A Vermont Traffic Cam Proves The "Bridges Freeze Before Roads" Warnings

Northbound Interstate 89 Exit 10 in Waterbury,
Vermont this morning in this screen grab from a 
Vermont Agency of Transportation webcam. Note the
area of snow and ice ahead of the vehicle. That's
a bridge, showing how they DO freeze before the road.

As of early afternoon, road conditions had vastly improved in Vermont since this morning. 

The snow has stopped, and there were only a few patches of non-freezing drizzle left behind. Most places were a little above freezing as of 2 p.m. 

This morning, the worry was bridges and overpasses freezing even if roadways stayed fairly clear due to warm ground temperatures. 

That set up is especially dangerous, because speeding traffic encountering frozen pavement on bridges is a recipe for crashes.

There was a great illustration of the bridges freeze before road rule this morning on a Vermont Agency of Transportation webcam. It showed Interstate 89 northbound in Waterbury, including Exit 10 to Route 100.

The long exit ramp includes a bridge over Graves Brook. The screen grab in this post shows what the exit looked like during this morning's storm. Click on the image in this post to make it bigger and easier to see. 

As you can see, the Interstate, and most of the exit ramp looked just wet, maybe a little slushy.  But see that stripe of white in front of the vehicle taking the exit?  That's the bridge I was talking about. It was snow and ice covered, unlike the rest of the road.

The vehicle in the photo appeared to be braking, the motorist probably wisely anticipating the ice on the bridge. 

The bridges freeze before road rule will be with us all winter. But it's especially prevalent this time of year, when lingering warmth in the ground radiates to the road surface. There's no ground under bridges, obviously, so those overpasses get cold, quickly. 

Let this be a lesson: Don't let icy bridges surprise you this winter. Keep your speed steady and slow on approach to the bridge.  Don't smash your foot on the brake as soon as you are on the bridge.  You will probably spin out. Don't do any sharp accelerations or turn your steering wheel much. Just coast across to the other side.  

By the way, if a thermometer in your car says it's above freezing, don't necessarily trust it. It might be, say, 34 degrees. But it could well have been below freezing recently, and the bridge might not have had a chance to thaw out yet. 

All this is just a word to the wise, as it's just the start of winter. 

Will Lake Champlain Freeze Over This Winter?

Screen grab from the WCAX Sky Watch 3 ECHO Cam on
Burlington, Vermont's lakefront Thursday, January 27
still showed plenty of open water, even inside
the breakwater, despite several bouts of subzero cold. 

It's been a cold month, with lots of relatively calm and frigid, subzero nights. 

That's perfect for forming ice on lakes.  Pretty much everything is frozen over in Vermont now, except for parts of Lake Champlain.  

That's pretty normal, since it takes a long time for a large and deep lake like this one to completely freeze. 

Much of Lake Champlain has frozen, but as of today, January 31, large areas in the middle of the lake are still open.   The WCAX Sky Watch 3 ECHO Cam at the Burlington waterfront showed that area to be largely ice free.  

Much of the area inside the breakwater was still open, which surprises me considering how cold it's been lately. The area inside the breakwater tends to freeze quite a bit sooner than the open lake beyond. Burlington was at or below zero on 15 days this January.  That's the most in one month since February, 2015. The lake did freeze over that year, starting on February 16

 Maybe an unusually warm December that notably lacked cold nights is a lingering reason for that remaining open water this year. 

Lake Champlain still has a relatively decent shot at freezing over this winter.  A brief thaw seems likely this Wednesday, but temperatures will fall well below freezing again by Friday. Long range forecasts, though somewhat unreliable, don't seem to indicate any huge warmups through mid-February. 

We still have plenty of winter left in which the lake can freeze over. Since 1960, when the lake has frozen over, it's happened anytime between January 14 and March 8.  The freeze over, when it happens, is usually around the middle of February. 

Although climate change makes it less likely, February can be brutally cold and plenty frigid enough to completely freeze the lake. Just ask the Februaries of 1934, 1978, 1979 and 2015. 

If the end of February and early March is particularly cold and calm, a freeze over can happen then, obviously. But after Valentine's Day, things start to work against a Lake Champlain freeze over.  Average temperatures begin to rise as we head toward spring, so frigid Arctic air begins to get a little less likely.

The sun angle is increasing nicely by mid-February too.  The dark open water next to the ice, or dirt particles on the ice become better at collecting the sun's warmth, aiding in daytime melting.  Nights are a little shorter, too, by late winter, so an overnight period of calm, subzero temperatures doesn't last as long as it did in January. 

Lake Champlain freezes over less frequently than it once did,  thanks to climate change. The last time it completely froze was as of March 8, 2019.  That was the last time we had any sustained winter cold spells, until this month. In the past decade,  the lake has only frozen over three times.

If you had to pick a time when Lake Champlain freeze ups really start to get less common, it seems to be in the 1990s. 

 You have to go back to the 1970s to see the lake frozen most years.   Going even further back before the age of airplanes, Lake Champlain was regarded as totally iced over virtually every year. However, in those days, the lake was eyeballed from the shore, and areas of open water were almost surely overlooked in some winters. 

By the way, if Lake Champlain does entirely freeze over this winter, don't be like some foolhardy people I've seen in the past and try to walk, say, from Burlington to Plattsburgh.  The middle of the lake in particular is pretty unsafe even when frozen. Plus, it's extremely easy to get disoriented and lost out there if it starts to snow or wind creates a ground blizzard.

If Lake Champlain completely freeze this winter. Enjoy it.  Chances are with our new, warmer climate, it could be a few years before you see it again.