Category Archives: Sunsets

Calming Cirrus

Feeling better now after some calming Cirrus uncinus and spissatus moved in yesterday.  Wasn’t sure we could have clouds anymore here above Catalina, AZ.  Really, there’s nothing like some uncinus and spissatus to make you feel better after  you get worked up over some global cooling stuff you thought was wrong.  And that nice sunset later on didn’t hurt either.   Its great to get stuff out after stewing over it for a few years, too.  Next, will certainly have to correct that National Academy of Sciences report on cloud seeding that came out back in 2003.   Still upset over some stuff in there….  Got our (Hobbs and mine) work wrong!  Unbelievable.  What were they thinking?!  Don’t think they read some of the things they cited!  They will be scolded royally after I have thought about it some more…

Oops, hope we have some more calming Cirrus today.

The End.

Sunrise and Cirrus splendor; the rarely seen Cirrus castellanus floats by

Gee, three days with a cloud or two over droughty Catalina!   Yay! Here’s yesterday morning’s nice Cirrus uncinus (icy clouds with long trails).

Then, later that morning, the RARELY seen Cirrus castellanus sporting some mammatus (downward protuberances at the bottom) showed up.  (I should note that some of the female atmos sci students at the U of WA preferred to call “mammatus” varieties, “testicularis”.)   I mention this in defference to their preference.

These icy Cirrus clouds, whatever you call them,  are probably the rarest of all Cirrus.  The noticeable cumulus-like shape shown in the second photo is rare up there.   Mainly a steep drop in temperature with increasing height up toward the top of the troposphere (the earth’s blanket of air that contains our clouds (moslty).

Turrets, or cumulus-like shapes in clouds like the “puff” of Cirrus in the middle of the second photo, are also thought to be driven by the release of the latent heat of condensation (in lower, warmer Altocumulus clouds) and latent heat of deposition in ice clouds).  When condensing droplets or as an ice crystal, heat is released to the atmosphere.  This is a HUGE factor in thunderstorms (a lot of heat is released during condensation in updrafts), frequent in cooler,  mid-level clouds such as in Altocumulus castellanus, but,  because there is so little water vapor at Cirrus levels, very unusual way up there.     Yesterday’s cloud were likely forming around -40 C,  at about 33-34,000 feet above the ground.

Below the Ci cas photo is a sounding from the folks at the U of WY.  It hints at a steeping of the lapse rate just above the 250 millibar level (between the 200 and 300 on the left side), and also just below a stable layer  or sideways “v” in the temperature trace up there.

I was quite pumped to see this rare display.   Out of thousands of cloud photos, I have but a dozen or so of Ci cas.   Unfortunately, it seemed, passersby in the Basha’s parking lot when this was about to go overhead, were non-plussed when I pointed out the unusual cloud.  They were mostly polite,  but generally said something like, “Huh?”  It made me wonder what is happening to us if we can’t get excited about a Ci cas?  I started to feel sad.

Later, in the afternoon, when the heavy ice clouds moved in (Altostratus translucidus and opacus) in the late afternoon, you probably were guessing that a good sunset was on tap.  And you were right.   Below an example of that Altostratus, followed by another neat sunset.   Likely to repeat all this today.

Hey, get excited!














The End

Sunrise and sunset heaven: Cirrus and maybe Altocumulus on the way

Yep, a cute tiny little upper air low with just a dollop of high clouds is going to be spit out of the eastern Pacific off Baja Cal today and tomorrow and toward AZ, and along with that will come some Cirrus and probably Altocumulus floccus and castellanus clouds, maybe with virga.  The first Cirrus cloud is likely to get here by late afternoon or evening today, and the sky should be full of high, icy Cirrus clouds tomorrow morning.   So charge your camera batteries now for some of the “everyday-but stupendous” AZ color at sunset today and at sunrise tomorrow.  You’ve been warned.

Below a map of the air flow and pressure patterns at 300 mb, or about 30,000 feet, the domain where cirriform clouds like to reside, valid at 5 AM LST this morning.

