Category Archives: Altostratus clouds

Sunset was pretty good; raindrops tomorrow morning? In nine days as well?

Haven’t had much to say, brain pretty empty again after the big review of the NAS 2003 review which really needed reviewing and commenting on real bad….

(More “late homework” in the offing.)

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Nice sunset last night; we have had a series of pretty nice ones over the past few days.

April 26th. Sunset over the Charoulou Gap.
April 26th. Sunrise over the Charouleau Gap.
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Orangy mountains highlighted by a gap in the Altostratus layer that allowed the setting sun to shine through.
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7:04 PM. There was some turreting in this line of Altostratus that passed over, and because of those deeper tops, indicating stronger, if still slight updrafts, larger snow particles developed and produced this line of heavier virga underneath it.
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7:10 PM.
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A contrail that’s more than about ten minutes old, now, after the new Int. Cloud Atlas has been released, termed, Cirrus anthrogenitus, maybe castellanus in this case, too.

From IPS MeteoStar, this interesting map for tomorrow morning.

The orangy colors denote the strongest winds in “Jetty Jetstream”, and as you know, the colder, low clouds, ones capable of reaching the temperatures where ice forms, are contained within that ring of strongest winds at this level (500 mb).  So, while the models I have looked at so far have no rain here, I think there’s a pretty good chance of a rogue shower tomorrow morning anyway.  At least there should be some nice Stratocumulus/Cumulus tomorrow and some will have ice in them.   As you know, it’ll be awful windy today, too, maybe 40 mph or so in brief gusts here in The Heights of Sutherland.

Also will be looking for some nice lenticulars since “Jetty” will be right over us, but a little toward the warm side where lenticulars mostly occur.

Map valid for tomorrow morning at 5 AM AST.
Map valid for tomorrow morning at 5 AM AST.

In the meantime, spaghetti suggests a big trough in our area again about nine days from now.  The later ACTUAL model outputs don’t show much of anything.  What’s up with that?  I’m hanging with spaghetti that later model runs will indicate a strong trough, and at LEAST another pulse of cooler air, and another minor chance of rain as we are going to see today and especially tomorrow as when become within the “ring of winds” aloft.  Didn’t Johnny Cash sing something about that? Maybe it was Wall of Voodoo

Below, some spaghetti for you showing a big trough over Arizona and the Great Basin which is not much reflected in the actual models, as noted.  But, just watch my friend, how those model outputs will change to reflect a bigger trough about this time!

Valid at 5 PM May 7th.
Valid at 5 PM May 7th.

 

The End

 

Thunderblasts after midnight awaken sleeping Catalinans with 50 mph winds, graupel, and R++; latest storm total now 1.38 inches!

In case you don’t believe me that over an inch fell, this digital record from Sutherland Heights with writing on it:

20170120-21 rain day
Your last 24 h of rain in the Sutherland Heights, Catalina, Arizona, USA. Total resets at midnight.

Probably a little more to come, too.  Got some blow damage, I’m sure.  Will be looking for roof shingles around the yard today.

12:45 AM. Your radar and IR satellite imagery for our blast last night from IPS MeteoStar
12:45 AM. Your radar and IR satellite imagery for our blast last night from IPS MeteoStar .  That tiny red region near Catalina represents hail and/or extremely heavy rain.

And, as everyone knows from their favorite TEEVEE weatherperson, “New Storm to Pound SE Arizonans!”  Begins Monday night, Tuesday AM.  May have snow in it as it ends.

Your know, its no fun telling people what they already know, so lets look ahead beyond the normal forecast period of great accuracy, beyond not seven days, not eight, but beyond TEN days!

First, we set the stage with a ten day look ahead (from last evening) in a NOAA spaghetti factory plot:

Valid for 5 PM, Monday, January 30th. If you've not seen this, you'll be screaming "warm in the West, and damn Cold in the East." Its a common pattern often associated with some of the driest years in the West when it recurs over and over again during a winter.
Valid for 5 PM, Monday, January 30th. If you’ve not seen this, you’ll be screaming “warm in the West, and damn Cold in the East.” Its a common pattern often associated with some of the driest years in the West when it recurs over and over again during a winter.

This plot indicates that the pattern of a towering, storm-blocking ridge is certain along the West Coast by ten days–will be developing for a day or three before this,  That ridge represents an extrusion of warm air aloft over the entire West Coast extending all the way into Alaska.  The couple of red lines in and south of AZ are due to the change of a minor, likely dry, cutoff low in our area about this time (plus or minus a day).

In other words, this plot suggests a warmer, dry period develops over AZ, and storms are shunted from the Pacific Ocean, located west of the West Coast, all the way to Anchorage and vicinity,  They will  be welcoming a warm up in weather up thataway at some point in this pattern.

Is that it, then, for the AZ winter precip?  It could happen.  Just one more storm after the current one fades away today?

Hint:  Sometimes anticyclone ridges like the one in the plot above get too big for their britches, and fall away, or, break off like a balloon from a tether, and a warm blob of air aloft sits at higher latitudes, often floating off to the northwest.

The exciting ramification of this latter scenario is that in the “soft underbelly” of the “blocking anticyclone” (as in American football), the jet stream throws something of a screen pass, goes underneath the belly of the blocking high,  and races in toward the West Coast at lower latitudes.  Having done so, such a break through pattern (“Break on through to the Other Side”) results in heavy rains in Cal and the Southwest.

Izzat what’s going to happen?

Let us look farther ahead, unprofessionally, really,  and see if there is evidence in spaghetti for such a development and you already know that there must be because it would explain why I am writing so much here.  Below, the EXCITING spaghetti plot strongly indicating break through flow breaking on through to the other side, i.e., the West Coast,  from the lower latitudes of the Pacific:

Valid on Thursday, February 2, at 5 PM AST. Flow from the lower latitudes of the Pac will, in fact, break on through to the other side, as told in song by the Doors1.
Valid on Thursday, February 2, at 5 PM AST. Flow from the lower latitudes of the Pac will, in fact, break on through to the other side, as told in song by the Doors1.  Who knows what they were talking about but here we’re talking about a jet stream….

Well, we’ll see in a coupla weeks if CMP knows what he is talking about..  I think this is going to happen, resembles what’s happening now, and weather patterns like to repeat, more so within the same winter.  However, how much precip comes with this pattern will be determined by how much flow breaks on through to the other side….

Yesterday’s clouds

Let us begin our look at yesterday’s clouds by looking back three days ago before the Big Storm.  We had a nice sunrise.   Here it is in case you missed it:

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7:21 AM. Altostratus sunrise. Virga is highlighted showing the precipitating nature of Altostratus. Amount of virga can vary.
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7:31 AM. Same kind of view, different colors.
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7:40 AM. Highlight on the Tortolitas. This is why you carry your camera at all times.
9:04 AM. Pretty much solid gray after that nice sunrise for the rest of the day with cloud bases lowering and raising. Early on, cloud bases were well above 10,000 feet; i. e;, above Mt. Lemmo, and would be called, "Altostratus opacus." The virga is very muted, and there are embedded droplet clouds as well as a droplet cloud layer (Altocumulus) encroaching on the right. Estimated ceiling here: 12,000 overcast." (Pronounced, "one-two thousand overcast" if you want to make your friends think that maybe you were a pilot at some time in your life.)
9:04 AM. Pretty much solid gray after that nice sunrise for the rest of the day with cloud bases lowering and raising. Early on, cloud bases were well above 10,000 feet; i. e;, above Mt. Lemmo, and would be called, “Altostratus opacus.” The virga is very muted, and there are embedded droplet clouds as well as a droplet cloud layer (Altocumulus) encroaching on the right. Estimated ceiling here: 12,000 overcast.” (Pronounced, “one-two thousand overcast” if you want to make your friends think that maybe you were a pilot at some time in your life.)
12:58 PM.
12:58 PM. Clouds began to appear on Samaniego Ridge as the moist air above us lowered steadily.  However, due to lowering cloud tops, the ice in the higher overcast layer was gone. Here there are two layers above the scruff of Stratus fractus (I would call it) on the ridge.  The lower one looks like its a Stratocumulus, and the higher one a solid layer of “Altocumulus opacus.”  Its already rained some, and we were in between storm bands.
2:48 PM. Looked like the Altocumulus opacus (stratiformis, if you want to be exactly correct) was breaking up just enough for a sun break. But no, kept filling in as it headed this way from the southwest.
2:48 PM. Looked like the Altocumulus opacus (stratiformis, if you want to be exactly correct) was breaking up just enough for a sun break. But no; it kept filling in as it headed this way from the southwest.  No ice, or virga evident, so tops are pretty warm, probably warmer than -10° C (23° F) would be a good guess. Hah!  Just now looked at the TUS sounding and tops were indicated to be at -11° C, still very marginal for ice (absent drizzle drops in clouds, which causes ice to form at much higher temperatures, but you already knew that.)
4:24 PM. Small openings allowed a few highlights to show up on the Catalinas underneath that Altocumulus opacus layer.
4:24 PM. Small openings allowed a few highlights to show up on the Catalinas underneath that Altocumulus opacus layer.  And  clouds were still topping Ms. Mt. Lemmon, indicating a good flow of low level moisture was still in progress.

