Water continues to flow in the Sutherland Wash!

It was a great day to hike to that wash, too.  Began with a nice sunrise; missed the nice sunset, darn.  Hope you didn’t.

But the highlight of the day was seeing that water was still running in the Sutherland Wash, some eight days after our great snow.  Like so many things that happen to meteorologists, I didn’t expect it.

Your cloud day yesterday

Was an interesting day because at times it looked summer-like due to Cumulus formations over the high terrain, Kit Peak to the Catalinas.   The scenes below are mainly from a hike1 out to some native rock etchings.

7:22 AM.  Sunrise Altocumulus.
7:22 AM. Sunrise Altocumulus.
10:38 AM.  Petting zoo.
10:38 AM. Petting zoo.  I wanted to hop on this cow and ride it so bad! It seemed so docile.  Wanted to just how riding a cow would feel like,  have a new life experience.  Didn’t seem to mind the several of us going by.
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10:42 AM. Glinting rocks through the Tucson smog layer. Yep, it rounded the corner and trucked on up along the Catalinas, kind of like our Stratus fractus does on some days. Mixed out later, of course, as Cumulus clouds ate some of it.

 

DSC_1593
11:07 AM. Its always so special to see water in our washes. This scene just due east of the “brown house” and before the “Rusty Gate” heading up the east side of the hills. Pretty regular equestrian crossing point.  The water was gone some few hundred yards farther downstream.
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12:09 PM. Nice display of Altocumulus perlucidus, while the summer-like scenes began to emerge. Note the Cumulus congestus forming over Kit Peak on the horizon, center. Pretty exciting to think of summer already!
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12:53 PM. This pretty summer-like scene out there on the trail just behind the Old Lloyd Golder Ranch. The small Cumulus clouds were even streaming off from the S and SSE just like they do so often in the summer! There are some Altocumulus perlucidus clouds above them.
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The grasses along the washes are already a few inches high! Nice to see that green coming along so well after 3.82 inches of rain in December (rainlog total that assigns the 7 AM measurement to the prior day since 0.96 inches was measured on Jan 1. Usually its put on the day of the measurement.)
Due to the wetness, Seattle-like mosses are beginning to appear.  Expect mushroom hunting to be a big tourist industry later this winter.
12:31 PM.  Due to the wetness, Seattle-like mosses are beginning to appear. Got a little homesick there for a second. Expect mushroom hunting to be a big tourist industry later this winter in Arizona as more storms line up for us.
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2:23 PM. Cumulus pile up into the Altocumulus layer above, helping to enhance it. Didn’t see any ice or sign of precip coming out of these clouds, though was watching closely as I am sure you all were, too, for a “first ice of the day” report in your cloud diary.

Detecting ice module below.  I hope most of you logged this as your first ice sighting of the day.

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4:08 PM. Whilst scouring horizon to horizon, saw this gem at last: ice! What, you can’t see the ice? Too far away? See the following photo for zoomed version.
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4:08 PM. Zoomed shot of glaciating complex of Cumulus, some virga, light rainshower below it. Still can’t make it out? See next shot with annotation.
Ann DSC_1634
Tops, from TUS sounding perhaps briefly as cold as -12 C before subsiding to lower, warmer levels. Almost certainly a case of “ice enhancement” or “ice multiplication”, a situation where there are many more ice crystals in a cloud than can be accounted for by ice nuclei, solid substances on which ice crystals form.

While waiting for still more rain, The End.

————————-

1Two of the people I was hiking with are very important meteorologists; faculty members at big universities with big Ph Ds,  Wikipedia pages, give lectures all around the world about what they know.  While I myself am not important, if you can align yourself with important people, befriend them in some way, and then go on to tell your friends that you have befriended that kind of person and do things with them, YOUR own mediocre life seems greatly enhanced.  Let us not forget the guiding words to a peaceful, successful life as told to us in “Deteriorata.”

Frosty, the Lemmon

When one first encounters this title with its unexpected play on words, we wonder what the author had in mind.   Of course, most of us know that at Christmastime, we are often regaled by a Christmas tune called, “Frosty the Snowman1“.   But here, we are surprised as we continue reading the title that instead of encountering the word, “snowman,” we encounter the word “Lemmon!”  Hah!

What is meant here?  What is author trying to tell us? Perhaps the word, “lemon”,  has been misspelled.   But if so,  why would a “lemon” be frosty?  Perhaps there was a cold spell in Florida and the author is harkening the reader to a long ago memory.  Or, perhaps misspelling “lemon” was a literary device to emphasize that word in an eccentric way.

Yet, upon further investigation, we find that the issue is more complexed than first imagined.  We find that there was an art teacher, nurse, and eventually, a self-educated botanist from New England, Sara Plummer Lemmon, who, with her husband and another worker, hiked to the top of the Catalina Mountains right here next to us, and while doing so, they logged the vegetation that was unique to the area.  In their excitement when reaching the top, they named that highest peak after Mrs. Lemmon.

So, what does this piece of history add to our literary dilemma encapsulated in the title?

Perhaps Mrs. Lemmon did some work in the field of glaciology as well, hence, the word “frosty” as a possible hint of that work.  Yet, upon investigation,  we find no mention of work on ice crystals, hoar frost, nor glaciology not only in the work of Mrs. Lemmon, but neither in the work of any the team that mounted what is now known as Mt. Ms. Lemmon.   We add that the note that the Lemmons, J. G. and Sara,  were on their honeymoon at this time, historians tell us.  Perhaps there is another avenue we can explore due to that latter element.

Could it be, too, that we are missing a characterization of Ms. Lemmon by our author?  Perhaps she was shy,  seen inadvertentlhy as “cold” by some, or was not particularly interested in the physical advances of her husband, J. G.  The word “frosty” alert may be alerting us those possibilities.

Ultimately, we remain perplexed by this title; it forms an enigma that may never be confidently resolved.

But then good titles,  and good books, are supposed to make us think,  try to imagine what the author is telling us through his/her use of metaphor and other literary devices, and  this title has done that.

We, of course, reject the most plausible, superficial explanation, that the author’s play on words was merely describing a local, snow and rimed-tree mountain named after Ms. Mt. Lemmon,  as in the photo below.  No, Occam’s Razor, the idea that the simplest explanation is usually the best one, will not do.

4:43 PM.
4:43 PM.  Those trees are rimed, like the airframe of an aircraft that collects drops that freeze and cause icing.  Here the wind blowing across the mountain top, and cloud droplets that were below freezing, hit the trees and froze over a period of many hours, creating this scene.  Its not snow resting on the branches.  That would’ve blowed off in the strong winds up there.

———End of Literary Criticism Parody Module———-

There was a rousing 0.24 inches of rain yesterday!  Our storm total has topped out at 0.89 inches!

