Check these out in yesterday’s “Olympics of optics” where all kinds of goofy optical things were seen:
Thickening and lowering, ho hum, the usual as a trough aloft (bend in the jet stream winds up there) off southern Cal and Baja approaches today. Ahead of the bend in the winds, seen in the map below, the vast layers of air rise ever so gradually, something like cm per second. But, its enough to produce sheets of clouds.
What kind of clouds?
Heavy, dense and gray ice clouds we call Altostratus (As), with thicker and thinner spots should dominate the day. Then as the moist layer lowers, that is, as the As “bases”, really just comprised of falling snow that only looks like a solid bottom, get lower, patches of virga will start to reach the ground later today. Altocumulus ought to be around, too, water droplet clouds not cold enough to be completely iced up. Expecting those layer clouds, or undercutting layers to be low and lumpy enough to be termed Stratocumulus late in the day.
The strongest winds at 500 mb (around 18,000 feet above sea level) will be to our south beginning today, a necessary condition for virtually ALL wintertime rain here. CM is expecting some rain to fall in Catalina later today, or tonight as this bend in the winds aloft goes by. Expected amounts in this first wave, trace, minimum to 0.25 inches max by mid-day tomorrow.
Its really dicey situation since its not clear how deep the moisture is off Baja now, but looks potent enough for as much as a quarter inch from this keyboard, though less is more likely. Sorry the range is necessarily so great.
BTW, the WRF-GOOFUS model didn’t have ANY rain predicted for this time frame period in both of the 5 AM AST and 5 PM runs of yesterday. So, we’re out on a bit of a limb.
After 5 PM AST tomorrow, all peoples and models see more rain for Catalina as two waves/troughs barrel in right behind the first one that goes over tonight. The 2nd and 3rd ones produce a couple of rains through Thursday with big breaks likely in between.
The total amounts for Catalina between now and Friday morning still look like they will be contained within the range of 0.25 inches (things don’t go so well; disappointing really) and an inch (things go really well). Best guess is average of those, for a few day total of 0.625 inches.
1Remember “Wrong Way Corrigan”? Picked up that fumble and scored a TD for the other team? Maybe it was an early sign of the effects of concussions in fubball.