Moving forward to only two days ago, the day preceding the nighttime blast:  a cold, windy day with low overcast skies all day, shallow, drizzle-producing clouds, something we don’t see a lot of here in Arizona.

8:08 AM, January 20th, 2017, btw. "Gray skies, nothin' but gray skies, from now on", by Irving B.
8:08 AM, January 20th, 2017, btw. “Gray skies, nothin’ but gray skies, from now on”, by Irving B.  Stratus fractus underlies an overcast of Stratocumulus.  Some light rain is falling toward Romero Pass on the right.
8:10 AM. A really special shot. Stratus with drizzle is a very difficult photographic capture. I can feel how enthralled you are with this view toward Oro Valley. You know, I do this for YOU.
8:10 AM. A really special shot. Stratus with drizzle, shown here,  is a very difficult photographic capture. I can feel how enthralled you are with this scene toward Oro Valley. You know, I do this for YOU.  Look how uniform the gray is!  It just takes your breath away!
9:44 AM. Before long, drier air down low moved in, eradicating our beautiful Stratus layer, leaving only holdouts (Stratus fractus) along the Catalina foothills below the heavy layer of Stratocumulus.
9:44 AM. Before long, drier air down low moved in, eradicating our beautiful Stratus layer, leaving only holdouts (Stratus fractus) along the Catalina foothills below the heavy layer of Stratocumulus.
10:20 AM. The wind had now shown up, and these ragged, shredded shallow Stratocumulus shedding drizzle or very light rain showers stormed across the Catalina Mountains. This was quite remarkable sight, since such shallow clouds as these are more often seen in clean maritime locations like Hawaii. Scenes like this suggest that the cloud droplet concentrations were very low, and that there were larger than normal cloud condensation nuclei on which the drops could form, getting a head start in the sizes needed to produce collisions with coalescene (larger than 30 microns in diameter (about one third to one half a human hair in diameter, for perspective.)
10:20 AM. The wind had now shown up, and these ragged, shredded shallow Stratocumulus shedding drizzle or very light rain showers stormed across the Catalina Mountains. This was quite remarkable sight, since such shallow clouds as these are more often seen in clean maritime locations like Hawaii. Scenes like this suggest that the cloud droplet concentrations were very low, and that there were larger than normal cloud condensation nuclei on which the drops could form, getting a head start in the sizes needed to produce collisions with coalescene (larger than 30 microns in diameter (about one third to one half a human hair in diameter, for perspective.)

 

3:12 PM. Lower, drier air moved in, eradicating the Stratocumulus and revealing the rarely seen Nimbostratus precip-producing layer. This layer, considered a mid-level cloud, is usually obscured by, you guessed it, Stratocumulus clouds.
3:12 PM. Lower, drier air moved in, eradicating the Stratocumulus and revealing the rarely seen Nimbostratus precip-producing layer. This layer, considered a mid-level cloud, is usually obscured by, you guessed it, Stratocumulus clouds.

By the end of the day, the clouds had lowered again, and we were about to have a very interesting night!

5:01 PM.
5:01 PM.

The End

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1Remember how great we hippie relics thought that first Doors album was? Later, the Doors, and that era were to be made fun of by 80s punk and humor group,  The Dead Milkman in “Bitchin’ Comaro.” (Its worth a listen.)

 

 

“Deception at its finest”….a study in cloud perspective

I am sure that many of you saw this last evening:

4:17 PM. Line of spreading out Altostratus translucidus.
4:17 PM. Line of spreading out Altostratus translucidus.  Many of you might have added, “radiatus” to that cloud name.  “Clearly” it is widening as it passes over.

While I hate to embarrass cloud acolytes, here’s the simultaneous satellite view, courtesy of our Banner University of Arizona Weather Department:

AZC
4:00 PM AST. That line of ice cloud looks pretty straight doesn’t it? Imagine how wide a cloud would have to spread, after seeing that Altostratus photo, to REALLY be radiating, spreading out!

As Einstein wrote, “Things are not always as they seem.”

Q. E. D.

Now, for the snow report

…from the Lake Tahoe area (after all, we made a BIG DEAL out of the incredible NWS, Reno, forecast in the prior blogulation):

0822 AM     HEAVY SNOW       NORTHSTAR               39.28N 120.12W
01/11/2017  M42.0 INCH       PLACER             CA   PUBLIC

NORTHSTAR AT TAHOE REPORTED 42 INCHES OF NEW SNOWFALL IN  THE LAST 24 HOURS. 48 HOUR TOTAL OF 78 INCHES AND A 7 DAY TOTAL OF 122 INCHES1.

1This note passed along to the Arthur by Mark Albright.

Looks like a bite has been taken out of the Cal drought this water year, a drought it was said would take years to end!  Folsom Lake, near “Sacramenta”, Cal,  has risen 30 feet in the past 30 days! Oh, my.

Now for some more of them cloud pictures…

Been holding out as other chores fill up the day:

7:19 AM, Jan 10. Pretty Altocumulus, some Cirrus above.
7:19 AM, Jan 10. Pretty Altocumulus, some Cirrus above.
7:19 AM, Jan 10th. Time seems to be standing still, as we look a a cloudlet spewing heavy virga.
Also 7:19 AM, Jan 10th. Time seems to be standing still, as we look a a cloudlet spewing heavy virga.
7:22 AM, Jan 10th, time moving ahead again. Close up of that Altocumulus with virga. Top must have been turreted, colder maybe a half hour or hour before this photo to have so much ice compared to its brethren.
7:22 AM, Jan 10th, time moving ahead again. Close up of that Altocumulus cloud with virga. Top must have been turreted, colder maybe a half hour or hour before this photo to have so much ice compared to its brethren.  That’s the learning part of this sequence.  Doesn’t look like an artifact from an aircraft because there is droplet cloud at the top, and not just a clear spot, which usually happens when an aircraft makes ice in a “supercooled” droplet cloud.
5:14 PM, Jan 10th. THought this was a neat scene, Cirrus uncinus, the long trail of ice crystals falling behind, the overhead view.
5:14 PM, Jan 10th. THought this was a neat scene, Cirrus uncinus, the long trail of ice crystals falling behind, the overhead view.
12:57 PM, Jan 8th. Makes you want to cry... This Cirrus spissatus is trying so HARD to be a precipitator to the ground, and doesn't know that those bottom ice crystals are evaporating 25,000 feet above it.
12:57 PM, Jan 8th. Makes you want to cry… This Cirrus spissatus is trying so HARD to be a precipitator all the way to the ground, and doesn’t know that those bottom ice crystals are evaporating 25,000 feet above it.

The weather just ahead

U of AZ latest mod output (from 11 PM AST last night) has a substantial rain on the doorstep.  Starts here in Catalina Saturday afternoon with projected totals over half an inch nu mid-day Sunday.  Check it out:

Totals valid at 11 AM AST, Sunday, Jan. 15th.
Totals valid at 11 AM AST, Sunday, Jan. 15th.

HECK, this storm wasn’t even predicted 10=12 days ago!  The major weather change was indicated about the 20th, plus or minus a day.  Those storms, indicated in the NOAA “spaghetti” plots more than 12 days ago, are still in the pipeline after we have a brief “recovery” from the “surprise” storm about to arrive on Saturday!  Yay.

