Dense Northern Vermont Smoke Ending; Otherwise Little Change In Soggy Forecast. Floods Next?

Motorists make their way through thick haze along
Interstate 89 in Georgia Sunday. Wildfire smoke
from Canada created an air pollution problem in
northern Vermont. 

 The dense smoke from yesterday lingered overnight in northern Vermont, causing dangerously toxic air all night, but relief was beginning to settle in this morning. 

As of early this morning, most of the bad air had been flushed out, except in the Champlain Valley, where it seemed to be temporarily trapped. 

The bad Champlain Valley air should gradually improve over the course of this morning. Then we go back to our regularly scheduled programming of watching for possible flash floods here and there in Vermont all week. 

Let's get into the deets, first with the remarkable amount of wildfire smoke on Sunday

VERMONT POLLUTION EXTREME

To get you oriented, here's the air quality scale:

0-50 - Air is clean, 51-100, it's' moderate, 101-150 it's unhealthy for sensitive people, 151 to 200, it's unhealthy for all of us, and 201 and above it's very unhealthy for everyone and we should really just stay indoors. 

I saw reports from people last night saying their air pollution apps were registering as high as 269, so that's bad. Official readings from the Vermont Department of Environmental Conservation at around 7:30 p.m. Sunday evening had the index at 215 in Burlington and 210 in Underhill.

Northern Vermont was truly one of the most polluted areas on Earth Sunday afternoon and night. 

Southern Vermont was never really affected by this. The air quality index at Bennington hovered at around 20 all day Sunday which is about as clean as you can get. 

Satellite photo taken around 5:30 p.m. Sunday shows
thick smoke over northern Vermont, but perfectly clean
air in far southern counties. It also shows a 
thunderstorm over Addison County, and more storms
over southwestern Vermont. 

Early this morning, east and southeasterly winds began to push the bad air northwestward out of the region. 

It looks like a temperature inversion was keeping the smoke in the Champlain Valley early this morning, though. The cleansing south winds couldn't yet dig down into the valley floor.  I notices the air quality in Underhill was quickly crashing early this morning.  It went from a kind of icky 132 at 6 a.m. to a very nice 40 by 6:30 a.m. 

Meanwhile, during that time, Burlington stayed stuck between 195 and 200. From my perch on a hill in St. Albans, the sky overhead was a nice blue, but there was still a bit of haze around my house, and you can see a thick brown cloud still covering the valley below. 

The temperature inversion should break up later this morning, and the Champlain Valley will clean out. That's not to say another smoke attack won't happen again this summer. Fires are still certainly burning in Canada, so there's nothing to stop the smoke from returning to Vermont if the wind is right. 

FLOOD RISK LOOMS

As we've been talking about for days now, a risk of local flash floods should be with us all week.  Already, a flash flood warning was issued for part of northwestern New Hampshire near the Vermont border last evening, and another flash flood warning was up for areas near Mount Washington, New Hampshire earlier this morning. 

That risk will spread into Vermont, probably starting today and lasting all week. 

At any given time, only small sections of Vermont will be under flash flood warnings. You'll probably see an alert from time to time covering just certain sections of Vermont counties, warning of possible flash flooding. 

During much of the time this week, there won't be any warnings at all, since these local floods will have short fuses.

It'll rain torrentially on a particular set of mountains, a big gush of water will come down the slopes from all the rain, the storm will dissipate and the water will quickly recede, having already done its damage.

Any flash floods we might get would probably be pretty small in area, but are quite dangerous. As the name suggests, they  happen in a flash. There's not much time to get out of the way.  If you're in a flood-prone area, this is a great week to stay on your toes and move quickly if you get a warning. 

If you're driving in a downpour and see a little water gathering on the road ahead, don't chance it.  Even if the water in that instance isn't enough to carry your vehicle away, the water could rise dramatically in seconds while you're trying to splash through it.  Not a good scenario. 

All of Vermont will get a lot of rain this week, but large sections of the state will escape any real flooding. It will be hit and miss.  If there's any flash flooding, it's most likely in the afternoons and evenings each day through the week. 

As expected, there wasn't much rain around Vermont this morning.  But as a disturbance riding through the big upper level low that's stuck to our west comes through, showers and storms will blossom this afternoon. 

They'll wane somewhat tonight, and redevelop Tuesday.  Tomorrow to me looks even potentially wetter than today.  Wednesday looks awfully soggy, too.  It won't rain all the time, but occasionally, it will really come down. 

The risk of flash flooding will grow as the week goes on as soil conditions get wetter and wetter from all the downpours.  I'm guessing that since most of the slow moving scattered showers and storms yesterday were in southern Vermont, that's the part of the state that seems most likely to have issues here and there today with high water. 

Where and whether any problems arise from tomorrow onward is anybody's guess