 |
Image from firesmoke.ca shows smoke from fires in central Canada is spreading far and wide in North America, including here in Vermont |
The smoke is back.
And it will probably harass us off and on all week while rain (mostly) stays resolutely away from the Green Mountain State.
Oddly strong high pressure will take the blame and the credit for a long period of dry weather, often smoky skies and warm summer weather.
Saturday started off pretty clear but the haze thickened through the day. The thickest smoke stayed aloft, but some of the pollution, inevitably, made it to the ground. Evening was a hazy mess, at least in northern parts of the state.
Canada has gotten even smokier as fires have intensify and grown widespread in central parts of that vast nation. New, large fires have also exploded in the Northwest Territories and Nunavut.
There's now a hell of a lot of smoke belching into the skies above North America.
This is a widespread smoke attack. Air quality alerts have been in effect for a few days, and remain on in places like Michigan, Minnesota and Wisconsin. Most of Maine and the northern half of New Hampshire joined the air quality alert party Saturday afternoon, warning residents that most of today would be smoky.
By late Saturday afternoon, the National Weather Service office in Burlington, in their forecast discussion, were already monitoring the smoke, which had already turned our skies hazy and greyed out some of our Green Mountain views.
Before dinnertime, the Vermont Agency of Natural Resources issued our own air quality alert.
TODAY
That bad air alert is now in effect at least until midnight tonight. The breezes, which had been from the north, have shifted to the south. That will keep the worst of the air toward northern Vermont. The smoke will be even thicker up in Quebec and Ontario.
Still there is some air flow aloft coming from the opposite direction - the north, which would bring more smoke our way. High pressure systems feature sinking air, so some of that smoke aloft will make it down here to the ground, where we all live and breathe.
The bottom line is that air quality was moderate to unhealthy for sensitive groups this morning. That already kinda bad air might worsen a little more through the day, but will not be as bad as the abysmal air quality we endured on July 26.
It'll still be a little rough on the lungs, though.
Otherwise, another comfortably cool morning will morph into a warm, sunny, if hazy day. The humidity will stay perfectly reasonable,
MONDAY
Weather systems - both storms and areas of fair, sunny weather - tend to be weak this time of year. But high pressure is growing over Quebec and New England.
This high pressure will be at near record strength for August. It's more typical of the super strong high pressures that give us periods of Indian Summer weather in October if we get lucky. High pressure means sinking air. Sinking air means it's really hard for rain clouds to form. Hence the very dry forecast.
The southern end of this high pressure over New England is weakening in favor of a center over Quebec. This will send a weak cold front our way tomorrow.
The air is so dry that at most the front might produce isolated light showers. More than 90 percent of us won't see any rain at all. The very few of us that do see raindrops will get only a trace to maybe a couple hundredths of an inch, Not even enough to wet things down at all.
The front will bring another wave of smoke with it. so I anticipate some possible new air quality alerts this week. Highs should make it into the 80s again.
REST OF WEEK
The high pressure will sit strong all week, only slowly dropping south from Quebec through New England between now and next weekend. It's huge, and will extend down as far south as Georgia this week.
Monday's cold front will make Tuesday a degree or two "cooler" with highs "only" in the 78 to 84 degree range for most of us.
The orientation of the high, and the fact that it pushed last week's cold front almost all the way to the Gulf Coast. That will deep tropical humidity away from us probably at least through the end of the week.
That means the air will stay fairly comfortable (aside from any smoke). I suppose an isolated shower or two could figure out a way to develop over the mountains on one or two afternoons this week, but almost everybody will stay dry.
We might, maybe could get a bit of a break from the smoke later in the week. Southerly winds in the worst often fire zone in Manitoba and Saskatchewan later this week might temporarily drive most of the smoke north into Nunavut and western Hudson Bay.
Back here in Vermont, the odd August combination of daily sunshine, sort of low humidity and warm temperatures sets the stage for a growing forest fire risk.
The brush fire risk was already high in the Champlain Valley this weekend, and I imagine the moderate risk on most of the rest of the state will increase to high this week. Watch those campfires, cigarette butts and backyard burns.
Also, unlikely but possible is the risk of a flash drought.
This is a weird, long stretch of dry weather with a lack of humidity, quite uncharacteristic of August. If this continues all month, then we have to start worrying about too-dry conditions and possible drought.
It's too early to sound the alarm on that. We could still get a lot of rain starting mid month, we just don't know yet. But I already have to water my gardens thoroughly today for the first time this summer, and that state of affairs should continue.
The next chance of any more widespread showers looks to be a week from tomorrow, and even that looks iffy at this point.