Check this jet stream forecast out, its pretty amazing now after such a long mid-winter oasis of sun and warmth, because in this link you will find that we here in southern Arizona are on the verge of being a trough magnet. The Great Southwest La Nina Rain Repeller is about to be mashed, chewed up and spit out. Six week droughty ridge? The one that’s threatened our emerging vegetation? Be-gone with you!
This upper level ridge collapse begins tomorrow with the first in an at least 15-day plus series of bone-chilling upper cold troughs from the north Pacific droop down the West Coast into Arizona. This could be fantastic for our spring flowers since above normal precip is just about a shoe-in now over the next two-three weeks! I am pumped since this pattern has now been calculated by our super computers for several days now and has, therefore, gained a lot of credibility, that is, this scenario is not a “one shot wonder” like some song groups such as the Strawberry Alarm Clock and that silly song they did, “Incense and Peppermint“, that sounded so profound but was just a bunch of words made up1 (hear footnote) to sound profound but I liked that song anyway back then. This is so great, enjoy this forecast sequence, get ready, and watch those upper lows tumble down the coast! I can’t remember such a stormful series appearing our model predictions for Arizona in the last few years. Snow here is still a possibility in the latter part of this series. Snow for “snowbirds?” Oh, yeah.
More webby Cirrus yesterday, and some pretty Altocumulus.
Gotta have a couple of cloud shots. Yesterday had, again, some pretty special clouds. Here they are for your edification. First photo, Altocumulus opacus or castellaus (turrets likely on the top but we can’t see ’em here. 2) webby Cirrus, possibly could be labeled a perlucidus variety due to the near honey-comb pattern. That little fleck at the bottom is a new Cirrus in formation probably one or two minutes after it appeared. The last photo is a good example of the formative period of Cirrus and how it can evolve to patches. That really bright cloud above the car and below the sun is the beginning of a Cirrus cloud, and might well be composed of droplets. Liquid water has been reported realiably at temperatures as low as -44 C by Sassen (Science mag) in 1986 and at that same temperature but less reliably since that paper was rejected, by Rangno and Hobbs, also in 1986 .
The bright white flecks are clouds where intense ice formation goes on, likely having a few hundred thousand ice “germs” per liter , ones that are less than 10 microns in diameter when they appear. Like a puff of smoke, it disperses after that with trails forming as the largest fall out. But the fall speeds are so tiny that what you mostly get is a “smear” of ice crystals, like those clouds shown in the distance in the last photo, ones that are not so white.
Some will note that the last photo APPEARS to have been taken while I was driving to Benson or someplace like that on I-10, but that would be a crazy thing to do.