Good morning bloggers,

Here is a video for tonight and Monday:

What just happened in California is rare, extremely rare.  Not only was there a “PyroCumulonimbus” cloud that formed over a fire in Northern California, but there were severe thunderstorms early Sunday morning over San Francisco and into the wine country of Napa Valley.

Everyone keeps looking at this incredible picture and the videos, but what is missing is the wider view, where you can see the Pyrocumulonimbus cloud.  Take a look at this:

Moisture was streaming up and around an Anticyclone forming over the southwestern United States.  This monsoon moisture was available for the updrafts, caused by the big fire, creating the actual cumulonimbus cloud.  The lower part of the strongly rising hot air, from the flames, is all smoke, and then the updraft reached the condensation level and the cumulus clouds formed.  This had to have been quite the sight to experience. This may have formed into a Supercell Thunderstorm and the conditions became favorable for a tornado to develop.

We will often see fire whirls, that are more like dust devils and land spouts. They are the flames we see forming into a funnel with a hot spot updraft.  What happened Saturday was likely a combined effort from the developing thunderstorm and the hot flames.  FASCINATING!


Gary Lezak

Author Gary Lezak

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Join the discussion 10 Comments

  • Willy Wallace says:

    Gary you mention a couple of times that we are in an interesting weather pattern. How so? If by interesting you mean dry, boring, and repetitive I would agree with you. It hasn’t rained in Topeka since the flood-rains in late July. Certainly hasn’t been interesting, just predictable, boring, summer weather where all the days run together more or less. We need some rain soon but nothing looks promising.

    • Gary Lezak says:

      It’s interesting to me, but also frustrating.

      • Willy Wallace says:

        That’s fair. A while back you mentioned in your old weather journals that sometimes in July/August you had days with no notes. Aside from a dry front here and there, I would say that describes the past few weeks and the upcoming week.

        Giving this pattern a letter grade has been hard. It has stretches were it is nearly at an A but then goes entire months where it just doesn’t show up to class. Overall it’s still at a C since August is generally a hot/drier month but if it doesn’t show up for September it’ll be hard to give it a passing grade.

        Looking forward to the next LRC.

  • Heat Mizer says:

    Hmmm……seems to be no weather blog here or on KSHB today.

  • Michael Garner says:

    Gary on the the 1 weather app it shows the temp forecast for 26 August at 97 degrees. Do you think that’s a possibility? Hasn’t been overall too bad I guess for the summer but as a fall and winter fan I’m so ready to be done with temps in the 90’s.

  • Three7s says:

    Something tells me there won’t be a blog today either considering there is next to nothing going on in this region for the considerable future.

    • Gary Lezak says:

      It is about as boring as can be right now, for us. We will discuss tomorrow. I did write a blog for KSHB.

      • Willy Wallace says:

        Instead of dog days, I like to call these the groundhog days of summer, in reference to the Bill Murray movie. Is one day any different than the previous handful? Maybe, but you wouldn’t know it from the weather.

  • Troy Newman says:

    It was exciting here just a couple days ago. (Not really the right word). Had some softball size hail just West of me. Destroyed crops, broke out windows and windshields. I can’t remember a storm like that in August before. Came in the Northeast.