Thursday, September 25, 2014

Classic Indian Summer Unfolding In Northern New England, SE Canada

Morning fog breaks up to reveal bright
fall colors during a 2012
Indian Summer in Vermont.  
One of the big joys of autumn is Indian Summer, and parts of northern New England, the interior Northeast and southeastern Canada are in the throes of a perfect one now.  

Indian Summer is loosely defined as a period of sunny, warm, calm weather after some of the autumn's first frosts.

Most of the area now heading into Indian Summer had a big frost last week. That chill is  all but forgotten as temperatures will rise into the 70s under sunny skies for the next few days.

The core of this Indian Summer, with the best weather now through Sunday, will be in northern New York, Vermont, New Hampshire, Maine and an area of southeastern Canada including Ottawa, Montreal and Quebec City.

A very common fall weather pattern causes Indian Summer. Sprawling, slow moving high pressure systems often linger over the northeastern United States or southeastern Canada this time of year.

High pressure systems feature sinking air. Clouds need rising air to form, so the sinking air encourages clear skies.

The air in these autumn high pressure areas is often dry, so you get cool nights, but warm days with the sun.

The only major exception to the "no cloud" rule during Indian Summer is dense morning fog, especially near rivers and lakes. Pretty much every morning now through Sunday will feature patchy early morning fog.

The air cools off a lot at night during Indian Summer. The ground, rivers, ponds and such are still pretty warm from the recently departed summer. As the air cools, the relative humidity goes up and the moisture from the warm-ish rivers and ground, etc. forms a dense fog.

On the negative side, dense fog is dangerous because anyone who's driven through it knows you often can't see a damn thing it's so thick.

On the bright side, the morning fog is almost always a sign of another beautiful day in store. The rising sun will quickly dissipate the fog, usually by mid-morning.

A Pro Tip here: If you want to photograph fall foliage, get out there when there is dense morning fog. Yeah,  I know you can't see the foliage through the fog, but just wait. The rising sun, with its low angle, combined with dissipating fog around brightly colored trees, often leads to some spectacular photos

Try it, you'll see.

Speaking of foliage, this current Indian Summer is hitting when the foliage is getting very colorful in some areas. The High Peaks of the Adirondacks, the Northeast Kingdom of Vermont, far northern New Hampshire, the mountains of western Maine and the Laurentians of southeastern Quebec are approaching peak color.

Lower elevations to the south of this region have some color, and it's nice, but there's still a fair amount of green.  It's still worth a look at the colors in those areas if you can't head to the north and mountains.

As always, Indian Summers have several days of wall to wall sunshine, but there are interruptions. The first nor'easter of the season is causing a rainy day in the mid-Atlantic states. That huge high pressure system causing the Indian Summer will block that nor'easter from reaching northern New England, but it will throw a few clouds into the sky today.

A cold front heading due south from Quebec later Sunday and Monday will cool off the weather a bit and create some clouds next week, especially since an east wind behind the front will bring in some low clouds from the Atlantic Ocean into parts of northern New England.

But meantime, enjoy this spectacular weather.



Go out and enjoy during this Indian Summer.

There's early foliage viewing to enjoy

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