Friday Storm Looks Increasingly Dangerous For Vermont - And Large Swaths Of Nation

If anything, the forecast map for Friday issued
early this morning, gives the expected storm
a more powerful look that previous forecasts.

 All eyes continue to be on that developing Arctic blast and giant storm that will affect most of the United States this week with often very dangerous weather. 

Vermont remains one of many states in the bullseye of this system. 

This will be a pretty memorable storm for much of the nation. This won't be the coldest blast of Arctic air ever. But we still expect some record lows. 

What makes this developing situation such a hazard is the combination of strong winds over a huge area, combined with snow to the west and heavy rain to the east. 

Strong to damaging winds are possible just about everywhere in the United States from the Mississippi River east, and in much of Ontario and Quebec.

As of this morning, some of the ingredients that will lead to this storm blowing up in the middle of the nation are already screwing around with things in Washington State and in British Columbia. 

Snow is causing some big flight delays in Vancouver.  Travel is also hampered by snow in and near Seattle. These problems will only spread as the week goes on.

Wind chill alerts for the upcoming Arctic blast now extend from Montana and Alabama, and those alerts will only expand over the next couple of days. Big swaths of the Midwest are under a winter storm watch, and a blizzard is likely in many of these areas by Thursday. 

National Weather Service meteorologists aren't mincing words with this storm:  In the Minneapolis NWS forecast discussion, they wrote: "This is still looking to develop as a high end, life-threatening event." 

The National Weather Service in Buffalo, New York is also warning of destructive winds, heavy rain and then a blinding lake effect blizzard Friday into the weekend. "This intense storm is forecast to be climatologically 'off the charts'........One could certainly describe this storm system as a once in a generation type of event."

The Chicago NWS office is warning of a blizzard, widespread power outages due to powerful winds, and lakeshore flooding. Ten to 14 food waves from Lake Michigan could slam the shoreline in northwestern Indiana.

So yeah, you get the idea. This storm will screw things up for lots of people. 

VERMONT EFFECTS

Here in Vermont, the hazards include a little freezing rain, a LOT of wind, a flood risk and a flash freeze. 

WIND

Meteorologists at the National Weather Service office in South Burlington, when forecasting, look at what are known as analogs. 

In other words, they look at what the forecast calls for, based on current information, and compare that to similar, real-world storms that occurred in the past.  

Roof and tree damage in Milton, Vermont, October, 2017
after a powerful windstorm. Some forecasts suggest 
the upcoming storm could be as destructive as
the one shown here. 

In their forecast discussion Monday evening, the winds with this expected storm remind National Weather Service meteorologists of either October 30, 2017 or December 10, 2010.

The October, 2017 wind storm was widespread across western Vermont, with damaging downslope winds on the western slopes of the Green Mountains extending all the way to Lake Champlain. 

That storm cut power to more than 150,000 people in Vermont, nearly a quarter of the state's population.  We saw quite a lot of power line, tree, roof and some structural damage in much of the state.

In that storm, winds gusted as high as 63 mph in Burlington and 78 mph in Wells. 

The December, 2010 storm wasn't as widespread but created some wild wind gusts on the western slopes of the Greens. Gusts exceeded 90 mph in some areas. To give you an idea of what December 1, 2010, click on this link for the scenes in Williston, Vermont during that storm. 

One slightly mitigating factor in the upcoming storm, according to the National Weather Service in South Burlington, is that an inversion layer just below summit level might deflect a bit of the wind. But the storm is forecast to be super strong, with near record low barometric pressure. So strong to damaging winds are almost inevitable.

Power outages are likely with this thing, and they might last awhile. We're still recovering from last weekend's storm.  In that case, Green Mountain Power was able to pull in crews from surrounding states to help restore power. Our snowstorm last weekend was fairly localized. It wasn't as if the entire Northeast was buried in snow.

It won't be so easy to get help restoring power from other states with this upcoming storm. They'll have their own problems to deal with. Damaging winds will hit from Minnesota to Maine and from Quebec to the Carolinas. 

FLOODING: 

This powerful storm will bring a slug of warm, wet air with it.  That'll get the snow melting pretty fast on Friday as temperatures rapidly rise to the low 50s. With such a dynamic storm, bursts of heavy rain are also inevitable. Current forecasts give us one to two inches of rain.

The following might change, but forecasts as of Tuesday put the heaviest rain in southern and southeastern Vermont, right where the deepest snow accumulated last weekend.  That could certainly spell flood trouble.

Already, forecasters are eyeing vulnerable waterways like the Mad River and Otter Creek for flooding.  Smaller streams are of course risky, too.  Forecasters will have more concise predictions for flooding as we get closer to the storm. 

FLASH FREEZE

At the onset of the storm, there might be a little freezing rain to slicken the roads for a short time, especially east of the Green Mountains, but that piece won't be a main player in this big show. 

Instead, the rain and warmth will end super abruptly sometimes later Friday, Friday evening or Friday night. A powerful cold front with this big storm will roar through. At this point, forecasts call for temperatures to fall from the low 50s to the mid and upper teens within something like four hours.

That sets up a flash freeze. All the water on the roads and sidewalks and driveways freezes in an instant. You can see how that would mess up travel. We'd also get a big blast of wind after the front from the southwest.

This wind for the most part probably won't be as strong as in the front side of the storm. But it could still be gusty enough to knock down more trees and power lines. 

Because the Arctic air behind the storm is not coming at us directly, it won't be nearly as cold in Vermont as it will be points west.  The bitter air will plunge southward into the Midwest and Gulf Coast states, then swing northeastward toward us. 

That'll give the air a chance to modify, and it will only get sort of cold up here in Vermont (Highs in the low to mid 20s, lows near 10 Saturday through Monday).  But if there's widespread power outages because of this storm, that will cause a lot of misery, and frozen pipes.

As always, changes in the forecast between now and Friday are inevitable. This does feel like kind of a gloom and doom post. As we draw nearer to the storm, things will either look as bad as they do now, or maybe less bad, who knows?

I'm going to be out of Vermont when the storm hits. Oddly, I'm a little sad I'm going to miss the excitement. 

In any event, I'll provide updates as I'm able while I'm traveling later this week.