Have cameras ready for interesting clouds today as yet more storms approach. Winds at 500 mb (around 18,000 feet above sea level) are forecast to approach 100 kts by tonight (oops, TOMORROW NIGHT! Egad). With winds like that, likely will be some nice lenticulars around to add to your collection. Oh, I already see one downstream of the Catalinas….
Maybe some photos later if the upload problem can be resolved.
Its not resolved…. But, trying to look at the bright side, while this ONE photo was uploading, I got some more coffee, read a book (Cadillac Desert, Marc Reisner, and got a good start on, Mythical Rivers by Melissa Sevigny–both highly recommended for cloud maven readers.
Some more on the upcoming rain and wind event in the next 24-36 h:
From this keyboard, 10% chance of less than a trace (pitiful forecast), in other words, a zero from this storm, and 10% chance of more than 0.40 inches. The average of those two, which helps center a forecast in the forecaster’s mind, great or small, would be, say, 0.21 inches.
But the wind max during this storm event will be the most “interesting” part of it: 10% chance of puffs less than 35 mph, 10% chance of more than 65 mph , in this forecaster’s opinion. The average of those would lead me to think that very momentary gusts will reach 50 mph (averaging those extremes to center a forecast). So, the wind in the next 24-36 h is really the most interesting thing to keep an eye on; stuff will blow around, shingle fragments likely to come off. This is NOT a NWS forecast.
——————— 1“Puffs”: almost instantaneous blasts of a few seconds.
They seem to go together every time we have Altocumulus clouds; aircraft flying through them create holes or canals! Have been photographing this phenomenon since the early 1980s, and I have not seen it so consistently occur every time there was a flake of Altocumulus around as has been the case here this winter! Its likely because our Altocumulus clouds have mostly been so cold, having temperatures lower than -15° C. Mid-level Altocumulus clouds can range in temperature from well-above freezing to below -30° C.
What was unusual about yesterday afternoon, if you caught it, was that you could make out the aircraft producing the “high temperature contrail” (aka, APIPs), a four engine prop aircraft flying just under the bottom of the Altocumulus layer. Even if you see a contrail in the Altocu, you can almost never make out the aircraft type for sure because its too high or in the clouds. But, because of our cool spell, those cold Altocumulus clouds were lower than usual, around 15,000 feet off the ground, or near the 500 millibar pressure level. The temperature at the bottom of this layer was -21° C. See annotated NWS sounding, courtesy of IPS Meteostar, below:
Here’s your aircraft shot, full size so’s you can really zoom in and see those engines:
The weather ahead, WAY ahead
Not a single model run since two days ago has produced a big trough in the SW US, in complete opposition to the interpretation of spaghetti ensemble output at that time. This would be, IMO, one the greatest busts of all time (not for me, of course), but for spaghetti ensembles (I was only foretelling what they told me), spaghetti considered to be one of the great forecasting advances of all time when computers became powerful enough to produce them in a timely manner.
If we believe these later model runs, it will be relatively hot and dry here, not cold and wet, as was suggested here.
But being of a stubborn nature, Cloud Maven Person is not yo-yo-ing on his forecast just yet. Surprises are almost certain in these model runs, since spaghetti still supports troughing beyond 10-12 days… Standing by for model yo-yo-ing….
A laugher (???) below from our very latest computer run (from IPS Meteostar again). This map in incredible in the lack of jet stream activity over most of the US!
Yesterday, after I finally saw the model run based on global data from 5 AM AST for Feb 6th, CMP (the writer) was gloating that bit. The troughy, cold spaghetti for AZ, that which had been excitedly written about yesterday, was being confirmed; the interpretation right on, it seemed. Why even look at more model outputs until later January, I thought.
Then, just now in the pre-dawn darkness, I examined the computer outputs from last night’s 5 PM AST global data, also for Feb 6th, 5 PM AST. That is, global data crunched just 12 h later than the first panel I was gloating over, feeling really great about.
But, a completely, ghastly different weather regime had popped out!
How could this be? We don’t know. Relatively small changes would be expected, but the model outputs should gravitate back to where spaghetti placed the high and lows aloft. But this change was ridiculous, and must be rejected.
Some people, like neighbor and big professor “emeritius” of meteorology at Colo State U, Bill Cotton, refer to such differences as “delta model”. “Hence”, if that word is still used, today’s title.