In other photos from yesterday:

9:42 AM.  Altostratus translucidus again, this time with bulging Stratocumulus giving portent of a good Cumulus day if the As clouds will only depart.  They did.
9:42 AM. Altostratus translucidus again, with a few scattered Altocumulus cloud flakes, but this time with bulging Stratocumulus topping Samaniego Ridge, giving portent of a good Cumulus day if the As clouds will only depart and allow a LITTLE warmth.  They did.

 

10:24 AM.  Before long, cloud bases darkened here and there, indicating mounding tops above a general layer, and with the low freezing level of about 7,000 feet, the formation of ice and precip was not far behind.
10:24 AM. Before long, cloud bases darkened here and there, indicating mounding tops above a general layer, and with the low freezing level of about 7,000 feet, the formation of ice and precip was not far behind.
10:51 AM.  Mountain obscuring showers were soon in progress due to both a little warming, but also because of a cloud energizing swirl in the upper atmosphere that passed over us at 1 PM AST.  Did you notice that windshift aloft as that bend in the winds went by up there?  You probably noticed that it was no dice, er, no ice, after 1 PM as the mash down of air that follows "troughs" did that very effectively after 1 PM.
10:51 AM. Mountain obscuring showers were soon in progress due to both a little warming, but also because of a cloud energizing swirl in the upper atmosphere that passed over us at 1 PM AST. Did you notice that windshift aloft as that bend in the winds went by up there? You probably noticed that it was no dice, er, no ice, after 1 PM as the mash down of air that follows “troughs” did that very effectively after 1 PM.

 

10:52 AM.  As the clouds (weak Cumulonimbus ones) broke, there was a fantastic rainbow for just a seconds to the north, landing on my neighbor's house.
10:52 AM. As the clouds (weak Cumulonimbus ones) broke, there was a fantastic rainbow for just a seconds to the north, landing on my neighbor’s house.  It was even better before this, but was slow getting to the camera!  Dang.

 

10:54 AM.  Pictures a poppin' now as breaks in clouds allows highlights of glinting rocks and scruffy Stratus fractus or Cumulus fractus clouds lining Sam Ridge.
10:54 AM. “Pictures a poppin’ ” now as breaks in clouds allows those fabulous highlights of glinting rocks and scruffy Stratus fractus or Cumulus fractus clouds lining Sam Ridge, those highlight scenes that we love so much when the storm breaks.  And these scenes change by the second, too!

 

11:00 AM.
11:00 AM.
Also 11 AM.  Out of control with camera now.....
Also 11 AM. Out of control with camera now…..

 

11:12 AM.  Meanwhile, back upwind...  This line of modest Cumulonimbus clouds fronted by a weak shelf cloud roared in across Oro Valley to Catalina.  What a great sight this was since now there was a chance of some more decent rains!
11:12 AM. Meanwhile, back upwind… This line of modest Cumulonimbus clouds fronted by a weak shelf cloud roared in across Oro Valley to Catalina. What a great sight this was since now there was a chance of some more decent rains!  Before long, the rains pounded down, puddles formed, and another 0.18 inches had been added to our already substantial total of 0.65 inches.

 

12:01 PM.  But that wasn't the end, was it?  Before long, a heavy line of Cumulus and weak Cumulonimbus clouds formed again to the southwest and drenched Catalina with another round of rain, this time, only 0.06 inches.  And with it came the End.  This line of showers was spurred by that upper level wind shift that was going to occur over the next hour.
12:01 PM. But that wasn’t the end, was it? Before long, a heavy line of Cumulus and weak Cumulonimbus clouds formed again to the southwest and drenched Catalina with another round of rain, this time, only 0.06 inches. And with it came the End. This line of showers was spurred by that upper level wind shift that was going to occur over the next hour.

 

1:01 PM.  Sometimes those clearing skies, the deep blue accentuating the smaller Cumulus clouds provide our most postcard scenes of the great life we have here in the desert.
1:01 PM. Sometimes those clearing skies, the deep blue accentuating the smaller Cumulus clouds provide our most postcard scenes of the great life we have here in the desert.
2:13 PM.  While it was sad looking for ice in the afternoon clouds and finding none, the scenes themselves buoyed one.
2:13 PM. While it was sad looking for ice in the afternoon clouds and finding none, the scenes themselves buoyed one.  The instability was great enough that even brief pileus cap clouds were seen on top of our Cu.
2:21 PM.  Pileus cap cloud (right turret) tops honest-to-goodness December Cumulus congestus cloud.  No ice nowhere.
2:21 PM. Pileus cap cloud (right turret) tops honest-to-goodness December Cumulus congestus cloud. No ice nowhere.

 

2:28 PM.  And if the sky and mountains splendor isn't enough for you, then consider our blazing fall-winter vegetation as evidenced by a cottonwood tree in the Sutherland Wash, that yellow dot, lower center.
2:28 PM. And if the sky and mountains splendor isn’t enough for you, then consider our blazing fall-winter vegetation as evidenced by a cottonwood tree in the Sutherland Wash,’ that yellow dot, lower center.  We have it ALL now!
2:48 PM.  And, as the cloud tops are kept low, we get those fantastic, quilted, rich color scenes on our Catalina Mountains.  Here, looking toward Charouleau Gap.
2:48 PM. And, as the cloud tops are kept low, we get those fantastic, quilted, richly colored scenes on our Catalina Mountains we love so much.  Here, looking toward Charouleau Gap and Samaniego Peak.   I could show you so many more like this from just yesterday!

 

5:08 PM.  Even our lowly regarded teddy bear chollas have luster on days like this, the weak winter sunlight being reflected off its razor-hook-like spines.
5:08 PM. Even our lowly regarded teddy bear chollas have luster on days like this, the weak winter sunlight being reflected off its razor-hook-like spines, ones that many of us know too well.

 

5:12 PM.  And like so many of our days here in old Arizony, closed out with a great sunset.
5:12 PM. And like so many of our days here in old Arizony, closed out with a great sunset.
 Possibility raised in mods for giant southern Cal floods, maybe some flooding in AZ floods, too

Something in the spaghetti plots has been tantalizing as far as West Coast weather goes.  They have been consistently showing a stream of flow from the tropics and sub-tropics, blasting into the West Coast.  Recall that yesterday, that tropical flow was so strong and so far south, that at least one major gully washed was shown to pass across central and southern California on New Year’s Day, but weaken and shift to the north of southern AZ after that.

Well, my jaw dropped when this model run from yesterday at 11 AM AST came out, re-enforcing, even raising the bar on flooding, in central and southern California, and with those stronger storms, the possibility of flooding and major winter rains here in Arizona was raised.  The severity of the pattern shown aloft is not one I have seen before, and for that reason alone,  might be considered somewhat of an outlier prediction, one really not likely to occur.

