That means that a deep Altostratus overcast will be in place by tomorrow with a load of virga and sprinkles, not really much rain since the bases will also be cold and…high. Top possible rain amount from these high cold ones is a tenth of an inch, but more likely will be traces. Chance of a trace in the area? Oh, about 99% IMO.
But that’s not our full rain destiny.
On the horizon, only a week from now, is the likelihood of a significant rain. Check the models and the spaghetti:
Here’s the rain prediction which I have not looked at until posting now to make the point you don’t need to look at it:
Would say the chances of measurable rain from this “incoming” are at least 90%; i. e., virtually certain. (Note that “virtually certain” is not the same as 100% certain, but its damn close.)
Problems with hoster and connections to hoster continue–must wait seconds to see what I’ve typed, then have to go back and correct the gibberish. So, not doing much as a result.
But here are a couple of cloud shots from yesterday anyway:
Addendum: Coupla of days ago saw the rare “Cumulo-cirrus” clouds, ones that appear to be Cumulus but are fakes, up at Cirrus-levels. You might call them Cirrus castellanus. I feel these are worth sharing so that the young cloud maven person doesn’t embarrass himself or herself when making a cloud call to friends and neighbors, as you would do. They occurred on March 7th between 11:30 AM and Noon. Can you tell, upon “zooming big” that these are mostly ice clouds? If droplets were present they were there for only a short time, thus (is that still a word?) indicating that these rag clouds were at very low temperatures.
A swatch of Altocumulus perlucidus translucidus (sorry, that’s the way we talk around here) passed over Catalina early yesterday afternoon, each “unit” nearly perfectly evenly spaced with its fellow cloud element creating a brief period of cloud awe for those Catalinans (or is it, “Catalina-ites”? “Catalinians”? Who knows, who cares?). Here it is, in case you work indoors and missed it. It was truly a fabulous sighting!
The afternoon was marked by a melange1 of middle clouds:
The weather just ahead
The local TEEVEE met men are, of course, pounding out the good news rain is just ahead for Catalina. Looks like, oh, 100% chance to CMP (Cloud Maven Person) starting after midnight Tuesday to Wednesday. How much?
This is a potent, but fast moving trough. Maybe will have only 2-4 h of rain with the passage of the cold front and its rainband. But, coming from the sub-tropics, should have a appreciable rain band with it.
I would expect rainrates to reach “moderate” as the heart of the band goes by for a coupla hours, anyway. Moderate rain is defined by the NWS as 0.1 to 0.3 inches per hour. So, only two hours of moderate rain should be at LEAST 0.2 inches, and most likely more.
We’re thinking here that there’s a 90% chance of more than 0.15 inches, and a 90% chance of less than 0.70 inches. So, averaging those two leads to a best estimate in CMP’s opinion of 0.425 inches! Wow. Nice.
Now, I will look at the U of AZ nested model and see what it thinks. Kind of game we play here, seeing how a seat of the pants forecast, made over a coupla minutes, measures up to a computer model with billions if not trillions of calculations:
The weather way ahead
After the nice rain just ahead, we have to get through the week-long dry spell before we move into a new stormy regime. First, a spaghetti depiction of the ridge after our nice storm:
Here’s what’s been exciting for a few days now, and below, from last evening’s global model output:
Let’s see what the actual and very latest model run from IPS Meteostar has for us:
How much these coming rains can benefit our spring wildflower bloom and spring grasses I don’t know, but I sure hope they can resuscitate what otherwise will be a dismal spring.
Expecting a snow event during the “new regime” that takes over after mid-month, too. Be ready!
Honestly, I gave up on the chance of rain overnight into this morning at sunset yesterday due to the absolutely clear skies. And, like you, woke up to not one cloud within a 100 miles! How could this be, given the synoptic situation? Started slicing apples for some humble pie, but then, when looking at a radar and cloud loop (this one from IPS MeteoStar) saw that lower clouds had magically erupted to our west before midnight, and by the time they got here in the early morning hours, had little showers coming out of them!
I did not park my own dusty car out from the carport, either. I thought I would at LEAST see a pile of clouds on Ms. Lemmon, too, this morning! Sure wrong there. Here are a couple of images from what has to be considered a tiny weather miracle:
Chances of rain increasing (imagine!), for just over a week from now as actual model outputs begin reflecting what spaghetti (the many outputs) was indicating, i.e., a big upper trough in the West-Great Basin area. At the time that spaghetti was indicating that, the actual model outputs were not, indicating that they were outliers.
