It was quite a surprise to this observer who claims to be a “cloud maven”, but whose credentials must be questioned, even if I do say so myself. Was thinking plain old small to moderate Cu, hold the ice.
But in a long cloud street, appearing to emanate from Kitt Peak, some ice started to show up in the cloud row upwind of us. Wonder if you saw it? The first ice happened around 3:45 PM, followed by a couple drops at 3:59 PM. Well, as Rob Reiner might say, enough of my yammering, lets get on with the cloudumentary:
Yesterday’s clouds, lot of ’em
Enough lower level moisture for Cumulus again today, but even smaller ones than yesterday. Since the wind is already noticeable now at 6:26 AM, better mention that we could have noticeable winds again today. (Much windier yesterday than anticipated by CMP; wind was not on my radar if wind could be seen by radar (well, of course it can when they are raindrops or bugs. Hah!)
Big intrusion of unusually cold air still coming into the West in about a week. Some of that will reach right here in Catalina really giving the sense that its truly football season.
Haha, most readers won’t even notice! But maybe some cow-centric, instead of cloud-centric, folks will drop by, raising the worth of this blog to above $35 if sold….that according to a “biz” site.
Had a rainbow yesterday. Hope you noticed. It was pretty early and overhead west. I think the clouds did not have ice in them. The rain echoes were not showing up on the radar, suggesting the beam went over the tops. Sounding suggested tops might have been as cool as -5°C. In any case, the drops were able to tip the bucket a couple of more times, and along with yesterday afternoon’s brief, light rain showers our total has climbed to 0.37 inches for the storm. Not bad, though as in money, you always want more.
These storm breakup days are always our prettiest, and that’s often what this site is about, being pretty. Yesterday had some fabulous scenes; couldn’t stop shuttering cam. It is a real neurotic compulsive behavior pattern, as afflicts some of us cloud and storm-centric folk. Check Mr. Olbinsky’s work; his work goes beyond phenomenal whether you want a wedding photographer or want to see a storm chasing video. But it takes that kind of eccentric energy to be special, to stand out as he does.
Here, though, we let the storms and cloud scenes, such as they are, hope for the best, and let them come to us…. Kind of a lazy storm chaser’s attitude.
Still cold aloft, so having some nice Cumulus today is in the bag, the early Stratocumulus devolving into Cu, that is.
Light rain showers overnight, just before midnight, and again just after 1 AM AST, raised our Sutherland Heights storm total to 0.33 inches, decent but disappointing in view of model and personal expectations (0.60 inches).
What was especially interesting is that those nighttime light showers didn’t show up on the TUS radar, suggesting very shallow tops, perhaps a “warm rain” event, one not having ice, or an “ice multiplication” event with tops warmer than -10° C, about where the tops were on the 5 PM AST TUS sounding.
By this morning, the tops were barely below freezing (about -3° C). Don’t expect to see ice today, except at Cirrus levels!
Last of the Cal rain blasters is making its way across the State today, with another 5-10 inches expected in favored Sierra and coastal ranges in the next 24-36 h. Numerous sites north of SFO have now logged over 100 inches since October 1st! Imagine. Great to see that Cal drought vanquished in a single year, so unexpected. Let’s hope the Oroville Dam, N of Sacto, holds.
PS: Using point and shoot cam now with “real” camera in the shop for awhile.
Catalinans experienced a FOURTH cloudy day in a row, and, over the past few days, including yesterday’s few drops that fell at 4:24 PM, have experienced over an inch of rain!
Some grumbling has started concerning muddy, pot-holed and puddled up dirt roads, about the washes running across roads lately, water and mud splashing on the car day after day, and brutally low temperatures dipping to well below 50° degrees in the morning now for several days in a row. Its 40° F here as I write this.
While a brief respite is in progress now, Catalinans were discouraged to learn that more strong storms are due in this weekend, bringing possibly damaging winds and heavy rains that will augment the poor road conditions.
How much rain?