Now, while there is some support in this model flooding “solution” in the spaghetti plots, the main reason I am going to present a series of what a disastrous Cal flood looks like is just FYI and how it develops.  The closest analog to this situation was in January 1969 when a blocking high in the Gulf of Alaska (GOA), forced the major jet stream far south across the central and eastern Pacific on several occasions producing disastrous floods in southern California in particular, where one mountain station received more than 25 inches of rain in ONE DAY!

Also that blocking high in the GOA in Jan 1969 also forced unusually cold air into the Pac NW, where Seattle (SEA-TAC AP) accumulated 21 inches of snow over the month, still a record.

Here we go, in   prog maps of our WRF-GFS rendered by IPS MeteoStar:

In the Beginning, the blocking high, shunting the jet stream to the south and to the north takes shape in the GOA.  Note low far to the south between Hawaii and southern California.  Get sand bags out now!
In the Beginning, the blocking high, shunting the jet stream to the south and to the north takes shape in the GOA. Note low far to the south between Hawaii and southern California. Get sand bags out now!  This is for 11 PM AST, 28th of December.

24 h later:

Valid at 11 PM AST 29 December.  Southern Cal flooding underway.
Valid at 11 PM AST 29 December. Southern Cal flooding underway.  Cold air pocket in Oregon has slipped southwestward helping to energize the lower band of jet stream winds by bringing cold air out over the ocean.  The greater the temperature contrast between the north and the south, the greater the speed of the jet stream between the deep warm air to the south, and the deep cold air to the north.  Note, too, high is getting farther out of the way in the Gulf of Alaska.

The situation continues to strengthen, and leads to this Coup de Gras, 11 PM AST January 1st.  A system this strong barging into southern Cal is mind-boggling, and this panel is what brought this part of the blog, to show you what a devastating flood in that area would look like:

Valid at 11 PM, January 1st.  In my opinion, I doubt the Rose Bowl game between the Oregon Ducks and Florida State would take place.
Valid at 11 PM, January 1st. In my opinion, I doubt the Rose Bowl game between the Oregon Ducks and Florida State would take place in Pasadena, CA, if this were to transpire.

Now for AZ.  Here’s the prog for 12 h later, 11 AM AST January 2nd, Cactus Bowl Day in Tempe, AZ between the Washington Huskies and the Oklahoma A&M Aggies, to continue with sport’s notes here.  Rain would be expected for that game should this pattern persist:

Valid at 11 AM AST, January 2nd.  This is an unbelievably strong wave that has roared in from the lower latitudes of the Pacific.  While it rushes through Arizona in a hurry, heavy rains, and some flooding are likely should things transpire like this.
Valid at 11 AM AST, January 2nd. This is an unbelievably strong wave that has roared in from the lower latitudes of the Pacific. While it rushes through Arizona in a hurry, heavy rains, and some flooding are likely should things transpire like this.

Now for a gee-whiz, scary analog….one from WAY back in the winter of 1861-62 when the situation decribed above was likely very similar to what it was in that terrible flood; severe cold in progress in the Pac NW, as it would be in the upcoming situation; a tropical torrent raging in from the Pacific.   This 1861-62 flood episode is still remembered.  However, it went on for 30-40 days (!) with recurring episodes turning much of California’s central valley into a lake, Los Angeles area, too, where there was a report of 35 inches of rain in 30 days.

What’s ahead, really?

Well the models are going to fluctuate on the strength of this breakthrough flow “underneath” the blocking high in the Gulf of Alaska.   But almost certainly one major rain event will break through as that this happens.   Its kind of a fragile flow regime, so it usually doesn’t last long.

Whether it will be stupefyingly historic,  or just another ordinary southern Cal gully washer, can’t be pinned down.  But, if you lived down there, you’d want to be looking around and seeing what you could do to divert water, fix a roof, etc.

There would be strong, damaging winds with one of these “coming-in-underneath”, too, and, for surfers,   giant waves!

Interesting times ahead!  “Floodmagedon”, as we like to say these days?

No real weather here for awhile, except around Christmas when a mild cold snap, and a little chance of precip occurs as a cold front goes by.

The End, for awhile.

—————————–

1The most intellectually satisfying version of “Frosty the Snowman” was, of course, has been rendered by Bob Dylan.

“Front Light”; compare to Bud Light

Front will roar across like a mouse, not a lion, as hoped for a few days ago.  Not too many rain “calories” in it.  Measurable rain will still occur, starting sometime between 9 AM and 10 AM AST–oops. raining now at 7:10 AM!   Check out U of AZ model for rain timing.   First drops fall here in that model output (from 11 PM AST last night), between 8 AM and 9 AM.  The frontal band, such as it is, is almost here!  However, the model rain tends to arrive  a little fast here,  though not always.  FYI, be on guard.

C-M is holding firm with a minimum of 0.15 inches today, but previous foretold possible top of 0.80 inches a few days ago is out of the question.  Will be happy with 0.25 inches at my house.  Since I am also measuring the rain as well as forecasting it, I have a feeling things will turn out fine.

There will be a nice temperature drop, windshift, and simultaneous rise in pressure as the cold front goes by–it’ll be fun for you to watch the barometer today and see the minute the front goes by as higher pressure begins to squash down on you.

Rain might reach briefly moderate intensity (defined by official weatherfolk as 0.10 to 0.30 inches per hour).  It would be great if it lasted an hour at that rate, but it likely won’t.  Its moving pretty fast, and it doesn’t seem like more than 2 h of rain can occur today.  Look for a nice clearing in the afternoon, and a COOL evening.

Drive south if you want to avoid rain today.  Jet core (in the middle levels, 500 millibars, 18, 000 feet above sea level) is almost overhead, and just to south, and that core is almost a black-white discriminator of rain here in the cool season.  So, we’re on the edge of the precip today.  More to the north;  less to the south.

Some clouds for you

1O:55 AM, December 11.  Thought you should see this nice line of Ac castellanus and floccus underneath Cirrus spissatus.
1O:55 AM, December 11. Thought you should see this nice line of Ac castellanus and floccus underneath Cirrus spissatus.
7:02 AM. Sunrise.
7:02 AM. Sunrise.
12:32 PM.  Wind picking up at the ground and aloft.  Note tiny Ac lenticular with Cu fractus clouds.
12:32 PM. Wind picking up at the ground and aloft. Note tiny Ac lenticular with Cu fractus clouds.
3:14 PM. The high cloud shield from the storm encroaches. Could call this either Cirrus spissatus or Altostratus translucidus.
3:14 PM. The high cloud shield from the storm encroaches. Could call this either Cirrus spissatus or Altostratus translucidus.
5:22 PM.  Now we're talkin' Altostratus with underlit mammatus and fine virga.
5:22 PM. Now we’re talkin’ Altostratus with underlit mammatus and fine virga.  So pretty.
5:29 PM.  A late "bloom", not really expected.  Shows that there was a clear slot far beyond the horizon.  Had to pull off by the Refuse Waste station on Oracle to get this.  I hope you're happy.
5:29 PM. A late “bloom”, not really expected. Shows that there was a clear slot far beyond the horizon. Had to pull off by the Refuse Waste station on Oracle to get this. I hope you’re happy.