This sequence of storms is so great for the AZ water situation, too, as well as giving it to Cal good again around the 20th as well.  No doubt, as the humans we are, the peoples of Cal  will be complaining about TOO MUCH WATER!

This will lead to apathy about water issues, you can bet on it!  See the well-known “cloud seeding cartoon” about drought and apathy posted so many decades ago in a journal article on cloud seeding by editorial nemesis1, Bernard A. Silverman, J. Appl. Meteor.,
termed the “Hydro-illogic Cycle”:

Published in 1978, but was around in the cloud seeding culture for many years before that. Used without permission. hahaha
Published in 1978, but was around in the cloud seeding culture for many years before that. Used without permission. hahaha  I believe it was drawn by the founder of Atmospherics, Inc., Tom Henderson’s daughter.  Atmospherics, Incorporated performed numerous cloud seeding operations in the US and around the world beginning in the early 1950s.  Yours truly worked for them on several occasions in the  early 1970s as a “radar meteorologist” directing seeding aircraft.  Later, I became a published critic, mostly with Prof. Peter V. Hobbs,  of a number of cloud seeding projects.

The End
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1Nothing yours truly submitted during the era of BAS as Editor of the J. Appl. Meteor. “got in”, including the benchmark paper reporting that our own aircraft was creating ice in clouds at temperatures as high as -8° C.   Three sole-authored papers critical of cloud seeding that I submitted were rejected in 1983 alone!  All or parts of them were published years later.

The paper on our aircraft, submitted originally in 1981, was rejected twice before being accepted and published in 1983. The effect was confirmed in experiments conducted in the Mono Lakes area in 1991, by the president of Atmospherics, Inc. mentioned above! Aircraft produced ice particles at unexpectedly high temperatures is a now well-known phenomenon that researchers have to be aware of when re-sampling the same cloud with an aircraft at below freezing temperatures.

Soap box:  It really is the editor of journals that determines whether you’re going to get in or not. They know, or should know, those who are going to keep you out or not, those with axes to grind, and those who are more objective.  However, let me say this, I like Bernie.  Has a great sense of humor. Below, Bernard A. Silverman.  You can see the twinkle in his eye:

Bernard A. Silverman, publisher of the "Hydro-illogic Cycle" at the Cape Town, SA, WMO award
Bernard A. Silverman, publisher of the journal article containing the  “Hydro-illogic Cycle” cartoon at the Cape Town, SA, 2006 WMO award ceremony for achievements in weather modification.  He acknowledged in that  1978 article that he was a cloud seeding advocate.

Altostratus opacus virgae transitions to Altocumulus during day! Storms to bring rain!

What a day for cloud maven juniors and me, too, watching the Altostratus opacus (but sometimes “translucidus” cuz you could see where the sun was) become Altocumulus!  It happens pretty often and is the result of lowering, and warming of the cloud tops, but I need to generate some excitement on an otherwise somewhat dull day.

What else is happened as tops warmed?  Good-bye virgae (“virga”, in plain speak), except in a couple of locations that raised the question, “Was it hers (Mother Nature’s) or ours (aircraft effects)?”

2016122912Z_SKEWT_KTUS
The TUS balloon sounding through all that Altostratus opacus virgae. Launched at about 3:30 AM. The top temperature is so cold (-60° C, -76° F) we don’t even want to know here in Arizona that such temperatures are possible. So, you can imagine all the ice that might form in a moist layer of air. The bottom is even cold at nearly -15° C, there were the temperature jumps out to the right.  This is a situation we call “overrunning”, where warmer air is going over a colder air mass.  This cloud was about 22,000 feet thick, 7 km at this point.

The slight spread between the two lines illustrates the classic representation of what we measure when the balloon passes through an all ice crystal/snowflake cloud like this version of Altostratus was yesterday morning.  The humidity element on the balloon measures the humidity relative to liquid water, not ice, so there will be some spread between the dew point temperature (line on the left) and the temperature (line on the right) when the balloon ascends through an ice cloud.   Saturation with respect to ice is indicated here in that deep “overrunning” layer, something also likely to happen tomorrow to the writer’s “company” fubball team tomorrow.

And here's the TUS sounding launched yesterday afternoon when we only had Altocumulus opacus clouds, just as dark as Altostratus opacus, but much thinner. Tops around -10° for the most part, but there may have been some turrets to almost -20° C. The balloon almost certainly passed between clouds, did not go exactly through a Altocumulus cloudlet.
And here’s the TUS sounding launched yesterday afternoon when we only had Altocumulus opacus clouds, just as dark as Altostratus opacus, but much thinner. Tops around -10° for the most part, but there may have been some turrets to around -20° C. The balloon almost certainly passed between clouds, did not go exactly through a Altocumulus cloudlet.  Don’t worry if you can’t make out the actual temperatures on the lines sloping up to the right, just take my word for everything I say.  You can easily see how much it dried out in the middle and upper cloud regions between the morning sounding and this one.

Yesterday’s clouds and the transition

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8:29 AM. Altostratus opacus virgae (has some downward pendants of ice and snowflakes coming out of it). The TUS radar had some sprinkles showing up here and there.
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8:29 AM. Altostratus opacus virgae (has some downward pendants of ice and snowflakes coming out of it). The TUS radar had some sprinkles showing up here and there. If this seems familiar, the caption is identical with the prior one. Redundancy is one of the niches we practice here, mostly in cloud photos of the same thing.

Now let’s look over here:

8:29 AM. The same.
8:29 AM. The same.
9:19 AM. Thin spot in the overcast.
9:19 AM. “Thin spots in overcast”:  we used to say that a lot in our human weather reports of ages gone by.  Here the thin spot makes this Altostratus translucidus.. While there is an irregular look to this Altostratus due to virga hanging down, there is no indication of liquid water elements, ones that would show up as sharply-outlined darker elements.  While this is hours later than that morning TUS sounding, it is likely that in spite of this thin spot, the Altostratus layer was still many kilometers (thousands of feet thick).  Ice crystals and snowflakes are far less numerous than droplets in liquid clouds, and,  therefore clouds composed of ice are more transparent given equal depths.   Compare the visibility in a dense fog with being in a light snowfall.
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9:38 AM. Example of a some sharply-outlined liquid clouds embedded in the Altostratus layer have formed. The growth of ice crystals and snowflakes is enhanced in  liquid clouds because they represent regions where it is saturated with respect to WATER, and highly supersaturated with respect to ice (the relative humidity with respect to ice is well over 100%).  Also, if the droplets in these clouds are large enough (larger than about 15 microns in diameter) they can be collected by the falling ice and snow, adding to their mass of those, causing them to fall faster.
10:29 AM. Had numerous, dramatic outbreaks of mammatus around this time, probably representing the fall back of turrets on top of the Altostratus as this time. We will say no more about mammatus since the author has tended toward the prurient to break up the tedium in past notations about mammatus.
10:29 AM. Had numerous, dramatic outbreaks of mammatus around this time, probably representing the fall back of turrets on top of the Altostratus as this time. We will say no more about mammatus since the author has tended toward the prurient to break up the tedium in past notations about” mammatus.”  This might be viewed as an upside down look at the cloud tops at this point, BEFORE they collapsed and dropped below the main bottom of this layer.  At the top (rumpled area), regions of a liquid cloud layer are beginning to appear, a sure sign that tops are receding.
11:55 AM. Moving along,looking upwind across the Oro Valley. Still looks composed mostly of ice, but liquid clouds are on the far horizon.
11:55 AM. Moving along,looking upwind across the Oro Valley. Still looks composed mostly of ice (Altostratus opacus virgae here), but liquid clouds are on the far horizon.
1:21 PM. Altocumulus opacus rules. The deep icy cloud is all gone by now.
1:21 PM. Altocumulus opacus rules. The deep icy cloud is all gone by now.  No virga.  Notice, too, in spite of being less than a kilometer thick, this cloud looks as gray as the Altostratus that was many kilometers thick.  The droplet concentrations in a liquid cloud such as this might be 200, 000 per liter, while the ice concentrations in that Altostratus cloud were likely in the 10s per liter.  The smaller particles in Altocumulus clouds, average perhaps only  15-20 microns in diameter  also are able to reflect far more sunlight back into space, and less sunlight reaches the bottom making it darker.  In contrast, the (ice) particles in the Altostratus would be hundreds of microns to millimeters in diameter (i.e., precip-sized).
2:22 PM. Looking around at these cold Altocumulus clouds, generally not showing virga, you begin to wonder if those areas you do see have been the result of an aircraft passage, as here in that little spot of virga.
2:22 PM. Looking around at these cold Altocumulus clouds, generally not showing virga, you begin to wonder if those areas you do see have been the result of an aircraft passage, as here in that little spot of virga.
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2:28 PM. Some breaks in the overcast allowed some nice scenes to fall upon our mountains. Here, the Charouleau Gap is highlighted.

