What good is Fog?
I don’t know about you but fog for me is a bummer. It restricts visibility and makes driving dangerous.
Pile ups on our interstates usually start with restricted visibilities. I can remember many a night coming up the summit mountain and barely being able to see the front of my car. On several occasions at the mountain summit I encountered confused motorists starting down this road on the wrong side of the highway.
Fog can be a killer and it is one of the most useless of weather events. Mountain tops are a favorite hideout for fog and our nearby mountains can be covered in a thick blanket of fog while the lower elevations are fog free.
Another hideout for fog is in our deep valleys, particularly if they have a river or stream at their bottom. Fall is a favorite time for valley fog to form when cooler air, which is heavier than warm air, likes to settle in our valley bottoms.
Our valley fogs rank third behind the Atlantic Coast fogs of New England and the Pacific Coast fogs of Washington, Oregon and California.
Foggiest of the foggy is Cape Disappointment at the mouth of the Columbia River between Oregon and Washington. Heavy fog is reported 2,552 hours a year, the equivalent of 106 complete days of dense fog of visibility less than 1/8 of a mile.
Wallapa, also in Washington, holds the record of 317 foggy days in a year. San Francisco, known as the foggy city, averages over 40 foggy days each year downtown while the airport just a few miles away has only 17 days on average per year. When you think about it, that was a smart move putting the airport location away from the fog as fog is a big hindrance to airport operations.
On the Atlantic coast Nantucket Island averages 85 days of dense fog and the entire coast of Maine is foggy.
Closer to home the Appalachian valleys of West Virginia see an average of 50 to 60 foggy days. In our area the summit sees about 50 foggy days mostly in the morning while Uniontown averages about 20 days.
The least foggy town in the United States is Key West where only one foggy day per year is the average.
The foggiest place in the world is Newfoundland, Canada with 158 foggy days on average each year. London like San Francisco is forever associated with fog even though their average is just 30 days of dense fog. It is the smog of the past that gave the city its foggy reputation.
Christopher Burt in his book “Extreme Weather” explains that until the 1960s Londoners heated their homes with soft coal stoves. Winter temperature inversions trapped the smoke from these stoves at ground level sometimes for days on end with catastrophic results. From December 3-10 in 1952 more than 4, 000 people died from inhaling the fumes of coal smoke and sulfur dioxide which mixed with the fog to form a lethal soup of air.
Great Britain passed the Clean Air Act in 1956 largely as a result of this disaster.
Even a cloudy day beats a foggy one.