The weather ahead and WAY ahead

Speaking of bowls, and let’s face it, with only a 100 or so we could use a few more1; we here in all of Arizona are in the “Trough Bowl” now.

This means that troughs (storms and cold fronts)  that barge into the West Coast will gravitate to Arizona instead of bypassing us and they will do that over and over again.    Being in the Trough Bowl is great fun! Lots of weather excitement for weather-centric folk like yours truly.    When you’re in the Trough Bowl, the weather is “unsettled”;  is NEVER really nice (if you like sun and warmth) for very long because a new front/trough is barreling in at you.

So, while today might be a little disappointing,  we will have many chances to get the “real thing”, i.e., a behemoth of a trough among the many that affect us in the weeks ahead.

In the longer view, a behemoth of a trough for the Great SW has just popped out of the models1 just last night in the 11 PM AST run! Gander this monster truck trough for AZ.  Where’s that monster truck event announcer, we need him now!

Valid for 11 PM AST, Christmas Day!  Wow.  Can't really take this at face value that far out, but if it did happen, likely would be snow in the Catalina area, and horsey would likely need a blanket after it went by.  Will keep you informed periodically about this as the days go by.
Valid for 11 PM AST, Christmas Day! Wow. Can’t really take this at face value that far out, but if it did happen, likely would be snow in the Catalina area, and horsey would likely need a blanket after it went by. Will keep you informed periodically about this as the days go by.

OK, enough weather “calories” for you today.   Hope you’re excited like me.

The End

———————————————

1Furthermore, why don’t we have bowls for women’s teams, what happened to Title IX there, maybe Beach or Sand Football? )

2As rendered by IPS MeteoStar, which is about to go from “free” to “fee” in January.  Dang.

Rain to fall in Catalina! (as shown in this latest model run shown below)

Finally found some rain for you.  Took awhile.  Came from the 11 PM AST global data from last night using the WRF-GFS model, our best.  The rain falls around the 19th,  “only” 11 days from now and during the “sweet spot” for southern California rain in mid-November, 10-20th, which gives it a few more percent of credibility than it otherwise would have.

BTW, there is virtually no support for this pattern from the NOAA spaghetti factory.  So, all of the discussion below about an upcoming rain in Catalina might erroneous, based on a personal hunch about an outlier model run being the correct “solution”,  one based on experience, and to HELL with spaghetti1, a study in forecasting subjectivity, etc.

Got that Bay Area rain timing info originally from C. Donald Ahrens,  the big author of Meteorology Today and Essentials of Meteorology, both of which have about 400 editions out by now, while he and I were at San Jose State College University.

Don, a grad student then,  and me, and undergrad,  worked and sang together to Top 40 songs radiating from  KGO-FM 2,3  in a little corrugated metal building there by the San Jose State football stadium back in the late 60s, and it was somewhere between songs that he told me about his findings.

Don had done a rain frequency study for the Bay Area for a local insurance company and it turned out that he found that it was somewhat more likely to rain in the middle of November than earlier or later in the month.  That rain fell more more often than earlier was no surprise, but more often than later in the month was.  Later I found that it was also true for southern California.

Sometimes oddities like these are referred to by big professors of weather,  like Reid Bryson at the U of Wisconsin Badgers, as “singularities”, a weather pattern that tends to recur year after year around the same time of the year, like the so-called “January thaw” in the East which I don’t think happened last year.

So, ever since Don told me about the mid-November peak of rain in the central and southern parts of Cal,  I have looked for it year after year and it seems to turn out quite often,  and this November seems to be no exception, though the models were resisting this pattern for quite awhile before “giving in.”

Well, anyway where was I?  It seems that the southern California rain is now being foretold for around 18th of November, and a day or so later it trudges on into Arizona.  From IPS MeteoStar, a Sutron Company, whatever that is, this wonderful map:

Valid the night of November 19th-20th.  Colored regions denote those areas where the model thinks it has precipitated during the PRIOR 12 h.  So, storm has arrived here during the day on the 19th.
Valid the night of November 19th-20th. Colored regions denote those areas where the model thinks it has precipitated during the PRIOR 12 h. So, storm has arrived here during the day on the 19th.

Some clouds

we have known over the past few weeks while CM was re-hydrating mentally:

Some ice for you on a warm fall day.
DSC_0109
Some ice for you on a warm fall day (virga from Altocumulus castellanus and or floccus)
DSC_0128
Pretty iridescence (or irisation) in a Cirrocumulus cloud.
DSC_0145
Pretty sunset, Altocumulus featured.
The End

—————————-

11The non-supportive spaghetti plot from the 00 Z (5 PM model run from last evening):

Valid at 5 PM AST Wednesday, November 19th.  Arizona is in a low amplitude ridge, according to most of the "members" of the repeat model runs with itty-bitty errors deliberately put into them.  I have rejected this plot and look for validation of this action around the 19th of November.   You will not hear about it further if I am erroneous in this action!
Valid at 5 PM AST Wednesday, November 19th. Arizona is in a low amplitude ridge, according to most of the “members” of the repeat model runs with itty-bitty errors deliberately put into them. I have rejected this plot and look for validation of this action around the 19th of November. You will not hear about it further if I am erroneous in this action!

2An odd, almost mysterious Frisco FM radio station with no commercials featuring,  “Brother John.”  We’d sing along to the Four Seasons, The Five Americans’, “Western Union” (about telegraph, the way people used to communicate before the Internet).

3 We both had quite a talent for falsetto it seemed at the time.

Trough, combining with Simon’s remains, delivers 5 inches to Ms. Mt. Lemmon! Clouds now clean and shallow!

Looked for a time that the rain might be over by mid-afternoon  and early evening here in Catalina with only a disappointing 0.40 inches here, but the rains kept coming overnight, piling up a nice 0.98 inches 24 h total for the storm.  In the meantime, Ms. Mt. Lemmon has gotten 4.29 inches!  Check out these eye-popping totals from the Pima County network, ending at 7 AM AST today (just updated.  These are so great in view of last October’s trace of rain:

