Satellite Photo Shows Wall of Fog Avoiding Bernal Heights

Our friends at NASA, that *other* space agency, shared a recent satellite photo that shows a massive wall of fog rolling in to San Francisco — and (in typical fashion) completely missing Bernal Heights:

For some people, the relentless waves of fog that roll off the Pacific Ocean into San Francisco each summerinspire awe. For others, they arouse frustration, even depression. Either way, fog is simply a fact of life for San Franciscans, particularly those who live near the Golden Gate Bridge.

The Advanced Land Imager (ALI) on NASA’s Earth Observing-1 (EO-1) satellite acquired this view of fog encroaching on the city on August 16, 2012. The fog is part of the marine layer, a mass of cool, dense air from the sea that was sandwiched beneath a layer of warmer air as part of a temperature inversion. Fog is often present in the lower part of the marine layer, whereas wispy stratus clouds form in the upper part.

Intrusions by the marine layer—and all of the accompanying fog and clouds—are routine in San Francisco during the summer. The intrusions are caused by westerly breezes that push cold air inland to replace the warm air rising off of California’s Central Valley. As it did on the day this image was taken, the marine layer often completely envelops the Golden Gate Bridge in a thick cloak of fog and clouds.


8 thoughts on “Satellite Photo Shows Wall of Fog Avoiding Bernal Heights

  1. I’ve lived with the marine layer my entire life, and I did not know that fog is only ‘the lower part of the marine layer’. I always thought fog WAS the marine layer. Yay NASA!

  2. That headline is ridiculous — the photo shows the fog missing a much larger swath of San Francisco than just Bernal Heights.

  3. Hmmm…not sure about this. I recently moved to Bernal and I have never seen SO much fog, felt so much wind and cold during the summer as I have here. Maybe it depends on if you’re on the Mission side of the hill or south side (where I am) – it’s foggy and cold all the time! The warmth of the community makes up for it though. 🙂

    • Wind we definitely get, but fog? Not so much compared to most of the rest of the city (re: Anything west of Twin Peaks).

      Or weather isn’t as nice as the weather in, say, Bayview, but the Bernal microclimate has the western and northern parts of the city beat all to hell.

  4. Pingback: That Cold Chill Means Karl the Fog Is Visiting Nearby | Bernalwood

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