Check this out from last night. Since this model output is more in agreement with that crazy spaghetti plot, it inherently has more credibility, and is likely not an outlier model run. That what the NOAA spaghetti factory is used for, getting a handle on those runs that might be wild, and those that are more likely to verify.
Its valid on the morning of May 8th and shows a trough coming out of the Pacific ahead of the one from the Pac NW, shown at this time over northern Cal. The hope here would be that the one from the SW would have a generous amount of sub-tropical clouds with rain in them.
Cloud shots will be posted later this morning of the next day….. (i didn’t get to is as I had planned)
Yesterday afternoon, the 29th. Here’s what shallow, icy clouds look like, reflecting the unusually cold air above us.
PS: Chance of rain still holding for the 8th. See below for new depiction of big “cutoff” vortex over AZ from last evening’s model run:
We’re often confused with the California island, Catalina, and even places in Spain. Google “Catalina” and see if I am lying again. Oh, maybe that was Catalonia, SP…
Nevertheless, isn’t it time to think about a new name for our “Census Designated Place”, Catalina? In fact, at one time, each Catalina island and our Catalina, each had a marina to further confuse things by adding superficial similarities….
Think about it.
Some sunrise scenes among too many available to the writer from his camera card:
Now, for sunset color:
As you may know, there is some violent weather hitting the West Coast, California in particular. Let’s see what the Reno office of the NWS has to say about the incoming storm:
“…BLIZZARD WARNING IN EFFECT UNTIL 10 AM PST WEDNESDAY…
...WINTER STORM WARNING IN EFFECT FROM 10 AM WEDNESDAY TO 4 AM
THE NATIONAL WEATHER SERVICE IN RENO HAS ISSUED A BLIZZARD
WARNING, WHICH IS IN EFFECT UNTIL 10 AM PST WEDNESDAY. THE WINTER
STORM WARNING IS NOW IN EFFECT FROM 10 AM WEDNESDAY TO 4 AM PST
* TIMING: DANGEROUS BLIZZARD CONDITIONS DUE TO HEAVY SNOW AND
STRONG WINDS WILL CONTINUE TODAY THROUGH WEDNESDAY MORNING.
PERIODS OF MODERATE TO HEAVY SNOW WILL CONTINUE THROUGH
SNOW ACCUMULATIONS THROUGH THURSDAY MORNING: 5 TO 10 FEET ABOVE 7000 FEET WITH 3 TO 7 FEET AT LAKE TAHOE LEVEL.(Note: The large font size, the capitalization, suggest, as we know, that the writer is screaming, which I am.)
* WINDS: SOUTHWEST 20 TO 30 MPH WITH GUSTS TO 60 MPH THROUGH
WEDNESDAY MORNING. SIERRA RIDGE GUSTS OVER 100 MPH.
* SNOW LEVELS: BELOW LAKE LEVEL...MAY BRIEFLY RISE TO 6500 FEET
THIS AFTERNOON BEFORE FALLING AGAIN.
* IMPACTS: DANGEROUS LIFE THREATENING BLIZZARD CONDITIONS WITH
NEAR ZERO VISIBILITY WILL EXIST FOR TRAVEL AND OUTDOOR
ACTIVITIES WITH HEAVY SNOW ACCUMULATION ON ALL SIERRA ROADS.
THIS IS A LIFE THREATENING SITUATION. DO NOT ATTEMPT TO TRAVEL!
ROAD CREWS AND FIRST RESPONDERS MAY NOT BE ABLE TO RESCUE YOU.
STAY INDOORS UNTIL THE SNOW AND WIND SUBSIDE. EVEN A SHORT WALK
COULD BE DEADLY IF YOU BECOME DISORIENTED1."
As we know, extremely heavy snows in the Sierras can trigger cannabalism, It is our sincere wish that those affected by this severe storm curb his or her appetite for humans, i.e, that cannibalism does not break out in the Reno-Tahoe area, or ANYWHERE (capitalization for emphasis) in the Sierras during this terrible storm or its aftermath.
————————– 1Thanks to Prof. (emeritus) Roger Pielke, Sr., Colo State, for passing this warning along. His son, a great scientist as well, btw, has the exact same name, and that’s why THIS Roger goes by “senior.” Thought you’d like to know that.
Yesterday, after an ordinary beginning,, finished in a spectacular, if likely artificial way. Let us work our way through yesterday’s cloudulations:
Later that morning…..
But let’s go zooming up to flight level and take a closer look for a second:
Now, where was I? Got mammatus on my mind again. I love mammatus so much… Oh, yeah, that sunset yesterday…..