(For snowbirds who have just moved to Arizona, the maps below have been annotated to show where you are relative to the rest of the US).
The first regime is cold, maybe some snow down in Catalina at some point about this time (early Feb), whilst the 2nd regime for the same time is suggests warm conditions, and definitely dry; no rain nowhere.
CMP (the writer) spoke of a high probability, based on ensemble spaghetti, of cold and lots of precip chances here in Catalinaland beginning at the end of January through the first week of February So, what’s up with that, this dichotomy?
Moving on to a new topic, let us look at last evening’s sunset rather than ponder what happened to the weather computer model, that is, which panel above is likely correct1:
1The first regime above, the troughy, cold one, is strongly supported by ensemble outputs whose crazy-looking output plots are fondly referred to as “spaghetti”. The second panel served up from just last night’s 5 PM AST global data is not.
Have not looked at last night’s ensembles, but will ignore the bottom run anyway; will not panic as weaker elements might, that is, change my overall interpretation of troughy conditions in late Jan, early Feb., that is#2, reverse course now, predict drought and warmth for early Feb. , that is#3, “yo-yo”, as forecasters describe reversing course, confuse the public, lose credibility, where are my pills?
Still, “egad re this delta model”, as Bill likes to say. Its astounding! A total joke! The later one to be totally and completely rejected!
In no way did I expect to see what’s in the bottom panel, which is now above here! Trying to not panic real hard. (more kidding)
Still, how can there be an outlier of that magnitude as we see from last night? Must be a real bad error somewhere (maybe 2 kts of wind, 1.5 deg in temperature, wind direction, 5 decameters in geopotential height, etc), not an itty-bitty error as ensembles start with. Maybe Russian2 hackers did something, the North Koreans, or the Chinese? Just kidding
with weather noise and pseudo-paranoia, your Catalina cloud-maven of sorts.
Speaking of Russia, my great-grandparents emigrated from the Ukraine, here’s the cover of my latest book, published a few years ago. Well, its not my book per sé, but all the cloud photos in it are mine! How great izzat?
0.22 inches was, indeed. how much rain fell in the form of drops from Nimbostratus clouds yesterday as a modest little rain band generated by a rapidly moving trough swept through during the afternoon. Regional precip values can be found here. Our local area got the most, up to about a quarter of an inch, as often happens in marginal storms.
Yesterday’s storm marked the beginning of the new, more normal weather regime for southern Arizona, as has been blabbed about here in recent weeks. No more week after week of droughty weather with temperature far above normal, the kind of weather that has marked this whole fall and winter so far! I. e., “Thank you very much, a snowbird might say, but get the hell out!”, the rest of us might conjure up, thinking about the needs of our desert’s wildlife and vegetation.
Indications are now that below normal temperatures and above normal precip are ahead for us and all of Arizona in late Jan and early February.
The evidence for these claims?
Below, the stunning, jaw-dropping evidence for this seemingly outlandish assertion in the form of an ensemble (spaghetti) plot generated by NOAA last night. I have followed these charts for almost ten years now, and I cannot remember when such a strong signal (clustering of flow lines) 15 days out has occurred before in our region.
So, excessively excited this morning when I saw it! Its been annotated with excitement text.
This troughy pattern begins to take place on January 30th. Until then, a strong but dry cold front with a lot of wind comes by in a few days, on the 25-26th.
The whole interesting, if excessively gray story is shown below:
The weather way ahead
The title sums up where we are now. Will we go have more rain? Oh, yeah. But not right away, as you already know.
What an amazing and “productive” little rainband that was just after midnight! And more rain is likely with weaker bands just upwind here at 4 AM. Could we really approach an inch? Amazing. Didn’t seem possible in this small mind that we could amass that much. For a full regional rain table, go here to the ALERT gauge records.
Now, after this ends, a long dry spell has to be endured, at least until around the 20th of Jan, at which time we hope the troughs and rain threats at least, will begin to barge in every few days, namely, and pattern more typical of winter sets in.
The weather ahead
After the last drops fall today, we’ll suffer through another dry spell and warm up though about the 20th when a major trough passes by.
Oops…. Have cameras ready for a great day of cloud shots once the sun breaks through.
I was thinking how great yesterday was for you. Started out with a spectacular sunrise (lasted just a couple of minutes), and then you could watch for pretty much the WHOLE day, orographically-formed Altocumulus opacus and castellanus transition to ice crystal clouds (in this case, Altostratus with virga and some mammatus) right before your eyes!