The weather just ahead

Here’s the latest projected rain totals from the U of AZ Wildcat Weather Department Weather Calculator:

From the global ingest of data at 11 PM AST last evening. Indicates that green Catalina will be in the half inch to three quarters of an inch between now and New Year's Day afternoon. Comes in two segments, the first overnight tonight, and then another starts New Year's Eve.
From the global ingest of data at 11 PM AST last evening. Indicates that green Catalina will be in the half inch to three quarters of an inch between now and New Year’s Day afternoon. Comes in two segments, the first overnight tonight, and then another starts New Year’s Eve.  Seems reasonable.  Probably not quite reasonable is the red on the Cat Mountains, indicating 3-4 inches accumulation during this time, probably a bit overdone.  Both storms are rather small in size, so the amount of rain depicted in these model runs has varied a lot.  But, they seem to be settling on something decent.  Seems the least we’ll end up with has to be more than a third of an inch, worst case scenario.  See Bob and the NWS for a good look at these incoming events.  We’re mostly about clouds here.

Undercutting flow from the tropical Pacific is on schedule.  So, a good chance for major rains along the southern portions of the West Coast in a few days, with a pretty good chance they’ll leak into Arizony.

 

The End

Strange sunset brew of clouds and color; but was it natural?

Cutting to the chase:  I don’t think so.

Yesterday,  after an ordinary beginning,,  finished in a spectacular, if likely artificial way.  Let us work our way through yesterday’s cloudulations:

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7:39 AM. I thought this was a cute display by this little cloud, making its own little shadow rays as the sun made its way up from behind the Catlinas.
7:40 AM. But what kind of cloud is it? It, to these eyes, is all ice, but LOOKS like an Altocumulus cloud. But those clouds are all or mostly comprised of liquid drops. And you can see that this little guy is well BELOW a higher layer of ice cloud, we might call CIrrostratus, or a thin Altostratus. Oh, well, let’s move on to something explicable….

 

7:41 AM. Hmmmm. Quite a linear virga feature over there.
7:41 AM. Hmmmm. Quite a linear virga feature over there.  There are THREE cloud layers evident here, a thin Altocumulus layer, that dark cloud on the left, and patch of what I could call, Altostratus extending from the left corner to the right corner, and a thin layer of CIrrostratus on top.
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7:41 AM. Let’s go zooming and check it out…. Though we don’t know for SURE, anytime you see this kind of linear virga anomaly, you should be smelling aircraft exhaust.  Now, when you think about our fabulous sunset last evening and what that looked like, take a closer look at this photo.

Later that morning…..

10:53 AM. 10:47 AM. It was nice to see low clouds topping Sam Ridge, the lower boundary layer air (where convection takes place) moist for a change.
10:53 AM. It was nice to see low clouds topping Sam Ridge at dawn yesterday, the lower boundary layer air (where convection takes place) moist for a change.  Later they devolved into small Cumulus (humilis and fractus).
3:29 PM. A day with mostly ice clouds on top of Catalina, but here, off in the distance below the Cirrostratus, is an invading layer of Altostratus and Altocumulus that will set the stage for sunset glory later.
3:29 PM. A day with mostly ice clouds on top of Catalina, but here, off in the distance below the Cirrostratus, is an invading layer of Altostratus and Altocumulus that will set the stage for sunset glory later.  You may be able to detect a faint halo, upper center.  By the way, Cirrostratus typically deepens downward to morph into Altostratus, usually an ice cloud, too, but is deep enough to produce gray shading, and when its really thick or has embedded droplet clouds, hides the sun.
4:02 PM. Yep, moving right in.
4:02 PM. Yep, moving right in.  This is a very complex scene.  There’s aCirrostratus ice layer. upper right quadrant , on top of everything.  Below that, what appears here as a distinctly lower separate layer, a mix of Altocumulus (those dark cloudlets composed all or mostly of liquid droplets) and Altostratus (mostly or all ice, the smudgy more diffuse dark areas) .  We can never forget that Altocumulus can morph into Altostratus, which would then be called, “Altostratus altocumulotransmutatus.”  Tell that to your friends!  (Well, maybe not.)
4:15 PM. Caught this bumpy aircraft contrail at CIrrus levels. Look how how the exhaust and water vapor that formed this, though output from an aircraft in a steady state, how the wing tip vorices (apparently) get entertwined at regular intervals with more exhaust and water vapor in those blobs.
4:15 PM. Caught this bumpy aircraft contrail at CIrrus levels. Look how how the exhaust and water vapor that formed this, though output from an aircraft in a steady state, how the wing tip vorices (apparently) get entertwined at regular intervals with more exhaust and water vapor in those blobs.

But let’s go zooming up to flight level and take a closer look for a second:

A mammatus (or as the ladies like to call it) testicularis contrail. Almost certainly this is due to combining wing tip vortices. Many aircraft now have devices to defeat wing tip vortices, phenomenon that reduce flight efficiency.
A “mammatus” (or as the ladies like to call it. a testicularis contrail (the resemblances are pretty good). Almost certainly this is due to combining wing tip vortices.  Many aircraft now have devices to defeat wing tip vortices, phenomenon that reduce flight efficiency.  In both cases above, the ice particles have not grown enough to produce fallstreaks.  These images tell us that SOME aircraft that produce ice in supercooled Altocumulus clouds, as we in Catalina have seen lately, are likely to have bunches of ice trails rather than a continuum if produced in a uniform cloud, anyway.

Now, where was I?  Got mammatus on my mind again. I love mammatus so much…   Oh, yeah, that sunset yesterday…..

5:13 PM. Ran out to check sunset status, and saw this feature advancing rapidly toward Catalina.
5:13 PM. Ran out to check sunset status, and saw this feature advancing rapidly toward Catalina.
5:18 PM. Zoomed view; getting close to passing overhead. You might be able to notice that these pretty regularly spaced trails are BELOW the Altocumulus clouds, and there's a clearing that's been produced. All evidence of an artificial production of these trails. But belng below the Altocu, you might also have started to wonder whether the setting sun would light them up....
5:18 PM. Zoomed view; getting close to passing overhead. You might be able to notice that these pretty regularly spaced trails are BELOW the Altocumulus clouds, and there’s a clearing that’s been produced. All evidence of an artificial production of these trails. But belng below the Altocu, you might also have started to wonder whether the setting sun would light them up….

And the sun did its job….producing one of the greatest sunset scenes we’ve seen in a long time, even if phony (haha):

5:23 PM. Not zoomed, still a few minutes away to overhead passage. Very exciting to think this was going to pass overhead!
5:23 PM. Not zoomed, still a few minutes away to overhead passage. Very exciting to think this was going to pass overhead!
5:23 PM. Zoomed view. Again the pretty regular spacing is circumstantial evidence that nature didn't do it.
5:23 PM. Zoomed view. Again the pretty regular spacing is circumstantial evidence that nature didn’t do it.
5:25 PM. Thank you sun! Looks pretty round again, which is good.
5:25 PM. Thank you sun! Looks pretty round again, which is good.
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5:27 PM. Oh, so pretty.
5:27 PM.
5:27 PM. Zooming again. Wow.
5:28 PM. Another view of the same thing.
5:28 PM. Another view of the same thing.
5:28 PM. Our trails compared to the rest of the Altocumulus deck. Not much going on elsewhere in the way of natural virga.
5:28 PM. Our trails compared to the rest of the Altocumulus deck. Not much going on elsewhere in the way of natural virga.
5:29 PM. Taking WAY too many photos of the same thing. Out of control... Here I demonstrate that with another photo of the same thing.
5:29 PM. Taking WAY too many photos of the same thing. Out of control… Here I demonstrate that with another photo of the same thing.