Let us look below and see how much has been calculated by our best model at the University of Arizona’s Wildcat Hydro and Atmos Sci Dept (I am so glad they provide this service; I donate to the Dept, as we all should!):
Hah! We can’t complain too much about inclement weather compared to California’s pluvialities. Here is a table and map of precip amounts for that State through just the first 14 days. Prepare to gasp:
The remarkable aspect of this rainfall anomaly on the West Coast and in the Southwest, which is also quite wet, is that it could not be seen in climate forecasts days to a couple of weeks in advance. Its not that the folks at the Climate Prediction Center aren’t the best that we can get, its just a statement about how hard it is to get a longer term forecast right. Many are right, but lately, recalling the “Big Niño Bust of 2015-16” where the forecasts of a wet Southwest and central and southern California went terribly awry, those forecasts have taken a beating. Here’s what was expected this winter by the CPC, first, for January, a forecast made on the last day of December. when the forecast models we use day to day would have had some influence:
As can be seen, the extreme rains that hit California, and our own well above normal precip, though on the doorstep on December 31st, were unforeseen. That’s how tough it is.
Below, the forecast for January through March, also going astray, though a recovery could be had by a very dry Feb and March in Cal and the Southwest, something not likely to happen now.
Glad I’m not forecasting for a month or three months! Gads, yesterday we had ice galore here and there, and I had predicted that morning that it was doubtful that ice could form in our clouds yeserday and how about that rainbow yesterday afternoon, to change the subject quickly, but smoothly; hardly a ripple, something gleaned from the election debates:
Some additional views, including a horse, which should increase web traffic:
OK, now for the rest of the day, your daily cloud diary:
But, then there were some great sun and lighting scenes in those showers, not to mention the brilliant rainbow that was to come:
0.24 inches was recorded after 7 AM yesterday, bringing our voluptuous rain total to 0.95 inches1. How nice.
Dry spell ahead now, maybe a LONG one. “Fiddle-dee-dee.”
Yesterday: another day shallow precipitating clouds and “ice multiplication”
Seemed to be another day of “ice multiplication” here in southeast Arizona, a term that was coined in 1969 by Peter Hobbs of the University of Washington when he and his group reported that clouds were snowing on the peaks of the Olympic Mountains when the cloud top temperatures were warmer than -10° C (14° F). They had a hut on the top of Mt. Olympus at 7,000 feet! Lots of stories about that experiment, many swirling around Abdul Alkezweeny, a Peter Hobbs grad student in those days. An aircraft with skis landed up there to bring supplies! Imagine. (Yours truly was not embedded in the Hobbs group at that time.) It was an exciting time in that group, prior to the acquisition of their first research aircraft, WWII B-23 “tail dragger.” Peter himself, did not fly in this with RARE exception. Many flights were quite sickening, bumping around in Cumulus and small Cumulonimbus clouds, spinning around power plants stacks, wings vertical to ground….
His group’s observations, however, were not the first, but were among many airborne and ground reports in the mid and 1960s that left jaws dropping about how much ice was in clouds at these moderately supercooled temperatures, even in clouds with tops as warm as -4° C. It was believed, in various ways that ice nuclei measurements were made on the ground, or in aircraft measurements, that not much ice would be found in clouds until the top temperatures was lower than -20° C. In fact, it was generally believed that only about one ice particle per liter would be found in clouds with tops as cold at -20° C, while actual observations were telling a much different story.
This discrepancy between measured ice nuclei concentrations is a scientific enigma that is still being investigated today! And it appears that me and you cloud maven juniors out there got to see it again yesterday, the second day in a row to see an cloud-ice enigma (“nigma” for short)!
Let us continue this module by examining the assertion of “ice multiplication” with the TUS balloon soundings for yesterday morning and evening as rendered by IPS MeteoStar:
These soundings strongly suggest at the start and end of the day, that coldest cloud tops were warmer or no colder than -10° C.
However, the fly in the oatmeal here is that a cold front and associated wind shift came through in the mid-morning hours, heralded by an little arcus cloud, and cloud tops would have been somewhat colder during that period of rain; we don’t know for sure how much, and satellite imagery suggested lower temperatures, though possibly due to over-riding CIrrus cloud above the “Nimbostratus” layer that produced the steady light rain.
However, the rain before the front went by, and the very light rain showers that fell in the late afternoon were likely well represented by the TUS soundings. That’s my case! Wish I’d had a cloud-instrumented yesterday and the day before. Woulda got a paper out of it: “Ice multiplication rampant in Arizona!”
Yesterday’s actual clouds
No more hand-waving…. Let’s see if it really was raining near the time of the TUS soundings above. Picture of the day:
That was phase one of yesterday’s weather, rain from shallow clouds.
Phase 2 is, “The front marches in across the OV! Cloud depth not so certain, but is probably not real deep, as inferred from the disappointing amount of rain that fell so lightly from the frontal band in spite of its dramatic entrance, fronted by an arcus, wind shift cloud.”
