Tuesday Evening Vermont Storm Update: Batten Down The Hatches!

Updated National Weather Service/South Burlington 
wind gust forecast for overnight. Click on image to
make it bigger/easier to see. If anything, the forecast
has shifted to include higher wind gusts in 
the Champlain Valley, compared to earlier forecasts.

 As of  5 p.m. Tuesday, snow has moved into Vermont a little earlier than forecast. 

That will make some roads dicey earlier than we thought they would, so the evening commute is turning out to be not great.  

The snow will be light to at times moderate, but won't amount to a huge amount before, say 7 p.m. We could see a couple inches by then. 

The evening snow is the opening act to the main show which will hit hard later tonight.  We've already seen wind gusts of 70 mph in western New York cities like Buffalo. That high speed air is heading right in our direction. 

The forecast hasn't changed much since this morning. We're in for an awful overnight here in Vermont, with strong winds, bursts of heavy wet snow, downed trees, power lines and blocked roads.

As of late this afternoon, you should have gotten all your outdoor errands done and huddling in your houses for the night. Here in St. Albans this evening, my husband is making a hearty stew to get us through the early evening . We've stored drinking water in jugs. LED candles and head lamps are at the ready. My cell phone is plugged in, hungrily accepting a nice battery charge. 

I don't know whether the power will be out at our house later tonight or for how long. But since widespread power outages are pretty much a sure bet in Vermont, everybody should be prepared. 

THE SCENARIO

Winds have started to increase as of 5 p.m., ,but are still reasonable, with gusts mostly at or under 30 mph. They'll gradually increase over the next few hours.

Heavier precipitation - the kind that will move in soon - more often than not suppresses high winds in Vermont, so the worst of the gusts won't happen  - at least for most of us - until after 10 p.m., when we should have somewhat of a lull in the precipitation.

We're still expecting a heavy thump of wet snow for the first half of the night, and that will prime trees, branches and power lines to fail once the wind really picks up. 

Since a lot of the precipitation will be snow, with only some rain late tonight and tomorrow, I'm even less worried about flooding than I was this morning. 

But of course we really have our hands full with the wind. 

A bit of drier air will move in aloft after midnight to suppress the snow and rain somewhat. At the same time, what is known as a low-level jet will move overhead. A low level jet is a band of high speed winds just a few to several thousand feet overhead.  

Screen grab of a video I took in January, 2016 of a 
downslope windstorm near Cambridge, Vermont 
that had broken trees looming over a road. 
Similar scenes should happen overnight and 
tomorrow morning. 

Meteorology is basically fluid dynamics physics. Air flow acts a LOT like water flow. The Green Mountains act as sort of a submerged boulder in a fast-flowing river in a storm situation like this.

 The strong east winds in the low level jet are forced to rise a bit to accommodate that "submerged boulder" consisting of the Green Mountains.  

It's basically the wave you see above the submerged boulder in the river, and the subsequent waves downstream. 

When the wave reaches its peak over the "boulder" the high speed wind is sort of grabbed and shoved down the western slopes of the Greens. The air gains momentum on its downslope path, which makes the wind even stronger.

 So, we're still expecting winds gusts late tonight in the 50 to 65 mph range. Local gusts very near the western slopes in particularly wind-prone areas could reach or go over 75 mph. 

One interesting - and rather ominous - subtle difference in the National Weather Service forecast since this morning, is the expected highest wind gusts have been nudged a little bit more away from the western slopes and closer to the Champlain Valley and Route 7 corridor in southwestern Vermont. 

It looks like top gusts of 60 to 70 mph could occur along and just east of Route 7. That's a pretty populated area. That makes us prone to more power outages and even some structural damage to buildings overnight. 

Much of the Northeast Kingdom also looks like they are in for quite a blow. 

We're still on track for lots of power outages. The majority  - but not all of us - should be fine though about 11 p.m. or so. Then it hits.

Mercifully, the period of highest winds looks like it will only last roughly six hours - from about midnight to 6 a.m. Then they'll diminish quite a lot. Wednesday will still be gusty, but not ridiculous. 

Actually, Wednesday in most of Vermont is shaping up to be a not terrible day, at least compared to the tempest we'll endure tonight.

Sure, it'll be breezy to windy, and we'll have a risk of showers through much of the day. But temperatures should peak in the low 40s, and only gradually cool down during the late afternoon and evening. 

This storm is being compared to that awful storm in December, 2022. But one big difference is that one featured a flash freeze and moderate snowstorm at the tail end.  That's not happening with this one.

I'm always looking for a bright side, folks! 

I won't get into it tonight, but we're still looking at another storm Saturday that will be similar to tonight's. So far, that Saturday storm is looking slightly weaker than tonight's but it will still cause additional problems. 

I'll get into that storm after we deal with tonight's mess. 

Video

To give you a taste of what to expect late tonight and early tomorrow morning, here's video I shot of a downslope wind event near Cambridge, Vermont in January, 2016. If anything, tonight's windstorm could be worse than this.

Click on this link to view, or if you see image below, click on that to view.