 

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5:30 PM. After the trail hoopla, it was time to concentrate on the fabulous sunset taking place to the southwest of Catalina.
5:30 PM. Zooming in on interesting features; long trails, one with a clearing above it. Was it another aircraft-induced trail of ice and clearing above it? Probably. The trails to the left aren't as obviously produced by an aircraft, but I do think so anyway in this burst of objectivity. Recall that I have been trained as a "scientist" and don't care if I am wrong, but only about truth, as best as I can make it out.
5:30 PM. Zooming in on interesting features; long trails, one with a clearing above it. Was it another aircraft-induced trail of ice and clearing above it? Probably. The trails to the left aren’t as obviously produced by an aircraft, but I do think so anyway in this burst of objectivity. Recall that I have been trained as a “scientist” and don’t care if I am wrong, but only about truth, as best as I can make it out.

Finally, let look at the TUS sounding for last evening, see how cold those Ac cloud were with the ice trail in them:

The Tucson rawinsonde balloon launch yesterday at about 3:30 PM. Goes up at about 1,000 feet a minute, so takes about 100 minutes to get to 100, 000 feet. They pop somewhere around that height or a little above. THought you like to know that. They have a little parachute to that when they come down, they don't bonk you too hard. Once in awhile people find them in remote areas downwind.
Results of the Tucson rawinsonde balloon launch yesterday at about 3:30 PM. Goes up at about 1,000 feet a minute, so takes about 100 minutes to get to 100, 000 feet. They pop somewhere around that height or a little above. THought you like to know that. They have a little parachute to that when they come down, they don’t bonk you too hard. Once in awhile people find them in remote areas downwind.  You can send them back in to the NWS, too!

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!

 

The End

——————————
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.

November thunderama

Doesn’t happen every November, thunder, but it sure pounded away at times yesterday.   Seemed louder than usual thunder a few times even with the lightning over there by the Tortolita Mountains. Of course, that’s where the heaviest rain fell as several T-storms tracked along a similar path over there just a little to the W through N of us, Bio2, in one of the heavier cloberations receiving 1.17 inches.

Here, in The Heights, we received a disappointing, but nevertheless welcomed final total of 0.24 inches.  This brings our total here in Sutherland Heights for November up to 0.60 inches.  Average is 0.96 inches1.  Here, the regional totals as the storm was coming to an end:

"Us" is here in the Sutherland Heights; "Them" is Bio2. Wanted to reflect the general world situation now days by using an oft used cliché.
“Us” is here in the Sutherland Heights; “Them” is Bio2. Wanted to reflect the general world situation now days by using oft used cliché terms.

As is proper, let us begin examining the nubilations of our storm by looking at those clouds that preceded the actual rain day yesterday.

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7:02 AM. This pretty sunrise over the Catalina features a couple of flakes of Altocumulus clouds, and a vast layer of Altostratus.
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7:04 AM. Yes, the sun is coming up, though really its the earth rotating toward the sun. The sun does not go around the earth every day; it only SEEMS that way. We’re looking at the same two cloud generas, btw. Nice rays produced by pretty regular humps in clouds over the horizon, a little row of Altocumulus castellanus might cause these rays/shadows.
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7:05 AM. This was pretty interesting, to use “pretty” again. This would be an Altostratus mammatus. Men often find this formation especially interesting and pretty. Here you can also see how a cloud protuberance can produce a shadow. But why is there only one feature like this? Typically mammatus are like upside down Cumulus turrets representing  downward moving cloudy, in this case, air filled with ice crystals).   Adjacent to this feature, the ice crystals and snowflakes are just settling out.   As the moving downward air in mammatus features slows, these breast-like globules open up and you’ll have ordinary virga. The ice crystals are typically rather small and not rimed (that is, have not collided with cloud droplets) or they would fall out and not be constrained to this pretty,  rounded shape.
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7:07 AM. The underside of the Altostratus is lit up, showing the detailed areas of virga. Altostratus, by definition, is a precipitating cloud. Its just that the bases are too high for the precip (snow) to get to the ground, though sprinkles could occur in the thicker, deeper versions. When and if it starts to rain steadily, the cloud is better termed a “Nimbostratus,”
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11:20 AM. The Altostratus deck departed with its pretty mammatus and virga, leaving great examples of Altocumulus opacus clouds most of the morning and into the early afternoon.
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3:24 PM. An example of Altostratus translucidues doesn’t get better than this.  Hope you captured it.  The As  (abbrev. for “Altostratus”) cloud over took over by mid-afternoon as the moist layer deepened again following the Altocu. Tops of this all ice Altostratus layer, in spite of being able to make out  (“discern,” not “make out” in the social sense of the phrase–still thinking about that mammatus formation) the sun’s position, are usually around Cirrus levels, the top of the troposphere.  The TUS sounding suggested “bases” (actually where the ice crystals are evaporating rather than droplets that comprise the bases of Cumulus, Altocumulus or other droplet clouds) at 14,000 feet ASL, and tops around 34,000 feet ASL  Subtract about 3 kft to get heights above the ground here in Catalina.

 

Moving ahead to yesterday…..

7:13 AM. With an approaching upper level trough and big low center in the Great Basin, the winds had become gusty, and the clouds had lowered to Stratocumulus status, topping the Catalinas. I thought the lighting was really pretty here, and that shaft out there shows that turrets are climbing shooting up well beyond the general tops of the shallow Stratocu. Pretty exciting since it meant that the tops of other Stratocu might bunch into other Cumulonimbus clouds, which is what that shaft tells you.
7:13 AM. With an approaching upper level trough and big low center in the Great Basin, the winds had become gusty, and the clouds had lowered to Stratocumulus status, topping the Catalinas. I thought the lighting was really pretty here, and that shaft out there shows that turrets are climbing shooting up well beyond the general tops of the shallow Stratocu. Pretty exciting since it meant that the tops of other Stratocu might bunch into other Cumulonimbus clouds, which is what that shaft tells you.
8:18 AM. A line of Cumulonimbus quickly erupted and it looked like it was about to crash into the Oro Valley Catalina area, but instead stayed to the west over the Tortolitas.
8:18 AM. A line of Cumulonimbus quickly erupted and it looked like it was about to crash into the Oro Valley Catalina area, but instead stayed to the west over the Tortolitas.  Thunder heard!
8:19 AM. Looking WNW toward the Tortolitas.
8:19 AM. Looking WNW toward the Tortolitas.
9:27 AM. After some light showers passed along the Catalinas, this pretty scene. Note the glistening rocks that added such pretty highlights.
9:27 AM. As some light showers passed along the Catalinas, this pretty scene the sun broke through.  Note the glistening rocks that added such pretty highlights.
9:28 AM. Pretty nice over toward the Gap, too! I will never get tired of these scenes!
9:28 AM. Pretty nice over toward the Gap, too! I will never get tired of these scenes!
11:12 AM. Disappointingly, in view of all the rain predicted here (0.575 inches) that first line of Cumulonimbus clouds stayed stayed west of Catalina.
11:12 AM. Disappointingly, in view of all the rain predicted here (0.575 inches) that first line of Cumulonimbus clouds stayed stayed west of Catalina.  But, that line of Cumulus or Stratocumulus clouds on the horizon is full of stormy portent, that a windshift line might be about to strike and generate another line of Cumulonimbus clouds.  Any solid line of clouds like that, kind of by itself, suggests a windshift; it more than just a fair weather “cloud street.”
11:11 AM. Zooming in on that line of clouds. Its fun to zoom, since you are in a way, flying toward what you're looking at, getting so much closer!
11:11 AM. Zooming in on that line of clouds. Its fun to zoom, since you are in a way, flying toward what you’re looking at, getting so much closer! I wish that line of clouds was here already!