The Twelve…rain drops in Catalina, that is

Well, maybe there were about 27, but anyway….not very many; still,  those drops were to be treasured after not seeing a single  “hydrometeor” display in SE AZ in so–ooooo LONG A TIME!


PG-13 advisory; DRIZZLE is discussed

I have to warn you at this point.  That rain event yesterday WAS NOT DRIZZLE!!!!!!!!!!!!!!!!!!!!!!!!!!!  I will be ROYALLY PO-ed if I hear someone in my social network or a TEEVEE weather presenter say that it “drizzled” yesterday!

Why make a BIG THING out of the correct type of precipitation?

I have to tell you a true story (well, I don’t have to, but I am going to anyway) about the importance of drizzle (i. e., fine, close together drops that appear to FLOAT in the air).   This event happened during my cloud seeding “vigilante” adventures (see Publications for samples).   A well-known professor of cloud seeding in a foreign country asked me to leave his office and never come back after I told him it had been “drizzling” outside, “10s per liter” in the air.

Drizzle is a profound indicator of cloud structure overhead, and the presence of drizzle falling from the clouds in that professor’s region’s meant his numerous reports of how clouds were, ripe for cloud seeding,  were in substantial error.   So you can understand why a report of true “drizzle” would naturally be upsetting to that professor.  Man, am I digressing here!  Yikes.  My apologies. (BTW, those reports WERE in error, confirmed by aircraft years later!   (Spiking football now, with a proper amount of decorum, of course!)


OK, back on task….

With the sky full of low (“boundary layer”) clouds by mid-day (f you’ve forgotten, that was yesterday, May 10th, 2011) and with RW— in the air  (“triple minus”, extremely light rain showers) by 1:30 PM,  with gusty winds,  temperatures in the mid-60s, it turned out to be quite a “storm.”  It just as well could have been but a mostly sunny day with just a scattered Cumulus clouds here and there the way some models were “telling it.”

Here’s a pictorial on how it went, from a Catalina, AZ, perspective:

1) 09:29 AM, itty bitty Cumulus (Cumulus “fractus”) starting to appear,

2) 12:03 PM, larger Cumulus growing up into Cumulus “mediocris” beyond Tortolita Mountains on the horizon,

3) 12:29 PM, virga and rain visible to the NW horizon!  Now I am getting apoplectic since the best models in the world did not have this precipitation over thataway!   But there it is, bigger than watermelons.  The models have to be really red-faced about this! Not everything in the world is predetermined by numerical models; you can  say things that might be right and those models are WRONG!  Just like in the 1970s when a lot people thought global cooling was underway and that’s where we were headed!  But they were WRONG!  Who were those clowns anyway?! (hahaha, sort of).

4) 1:25 PM.  Now where was I before all that excitement?  Oh, yeah.  Here’s some ice for you.  See the frizzy top parts of this cloud in the center of this photo above the dead tree that the birds like to sit in?  Well, them’s ice crystals, and likely snowflakes that have formed in that medium-sized Cumulus cloud (above the dead tree) and its in the upwind direction.  Behind that is more ice and precip falling from a wide area of a Cumulus-Stratocumulus complex.



Quiz.  How cold does the top of THAT cloud have to be to look like that (have that much ice in it, probably a few per liter to maybe 10 or so, not a tremendous amount but significant)?  Well, with bases as cold as they were, near freezing by this time of day at around 7, 000 feet above the ground or 10, 000 feet above sea level, around -15 C (or about 5 F).  Amaze your friends with cloud trivia like this!  Well, maybe not.


5)  1:25 PM.  Here it is, a band of precipitating clouds overhead.  Now the ONLY question remaining, as you gaze upwind at Twin Peaks clearly visible through the precip and virga is, how much will there be?  None? Or as much as a “trace”?   Measurable is out of the question,  looking at this scene below the clouds.  Most of the visibility degradation is due to dusty air, not precip.  Darn.   (Amaze your friends with skills like this!  Well, maybe not.)