Gauge    15         1           3          6            24         Name                        Location
ID#      minutes    hour        hours      hours        hours
—-     —-       —-        —-       —-         —-       —————–            ———————
Catalina Area
1010     0.00       0.00       0.00        0.24         0.71      Golder Ranch                 Horseshoe Bend Rd in Saddlebrooke
1020     0.00       0.04       0.04        0.28         1.06      Oracle Ranger Stati          approximately 0.5 mi SW of Oracle
1040     0.00       0.08       0.12        0.43         0.94      Dodge Tank                   Edwin Rd 1.3 mi E of Lago Del Oro Parkway
1050     0.00       0.16       0.20        0.67         1.26      Cherry Spring                approximately 1.5 mi W of Charouleau Gap
1060     0.04       0.16       0.20        0.83         1.93      Pig Spring                   approximately 1.1 mi NE of Charouleau Gap
1070     0.00       0.08       0.20        0.59         1.14      Cargodera Canyon             NE corner of Catalina State Park
1080     0.00       0.00       0.00        0.31         0.91      CDO @ Rancho Solano          Cañada Del Oro Wash NE of Saddlebrooke
1100     0.00       0.12       0.28        0.55         1.06      CDO @ Golder Rd              Cañada Del Oro Wash at Golder Ranch Rd

Santa Catalina Mountains
1030     0.00       0.04       0.08        0.55         1.57      Oracle Ridge                 Oracle Ridge, approximately 1.5 mi N of Rice Peak
1090     0.08       0.31       0.67        1.42         4.96      Mt. Lemmon                   Mount Lemmon
1110     0.04       0.12       0.12        0.71         1.61      CDO @ Coronado Camp          Cañada Del Oro Wash 0.3 mi S of Coronado Camp
1130     0.00       0.24       0.47        1.89         3.46      Samaniego Peak               Samaniego Peak on Samaniego Ridge
1140     0.04       0.12       0.24        0.39         1.73      Dan Saddle                   Dan Saddle on Oracle Ridge
2150     0.08       0.12       0.28        1.14         3.50      White Tail                   Catalina Hwy 0.8 mi W of Palisade Ranger Station
2280     0.00       0.04       0.12        0.31         1.93      Green Mountain               Green Mountain
2290     0.04       0.08       0.20        0.75         2.40      Marshall Gulch               Sabino Creek 0.6 mi SSE of Marshall Gulch

 

Misty drizzle with very low visibilities is still falling here in Sutherland Heights, Catalina,  at 3 AM.  The Catalina Mountains are not visible from just a couple of miles away.  This suggests the clouds overhead are now “clean and shallow” and rain is forming via collisions of cloud drops with coalescence rather than because of ice in the overhead clouds, often called “warm rain,” a rare occurrence in Arizona.   You’ll definitely want to log this in your cloud diary!

“Clean” means that the clouds have low droplet concentrations, viz., are not choked with anthro and natural “continental” aerosols but are more “maritime”, almost oceanic in composition, something that easily leads to “warm rain/drizzle”  formation.  In oceanic clouds far from pollution sources droplet concenrations usually are less than  100 cm-3.  They average about 60 cm-3 in Cumulus clouds in onshore flow along the Washington coast, as an example.  Cloud appearance should look a little different to the discerning eye, too.  With low droplet concentrations, the clouds appear “softer” than usual, not a hard.

Normally, our clouds likely have a few hundred per cm-3 or more and appear darker from below since higher droplet concentrations is also associated with bouncing more sunlight off the top of the cloud1.

With vort max (aka, curly, or curling, air) still well to the west of us at this time (3 AM AST) as seen here.  This sat imagery also shows plenty of shallow clouds upwind of us, so it seems like the very light rain and drizzle will continue well into the morning, likely adding a few more hundredths to our generous totals.  Remember that the air likes to slide upward as curly air approaches, that is, produce a lot clouds,  and today, a last bit of precip.  Did pretty good last night, too!

Honestly, you really want to get out and experience our misty, drizzly rain (drop sizes mostly between 200 and 500 microns in diameter; a few human hair widths), before it ends; the kind of precipitation that makes riding a bicycle even with a big hat impossible.  You might even try the near impossible trick of photographing the drizzle drops, too, as they land in puddles, see if you can catch the tiny disturbance made by drizzle drops.  That would be great photo!  I know, too, that experiencing real drizzle will give you a bit of a chuckle as you think of all those less informed folks, some of whom are even on TEEVEE, who call a sparse fall of raindrops, “drizzle.”  Oh, my, WHAT has happened to our weather education?!

Yesterday’s clouds

Lots of gray cloud scenery yesterday, including a stunning example of Nimbostratus (Ns), the steady rainmaker (at least here we had that, anyway.)   In other places, Cumulonimbus clouds were also contained within that rainy cloud mass and dumping an inch or so in an hour in TUS with LTG (weather text for “lightning2“), as you likely know.  Didn’t hear thunder here, but coulda happened since I was off to the new Whole Foods market at Ina and Oracle as the steady rain from Ns moved in it because it said online that they had Brother Bru Bru’s African Hot Sauce which I had been looking for for a long time but when I got there they didn’t have it! The grocery manager apologized profusely and then we started talking about haloes and the ice crystals that cause them.  So, you never know when your cloud mavenhood will come in handy in everyday conversations, maybe make that friend you’ve been looking for:

 

7:14 AM.  The many layered remnants and distant rain creeping toward Catalina from the southwest are evident soon after dawn
7:14 AM. The many layered remnants and distant rain creeping toward Catalina from the southwest are evident soon after dawn

 

7:34 AM.  New round of rain begins on the Catalinas.
7:34 AM. New round of rain begins on the Catalinas.  Shafting here implies mounding cumuliform turrets on top, likely glaciating.  From up there they would probably look like soft Cumulonimbus capillatus clouds, ones with weak updrafts.

 

8:34 AM.  One of the prettiest sights can be just a tiny little cloud like this when a sun glint falls upon it.  It looked so CUTE!  Imagine, you could be up on that little knob and run in and out of it, maybe play hide and seek with your friends, except that being a "clean" cloud, the visibility would be pretty good in it, not like the shallow, impenetrable fogs you sometimes get around Bakersfield, CA.  There, you could play really great hide and seek!
8:34 AM. One of the prettiest sights around here can be just a tiny little cloud (Stratus fractus) like this one when a glint of sun falls upon it.  It looked so CUTE!  Imagine, you could be up on that little knob and run in and out of it, maybe play hide and seek with your friends, except that being a “clean” cloud, the visibility would be pretty good inside it, not like the shallow, impenetrable fogs you sometimes get around Bakersfield, CA. There,  in one of those, you could play really great hide and seek!  I’m guessing that  if you’re reading this far, you may not have a lot of friends. :}
1:23 PM.  In the midst of our mid-day light rain, a clear example of Nimbostratus with underlying Stratus fractus and Stratocumulus.  Remember, its not the LOW clouds that are raining, its the deep Ns layer above them.  However, it is OFTEN true that the lower clouds ADD to the rain because as the rain falls from the Ns layer, those drops often collide with the floating drops in the lower clouds thus making a raindrop bigger.  That's one main reason why rain and snow are so much more on the upslope side of mountains just due to that collection of non-precipitating cloud drops!  Its so cool!  Away from mountains, you likely won't have so many clouds on the bottom of Ns, and the rain is less.
1:23 PM. In the midst of our mid-day light rain, a clear example of Nimbostratus with underlying Stratus fractus and Stratocumulus. Remember, its not the LOW clouds that are raining, its the deep Ns layer above them. However, it is OFTEN true that the lower clouds ADD to the rain because as the rain falls from the Ns layer, those drops often collide with the floating drops in the lower clouds thus making a raindrop bigger. That’s one main reason why rain and snow are so much more on the upslope side of mountains just due to that collection of non-precipitating cloud drops! Its so cool! Away from mountains, you likely won’t have so many low clouds at the bottom of Ns, and the rain is less.

