For the second time this month, cloud-centric folk had a rare and happy sight: “naked” Nimbostratus, that is, the well-known mid-level1 precipitating cloud layer was present for all to see, but without the obscuring lower cloud decks normally associated with it, clouds like Stratocumulus or Stratus. Time and time again those pesky lower layers prevent one from seeing whose really producing the rain or snow at the ground because when precip is falling, its normally moist enough that lower clouds are present.
Those lower layers are important in enhancing precip because while they aren’t precipitating themselves (though it may seem like it) the drops falling into them from the Nimbostratus higher up, 1) won’t evaporate inside the cloud, and 2), if the droplets in the Stratocu are large enough, some of them will be collected by the raindrop falling through it and it becomes larger, the rain that bit heavier! How great is that?
Its really hard to compare how rare yesterday’s sight of “naked” Nimbostratus was yesterday, but offhand, I would say its about as rare as a professional wildlife photographer2 catching a shot of Cockrum’s Gray Shrew, aka, the “Hairy Packrat” or just “Harry Packrat”, shown below:![Desert-Shrew-or-Cockrum's-Gray-Shrew-0002[2]](https://cloud-maven.com/wp-content/uploads/2015/09/Desert-Shrew-or-Cockrums-Gray-Shrew-00022.jpg)
Oh, yeah, that Nimbostratus layer sans lower clouds….
Except for the rarity of the view, not much to see. The bottom is blurred by falling precip, and when its snow, where that snow melts into rain is perceived as the base of Nimbostratus. So…….in the warmer time of the year, “naked” Nimbostratus has a higher perceived “base” than in the cooler time of the year.
There was also another unusual situation, a cloud layer that really has no good name which I will now call from here on, “Cumulostratus.” See below:
- 2:07 PM. Kind of fun to see the hide and seek the “Cumulostratus” clouds were playing with Samaniego Ridge and Ms Mt Lemmon, too.
Not much immediately ahead in weather, oh, maybe some scattered showers later Sunday through Tuesday. Nothing really great jumps out of the spaghetti plots in the longer term.
The Canadian model thinks the newly formed desert lands of northern Cal all the way down to “Frisco” will get drenched, beginning in five days or so. That’s good. The USA model, using the same global obs at 5 PM AST yesterday, do not see that happening, but rather just some very light rains. Go Canada!
The End
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1Probably doesn’t seem like Nimbostratus should be grouped with mid-level clouds like Altocumulus and Altostratus, but it is, strangely believe it, as I like to say. On synoptic weather maps it was placed above the station circle, indicating a mid-level or high cloud was present, as a “lazy F”, the character “F” lying on its back. Cloud types are no longer plotted on surface weather maps since today, clouds are mostly detected by machines, not humans. “Rise of the machines.” You know the story.
2The shot here forwarded to me with much excitement by pro photographer, Rick Bowers, of Bowers Photo, who had tried to photograph this vermin for about 20 years he reported.
3“Cumulostratus” is a name I made up because IMO there really is no satisfactory name for the cloud that lined the Catalinas/Samaniego Ridge yesterday.