6) 3:03 PM.   The End is Near

7) 7:06 PM.  Nice sunset with traces of Cirrus and Ac len on the horizon, driblets from a storm striking the Pac NW.  Isn’t there always a storm striking the Pac NW? I digress again.

Man, I could go on about the weather maps of yesterday, but will quit here.

The end.






















































If you REALLY want to see how it went, take a look at the U of A time lapse video here.

“Pretty in Pink”

Well, “tending” toward pink, anyway…  But who remembers the Psychedelic Furs and what their song title alluded  anyway?  Of course, no one.  But I liked its dark sound.   Oh, well.

But here it is, that “pretty in pink” sky (2 shots) from yesterday evening in case you missed it.  Again these are Cirrus and Altostratus ice clouds with an isolated exception of Altocumulus lenticularis (just above horizon in the second shot), which is composed of droplets.  The second photo is a zoomed shot of the stack (several pancakes on top of one another) of a lenticular cloud off to the NW of Catalina.

Those lenticular clouds should always bring some excitement that things are changing, maybe heading toward a rain situation.   Rain did fall in the northern third of AZ when these Ac len clouds were present yesterday evening.

Why the excitement?

While these clouds don’t rain themselves, they are usually precursors of rain situations in the region because they illustrate that the winds aloft are relatively strong, the air in the “mid-levels” (roughly 10 to 20 thousand feet above the ground) has some moisture, and they indicate the kind of “stable” conditions in the mid-levels in their flatness, “pancaked-ness”, that precedes fronts.  Of course, we also had those moderate SW winds yesterday that also indicates that “something is going on”.

And something was going on as a cold front traversed the Great Basin yesterday.  Even this morning there is still precip in NW New Mexico as of 6:30 AM LST this morning.

And how do we know a new air mass came by?

The temperature change over the last 24 hours, from yesterday at this time to today at this time is one of the best ways of keeping track of fronts and changes in air masses.   Here is a plot of that 24 h change.  As you can see, the drop in temperature, while it has occurred at my gravel driveway (-5 F) is not quite here in Catalina (though it really is) according to the venerable The Weather Channel’s data which does not have my data (or pressure trace which has the usual sharp rise following a cold front–that heavier, denser, cold air is pushing down on all of us this morning and on my aneroid (not a body part, but a name for a barometer, BTW.)

The last shot here is what the clouds looked like before sunset.  Lots of gray indicating they are quite thick and fall into the Altostratus category even though they are very high.  Cirrus, by definition, cannot have this much grayness.  But, when you see this kind of  late afternoon sky, you can almost always count on a great evening scene, that sky especially “pretty in pink.”

Don’t see too many misspelled words, bad sentence structure and other grammatical lapses so will post this now…











Exit right (or to the east)

Here’s what happened on top of us yesterday, that gorgeous snow day with so many wonderful sights to see. These maps below,  courtesy of San Francisco State University , for 500 millibar pressure level, about 18,000 feet above sea level, for 5 AM LST as the snow band moved through Catalina, and then 5PM LST,  a little before sunset:



A visual on what the clouds did as this happened yesterday is below. Interpretative cloud statements on the following gallery: shallow, deeper (precip begins in distance), deepest (small, soft hail falls here and there from miniature cumulonimbus clouds), less deep (barely-able-to-precip stage again), shallow, nil. Pics 1,2, 3, 4, 5, and 6, respectively.  If you want all the visual glory of yesterday, go to the U of A time lapse movie here.  However, you’d better hurry, these wonderful films are overwritten each day.  You can really see the clouds flatten out after about 3 PM LST here, and there are some spectacular snow showers going by on the Catalinas.

The end.

