And the sun did its job….producing one of the greatest sunset scenes we’ve seen in a long time, even if phony (haha):
Finally, let look at the TUS sounding for last evening, see how cold those Ac cloud were with the ice trail in them:
The astounding thing here, something that goes against everything I believe about clouds, is that it is indicated that the Altocumulus, lacking much natural ice, was at -30° C! Yikes! No wonder aircraft were producing ice trails and stuff yesterday afternoon.
You have to conclude there were almost no natural “ice nuclei” up there at, oh about 24,000 feet above sea level. This is not the first time for such an occurrence of liquid clouds sans much ice at low temperatures1, but they are rare IME. This would never occur in a boundary layer cloud, that is, one where material from the earth’s surface is getting into the clouds, like the omnipresent dust, or biogenic ice nuclei.
The weather ahead
Some “fantasy” storms with rain in them for Catalina, are now seen on the model predictions beyond a week. Spaghetti is favoring this new development now. So, something to keep an eye on.
The view from here? Precip here is “in the bag” because going on subjective feelings, I really want to see a good rain here!
1The famous John Hallett said he saw an Altocumulus lenticularis sans ice at -35°C in a conference preprint! Rangno and Hobbs (1986) claimed to have detected droplets in Altocumulus like clouds at the top of a storm on the Washington coast at -44°C. Their claim, first published in a conference preprint, was later rejected by the J. Atmos. Sci.
4:32 PM. Mix of Altostratus and Altocumulus clouds, with just remnants of the lower Cu. Here it appears that a liquid layer of Altocumulus now resides at the bottom of the Altostratus, or may be embedded in it. The globular masses in the middle of this photo represent droplet clouds that appear to have merged into a plate. In the distance, the telltale sign of lowering tops: only droplet clouds, with a occasional splash of virga can be seen.
5:23 PM. Just a little before a great sunset, which I missed due to a social engagement, the shallow Altocumulus droplet clouds are plainly evident around the sun’s position. Above to center, the backside of the deeper Altostratus clouds with much higher tops, is about to pass over us. Here you can see, how much lower the Altocumulus cloud fragments are than the Altostratus layer as they are illuminated by the sun (upper center highlighted clouds).
All in all, a pretty pleasant day with interesting clouds passing by, though ultimately disappointing since at one time, this was to be a day with showers here. Oh, well, that’s weather forecasting for you.
Another minimal chance for showers comes up in the middle of next week…
A horse photo will always enhance a blog about clouds. Expecting a little uptick in readership due to this ploy, maybe will break out of the single digit column.
Not much happened early on, a thin film of Cirrostratus covered much of the sky, delaying the expected development of convection, as would be evidenced by the formation of Cumulus clouds, until mid-afternoon.
But they did form, mostly to the S through W of Catalinaland, upwind of us, and eventually rumbled in on their last legs as weak thunderstorms with gushes of sprinkles and gusty breezes, maybe ones over 15 mph!
Over there in Marana and Avra Valley, those places upstream of us, some spots got more than half an inch. But, i it seems this year that storms die when they move toward Catalina, and especially, toward MY house and its many raingauges (3).
Still, it was nice to feel cool breezes, air chilled by falling rain, even if elsewhere.
Here are a few dull and disappointing cloud shots from yesterday, including one with a horse:
Still have rain chances last few days of Oct into early Nov.
Actually, there are no thoughts about the Super Bowl here. The title was just another cheap attempt to attract a reader that might be both cloud-centric AND a football fan, creating a moneyful increase in web traffic for this blog.
First you had your Cirrus, the highest of all clouds except for stratospheric nacreous clouds which kind of mess things up up there by eating ozone. We will not display n-clouds.
Cirrus, as you know, ALMOST always precedes lower clouds since they’re moving so much faster than the lower ones. So we get a sequence of clouds before it starts to rain that generally is the same, over and over again as in that movie about weather, Ground Hog Day. But let us ramble on…
First, patchy Cirrus, then maybe a sheet of Cirrostratus, then the lower stuff as Cirrostratus thickens downward to become that gray sheet called Altostratus. Throw in a few Altocumulus clouds that become a sheet underneath, and voila, your in Seattle, with rain on the doorstep. Yep, that’s the Seattle, and well, the Middle Latitude Pre-Storm Cloud Sequence (MLPSCS)2.
The weather just ahead
Of course, everyone, including media weathercasters, are all over the incoming stupendous storm event. For a more technical discussion, here’s one by Mike L., U of AZ forecasting expert, who got excited enough about our storm to come to send out a global e-mail. I think you should read it, though I left out all the graphics. I’ve already been too graphic today.