 

2:50 PM.  After the rain ended, suddenly this lower cloud line formed representing a wind puff from the west.  It headed toward the Catalinas, but then, within a few minutes, pooped out with no precip having fallen out.
2:50 PM. After the rain ended, suddenly this lower cloud line formed representing a wind puff from the west. It headed toward the Catalinas, but then, within a few minutes, pooped out with no precip having fallen out. It was quite a bit fatter before this photo, too.  That dissipation indicated that whatever wind source had produced had died out.  But anyway, when you see a cloud line like this, think “windshift.”

 

4:57 PM.  Expansive deck of Stratocumulus with spots of very light rain in the distance promises, along with the curly air feature being so far to the west of us at that point, promises that the rain is not over.
4:57 PM. Expansive deck of Stratocumulus with spots of very light rain in the distance promises, along with the curly air feature (an upper level vortex) being so far to the west of us at this point, promises that the rain is not over.

The weather way ahead

Dry for almost two weeks.  However, a crazy NOAA spaghetti factory plot suggests rain in about two weeks, around the 23-25th, as you can plainly see here:

NOAA spaghetti factory plot (aka, "Lorenz plot", after chaos scientist, Edward N. Lorenz--he would really like this plot!) valid for 5 PM AST Oct 23rd.  Rain is hinted at by loopy lines in Arizona dipping down to the south.
NOAA spaghetti factory plot (aka, “Lorenz plot”, after chaos scientist, Edward N. Lorenz–he would really like THIS plot!) valid for 5 PM AST Oct 23rd. Rain is hinted at by the loopy lines in Arizona dipping down to the south.  Will keep you posted on that, but not very often.

The End.  Its really amazing how much information I have passed along today!  Most of it correct, too!

——————————————————————-

cCoCoRahs gauge, not Davis tipping bucket which seems to have a problem of late.

1This is the concept behind kooky schemes to defeat potential global warming which hasn’t happened for 18 years or so by polluting oceanic clouds, making them “brighter” on top, darker on the bottom by inserting extra aerosols into them.  Ghastly thought!  Haven’t we polluted enough?

2Recall that weathermen and women were WAY out in front when it came to what we now call “texting”, as in “2KOLD4me” that kind of thing.

Let me give you an example from the 50s when we were rocking around the clock:  “M8BKN15OVC2R-F68/661713G24989 R-OCNLY R”,  a text phrase that would take a paragraph to unravel, to paraphrase language maven, Noam C3,4., except in those days we had our own private symbols which I can’t duplicate for “BKN” (a circle with two vertical parallel lines in it) and “OVC” (a circle with a plus sign in it).  Weather typewriters and teletypes came with those private symbols!

3Wow, a footnote in a bunch of footnotes!  Breaking ground again I think!  What Noam C. said:  “takes a phrase to tell a lie; a paragraph to unravel it.”

4Factoid, one not having to do with weather: Language maven, NC,  really liked Pol Pot and his “restructuring” of society back then until he learned about all the millions of skulls were piling up along with that “restructuring.”  You can hear about Pol Pot (and hypocrisy) here in Holiday in Cambodia, one of the defining songs of the 1980s IMO, as interpreted by The Dead Kennedys featuring lead singer, Jello Biafra.  (You remember Jello don’t you?  Ran for president a while back.  Kind of surprised we didn’t elect him…)

Stationary rainbow sets duration record, maybe

Had another rainbow from those cloud “warriors” we call Cumulonimbus on the Catalinas.  But, “If traces are your thing, Catalina is king!” as we recorded but a trace of rain again while soaking rains poured down just a couple of miles away on the Catalinas, to form a sentence with too much punctuation and a sentence within a sentence1.

More interesting perhaps to some, this modest rainbow formed just after 5 PM yesterday toward the Charouleau Gap, as seen from Catalina, and was still in almost the same spot after 30 minutes.  Have never seen that before since both the sun and the showers are drifting along and so the rainbow should change position.

First, in today’s cloud story, the strangely believe it rainbow part:

5:12 PM.  Rainbow first spotted toward the Gap.  Cumulonimbus cloud not sporting ice at top; ice is below flat top due to weak updrafts that allow the ice crystals to subside.
5:12 PM. Rainbow first spotted toward the Gap. Cumulonimbus cloud not sporting ice at top; ice is below flat top due to weak updrafts that allow the ice crystals to subside while the top remains mostly liquid appearing.  The smoothness on the side of the cloud above the rainbow  is due to ice particles
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5:42 PM. While the observer has moved some few hundred yards, the rainbow has stayed pretty much where it was after 30 min. A course in optics would be required to explain this and that’s not gonna happen (accounting for the sun’s movement, the rain, and the observer’s movement).

 

 
 

 
 

 

 

 

 

 

 

 

 

 

The whole day represented several phases, the early, spectacular eruption of clouds on the Catalinas as it started to warm up under clear skies,  those low bases topping the mountains again indicating stupendous amounts of water are going to be in them when they grow up, the rapid appearance of “first ice” just after 10 AM, the heavy showers and cooling on the mountains and here (little thunder heard), the clearing due to the cooling, the warming, the rebuilding of the Cu on the mountains, and new showers–the rainbow was part of the second growth phase, and then the gradual die out of the Cu as sunset occurred.

Huh. I just realized that what happened to our temperatures yesterday was like a mini-sequence of the earth’s climate over the past 200,000 years or so, the prior Ice Age in the morning temps, the warm Eemian Interglacial as it warmed up, the last ice age when the cooling wind from the mountain showers hit, then the warm Holocene when the clearing and warming started up again in the afternoon!  Cool, warm, cool, warm.  Below, the Catalina temperature record that emulates earth’s climate over the past 200,000 years, beginning with next to last “ice age.”  I can’t believe how much information I am passing along today!  What a day you had yesterday!

Mock climate change for the earth's past, oh, 200, 000 years or so as indicated in yesterday's Catalina/Sutherland Heights temperature scale.
Mock climate change for the earth’s past, oh, 200, 000 years or so as indicated in yesterday’s Catalina/Sutherland Heights temperature scale.  But, we have a LOT of days like yesterday’s in the summertime, but only now after 7 summers has it hit me how it mimics our earth’s “recent” past climate.