“Little snowstorms in the sky, I think I’d like to have some pie”

You’re probably smiling now remember singing this little ditty as a kid, maybe singing it with your friends on the bus, whenever you saw “Altocumulus floccus virgae” clouds such as are pictured in the first photo.   Wasn’t it great when you saw these kinds of clouds while on a vacation trip and mom and dad had to stop somewhere to get you some pie after you sang that song?   Well, I nostalgiate here.

To the right of the dead yucca stalk, Altocumulus tufts are shedding snow.  The opacity of the virga is a give away that its snow, and not rain.  In some of these little tufts, the water droplet cloud that preceeded the formation of ice has disappeared, and all that is left is falling snow.  How much snow is it?  Just a flurry, if you were up there, even though it looks pretty thick.  Once in awhile in our research on ice in clouds at the University of Washington, we got to sample these from top to bottom.  Because the ice crystal concentrations are usually pretty low in clouds like the ones shown, a few per liter and often less than 1 per liter, those delicate ice crystals don’t bump into each other much and break up,  and you find gorgeous images of star-like crystals in these fall out streaks, the kind you see on Christmas cards (examples here).   How do I know what from ten miles away and 16,000 feet or so below them.   Its a funny thing, but ice crystals are differently shaped depending mostly on temperature.  To get the temperature of these clouds you can get a pilot report (unlikely) or examine the humidity profile of the Tucson sounding for “00 Z” (5 PM LST yesterday afternoon and make an educated guess.   The highest relative humidity on that sounding was at 525 mb ) about 15-16, 000 feet above the ground) with a temperature of -16 C (about 3 F), namely, darn cold.  Continuing, we in this field have a well known chart by Magono and Lee (1966)  that shows the temperature at which certain forms of crystals grow.   At the temperature I am guessing those clouds were at, those crystals would have grown as stellars and dendrites, which grow between about -12 C and -18 C.  Sometime I will show you some of these crystals, but for brevity will quit here on this topic.

The second and third photos show what one of these tufts looks like before the crystals have grown and fallen out.  Top center, the largest raggedy tuft (Altocumulus floccus) show no fallout of ice.  In the last photo, twenty-nine  minutes later, there is a fine veil of ice crystals below it (upper right hand corner).  Only now, with virga, are they “Altocumulus floccus virgae”!   I’m singing right now!  And, if you look really carefully you’ll see that most of those little guys have a little ice fall underneath them.  Certainly, in those clouds you would find PERFECT crystal specimens!

I’ll end here on an exciting note.  The Enviro Can model CONTINUES to show a very strong system moving into our area on Saturday afternoon, likely accompanied by winds as strong or stronger than we saw last Saturday,  before the rain and cold air hits on Sunday.  Snow levels are going to be really low and we might see some ice in the rain on Sunday here in Cat (alina) Land.  Amounts are looking substantial at this point.  Man, do we need it!

In the meantime, an upper trough off Baja passes over tomorrow.  It has enough moisture with it to provide more “clouds for pies” (Altocumulus floccus virga, and, of course, Altocumulus castellanus virgae, which also qualifies as well for a pie).   And, some cirrus will be around, too.  However, I am going to stick my neck out and say there will be sprinkles tomorrow.  Mods really don’t have a thing, so you’ll have to keep that in mind.

Be sure to keep you’re camera ready for sunsets like last night (see below)!

Trick and treat sunset yesterday evening

Late yesterday afternoon, the sun appeared to be setting in the wrong location, about 20-25 degrees south of where it is supposed to be at this time of year.  Perhaps something horrible had happened, I thought.  Retirement with a happy ending here in Arizona was too good to be true, I thought, and now it was all going to come to an end.  First, some perspective on where the sun was going down BEFORE yesterday.   This first shot was taken just a few days ago (Feb 13th).  Note where the sun is relative to the Tortolita mountains on the right, and Twin Peaks, the two itty bitty humps to the left.  For further perspective, at the winter’s solstice, December 21st, and from this same location, the sun sets next to Twin Peaks.   So,  in this first shot you can also see how much the sun has moved in two months.