———–Special Statement by Mike L———————————-
“A very unusual heavy precipitation event is forecast for the next few days across Arizona and New Mexico as extremely moist air interacts with multiple short waves. As seen in the below data from the NWS, the maximum monthly IPW for Jan is about 28-29mm. If the various WRF forecasts verify, the upcoming storm will set new a new January IPW record.
The 12z WRFGFS indicates very high moisture levels being advected towards Arizona due to a low latitude low located west of the Baja spur. While IPW has slowly decreased from the previous storm over much of the area, La Paz is seeing a upturn in observed IPW.
As seen below, at 5pm today, some convection is forecast near to the low. Lightning data has indicated there has been some strong convection during the day today. Model initializations are normally suspect so far from any upper air stations, but it seems that both the NAM and GFS seem to have the intensity and location initialized well. One item of note is that during the past few days, the models have had a trend of moving the heaviest precipitation back to the west. Initially, the heaviest band was well in to NM whereas you’ll see later, it is now over much of eastern/central Arizona.
By late tomorrow afternoon, the low has only moved eastward slightly, but IPW continues to increase over NW Mexico and into Arizona. Precipitation begins mainly over the higher terrain of eastern Arizona.
By Wednesday morning, the mid level low has intensified as a strong short wave dives down behind the mean trough along with CAA into the back side.
Significant synoptic scale lift is present over southern Arizona and into northern Mexico by this time.
Extreme IPW is forecast to be present during the morning hours on Friday and combined with the favorable dynamics, widespread moderate to heavy rain is predicted. As the low becomes cut off, there will be an extended period for precipitation.
Precipitation rates are forecast to be above .25″/hour in some locations during the morning hours.
Partial clearing is forecast by Friday afternoon which allows some heating. Combined with cooler air aloft and high IPW, moderate amounts of CAPE are present during the afternoon.
By later in the afternoon, as Bob Maddox pointed out, convection forms and results in some locally heavy precipitation.
Tucson’s vertical profile is quite impressive with 700 J/Kg of CAPE and some vertical shear to support organized convection. Hail is also a threat.
Convection continues into the evening over southern Arizona with a continued threat of hail and some lightning.
The 3 day QPF is very impressive with widespread 1 inch amounts with some areas receiving over 3 inches. Some of these areas are associated with the strong convection present on Friday afternoon/evening. Confidence is low to medium due to the lack of upper air data and lack of run to run consistency as discussed previously. Also, the output in this discussion was solely from the 12z WRFGFS. The WRFNAM from last night had the heaviest precipitation somewhat to the east. It will be informative to see the next suite of model runs overnight to see if this westward trend ceases. There is a chance that it could continue and the heaviest precipitation is actually farther west than depicted below.
Very little of this precipitation falls as snow except at the very highest elevations, above 9k feet due to the sub tropical air-mass and lack of cold air.
Note that this discussion will only be available for organizations who are (or have) supported the Arizona Regional Modeling Program. This change will take effect before next monsoon season. Private individuals not associated with commercial/governmental agencies will continue to receive the discussions. If your agency would like to support the Program, please email me for details. “
————–End of special statement by Mike L—————————
1Let us not forget Simon and Garfunkel’s telling descriptions of Patterns of life; they repeat in clouds, too. (Pretty funny lead in commercial where Bryant Gumbel is asking, “What is the internet?”)
2Back in the old days when cloud forms were used to tell weather, Cirrostratus sheets, those high thin sheets, often with a halo, foretold rain 70% of the time here in the US (see Compendium of Meteorology, 1951). Deserts don’t much see this sequence. Cirrus are mostly meaningless in them, just indicating some withering tail of a system with rain that’s far away most of the time.
Like scientific opinion1, climate change happens. You may not know this, but only 15,000 to 20,000 years or so ago, a blink of an eye in light years, the earth was gripped by an Ice Age. No “hockey stick” handle back then! Snow and ice piled up over a kilometer deep on top of the Space Needle in Seattle. And the polar ice cap extended to places like Cahoga Falls, Ohio, while burying the Great Lakes, which didn’t exist.
NOW, of course, we’re in an “Interglacial” period called the Holocene, where its nice and toasty, for the most part, the way we like it as a people. Really, human beans do not like Ice Ages; they can really die off in a hurry2 and have to repopulate themselves afterwards! Well, I suppose that part might be fun.
The forecast models are foretelling something in the way of a flashback in the way of a pressure pattern over nearly ALL of North America that might well have been the average pressure pattern day after day during an Ice Age (there have been many), the last one, at its peak, not surprisingly, was called, “the Last Glacial Maximum.” I’d call it that, too.