 

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11:27 AM. Yep, there it goes, fattening upward into Cumulus congestus and to the N, Cumulonimbus clouds! This one will surely blast across Catalina as the upper trough and associated cold front approach; heck, maybe that’s the cold front windshift line and temprature drop right there!
11:27 AM. Yep, there it goes, fattening upward into Cumulus congestus and to the N, Cumulonimbus clouds! This one will surely blast across Catalina as the upper trough and associated cold front approach; heck, maybe that's the cold front windshift line and temprature drop right there!
11:27 AM. Yep, there it goes, fattening upward into Cumulus congestus and to the N, Cumulonimbus clouds! This one will surely blast across Catalina as the upper trough and associated cold front approach; heck, maybe that’s the cold front windshift line and temprature drop right there! Repeated for emphasis.
11:29 AM. A Cumulonimbus cloud is a bit farther north in this line.
11:29 AM. A Cumulonimbus cloud is a bit farther north in this line.  This HAS to be the windshift and cold front!
11:46 AM. Was inside for a few minutes (18) and that cloud line just exploded over there. Here looking again toward the Tortolitas. But surely they will wall out and crash the sunny party in Oro Valley (I was thinking).
11:46 AM. Was inside for a few minutes (18) and that cloud line just exploded over there. Here looking again toward the Tortolitas. But surely they will wall out and crash the sunny party in Oro Valley (I was thinking).
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11:52 AM. Well, these followup Cumulonimbus clouds aren’t looking so great, no evidence of strong turreting, weak and leaning, wispy, frail, “indolent”, cloud “couch potatoes.” Hope fading for a big shafting here in The Heights
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12:12 PM. The cloud line, as expected is progressing across Oro Valley, but shafting is meager. Its real windy, though, adding some drama. Gusts to 40 mph! Note however the weak shafting, as evidenced by a slope across the whole thing; no heavy, large particles falling out of this guy as we see in those vertical summer shafts. Indicates that the tops are getting very high, producing lots of condensate. So even here, with a nice dramatic scene, you’re thinking (to put words in your brain) that its going to be a disappointment in rain production, and you might be missed altogether!
12:24 PM. It was pretty much all over 12 min later, that is, the chances for a real shafting. A well formed Cumulus congestus base formed just upwind of Catalina, but as so many do, slipped a little east before reaching Cumulonimbus stage and unloaded on the Catalina foothills NE of Catalina. Sometime, when clouds like this are overhead and show no precip, it just can dump out of the black. But, it didn't happen yesterday.
12:24 PM. It was pretty much all over 12 min later, that is, the chances for a real shafting. A well formed Cumulus congestus base formed just upwind of Catalina, but as so many do, slipped a little east before reaching Cumulonimbus stage and unloaded on the Catalina foothills NE of Catalina. Sometime, when clouds like this are overhead and show no precip, it just can dump out of the black. But, it didn’t happen yesterday.  By now, the wind had shifted, the temperature was falling, and soon, the light to briefly moderate rain fell as the cold front went by.
DSC_9428
1:14 PM. By this time, you could pick up a couple of nice photos of just Stratocumulus clouds following the passage of the front. Here we see some indications of mammatus formations (upper center, right) in a droplet cloud, an extremely rare event since droplets evaporate so much faster in downward moving air that the pouches represent. One can surmise that those pouches may have contained higher amounts of liquid water, and the downdrafts were very slight.  OK, so we’re kind of fixated on mammatus today….  No apologies; I’m just a man.

The great thing about yesterday was that because the upper trough lagged so much behind the cold front, you could be sure it wasn’t over, that is, the rain chances.  In fact, as the wind turns aloft from a southerly or southwesterly direction to a more westerly one, we here in Catalina have a better chance of having the clouds pile up over us, even if they’re not full fledged Cumulonimbus clouds, they can still reach depths where they precipitate while upwind, they don’t because they may not be deep enough.   The Catalina Mountains provides the lift that helps do this, and we saw that happen later in the afternoon and evening when it began to rain again long after the cold front and it so-so rain band went by.

3:06 PM. Starting to look more favorable for rain and the clouds began to cluster after the boring spell of Stratocumulus except for the brief display of pretty mammatus.
3:06 PM. Starting to look more favorable for rain and the clouds began to cluster after the boring spell of Stratocumulus except for the brief display of pretty mammatus.  The air aloft was getting a little colder, too, helping the Cumulus clouds deepen upward in spite of cool temperatures following the front.  This view is looking upwind to pal Mark Albright’s house there in Continental Ranch, Marana.  Mark is a fellow U of WA research meteorologist, though he hasn’t thrown in the towel yet, is still working.
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3:34 PM. Even as the clouds filled in and the light showers began, some pretty highlights were observed where the sun peaked through holes in the overcast. Here, Eagle Crest to the north of The Heights is spotlighted. If you are a resident of Eagle Crest and you would like a copy of this photo entitled, “Spotlight on Eagle Crest”, you can get one today for $1200, If you call now, you can get two for $2400.
5:25 PM. FInally, as the light rain fell, adding a few more hundredths to our total, sunset occurred! You can see it WAS raining by the drop on the camera lens, I didn't just say it was raining because I wanted it to. Note the lack of shafts. This tells you the tops of the clouds are pretty uniform, not protruding much above us. The rain was "pretty" steady, another indication that the clouds are relatively uniform in the horizontal.
5:25 PM. FInally, as the light rain fell, adding a few more hundredths to our total, sunset occurred! You can see it WAS raining by the drop on the camera lens, I didn’t just say it was raining because I wanted it to. Note the lack of shafts. This tells you the tops of the clouds are pretty uniform, not protruding much above us. The rain was “pretty” steady, another indication that the clouds are relatively uniform in the horizontal.

The End, FINALLY!

—————–

1If we don’t get more rain by the end of November, I will delete the sentence of a week or so ago stating that November would have above average rainfall.  No use having people see that.

More odd optics; a Cirrostratus halo with a suggestion of a lower tangent arc

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7:25 AM arrives as usual. Seeming radiating bands of Altostratus stream toward Catalina (little too thick and gray to be “Cirrus”). They also appeared so smooth as to resemble lenticular clouds.
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1:14 PM. Since its summer again in Arizona in late October, not surprising to see afternoon Cumulus clouds originating in air from the Tropics clustering over our mountains again.
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1:38 PM. The curved brightening at the bottom of this otherwise normal halo is likely a “lower tangent arc.”
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1:40 PM. Zooming in with excitement here. Is it really a lower tangent arc? Not positive, but will go with that description anyway.
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2:59 PM. That Cirrostratus thickened into Altostratus (usually, btw, due to the bottom of the cloud lowering) and at the same time the lower moisture, evidenced by these Cumulus and Stratocumulus clouds, also increased. However, none of these lower clouds got cold enough to produce ice, so likely tops were warmer than -10°C (14°F).

DSC_90074:32 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.

DSC_90115:23 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…

The End

Ice optics extravaganza; Cirrus uncinus fallstreifen going in different directions!

What a day, Mr. and Mrs. Catalina!

Not as good as a rain day with lightning, but yesterday did have its moments in the sky, enough to make the astrologers  on Mt. Lemmon jealous with displays of parhelia (“sun dogs”, or “mock suns”), faint haloes, a rare parhelic circle, something you don’t see but once every year or two,  and fallstreifen (fall streaks) from Cirrus uncinus clouds going in almost opposite directions, an extremely rare sight.

The rare “parhelic circle” is a local brightening often extending out from a parhelia (sun dog) at a sharp angle, which I just learned about here1.  Usually you don’t see a whole circle, just part of one.  

These optic displays are caused by ice crystals, of course, ones not too complex, but rather simple ones like prisms, short solid columns, bullets, and hexagonal plates.  Some examples of these can be seen here.

The bottom of yesterday’s moist layer was just above 30,000 feet at a temperature of -35° C and extended all the way up to about 40,000 feet above sea level where the temperature were around -65° C.

Ann 2016102800Z_SKEWT_KTUS
The balloon sounding launched around 3:30 PM AST yesterday from the Banner University of Arizona.