But then yesterday, something awful seemed to be happening.  The next photo was one to send chills down your back, and in fact, if the sun was setting over there in the winter as a matter of routine, the northern hemisphere would likely glaciate down to about Blythe in the winter, due to the NH sunlight being so weak (that is, with so much tilt of the earth’s axis about which it spins).   The days here would, in that case, be about the length of those in Seattle with daylight only from about 8-4 PM in the wintertime because the sun would be taking such a low trajectory in the sky;  would rise late and sink early.

So, while I was concerned with the earth-sun system and some kind of apocalypse yesterday evening, I have feeling that most people were thinking, “Well, I guess we’re not going to have such a great sunset.  Seems to be too many clouds over there where the sun is setting.”

Or maybe you were thinking about that important Washington Husky  Arizona Cats basketball game today and how it might go.

But “No!”, a little later the sun underlit all those clouds, appearing to have sunk in its proper position for this time of year (3rd photo)!

I felt relieved and started thinking about that important Washington Husky -Arizona Cats basketball game today and how it might go.  Then I also started thinking about how I might have been the ONLY person to notice something was terribly WRONG with that sunset.  I feel pretty good about that part.

So, what happened?  This “trick” sunset, followed by a treat of a sunset was caused by a parhelia (explanation by my friend, Bob, here) whose accessible name is “sun dog” or “mock sun”, which we CERTAINLY had in this case!

Parhelia appear, if you don’t go to the site above for a more complete explanation,  when the ice crystals in the cirrus clouds up there are hexagonal plates, and fall with their faces down.   The sun’s light is refracted (bent) as it passes through jillions of these plates and at about 22 degrees from the sun’s position, an observer on the ground will see a bright spot, sometimes with a little coloration.  Sometimes there is also a “22 degree” halo along with the sundog.

I should add that the “trick” parhelia was being produced by ice crystals in the cirrus clouds above and behind the altocumulus cloud deck yesterday.  Of course, as you know, altocumulus clouds are comprised completely or mostly of droplets and cannot, therefore, produce parhelia.

Finally, to end, the last shot is almost at the winter solstice, taken on December 26th, and has a parhelia, aka, sun dog, mock sun, at left so you can see what they usually look like and how far away from the sun they are near sunset.   Yesterday’s, though, I thought was astoundingly bright and really made it look like the sun was going down in the WRONG place.

The end.

Distracted jet pilots or WHAT?

Now here’s something I have NOT seen before, which is pretty hard to have happen after decades of photographing the sky.   Here’s what I saw around 1:30 PM yesterday over Catalina.  I took three photos starting at 1:27 PM, 1:31 PM and 1:37 PM.  Here they are:

So, how to explain this odd “stitched” contrail?  Well, we can start with a few “facts” and hypotheses concerned with the aircraft and its crew.

1) Of course, with today’s modern instrumentation, pilots no longer have to actually fly commercial jets anymore.   They simply set their destination with their Tom-Tom GPSes;  flight levels and so forth, and then go to sleep until near landing time when they have to wake up again to be sure the automated process is still working.  Perhaps when I took these photos, the flight crew was napping and the plane was kind of zig-zagging around that bit, I’m sure  to the amusement of the passengers, who probably needed some excitement anyway to distract them from their cramped quarters.

2)  The pilots WERE flying the plane, but weren’t focusing on the task at hand, but were distracted while talking about stuff, maybe sports; perhaps recounting the great classic Superbowl game matching up two historic Rust Belt sports franchises, the Packers and the Steelers.

3) Since alcoholic beverages are available on flights, perhaps the pilots had some beer and while not necessarily really drunk, weren’t able to fly in a straight line.

Personally, I reject all of the above.  They appear to be “strawmen”, the result of superficial thinking strictly for entertainment purposes rather than having any intellectual depth.

Now for the “WHAT” part.