Here are a coupla panels from the venerable Enviro Can computer model with its FOUR panels of weather. Take a look at the pressure patterns in the right side panels, you may have to use a magnifying glass, both showing the predicted sea level pressure pattern. These forecast maps are astounding to C-M and will, therefore, be likewise to you, too: a high pressure area so expansive with cold dense air that it covers millions of square miles, even more in square kilometers, maybe billions, since the kilometer is a smaller Euro unit of measurement that makes everything seem farther away when you’re driving to someplace and the distance is in Euros. (hahaha, just kidding folks).
So, we have an historical treat coming when the average temperatures every day in the US were 15-20 F lower during the Last Glacial Maximum! (Ugh.) The oceans were at lot smaller then, too, because a lot that water was piled up on top of the Space Needle, etc.
You might have noticed in these panels that the Ice Age-like conditions are plummeting rapidly southward, and big trough is starting to curl over the interior of the Pac NW. Yes, since we are still in the Trough Bowl, that curling air pattern, containing frigid air is headed toward Arizona, and will be here or not in early January.
Why a bifurcated statement?
Models are confused. Two model runs, only 6 h apart (5 PM and 11 PM AST last evening have the low center aloft for the SAME time, January 1st at 5 AM AST over a) Pebble Beach Golf Course, Carmel, CA; b) over Gallup, NM! How funny, outrageous, and frustrating is that? See below:
But, we are “gifted” with an opportunity to learn about chaos in the atmosphere, aren’t we, that is, those times when little errors can lead to huge differences in future states.
So, to resolve this weather conflict, and lose a few more readers, we go to the NOAA spaghetti factory, and examine the “Lorenz plot” for this time period and see which one is looney:
Well its pretty obvious that the goofy one is the one having the low over SFO and vicinity. Most of the circulation pattern has a center in Arizona somewhere. But this interpertation means that extremely cold air is likely to invade at least the northern half of Arizona as January begins. The good side is that there would be substantial, and later, reservoir filling snows in the mountains, and a good chance of substantial rain here in Catalina as the year begins.
The end of maybe solving a prognostic conundrum.
Well, its all “out there” by your favorite weathercaster, and they all do a pretty darn good job, and so no use hacking over what’s already known by everybody except to say that the jet streak at 18,000 feet (500 mb), that core that circumscribes precip from no precip areas during our winters, passes over Catalina (our area) around 5 PM AST according the latest model run.
And that’s, too, when the models expect the first rain around Catalina to arrive. As before, this ain’t gonna be too much unless we get real lucky, top amount likely below a quarter on an inch between 5 PM today and the end of possible showers later tomorrow afternoon.
And of course, there’ll be lots of wind, maybe gusts to 40 mph today, a windshift to the NW here when front goes by overnight, with a temperature drop of about 10 degrees almost simultaneously. Expect a frosty Lemmon on Friday morning when the clouds part.
The interesting part is that echoes and clouds will appear out of nowhere as that big trough expands southward, cooling the air aloft, allowing cloud tops to rise to ice-forming levels. Also, if you go there now, you will see giant clear slots between those middle and high clouds that passed over last evening until right now (Ac castellanus visible to SSW now), and a tiny band in west central Arizona, and the echo-producing clouds in the NW part of the State. Those unstable-loooking clouds will be gone soon.; they’re more from tropical locations.
Keep an eye on that little band in the middle; it may turn into a bona fide rainband as clouds add onto it, widens and thickens. That’s probably what’s going to bop us this evening with rain.
Expecting to see a nice lenticular cloud downstream from the Catalinas today. They’re common AHEAD of the jet core since the air is much more stable then, resists lifting and so you get cloud pancakes that hover over the same spot. How you log them if you see any.
Will we see our usual, “clearing before the storm”? This is when middle and high clouds depart, there’s a big clearing followed by an inrush of low, precipitating clouds. Not sure, but will look for it if that little band of middle clouds ends up as only that as it passes by today. The invasion of low clouds would follow that. Too much speculating today!
Finally, the End. I’m sure you’re glad, too, if you got this far!
1Remmeber back in the late 1960s and early 1970s when it was widely believed that a new ice age may be at hand because the earth had been cooling off for a coupla decades? It was also being pointed out that an ice age could onset in a hundred to a few hundred years from past ice age onsets! Yikes. Scary times on earth then when the Beatles were popular.
2Of course, if you were to die in an Ice Age, you might end up being well-preserved and then people would see what you looked like, the hair style you had, tattoos, etc, as we’ve seen with a few dead people that have been found from those glacial times. I guess that’s something positive to say about cold times.