After sunrise….this odd scene below of an extended Altocu lenticular cloud:
Brain’s been pretty empty lately, not much to say except “same old same old”, as here.
But then some wild computer forecasts came out last evening that were worth mentioning in light of the fires that have plagued southern California.
Because they suggest that a belt of tropical flow will break through under the gigantic ridge that has blocked storms from the entire West Coast over the past weeks.
Sometimes, as most weathermen know, such persistent ridges get too big for their britches, that is, over-extend to the north, and then fracture, letting through moist tropical air from lower latitudes of the Pacific ram into the West Coast. Often the very greatest rains in California are associated with such patterns, as you could guess since there is so much water with those lower latitude-originated jet streams that strike the coastal mountains head on. Here’s the concern, this output valid for Christmas Day:
Rain is forecast to have fallen in southern Arizona before this point, however; our measly 0.01 inches so far here in Sutherland Heights so far in December will likely be added to along with a switch to uncomfortably cold weather.
Of course, we look for support in these longer range forecasts by having some spaghetti–that is, take a look at what we call “spaghetti”, those crazy plots in which the model starting conditions are tweaked that bit to see how the model runs change. Here are some plots, also from last night’s model.
As you can see in this first plot for the evening of December 22nd AST, the clustering of blue and red lines off the West Coast, that our blocking ridge (composed of a deep mass of warmer air) is extruding all the way almost to where Santa Claus lives, yes, that far to the north. In fact, so far that it will be unsustainable over that distance fromt the deep tropics to almost the North Pole. At this point, cold air is pouring down the east side of that ridge and into the Pac NW and eventually down toward us. Does that extremely cold air make it here? Not sure yet, but its something to watch out for before that ridge fractures and allows warmer, moist Pacific air to reach us. So much uncertainty, so much fun! I am really pumped up about all this uncertainty!
Below is the spaghetti dish for the “breakthrough” flow situation shown in the prog output valid for Christmas Day with some annotation on it.
Looking at the above, I think we can count on a breakthrough flow pattern from the Pac. Where it barges into the West Coast will be subject to question over the next week or so. That really can’t be determined right now.
I am sure those in southern Cal hope, if there is a breakthrough from the Pac, it comes in farther north than shown in the model run here today! Patterns like the one shown in that run can routinely produce 10 inches in a day once they get going should something burst through at low latitudes.
The brighter side would be that the chances of a significant rain here droughty southern AZ would at last increase.
Hope you saw them and recorded them in your cloud and weather diary. I’m thinking that at the next Cloud Maven Junior meeting we should devote a lot of time to this issue. It was a rare day yesterday that the WHOLE day had that phenomenon occurring as aircraft penetrated those clouds, usually on ascent or descent. Sharp descents/ascents produce holes. See the sequence below if you don’t believe me (ppt from a recent talk):
Yesterday’s clouds: lots and lots of aircraft-produced ice
(btw, see note below about pop-up ads in this blog, ones that started to appear after downloading latest WP software)
——————About those nuisance ads—————
Note to me and the two other people that drop by my cloud or “clod” blogulations: The embedded pop-up ads are due to a WP third party plug-in that needs to be repaired. It will likely happen today.
After consultations about ads…
Oddly, those pop-ups and blue highlighting and double underlining do not seem to be present outside of my personal view of my own blog, this according to hoster, “godaddy.” Even using a different browser other than FIrefox does not show them as I have just verified.
Been busy as a briefly unretired science worker (gave a stressful talk at a university last week) and thought maybe a lot of usual drop ins to this site might not anymore. So, in the title for today, am reaching out to a new demographic: persons interested in congealed soil matter. They might later, after stopping by, discover a new interest; that in clouds, pretty ones. Most of the cheap tricks I try like this don’t have any effect, though. Oh, well.
Let us go forward after backing up:
But the Cirrus kept coming and more odd sights were seen:
Heavier Cirrus, increasing and lowering to Altostratus finished off the day as a heavy shield of middle and upper clouds raced toward southern Arizona from the Pacific:
“Due to time constraints, we move ahead in the action…”
Sunday, November 5th:
4:26 PM. Perhaps the brightest example of iridescence I have ever seen! Just spectacular for a few seconds in this patch of Cirrocumulus. Iridescence is caused by diffraction around the tiny of droplets, less than 10 microns in diameter, as are present when a cloud just forms.