4) There are rarely seen regular undulations in the higher cirrus clouds in these photos, amazing ones really.  These reveal  waves pretty much perpendicular to the wind direction.  The flight track is along the wind (tail wind).   These waves in the atmosphere are like gigantic ocean swells, usually occurring where there is an noticeable increase in the wind with height.

Could these waves have produced this stitched pattern?   I am thinking “yes.”  That aircraft was likely close to the bottom of those cirrus (undulatus) clouds, and was SURELY experiencing those atmospheric waves, and likely exciting the passengers who probably needed some excitement to distract them from their cramped quarters-worth repeating.

We can’t tell here whether the contrail is rising and falling as would be happening in the cirrus lines and between them, respectively, or whether there is a perturbation to the horizontal winds associated with those waves.  A time lapse would be great here, and here’s one though it had some problems yesterday, from the University of Arizona’s Atmospheric Science Department.  A part of the contrail moves into the time lapse frames at 1:30 PM over Tucson, and from this angle, looking toward the Catalina Mountains to the N-NE, it does give an impression that the contrail was rising and falling.  Confidence is low here, though, in that description.

Here’s the last shot as this phenomenon and cirrus waves raced over the east horizon.  This last one makes it appear that the horizontal winds fluctuated more than the vertical winds under these waves producing a zig-zag in the horizontal.

With all the wonderful cirrus clouds around yesterday after a long absence, we had another one of those memorable Arizona sunsets, see last photo.

The End.

Was it smog or dust? How to tell

OK, climbing down off soapbox today….just don’t read the Hockey Stick Illusion by A. W. Montford unless you want to be upset by some climate scientists pretending to be scientists when they are being something antithetical to science.  Reminds me of the 30-odd years of cloud seeding reanalysis experiences I had as a skeptic in that domain.  Oops, haven’t climbed completely down yet.  Montford should get a Pulitzer for this well documented tale, and his main protagonist, Steve McIntyre, the Rossby Medal or maybe a couple of Nobel Prizes for diligence.  Just about off “box” now….but this tale REALLY does remind me of the shenanigans that happened in cloud seeding to repeat myself again and again and again.

It got pretty hazy yesterday afternoon into the time of sunset.   This is what it looked like as the sun rotated away from the earth (hahahah).  Note the yellowish tinge of the sun.  Smog (urban, biomass smoke and hazes, are comprised of smaller aerosol particles, around a 0.01 to 0.1 microns in diameter, whereas dust particles, something that you find around the house everyday here in AZ (to quote Groucho Marx from his quiz program, “You Bet Your Life”) are generally much larger and can extend into sizes of  1-10 microns in diameter.    So, in interfering with the transmission of the incoming white sunlight, small aerosol particles in smog take out (scatter) the short wavelengths like the blueish ones) and only the longer wavelengths, the reddish ones,  giving the sun an orange or reddish hue.  Dust particles, because they are larger, and do not interfere with the short wavelengths of light coming from the as much produce a whitish yellow colored sun.   Below yesterday’s sunset is a smokey one from Cuiaba, Brazil,  during the burn season, a strawman to show a large, obvious difference.  It’s often more subtle than this, so you need to practice labeling sunsets for aerosol sizes.  Your neighbors will be impressed.

Since dust particles are larger than smoke particles, they don’t stay afloat as long as smoke particles do, though dust can still drift away from where it was generated before dissipating.  It depends on the nature of the surface dust.   In Saudi Arabia, dust was often observed without much wind due to the fine nature of the sand (see last photo from Qassim, SA–looks pretty much like pure dust whereas the Catalina sunset suggests dust with smoke due to its more orange coloring).

Factoid:   some Gobi Desert dust has impacted the West Coast of the US from time to time!

Clouds?  Well, if you looked, you saw a few low cloud shreds called Cumulus fractus (Cu fra) over the Catalinas yesterday afternoon.  Some rain fell as close as central AZ as a cold front blew by.  But only the cooler air got here.  Its 13 deg cooler here than it was yesterday at this time (4:30 AM LST), a sure sign of an air mass change and “fropa” (frontal passage).