Fog Season In Vermont; Fog Attacks Power Grid On West Coast

In this morning visible satellite photo, you can see
fog hugging the Connecticut River Valley, and parts 
of the Winooski and White River Valleys. You can 
also see fog running up the valleys that go along
the tributaries of these rivers.

 I'll get to the first part of the above headline first, because - huh???   

Usually, when electricity goes out for weather related reasons, it's because of high winds or lightning.

But in the San Francisco Bay Area on Sunday, 29,000 lost power because of a decidedly non-violent weather event: Fog and drizzle.

In the Bay Area, it generally doesn't rain in the summer.  According to television station KPIX, dust and debris settles on power lines and power equipment over the dry summer months.

  When dense fog and drizzle finally arrives with the first autumn storm, as it did Sunday, the moisture interacts with the debris and dirt to cause flashovers. And Voila! power failures.

I mention that weird Bay Area weather story in part because here in Vermont, we're in peak morning fog season. We don't have to worry about fog-related power failures, because it rains so frequently here in the summer that dust and debris don't accumulate on power equipment.  

Here's why we get so much morning fog this time of year:  The ground and the water are still warm from the summer. Nights are getting cooler, especially the nights with clear skies and light winds, like we had last night. 

Warmth and moisture rising from the ground and water hits the cold air and condenses into fog.  Often thick fog.  You really have to be careful driving early in the morning on days like this because of the patchy nature of the fog.

You're cruising along and you can see for miles and suddenly you're in a fog bank and you can't see a thing. If you're not paying attention and you're unlucky, you then crash into the invisible car in front of you in this pea soup. 

On the literally bright side, the sight of morning sun piercing the fog is gorgeous, and makes for some absolutely stunning photography.  So it's probably a good idea to have your camera with you on foggy mornings.

This morning was a classic Vermont fog morning. Last night, as noted, was clear and a bit chilly. Dense fog filled many of Vermont's river valleys. I noticed towns like Montpelier, Morrisville, Lyndonville and Springfield all reported dense fog this morning. 

Meanwhile, my place is perched on a hill in St. Albans. Nothing but blue sky out there for me. 

You can see the fog outlining river valleys in the satellite photo in this post. 

The next few nights will probably have less fog than this morning, because breezes will be picking up.  Overnight winds tend to disperse fog before it can get too dense.  The fog for the next few mornings will probably limited to the deepest valleys most protected from the wind.

However, we're likely to have more foggy mornings, at least until most of the leaves are off the trees.  Leaves emit moisture, and losing those means a source of water for the fog goes. Also, once we get into late autumn, it's more often than not too windy to sustain morning fog.