 

 

Cloud Alert:  Yesterday might have been the last day for summer rain here.  U of AZ mod from last night has plenty of storms, but we’re on the edge of the moist plume, and those storms take place just a hair east of us it says.  So, while they may be on the Catalinas today, unless we get lucky, they’ll stay over there.  Drier air creeps in tomorrow, too.

Here is the rest of our day in clouds, from the beginning, even if its not that interesting.  In the interest of efficiency, you’d do a lot better by going to the U of AZ time lapse site to see all the wonderful things that happened yesterday, instead of plunking along one by one as you have to do here.  (PS:  Some functions in WordPress not working, would not allow some captions to be entered as usual.)

9:21 AM.  This tall thin Cumulus cloud was a reliable portent for yesterday's early storms on the mountains.  It just shot up!
9:21 AM. This tall,  thin Cumulus cloud was a reliable portent for yesterday’s early storms on the mountains. It just shot up!

 

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11:57 AM.  Thunder and downpours are widespread on the Catalinas.
11:57 AM. Thunder and downpours are widespread on the Catalinas.

 

 

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2:46 PM. After the long clearing, Cumulus begin to arise on the Catalinas again.
DSC_0005-1
5:46 PM. A pretty, and isolated Cumulus congestus with a long mostly water plume ejecting toward the NW. Some ice can be seen falling out of that ejecting shelf. Now here’s a situation where an aircraft measuring the ice output from such a cloud can miss it because its formed as the turret subsides downstream, and most of the ice is substantially below its top, and under the shelf. If you cruised along the top of the shelf, you would miss most of the ice and measure ice particle concentrations that are much lower than what the cloud put out.
DSC_0017-1
6:17 PM. This same quasi-stationary cloud with its long shelf, still shedding ice just downwind of the cloud stem, is about to disappear. Note, too, that the ice fall quits after awhile going downstream even though cloud top temperature is the same for quite a distance. The ice was actually formed at lower temperatures in the protruding turret, not at the temperature of the shelf, which apparently were too high for ice to form. Also, cloud droplet sizes shrink from those in the protruding turret as evaporation takes a stronger hold. Larger droplet sizes are associated with greater ice formation at a given temperature.
DSC_0015
6:12 PM. Like aspen leaves in the fall, but every day, our clouds change color as the sunsets. Here’s another memorable site, not only due to the color, but how tall and thin these Cumulus clouds are, showing that the atmosphere was still extremely unstable over the depth of these clouds, probable 2-3 km deep.

 

The End.

——————————-

1Hahah-these are just a couple of the grammatical gaffes I actually know I’ve done!

Morning delight

The sky was packed with tropical Cumulus congestus and a few Cumulonimbus clouds in the distance at dawn yesterday, an unusual sight for Catlanders.   A few of those Cu around the Catalina/Saddlebrooke/Oro Valley area grew overhead into “soft-serve” Cumulonimbus clouds with heavy, tropical-feeling showers you could hike in with great comfort; no lightning/thunder observed.

Up to an inch likely fell out of the core of the largest ones yesterday morning, but only .09 inches was recorded here in the Sutherland Heights.  The Golder Ranch Drive bridge at Lago del Oro got 0.28 inches, Horseshoe Bend in Saddlebrooke near one core got 0.71 inches, Oracle, a half inch.   Due to the exceptionally warm cloud bases, about 60 F again, warm-rain processes were certainly involved with those showers, though glaciated tops were usually seen, too.  In warm base situations, they can act together.

Now here’s something interesting of me to pass along to you, something you might want to pass along to your friends when the opportunity arises:  ice doesn’t seem to make much difference in the rainfall rates of true tropical clouds in pristine areas, only a little “juicier” than the ones that we had yesterday.  Early radar studies in the 1960s1 indicated that the rainrates of tropical clouds peak out BEFORE the cloud tops reached much below freezing, a finding that has been confirmed in some aircraft studies of rainrates in tropical clouds2.  Icy tops going to 30 thousand or more really didn’t do much but add fluff.  All that really heavy rain that developed before the cloud tops reached the freezing level was just due to collisions with coalescence (AKA here, but nowhere else because its too silly, as “coalision.”)  So, “coalision” can be an extremely powerful and efficient way to get the water out of clouds and onto the ground!

Scattered storms beautified the sky the whole day in the area.  More are expected today, as you likely know.  Have camera ready!  Hope you get shafted!

Cool snap, maybe with rain, virtually guaranteed now for about the 26th-27th.  Should make a good dent in the fly season, if you got horses and have been battling them all summer you’ll really welcome this.

Your Cloud Diary for September 19, 2014.

We start with an early morning vignette, down there somewhere:

DSC_0001

6:32 AM. Overcast Stratocumulus (likely with bulging tops) and the distant top of a Cumulonimbus, that bright sliver, lower right.
DSC_0003-1

6:33 AM. Cumulonimbus top NW of Catalina, an usual sight since it had arisen from such low based clouds in the “boundary layer”. Usually this only happens due to heating by the sun later in the morning or in the afternoon, of course.

DSC_0004

Vignette: When this cloud bank above Sutherland Heights (shown above) darkened up, looked more organized, and with Cumulonimbus tops visible and showers already nearby, I made the not-so-surprising comment to two hikers about to leave on their hike hour long hike, “Watch out for these clouds overhead!”

They got shafted,  see photo below; came back soaked, their dogs, too.

But, I had done my best. True, it was early morning, and after all, those hikers were likely thinking, “it doesn’t rain much here in Catalina in the early morning” (unless its FOUR inches like two weeks ago).

7:30 AM.  Heavy rain falls S of Sutherland Heights, on hikers who had been warned about a dump, producing a warm feeling.
7:30 AM. Heavy rain falls S of Sutherland Heights, on hikers who had been warned about a dump;  produced a warm feeling.

 

 

8:14 AM.  Those showers moved off into the Catalina Mountains and the early morning sun provided a spectacular scene.  (From the "Not-Taken While-Driving" Collection, though certain attributes here suggest that someone just pointed a camera in any old way and got this shot.  Pretty clever to make it look that way, kind of adds an "action: attribute to the shot.
8:14 AM. Those showers moved off into the Catalina Mountains and the early morning sun provided a spectacular scene. (From the “Not-Taken While-Driving” Collection, though certain attributes here suggest that someone just pointed a camera in any old way and got this shot. Pretty clever to make it look that way, kind of adds an “action: attribute to the shot.

Cloud of the Day:

DSC_0076-1

1:47 PM. I meet a friend, southbound, on Equestrian Trail. I advise her that if she drives under this cloud, she will get dumped on. She continues on.  There is no outward sign of ice, and no shaft, however.

 

DSC_0078

1:49 PM. Thunder begins to grumble repeatedly from this cloud only two minutes later! The conversion from a droplet top to an ice (glaciated) one is clearly in progress. My friend has disappeared over the horizon, which isn’t that far in only two minutes.