But, as those who live here know, some of our best scenes are AFTER after the rain has stopped and the skies partially clear. Yesterday was no exception. But first, the Stratus, which you don’t see too often:
Looks like only streamers of high and middle cloud from the tropics as California gets blasted with extremely heavy rains over the next two weeks. Totals in favored central and northern California coastal ranges, and in the central and northern Sierras will fall between 20 and 30 inches of rain during this period. A great place for you and me to be would be near the King Range, Shelter Cove (see below), or Honeydew to see those pounders.
—————————– 1The online gauge is a Davis tipping bucket. It has been consistently under-measuring totals recorded in the NWS 8-inch diameter gauge, and the 4-inch diameter, ground-mounted (it sits on the ground among grasses and weeds) CoCoRahs gauge. CoCoRahs is a national organization of rain and snow measuring nuts (haha, just kidding-they’re really precipophiles like me) all over the country and overseas as well. You can find them here. Part of the reason for the under-measurement of the Davis instrument is loss due to wind. That tipping bucket sits up at about 6 feet off the ground, thus sees a lot more wind than gauges on the ground. A gauge on the ground, away from tall objects, is always the best way to go! The reason for this explanation is because if you go to Wundermaps or Weather Underground and see the total for this site, it is ALWAYS going to be low compared to the actual amount that fell. This is a degradation that has come up over the past year or two.
Here’s a nice one from the day before as the clouds rolled in, starting with Cirrus and Altocumulus, lowering to Stratocumulus later in the afternoon.
Yesterday’s clouds; an extraordinary day with a little drizzle amid light showers
Hope you noticed the true drizzle that occurred yesterday, namely, fine (larger than 200 microns, smaller than 500 microns in diameter), close TOGETHER (critical to the definition of “drizzle”) drops that nearly float in the air. They may make the least impression, or none, when landing in a puddle.
When you see drizzle, you have the opportunity of chatting up your neighbor by educating them informally to what drizzle really is (many, maybe most, TEEVEE weatherfolk do NOT know what “drizzle” is, btw), and 2) by telling your neighbor, if he/she is still listening to you, that the droplets in the clouds overhead must be larger than 30 microns in diameter, or better yet, “larger than the Hocking-Jonas diameter of 38 microns, at which point collisions with coalescence begins to occur” and “drizzle is not produced by ice crystals in the clouds overhead; they’re not enough of them to produce ‘fine, close together drops.'” Your neighbor has likely left the building at this point, but, oh, well, you tried.
Here, in Arizona, shallow clouds, such as we had yesterday, hardly ever can produce the broad droplet spectrum in which clouds have droplets larger than 30 microns in diameter. Its because this far inland from the ocean, where the air is very clean, the air has picked up natural and anthro aerosol particles that can function as “cloud condensation nuclei” (CCN). As a result of ingesting dirt and stuff, clouds have too many droplets here as a rule for the droplets in them to grow to larger sizes. They’re all mostly less than 20-25 microns, sizes in which even if they collide, they can’t coalesce.
In “pristine” areas, if you go to one, such as on a cruise out in the oceans, droplet concentrations in clouds are much lower, and even a little water that might be condensed in a shallow cloud can produce a broad spectrum, one that extends to droplet larger than 30 microns.
So even little or shallow layer clouds can precip over the oceans, produce drizzle or light rain showers (in which the larger drops are bigger than 500 microns in diameter). Of course, here we recall that the (whom some consider “villainous”) geoengineers want to stop drizzle out over the oceans so that clouds have longer lifetimes, are darker on the bottom, and reflect more sunlight back into space.
Those guys can be lumped into the same ilk as those who want to change the color of the sky from blue to whitish or yellowish by adding gigantic amounts of tiny particles in the stratosphere, again for the purpose of cooling the planet! Unbelievable. Please ask before doing this!!!
A Pinatubo sampler for what “geoengineering” would do to our skies, say, sunsets in particular. I took this photo from the University of Washington’s research aircraft in 1992 off the Washington coast in onshore flow. But we saw these same sunsets, sunrises, yellowed by the Pinatubo eruption of June 1991 everywhere we went, including in the Azores in June 1992.
