Early Thursday Update: Worrisome Wind Forecasts For Much Of Vermont

Updated wind forecast issued Wednesday afternoon. Peak
gusts for Burlington and St. Albans might be under-done
a bit. But note the 74 mph expected gusts in Rutland. 

UPDATE: 8:30 AM

I'm able to update this post, which I first wrote at 2 p.m. today.  In my travels, I'm waiting for a connection to Baltimore from JFK. 

Not much updating needs to be done to the previous discussion, below.  

The wind threat remains very, very real.  To the point where I see storm chasers appear to be on their way to Vermont to see the show Friday. 

Anytime storm chasers take an interest in your state, you know you have trouble.

One added piece of danger. It looks like some of the higher elevations could have two to six inches of wet snow tonight before the changeover to rain.

Some of that wet snow could still be clinging to trees when the howling winds arrive later Thursday night. That would only compound the inevitable power outage issues. 

The only other additions I'd make for now to what I wrote below is the powerful cold front that will sweep through Vermont will have its own batch of interesting weather. As if there wasn't enough of that already.

We already know temperatures will crash with the passage of the front, yielding to that vaunted flash freeze.  According to the National Weather Service, the front could be so dynamic that we could have thunder, torrential rain, heavy sleet and possibly a quick burst of snow toward the end.

Previous discussion follows, which is worth the read, as it's got some important info:

PREVIOUS DISCUSSION

Unfortunately, if current forecasts are true, the upcoming storm might be among the worst wind storms Vermont has seen in decades. 

According to forecasts issued last night and early this morning, the biggest worry spot is the Champlain Valley. 

Meteorologists have known for days that downslope winds on the western slopes of the Green Mountains would become ferocious on Friday morning. In favored spots right near the mountains, winds could gust to 70 or 80 mph or more.

That's bad, and would cause some damage, but it's happened before. This region is fairly sparsely populated, and the people who do live in this region have some experience with such powerful gusts. However, it's looking like the damaging winds might well  extend much further west into the Champlain Valley. 

Here's an excerpt from the forecast discussion from National Weather Service office in South Burlington, issued late Wednesday afternoon:

"Peak gusts comparable to a category 1 hurricane are forecast in the western slopes of the Green Mountains. We're increasingly concerned by the likelihood of populated areas well away from the mountains, including the populated Champlain Valley towns in Chittenden and Addison  counties, not accustomed to seeing winds of this magnitude."

This translates to winds gusting to more than 65 mph in these populated areas. It's not out of the question winds in the Route 7 corridor could reach 75 mph.  For comparison's sake the strongest wind gust ever measured in Burlington since at least 1900 was 72 mph. 

This could well be one of the worst wind storms in history, at least in the western half of Vermont. "Multiple long time forecasters have not seen winds at this pressure level at this magnitude in our region," the Wednesday evening forecast discussion stated, ominously."

The winds are forecast to ramp up quickly late Thursday night and early Friday and peak during the early to mid afternoon. 

According to the high wind warning that's been issued: "People should avoid being outside in forested areas and around trees and branches. If possible, remain in the lower levels of your home during the windstorm, and avoid windows."

What worries me the most is those many neighborhoods in the Champlain Valley that have lots and lots of trees. Some of those trees seem like they might crash onto or through some of those houses. This is dangerous!

I'd also expect some long lasting power outages in the worst hit areas.

Green Mountain Power announced Wednesday that they were able to keep a lot of the crews that came from out of state to deal with last weekend's massive snowy power outages here in Vermont to deal with this new storm. 

Despite the big crews ready to help with outages, GMP urged customers to be prepared for real trouble:

"With cold temperatures forecasted, customers should have a plan for where to go if they need to leave their home and how they would get there. With extreme high winds, there can also be hazards like flying debris that can make it unsafe for anyone outside, including crews." 

It's a tricky forecast, so it's still possible the wind could under-perform in western Vermont. But definitely don't count on that! The wind doesn't look like it will be as bad in eastern Vermont, but some tree damage and power outages seem likely even there.

The wind is obviously the biggest danger from this storm, but we continue to watch other issues:

 INITIAL ICE

Forecasts have trended a little colder with the onset of the storm. That means some places might receive a couple inches of snow, and some other areas will see some sleet and freezing rain. This will be a problem for anybody on the roads overnight Thursday. Rapid warming early Friday morning will erase this hazard.

FLOODING

This is still a real issue. The storm's powerful cold front will produce a period of heavy rain. Right ahead or along the cold front, a narrow band of torrential rain, similar to a summer squall line, seems possible.

Total rainfall looks like it will be in the one to two inch range, with higher amounts in some spots Combine that with rapidly melting snow, and you have a real problem.  A flood watch is up for much of Vermont, especially central sections of the state. 

River forecasts have gotten more detailed with updates. The Mad River at Moretown is expected to come close to moderate flood stage. Many if not most other rivers in Vermont will probably reach minor flood stage.

I'm especially worried about some of the smaller rivers in southern Vermont. The heaviest rain is expected to fall there, and the deepest snow from last weekend also accumulated there.

FLASH FREEZE 

The anticipated flash freeze is still on. With the cold front, temperatures will crash from the low 50s to the 20s in a matter of as little as two hours.

The freeze looks like it wants to come just a bit earlier than first forecast - probably late afternoon.

Roads will freeze instantaneously.  We also expect a brief period of freezing rain, sleet and snow as the temperatures plunge. 

BOTTOM LINE

If forecasts hold, this could be an historic storm for Vermont, comparable to the Great Appalachian Storm of 1950.  Hang onto your hats!