at Passumpsic. It should just barely reach minor flood stage, based on current forecasts.

Otter Creek at Center Rutland: 11.8 feet, just shy of the 12 food major flood stage. This could result in some flooding around homes on Dorr Drive and Park Street in Rutland and near Route 4 in Center Rutland.

Mad River at Moretown, 10.8 feet, which is a wee bit below the 11-foot moderate flood stage. At this level, water could easily reach Route 100 in Moretown and started getting onto Route 100B in the same town.

Winooski River at Montpelier, 10.3 feet. which is just shy of minor flood stage. Downtown Montpelier looks safe from this one, but if you're a store owner downtown, I'd get stuff out of the basement ahead of the storm, just to be on the safe side.

Winooski River at Essex Junction. 14.5 feet. that's just a half foot below moderate flood stage. The crest probably won't come until midmorning Thursday. That'll be enough to cover and close North Williston Road and maybe part of Route 2 in Jonesville. Part of Bridge Street and Volunteers Green in Richmond stand a decent chance of going under water, too.

Lamoille River at Johnson, 13.1 feet, minor flood stage. If the water stays below 16.5 feet, buildings in Johnson should be safe, but you might not be able to get through the area around the Wrong Way Bridge near Route 15 in Cambridge.

White River at West Hartford. Should crest near the minor flood level of 16 feet Thursday morning.

Walloomsac River, North Bennington: 9.8 feet crest, moderate flood stage. 

RAIN ENDS COLD

As these rivers are rising and approaching their crests, temperatures will crash sharply with a cold front. Rain will change to snow, but that won't amount to much. But all that water on the roads will freeze, so even spots that haven't flooded will be treacherous. 

So yeah, another annoying commute on Thursday morning. The lower reaches of the main rivers won't crest until the morning or even early afternoon Thursday, so keep on top of those road closures. There should be at least a few of 'em.

Overall, this whole episode should be less bad than in a very similar storm and flood last December.  Rivers are much lower, and soil moisture is much lower than last year, so we have room for water to soak in.

This storm will also move more quickly than the one in December, 2023.  That means it will have less time to unleash its downpours on New England. Shorter downpours, smaller floods, is the hope. 

I still don't see any big storms on the horizon after we get this week's mess out of our hair. We have a relatively cold shot of air Thursday through Saturday but nothing exceptional for mid-December.

Little systems and milder temperatures next week give us the the threat of light mixed precipitation occasionally.