OK, pretty boring, whiney, really, so inserting picture of a nice horse here to make people feel better if you’ve been depressed about what our scientists have been pondering to do about global warming other than controlling emissions:
Later….drizzling Stratocumulus, same view:
The second extraordinary thing about yesterday was that the top temperatures of these clouds was around -10° C (14° F), temperatures that ice does not form act as a rule in Arizona. To get ice at temperatures that high, you also need larger cloud droplets, and they have to occur in the -2.5° C to -8° C range. In this range, it was discovered that falling ice crystals, mostly faster falling ones like “graupel” (aka, soft hail) when colliding with larger drops, ice splinters are produced. The cloud droplets must be larger than 23 microns in diameter in THAT particular temperature zone, something that would occur more often in our warm, summer clouds, but would rarely be expected in our winter ones.
Again, it goes back to clouds in inland regions ingesting lots of natural and anthro aerosols that cut down on droplet sizes in clouds (by raising droplet concentrations in them). Our recent rains have helped cut down on that process on ingesting dirt, for sure, and was a likely player yesterday. Furthermore, our winter clouds are moisture challenged relative to the summer ones with their tropical origins and high cloud base temperatures, a second reason not to expect larger droplets in our winter clouds.
Here is the TUS sounding with some writing on it for yesterday afternoon from IPS MeteoStar. (Satellite imagery was also indicating warmer than usual tops for precipitating clouds yesterday.):
Here’s the punchline: If clouds are drizzling, then they are ripe, if the tops get to lower temperatures than about -4° C for what we’ve termed “ice multiplication” or “ice enhancement”. A very few natural ice nuclei at temperatures between -4° and -10° C, say, starts the process, those forming “soft hail” which then leads to ice splinters. This is the leading theory of this anomaly of ice in clouds at temperatures only a little below freezing, if you think 23° to 14° F fits that definition.
There are exceptions where this process did not explain the ice that formed at such high temperatures, so standby for further elucidation about how in the HECK ice forms in clouds at some point in the future.
As usual, no time to proof, so good luck in comprehending what’s been written.
The weather just ahead:
The second main rainband is just about here at 9:25 AM. Cloud tops will be deeper and colder than in the prior rains, raising the possibility of some thunder today, and maybe another third of an inch of rain. Watch for an windshift line cloud (“arcus” cloud) might well be seen today. That’s always dramatic and exciting here in Catalina cloud heaven.
Let’s face it, for most of the people living in Arizona, their best years are in the rear view mirror, as are mine which were probably about 50 years ago… Following that thought, let us not look ahead to further declines, but rather look back at the last water year for Catalina, ending this past September 30th, and see what it says, if anything, about the changing global climate we hear so much about:
Can’t say I see too much going on here in Catalina so far; things seem pretty stable in the precipitation arena for the full water year’s rainfall.
I point out again, with great redundancy since I have pointed this out before, that the Our Garden climate record started just as a monumental change in circulation patterns occurred. Most climate scientists would attribute that to a shift as due to the Pacific Decadal Oscillation, discovered by important scientists I know well, like Mike Wallace1, of the University of Washington Huskies Atmospheric Sciences Department where I worked for about 30 years, but in airborne studies of clouds.
The PDO shift, if that’s what done it, was a circulation pattern change that brought astoundingly wet conditions to Catalina and the whole Southwest US, wet conditions unlikely to be seen in our remaining lifetimes, which aren’t that much longer anyway.
You may remember that bristle cone pine tree rings in California, analyzed by Haston and Michaelson in 1994, found only one period in the last 600 years (!) that was as wet as the late 1970s into the 1980s there (certainly spilling into AZ).
Remember how the Great Salt Lake was filling up to record levels back in the 1980s?
And any long term resident here, like the ones that I have spoken to, will tell you about the days of yore when the washes around here were running all year.
Well, that wasn’t the norm. sadly. They were just so lucky to have seen that era.
In weather, what goes around, comes around. Count on it happening again at some point in the future IMO. (Some climate changers might disagree with this assertion.)
How about our summer rainfall, June through September. Well, here’s that graph, updated through this past summer! Hope you like it:
Not much going on here, either.
Yesterday’s clouds–another day, another rainbow, of course.
Sprinkles of rain occurred off and on all day yesterday, but couldn’t muster even one hundredth of an inch of rain! With a few exceptions, the clouds producing the rain weren’t too deep, though still icy ones, and pretty high off the ground, mostly above 8,000 to 9.000 feet above us, which doesn’t help.
