Smoky High Up Over Vermont, Some Fire Risk Down On Ground, And A Bit Of Frost?

Visible satellite photo from this Monday afternoon. Those
milky streaks you see running from Ontario into northern
New York and New England is smoke from fires 
burning in Alberta, Canada.

It's been another beautiful spring afternoon in Vermont this Monday, but you might have noticed the sky went from blue to a hazy, milky kind of look during the afternoon. 

That's not high clouds. It's smoke. You might have read in a previous post I wrote recently noting the big fires burning up in Alberta, Canada. That smoke was pushed high into the atmosphere and rode west to northwest winds to be over New England today. 

Satellite photos, like the one taken this afternoon shown in this post, shows those streaks of smoke overhead. 

The smoke is many thousands of feet overhead, so it's not really affecting air quality down here on the ground. If you're having respiratory or sinus issues, it's likely allergies from all the trees blooming at once, and not smoke. 

We are, however, at some risk of smaller scale smoke generation here in Vermont. Believe it or not, the fire danger has crept upward again. 

Yes, last week was rainy, so it should still be pretty soaked out there. But this time of year, as noted in a post back in April, we can get some very dry air masses from southern and central Canada this time of year. That's just what's happening now. 

The relative humidity is in the 20 to 28 percent range for most of us this afternoon. That's really, really dry. At least by our standards. That's once again drying out last year's dead vegetation, setting us up for a fire risk. 

It's also breezy out there this afternoon, so that could spread fires. 

Tomorrow, it's more of the same. It might not be quite as breezy as today was, but it will be sunny and super dry again.  This is not the week to set your burn pile alight. Wait for a rainier period. 

The dry air poses another seasonal risk: Frost.  

The sky had a sort of hazy, milky character this afternoon
over Vermont. That was smoke thousands of feet overhead
generated by wildfires in Alberta, Canada. 

When the air is dry, temperatures tend to fall off very fast after sunset. Sure, it was near 60 this afternoon. But you'll notice it getting colder fast as the night goes on. 

A frost advisory is in effect for the Champlain Valley away from the lake tonight. Another frost advisory will probably be needed for the same area tomorrow night. 

This won't be any means be a deep freeze, at least in the Champlain Valley.  But with temperatures tonight and tomorrow night expected to touch the mid 30s, frost is a good possibility if you're inland from the lake. 

Cover your sensitive plants or bring them in. For instance, if you're trying to harden off your tomato starts by leaving them out on the deck, bring them inside tonight. More hardy blooms, like your lilacs and crab apple blossoms, will be just fine. Don't worry about 'em. 

Elsewhere in northern Vermont, it will be even colder tonight and tomorrow night than in the Champlain Valley. Lows there will be within a few degrees either side of 32 degrees.

The reason we have a frost advisory in parts of the Champlain Valley and not elsewhere is that the growing season is considered to have started now in the warmer valley. The growing season is not regarded as underway yet elsewhere in northern Vermont, so there's no need for any kind of frost advisory.