Not expected, but it missed anyway

Woke up to Cumulonimbus clouds NW-N of Catalina.  Hmmm.  Here’s the unexpected, pretty sight just after sunrise:

7:24 AM. “Pretty, but will likely die much after sunrise.” Cumulus and Cumulonimbus clouds along a windshift line moving toward Catalina continued to develop throughout the morning while getting closer.
9:34 AM. Odd line of Cumulus congestus growing into Cumulonimbus clouds with major rainshafts is getting closer still. “What’s keeping this going so early in the day?”


10:00 AM. “Upon closer inspection….”, a windshift line is detected via photography!
Arrow point to shred cloud below base of the turret at left. This is a great example of how clashing winds build clouds. Above the shred clouds is that vigorously growing turret trying to reach the glaciation level.
10:06 AM. It made it! (to the glaciation level)  Maybe it means that the line of fat Cumulus-Cumulonimbus might make it here to Catalina and rain on me! I’m getting excited. Arrow points to icy top, though as cloud maven juniors you would already recognize that icy top, so I left the arrow out since I forgot add it anyway.  These are the best kinds of icy tops to study with an airplane because they near the threshold temperature where ice forms in clouds on this day.  That threshold level changes from day to day, strangely believe it, and the warmer the BOTTOM of the cloud, the HIGHER the temperature at which ice forms, strangely believe it#2.  Even stranger, Mr. Cloud-maven person thought he had discovered this interesting fact back in 1988 and then he found that this guy, the Englishman, Frank Ludlum, one of the best we’ve ever had in cloud studies, and I should have known better, had reported the SAME THING 36 years earlier in 1952!  There is nothing new under the sun, Ecclesiastes said, and I guess I found out first hand.  Darn.  I laughed bitterly when I saw that Science mag cartoon about stuff like this, posted below because it won’t fit in this caption.  Darn.  You can see I still have some feelings about having something to report but then finding out that it had already been reported. I thought maybe I was gong to be famous, perhaps win a prize of some kind, but no.  (See second cartoon)

Well, the end of the story (told in the captions) is that a windshift producing this line of heavy Cu and a Cb or two and it “struck” Catalina about 11 AM;  the wind turned from the SW to the N, but the heavy line of clouds riding it were nowhere to be seen at that time; the last Cumulonimbus cloud disappearing beyond the Charoleau Gap. Tough to take after hopes up.

Only in the early afternoon did a gift of a few drops from a towering Cumulus directly overhead produce the final surprise. The drops fell from 1:22 PM to 1:23 PM. I rushed outside to see what the heck was doing it and here that cloud is (last two photos) from the bottom up.

1:23 PM. Its raining!

1:23 PM also. Arrow points to ice, showing that this little guy got to the ice-forming level, and would have been another great subject for an aircraft study of ice formation.

Mods see afternoon isolated Cumulonimbus today.

The End.

By Art Rangno

Retiree from a group specializing in airborne measurements of clouds and aerosols at the University of Washington (Cloud and Aerosol Research Group). The projects in which I participated were in many countries; from the Arctic to Brazil, from the Marshall Islands to South Africa.