Cirrus on parade, showing off

Here they are:

2:11 PM.  Cirrus uncinus march in tandem across the NW sky.
2:11 PM. Cirrus uncinus march in tandem across the NW sky.
2:19 PM.  One Cirrus uncinus element playfully mimics Comet Panstarrs, trying to get in on some of the publicity.
2:19 PM. One Cirrus uncinus element playfully mimics Comet Panstarrs, trying to get in on some of the publicity:  “I can be a comet, too!”

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:

2:39 PM.  Cluster of new Cirrus elements appears--could be termed Cirrus floccus maybe.
2:39 PM. Cluster of new Cirrus elements appears–could be termed Cirrus floccus maybe.  Some fine trails are already beginning to emit from these elements (center where its starting to look like chicken scratches.  The youngest burst is in the upper third of the photo.

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):

Valid on March 24th, 5 PM.  The warm and the cold exceptionalism, almost always to
Valid on March 24th, 5 PM. The warm and the cold exceptionalism at 500 millibars, almost always together as a couple.

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…

Valid for 5 PM AST., March 24th.
Valid for 5 PM AST., March 24th.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The End.