Saturday Morning Vermont Storm Update: Confidence Increasing With Heavy Snow Forecast; Flooding Still In Play

Saturday morning's snow prediction map from the 
National Weather Service office in South Burlington.
Expected totals have noticeably increased in
the Champlain Valley compared to previous forecasts.

 I'll start with the bottom line: That long-awaited storm Sunday and Monday now seems more certain, with the flood risk Sunday night transitioning to a nasty snowstorm, at least for many of us in the Green Mountain State.  

Forecast models, which were kind of all over the place Friday evening, have gotten their ducks more in order. Though some surprises with the upcoming storm are inevitable, confidence is definitely up on the rain and snow scenario.

Expect some flooding, and a horrible, snowy, windy Monday, especially north and west. 

Let's break it all down step by step:

BEFORE THE STORM

The Champlain Valley really warmed up overnight, rising through the 30s to reach the low 40s this morning. Highs should flirt with 50 degrees this afternoon. Eastern Vermont is cooler, near freezing, but they should get to around 40 later today. 

All this is getting the ball rolling for snow to begin melting in the mountains. Today is an excellent day to stock up on groceries, LED candles and such and do other errands. You might need these supplies by Monday. 

The warm air will continue overnight tonight and Sunday, and the rain will move in during the day. 

THE RAIN/FLOODING

The rain might start out showery on Sunday amid temperatures in the 40s to low 50s, but it will grow steadier and heavier as the day and evening wear on.  The rather heavy rain will continue into the wee hours of Monday morning before the snow arrives - which I'll get into in a bit.

All rivers in Vermont will see sharp rises, and minor flooding is likely anywhere. The rivers most likely to spill over their banks continue to be the Winooski downstream from Montpelier, the Mad River in central Vermont and the Otter Creek in Rutland and Addison counties. 

Southeastern Vermont has probably a higher flood risk than other areas because the rain there will last quite a bit longer before the changeover to snow.  Still, the entire state of Vermont is under a flood watch from Sunday afternoon through Monday afternoon.  

Note that it will have been snowing for hours Monday morning with a flood watch still in effect. That's because it will take time for runoff to reach larger rivers. Flood crests should come Monday morning or afternoon.    

It continues to look like any flooding will be much less serious than what we had in the summer, but expect some road closures in low lying areas, wet basements, standing water on roads and maybe some urban street flooding here and there. 

WET, NASTY SNOWSTORM

The biggest question marks with this storm has been how much snow will fall. We still have some disagreements in the various forecasts, but the range of possibilities has narrowed. And not in a good way. 

The winter storm watch remains in effect generally for northern and central Vermont. The big change in the forecast is that winter storm watch has been expanded to include the Champlain Valley from about Charlotte north to the Canadian border (It will also end up being unpleasantly snowy south of Charlotte, too.

The storm that will form along the cold front will be oriented such that it will easily be able to funnel cold enough air into the Champlain Valley to produce four to 10 inches of heavy, wet snow. That's a change from the previous two storms, which spared the Champlain Valley. 

Elsewhere across northern Vermont, six to 10 inches of snow is in the cards, with locally up to 18 inches in the mountains. Southwestern Vermont is in for two to four inches, with more in the mountains. 

The only place in the Green Mountain State that looks like it will be mostly spared is the Connecticut River valley floor from about White River Junction south.  Those places should only get a dusting to three inches of snow. Amounts will go up pretty fast as soon as you start climbing the hills west of the Connecticut River valley. 

This still looks like it will be a wet, heavy snow, with temperatures in most areas around 32 or 33 degree during the heaviest snow.

As it looks now, the rain will change to snow before dawn in all but southeastern Vermont. The heaviest snow will probably fall during the Monday morning commute. It's going to be a huge mess. Snow could be coming down at a rate of an inch per hour, which makes it hard for snow plows to keep up. 

Wet snow is worse to drive on as it tends to compact into ice. If you can work from home Monday, do that. We'll probably have lots of school closings, so pay attention to that.

With the heavy, wet snow falling and winds increasing, power outages will be a problem. Green Mountain Power is already warning people to stay away from fallen wires or collapsed trees or branches that might have live wires in them. 

I give this storm a high potential to cause even more outages than the 16,000 outages that occurred on December 4 and  34,000 that occurred on November 27 during two previous wet snowstorms. 

I think road conditions will remain bad throughout Monday, but start to improve at least a little toward the end of the day as snow tapers off. Strong winds will continue even after the worst of the storm is over. That means snow loaded trees will probably continue to collapse onto utility wires into Monday evening 

On the bright side, ski areas and other winter sports areas in northern and central Vermont that lose their snow in the thaw Sunday and Sunday night will get most of their snow back Monday. Southern Vermont ski areas will get snow, but it won't be a gigantic dump.

There will be changes to this forecast, so as always, I'll provide updates.