Some photos documenting the excitement of yesterday

5:30 PM. Cirrus uncinus crystals heading in two very different directions. Wow. Notice the fibers from the contrail that are starting to fall out are going in the "correct" direction, back toward that west.
5:30 PM. Cirrus uncinus crystals heading in two very different directions. Wow. Notice the fibers from the contrail that are starting to fall out are going in the “correct” direction, back toward that west or southwest.
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3:04 PM. Parhelic circle erupts in mostly Cirrus uncinus clouds.
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3:06 PM. The astounding sight continues, but fades away just after this.
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3:33 PM. Local brightening at the position of a sun dog suggests these are tiny ice crystals or possibly even droplets that have just formed, the sizes too small to allow refraction into color normally seen in sun dogs.
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3:32 PM. A zoomed view of that little bright spot. Sure looks like it may have been droplets. Droplet clouds have been reliably reported to temperatures as low as -44° C. Of course, wouldn’t stay liquid long!  I thought this was a pretty exciting shot!  Hope you got it, too.

 

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3:42 PM. Amid all the optical excitement was this ghost-like halo. Can you make out the faint circle around the sun? In ascents through thick ice clouds having complicated ice crystals like bullet rosettes down below the tops, as you climb to the top of such clouds, amazing haloes can be seen where the crystals are newly formed and quite simple in structure, allowing the refraction required for a halo. So, this halo was likely at the top of these thicker Cirrus and Altostratus (dense portions) clouds, though no one would penalize you if you just said they were all Cirrus clouds.

 

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3:59 PM. Another spectacular bright spot at the sun dog location (which is also at the 22° halo location, faintly evident here).
3:59 PM.
3:59 PM. Zoomed view of this sun dog/parhelia. Lots of fine structure evident, which is not usually the case with parhelia.
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4:25 PM. Another finely structured parhelia/sun dog suggesting the ice crystals were newly formed. Fine structure like this can’t last long with the usual turbulence, and so that’s a sure sign this feature has just formed.  I don’t recall seeing so many atypical sun dogs in one day!
5:09 PM. The normal, amorphous sun dog. No really fine detail can be seen here.
5:09 PM. The normal, amorphous sun dog. No really fine detail can be seen here.

Below, examples of cold Cirrocumulus, ones that quickly transition to Cirrus clouds.

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5:19 PM. This group of CIrrocumulus clouds appeared very quickly almost overhead. The tiniest elements are those that have just formed. These are composed of ice crystals in extremely high concentrations, perhaps 10,000 per lilter. Once that ice has formed, its gradually spreads out, much like a puff of smoke would, thinning, some crystals growing large enough to start fall steaks.
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5:19 PM. Some elements are still forming, but the spreading of the older ones is well underway, producing a “blurred” look as the elements merge and thin out.
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5:28 PM. Off to the southwest of Catalina, a promising intrusion of lower moisture indicated by these approaching Altocumulus clouds. Will there be enough today for a sprinkle somewhere?  Not looking so good now, clouds did not lower much overnight.   Well, maybe if it doesn’t sprinkle, maybe we’ll get to see some nice virga and dream about rain…

 

The End

——————————–

1I was going to call it something else.  Egad.  Let us remember the words of the B-52s:  “Before I talk, I should read the book.

Cirrus, Cirrocumulus and Altostratus day closes with a painting-like sunset (now updated even more!)

No rain in sight for Catalinans, to get that over with.

However, if you’re bored and are thinking about a quickie storm chasing vacation with the family, monster storms, likely to produce newspaper headlines will be smashing the Pac NW in the next few days.  Expect to read about flooding and hurricane to 100 mph winds on the Washington/Oregon coast sometime.  Also, Tofino, British Columbia, along the SW coast of Vancouver Island, would be a great place to head for, watching giant waves crash up against the coast and around that lighthouse they have around there, pounding rains…

The long fetch with these storms in the Pacific guarantees some monster waves.

3:49 AM, 14 Oct:  Mark “WeatherPal”  Albright informed me that a 94 mph wind was observed last evening (the 13th) near Astoria, OR.

The next low,   a “regular low” but one energized by leftover moisture from Typhoon Songda,  looks to be even stronger than last night’s low.  This one comes  in  moving really rapidly tomorrow evening while deepening (central pressure is dropping further) as it passes over the Washington coast.  Looks like that one will be a “blow-down” storm;  good-bye timber.

The synoptic pattern (placement of jet streams and lows) is       “Freda-esque”, that is, similar to that of October 12, 1962, the infamous Columbus Day storm where a remnant of Typhoon Freda zipped in as a regular low that deepened explosively as it raced up the Pacific NW coast bringing winds of 100-200 mph and blowing down BILLIONS of board feet of timber as well as weather pal, Mark Albright,  mentioned above,  when he was a kid1

Well, we sure hope its not THAT similar!

Yesterday’s Clouds

Lots of interesting patterns and complexities in yesterday’s skies. If you didn’t see them, here they are, though its kind of a much ado about nothing, really:

