Here they are:
Cirrus get this way after an initial “formation burst”, often like a bunch of porous tiny Cumulus clouds with very slight updrafts, maybe centimeters (inches) per second. But those there is enough structure/variation in those tiny updrafts that some of the ice crystals that form get larger than most and begin to fall out. These bursts of formation, from vertically-pointed radars, are usually in a thin layer of air that has no wind shear, that is, the layer is moving at the same speed over a thin depth. So the clouds that form in this “mixed out” layer, are vertical.
However, when the largest ice crystals settle out, they usually encounter layers of air where the wind twists in direction and it loses some velocity compared with the thin layer in which the clouds originally formed. So, those lonely larger crystals get left behind. And they usually fall into drier air and gradually start getting smaller, the trail of the uncinus flattening because they can’t fall so fast as they get smaller. Its kind of sad when you think about it; getting left behind, withering away, usually all the way to nothing at all, being vaporized. We used to sing about being vaporized during the Cold War, or at least, the band X-15 did there in SEA, an anti-“pop” band.
Below, a Cirrus formation burst. Look at how they look like tiny, porous Cumulus clouds:
The weather ahead
NOAA’s not helping out with any green rain “pixies” (aka, “pixels” in model forecasts) in southern Arizona through the end of the month. That’s really sad. However, there is a close call on the 28-29th. It will get windy. and much cooler at that time.
Any blobs of anomaly in the US future again? They’re back! Happen around the 25th (as rendered by IPS MeteoStar):
So, while we’re complaining about another March heat spell, the folks back in the East, and especially the southeast, will be complaining royally about how cold it is for late March. Few will be happy.
Spaghetti virtually confirms this pattern. So, let’s say you have a brother and his family living in Asheville, NC, maybe he’s a retired policeman or something, you’ll want to call him and advise him of some cold air ahead, as an example of taking action on the weather ahead you’ve just found out about…