First, a rainbow shot:
1Well, actually we said “hi” in the halls once in awhile, I gave a talk in his class once, and, along with a bunch of Atmos Sci faculty, got to watch the 1992 New Year’s Day Rose Bowl mash down of Michigan for the Washington’s 1991 NCAA Division I fubball championship at his house. He also mediated an authorship kerfluffle between Peter Hobbs and me.
Kind of getting tired of gorgeous rainbows every day, ones without a lot of rain here in The Heights. But, here they are again:
Upwind Cumulonimbus clouds faded as the trudged toward Catalinaland yesterday, bottoms evaporating, raining out, leaving only a big patch Altostratus cumulonimbogenitus way up (at least ten kft above the ground) there with rain drops just big enough to survive evaporation and reach the ground just before 3 PM.
In the meantime, all the excitement, possibly spurred by the gusty outflow winds that accompanied the above seen, was happening almost overhead to the NW-NE, as a great line of Cumulus bases blackened. They were already passed us, but if they unloaded and sent a pulse of wind out and toward us, then we might end up in a wind clash zone, with huge clouds forming overhead. OK, was dreaming again, but here’s what was going on, which ultimately led to another major dump on the CDO watershed.
Hiked over to see if the Sutherland Wash, east of the similarly named housing development, Sutherland Heights, had a good flow from our “Mighty Kong” of prior day. It had:
The weather ahead
Seems Remnant Roslyn will spit out another snippet of moisture ahead of our fall-like cold front passage late Sunday or early Monday bringing clouds, and with clouds, a slight chance of measurable rain. Don’t hold your breath for measurable rain IMO. Hope I’m as wrong as the prediction I made to a friend that the Stanford Cardinal would trounce the wildly overrated Washington Huskies fubball team last night.
Just back from a horsey ride with Zeus the horse. Rode into the CDO to see the surprising view that it had run bank-to-bank last night after that mighty cell passed by along the foothills. In the wash, were golf ball-sized golf balls scattered throughout the wash, indicating that it hit the planned community of Saddlebrooke with it many golf courses very hard. No golfers were found.
The Pima County ALERT gauges really did not call out that such a flow would occur from precip data around here, the greatest amount being barely over an inch, and its likely that such a flow in the CDO, bank to bank would need 2-3 inch dump in its watershed.
———-end of updated material unless I get more updated——
After an afternoon of “steady-state” Cumulus congestus and small Cumulonimbus clouds trailed northward from the Catalina Mountains, the “Mighty Kong” erupted about 5 PM providing one of the most intimidating, yet majestic and beautiful scenes of the summer rain season; this or any.
Cloud Maven Person was indoors drowning his sorrows concerning what appeared to be a a grotesquely failed forecast of a good rain day (“about half an inch”) here in Catalina in flavorful Indian cuisine when the unexpected began to take place outside. So, the photo record is incomplete for this event. “CMP” had given up on the day.
Just measured in NWS-Style 8-inch gauge and CoCoRahs gauge:
0.12 inches was our total here in the Heights.
And, the photos aren’t quite as good as they should be, slightly out of focus since CMP didn’t adjust his camera for the dark scenes his was seeing. Oh, me. Missed the great sunrise, too, due to not having memory stick in the camera! Oh, me.
However this line faded, bringing only sprinkles, a trace of rain to Catalina, and was followed by a huge clearing and sunny skies, thought to be a good thing at the time. Soon, gigantic Cumulonimbus clouds would erupt to over the mountains all quadrants… Nope. By mid-afternoon, only Cumulus congestus had formed with an occasional bit of ice and rain visible, all to the north.
This was the last photo I took until walking out of a local Indian restaurant and exclaiming, “What? When did this happen?” It was so clear to the S-W with the exception of a single dissipating Cb that it didn’t even seem worth a photo.
Well, as it turned out it was a near hit, only 0.06 inches fell in a violent few minutes of huge drops at my place in Sutherland Heights. From what I saw going by, and needing 0.44 inches on yesterday morning’s forecast of 0.50 inches in Sutherland Heights. about 500 yards farther west for this remarkable, dramatic storm would have given us that amount easily. 1.06 inches was recorded at Cargodera Canyon, NE corner of Cat State Park, and several sites in the foot hills of Catalina toward the mountains area had more than half an inch.
A quickie take on a U of AZ model run from last evening’s global data, has Cumulonimbus clouds developing to our southwest and rolling across Catalina in the afternoon. This would be, appropriately, considering the definition of the end of our summer rain season as September 30th, very appropriate.