1:23 PM. Icy Cirrocumulus. As a solid band of high and middle clouds approached, the first things we saw as the moisture began to increase aloft were some spectacular patterns in isolated high clouds as it approached. Probably most of the Cirrocumulus we see is composed of droplets, but here, it appears to be composed of ice, possibly starting as droplets at the upwind edge,
1:23 PM. Icy Cirrocumulus. As a solid band of high and middle clouds approached, the first things we saw as the moisture began to increase aloft were some spectacular patterns in isolated high clouds as the solid band  approached. Probably most of the Cirrocumulus we see is composed of droplets,  and never glaciates, but here, it appears to be composed of ice, though likely started as droplets at the upwind edge (middle of photo).  At the top of the photo, the tiny “granulets” are fibrous, clearly ice, and strands of ice crystals are starting to make their way down.
1:23 PM. Got excited and thought you might like a zoomed view of this patch in case you didn't get one.
1:23 PM. Got excited and thought you might like a zoomed view of this patch in case you didn’t get one.
1:30 PM. I thought this was kind of a strange and fun pattern for you. Look how the youngest cloud elements are over there beyond the Catalinas and the oldest ones with strands of ice crystals falling out are overhead. Besides perspective giving you a sense of radiating lines, one would normally guess that the wind way up there (about 30 kft above the ground) is heading toward you, newest parts back there, oldest ones arriving overhead, which would be from the south in this shot. But the wind was from the west-southwest at this level, perpendicular to this scene. Can't say either of us has seen this before, quite the "Tom Foolery" in a cloud scene.
1:30 PM. I thought this was kind of a strange and fun pattern for you. Look how the youngest cloud elements are over there beyond the Catalinas and the oldest ones with strands of ice crystals falling out are overhead. Besides perspective giving you a sense of radiating lines, one would normally guess that the wind way up there (about 30 kft above the ground) is heading toward you, newest cloud (Cirrocumulus, maybe lenticularis)  back there, oldest ones arriving overhead, which would be from the south in this shot.  But the wind was from the west-southwest at this level, perpendicular to this scene. Can’t say either of us has seen this before; quite the “Tom Foolery” in a cloud scene, a real knee-slapper.  Clouds do that a lot where we think we know what is going on, but, as they say, “upon further review”…..
1:32 PM. Confusion? Strands of ice and waves in this cloud seem to run in various directions.
1:32 PM. Confusion? Strands of ice and waves in this cloud that produced lines seem to run in various directions.  Some lines are perpendicular to the wind, blowing from the lower right to the upper left side, representing little bumps in the air, ones resembling sea swell rolling in to the shore,
1:40 PM. Pretty much unfathomable, too complex to even begin describing, which makes it worth photographing. We can make out some icy Cirrocumulus though, here and there, with that lenticular-looking backside beyond the mountains, though perspective may be bunching it up to look that way.
1:40 PM. Pretty much unfathomable, too complex to even begin describing in less than a page, which makes it worth photographing. We can make out what CMP deems as some icy Cirrocumulus though, here and there, with that lenticular-looking backside beyond the mountains, though perspective may be bunching it up to look that way.  I’ve already taken too many photos in just eight minutes!
2:10 PM. Breathing easier now, here, "simple" Cirrus fibratus, lined Cirrus clouds with mostly non-curving fibers,
2:10 PM. Breathing easier now, here, “simple” Cirrus fibratus, lined Cirrus clouds with mostly non-curving fibers,
Also 2:10 PM. The scene upwind of that "liney" Cirrus. Also "fibratus" except overhead there looks to be "uncinus" as evidenced by those thick regions likely trailing ice strands back toward the viewer.
Also 2:10 PM. The scene upwind of that “liney” Cirrus. Also “fibratus” except overhead there looks to be “uncinus” as evidenced by those thick regions (upper right hand corner) likely trailing ice strands back toward the viewer.
2:18 PM. Pretty soon the heavier masses of CIrrus began to appear, with lower, but still very cold droplet clouds just below them.
2:18 PM. Pretty soon the heavier masses of CIrrus (Spissatus) with some gray shading began to appear, with lower, but still very cold and at least momentarily,  Altocumulus droplet clouds  (above bush on the right) began to appear just below the Cirrus.  Clouds almost always lower in time, even when they don’t lead to a storm.
2:18 PM. More patterns. Here we have a mush of Altocumulus, very fine granulation of Cirrocumulus (top) and CIrrus clouds passing overhead. You can tell if clouds are at different levels by looking to see if they are moving all at the same rate. Here, if you looked really carefully, the little white tufts of Altocumulus clouds were moving in a slightly different direction than the Cirrus clouds were. How important is this. Not too much.
2:18 PM. More patterns. Here we have a mush of Altocumulus, very fine granulation of Cirrocumulus (top) and CIrrus clouds passing overhead. You can tell if clouds are at different levels by looking to see if they are moving all at the same rate. Here, if you looked really carefully, the little white tufts of Altocumulus clouds were moving in a slightly different direction than the Cirrus clouds were. How important is this. Not too much.
4:18 PM. Skipping ahead, the full boatload of this band, consisting of a thick Altostratus, was passed over at this time. The clearing on the right told you there was going to be a nice sunset in a couple of hours. This was the lowest level the moisture got to. somewhere in the 22-25 kft above the ground, according the the TUS sounding though the darkness of it may make it look lower.
4:18 PM. Skipping ahead, the full boatload of this band, consisting of a thick Altostratus, was passed over at this time. The clearing on the right told you there was going to be a nice sunset in a couple of hours. This was the lowest level the moisture got to. somewhere in the 22-25 kft above the ground, according the the TUS sounding though the darkness of it may make it look lower.
6:01 PM. Almost could have been a painting. The gradual ascent that produced the heavy line of Altostratus is now being broken up by patches of downward moving air, leaving holes and streakiness in the former solid cloud shield. But who cares when you can just sit and take scenes like this in!
6:01 PM. Almost could have been a painting. VIncent Van Gogh himself could not do this scene justice.  If you’ve seen his work, like “Starry Night“, you’ll know how bad he was at capturing the sky.  But for him to try to capture this scene, it would be beyond “bad”, but rather a total and complete travesty,.  The gradual ascent that produced the heavy line of Altostratus is now being broken up by patches of downward moving air, leaving holes and streakiness in the former solid cloud shield. But who cares when you can just sit and take scenes like this in!
6:06 PM. The moon amid CIrrus spissatus and other varieties of Cirrus. Notice that the disk of the moon is just a bit blurry, out of focus. That blurring is due to ice crystals in those Cirrus clouds. If it was a thin droplet cloud, the disk would appear crisp and very sharp.
6:06 PM. The moon amid CIrrus spissatus and other varieties of Cirrus. Notice that the disk of the moon is just a bit blurry, out of focus. That blurring is due to ice crystals in those Cirrus clouds. If it was a thin droplet cloud, the disk would appear crisp and very sharp..

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1Mark. like most kids who are blown over in a windstorm,  wanted to be a meteorologist right after that.   Its pretty traumatic and life changing when you’re blown over by wind.    CMP’s life was traumatized and changed forever when it snowed a few inches in the San Fernando Valley of southern California when he was six year’s old.  Not sure you’ll find this information in the latest Diagnostic and Statistical Manual of Psychiatric Disorders #5, however, but its a well-known phenomenon in the weather subculture.

Traces of rain and a Lemmon rainbow

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6:25 AM. Altocumulus perlucidus. According to my cloud chart, informally known as “America’s Cloud Chart”, it could rain within 6 to 196 hours. Its quite useful.
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10:24 AM. Altocumulus opacus. Note the rumpled look of the sky. Indicates that the clouds are rather shallow and composed of droplets rather than a mix of ice crystals and droplets. However, if you strain your eyeballs and look to the horizon, you can see a smoothing and a little virga showing that the cloud tops are rising and they’ve gotten cold enough to produce ice. According to my cloud chart, when you see “Ac opacus” it could rain within 6 to 196 hours.
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1:44 PM. While the clouds are pretty much the same gray color as in the prior photo, they’re much thicker here and are “Altostratus opacus”. “opacus” because the sun’s position is not visible, though it wouldn’t be in this direction anyway, but to the right. The bottom of this is smooth due to widespread, light falling snow, though it not in a localized area enough to be called virga in this shot. The lack of bunched or heavy virga somewhere tells you that the cloud tops are pretty smooth, too, not a lot of variation in height.  The base is really determined by the point that you descend out of this precip, in this case up around 10 kft above the ground over Catalina.
4:12 PM.  Altostratus opacus praecipitatio or Nimbostratus, either name will do.  Recall the quirk in our cloud naming system that makes, "Nimbostratus" a middle-level cloud.  The base of these clouds is the general level where the snow falling out has evaporated.  Due to bulging tops, and stronger updrafts, a little of the precip was able to fall out because the snowflakes coming out the bottom had grown larger and were able to survive the dry air below cloud base.
4:12 PM. Altostratus opacus praecipitatio or Nimbostratus, either name will do. Recall the quirk in our cloud naming system that makes, “Nimbostratus” a middle-level cloud. The base of these clouds is the general level where the snow falling out has evaporated. Due to bulging tops, and stronger updrafts, a little of the precip was able to fall out because the snowflakes coming out the bottom had grown larger and were able to survive the dry air below cloud base.

Some rain fell about this time in Catalina.  Not enough to darken the pavement completely at any time.  The main thing to take away from that hour of very light rain is that it was not “drizzle” as even some errant meteorologists call such sprinkles.

You will be permanently banned from attending any future meetings of the cloud maven club if you refer to such rain as we had yesterday afternoon as “drizzle.”  Drizzle is fine (200-500 micron in diameter drops that are very close together and practically float in the air.  Because they fall so slowly, and are so small to begin with, you can’t have drizzle at the ground from clouds that are much more than a 1000 feet or so above the ground because as soon as they pop out the bottom, those drops start evaporating and fall slower and slower by the second, and in no time they can be gone even in moist conditions.  That’ s why its somewhat hilarious and sad at the same time,  when, in particular, military sites for some unknown reason, report ersatz “drizzle: (coded as L, or L-) in our hourly aviation reports from clouds that are based at 5000 feet or something CRAZY like that.

This band of Nimbostratus/Altostratus had a backside that approached as the sun went down, and as you know, that clearing let some sunlight enrich and dramatize the views of our beloved Catalina Mountains:

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5:39 PM.
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5:41 PM.

Finally, dessert:

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5:47 PM. Rainbow lands on the University of Arizona Wildcat’s Skycenter atop Ms. Mt. Sara Lemmon.
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5:48 PM.

The amazing rains ahead

Nothing that you don’t already know about, so no use me blabbing about it too much.  But in case you haven’t seen it, The Return of Joe Low (after over-hydrating over the warm waters of the eastern Pacific), is expected over the next couple of days, with a little help from another disturbance, to bring colossal rains to eastern Arizona and especially New Mexico.

Below, from our friendly U of  A Wildcat Weather Department a model run from yesterday’s 5 PM global data (the Wildcat’s downsize the US WRF-GFS model in this awesome depiction).

Check out the totals expected by the evening of October 23 rd.  Stupendous.  Usually these totals are a bit overdone, but even so…… Will take a nice bite out of drought.

Precipitation totals expected by 5 PM AST October 23rd.  Looks something like a tie-dyed Tee.
Precipitation totals expected by 5 PM AST October 23rd. Looks something like a tie-dyed Tee.

The End