 

DSC_0081-1

1:58 PM. Kaboom! I was actually a little late getting the fallout to the ground. Will have to look at the video to see the shaft plummet down. Produced a nice little haboobula, too, on the left side, where the shaft is densest. I wondered if my friend had gotten “shafted”, as we say here when folks are under the rain shaft.

 

2:57 PM.  An isolated Cu congestus thrusts three turrets out.  Who will it turn out to be?
2:57 PM. An isolated Cu congestus thrusts three turrets out. Who will it turn out to be?
2:53 PM.  Stable layer halts growth of the two outer turrets and they begin to flatten, but caulifower top in the middle shows that further growth will occur.  Will those wings develop ice?   Beginning to look like a rocking horse, I see...
2:53 PM. Stable layer halts growth of the two outer turrets and they begin to flatten, but caulifower top in the middle shows that further growth will occur. Will those wings develop ice? Beginning to look like a rocking horse, I see…
Look!  Its Snoopy with wings!  (Ice seen on the right, also on the left, but less obvious).
Look! Its Snoopy with wings! (Ice seen on the right, also on the left, but less obvious).
4:31 PM.  Pile of Cumulus congestus clouds weighs down the Catalina Mountains again as they did the previous evening.  Had to stop, jump out car to get this grand scene, well, to me anyway.
4:31 PM. Pile of Cumulus congestus clouds weighs down the Catalina Mountains again as they did the previous evening. Had to pull off the road this time, jump out car to get this grand scene, well, to me anyway. Hungry passengers a little annoyed at the pre-dinner delay. You know, had to complain a little.
6:18 PM.  Another sunset reason why we live here and love it so much.
6:18 PM. Another sunset reason why we live here and love it so much.
6:20 PM.  Late storms continue on The Rim, toward Globe
6:20 PM. Late storms continue on The Rim, toward Globe

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The End, enjoy our last couple days, it would seem, of our summer thunderstorm season.  Oh, me.

 

————————————

1Saunders, R. M., 1965; J. Atmos. Sci.

2Cloud Maven Person with Hobbs, 2005, Quart; J. Roy. Met, Soc.

 

Hawai’i in Arizona

Yesterday, in the wake of TD Odile, it was about as Hawaiian a day in Arizona as you are ever likely to see. First, the high dewpoints, ones that replicate those in HI, mid and upper 60s (69-70 F in HNL right now), cloud base temperatures of around 60 F, and with misty, even drizzly warm rain around at times. The only thing we didn’t see was a rainbow, so common in HI they named a sports team after them.

If you thought the clouds looked especially soft-looking yesterday, I thought they were, too.  That soft look that also characterizes clouds in Hawaii and other pristine oceanic areas arises from low droplet concentrations (50-100 per cc),  characteristic of Hawaiian clouds.1   Both low updraft speeds at cloud base, and clean air result in low droplet concentrations in clouds.

The result of these factors?

The droplets in the clouds are larger than they would be forming in air with more aerosols (having “cloud condensation nuclei”, or CCN) and stronger updrafts at cloud base.  Yesterday, you could have remarked to your neighbors late yesterday morning,  as the rain and true drizzle began to fall from that Stratocumulus deck out to the SW-W, that the droplets in those clouds, “….must’ve exceeded Hocking’s threshold” of around 38 microns diameter.  Lab experiments have demonstrated that when droplets get to be that large, which isn’t that large at all, really, that they often stick together to form a larger droplet, which in turns, falls faster and bumps into more droplets, and collects them until the original droplet is the size of a drizzle (200-500 microns in diameter) or raindrop (greater than 500 microns in diameter) and can fall out the bottom of the cloud.2

DSC_0136

6:10 AM. Light drizzle or rain due to collisions with coalescence rather than due to the ice process falls from yesterday morning’s Stratocumulus deck (fuzzy, misty stuff in the center and right; eyeball assessment).  Quite exciting to eyeball.
DSC_0166

9:46 AM. So clean and pure looking, these clouds during a brief clearing yesterday morning. These might well have been seen off the coast of Hawai’i.
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10:23 AM. One of the Hawaiian like ambiance of yesterday was both the low clouds, the humid air, and the green texture on the mountains highlighted by the occasional ray of sunlight. Fantastic scenes!

 

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11:31 AM. Being a cloud maven, I wasn’t too surprised to see drizzly rain start to fall from our Hawaiian like Stratocumulus clouds, but I was excited!

 

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11:41 AM. Stratocumulus clouds mass upwind of the Catalinas. Hoping for a few drops at least.

 

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12:07 PM. An especially tropical looking scene I thought, with the very low cloud bases, the humid air; the warm rain process likely the cause of the rain on Samaniego Ridge.

 

6:08 PM.  As the day closed, this fabulous scene on Samaniego Ridge.
6:08 PM. As the day closed, this fabulous scene on Samaniego Ridge.  Clouds might be labeled Stratocumulus castellanus.

 

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6:25 PM. As the air warmed in the clearings to the southwest and west of us, King Cumulonimbus arose. Expect some today around us.

Mods still coming up with cold snap at the end of the month, even with rain as the cold front goes by.  How nice would that be to finish off September?  Still have a couple of days of King Cumulonimbus around as tropical air continues to hang out in SE Arizona.  Hope trough now along Cal coast can generate a whopper here before that tropical air leaves us.  Am expecting one, anyway, in one of the next two days, probably our last chances for summer-style rain.

Speaking of Odile….

the thought that inches of rain might fall in Tucson, something we all heard about two eveings ago WAS warranted by the gigantic amounts that occurred as Odile slimed its way across extreme southeast AZ.  In modeling terms, the error in its track was pretty slight, but the predicted amounts that we COULD have gotten were pretty darn accurate.  I did not see these amounts until after writing to you yesterday.  Note those several four inch plus values around Bisbee, and the one in the lee of the Chiricahuas.  That one 4.45 inches over there suggests to me that the Chiricahuas like got 4-6 inches.  Check’em out:

24 h rainfall ending at 7 AM AST yesterday for SE AZ (courtesy of the U of AZ rainlog.org site).
24 h rainfall ending at 7 AM AST yesterday for SE AZ (courtesy of the U of AZ rainlog.org site).

The End

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1Except those affected by Kilauea’s “VOG” which have much higher concentrations, and look a little “dirty.”

2A thousand microns is a millimeter, in case you’ve forgotten, and that’s only about 0.04 inches in diameter.  Most raindrops are in the 1000 to 3000 micron diameter range, though the largest, measured in Brazil, the Marshall and Hawaiian Islands, can be about a centimeter in diameter.

O, models, disappoint

Odile passed to the S and E of Cat land, leaving only 0.13 inches here in the Heights, the Sutherland ones.  Didn’t even get the half inch I hoped for.  Oh, well, we can be happy for the droughty areas of New Mexico that got the brunt of that tropical system as did portions of extreme SE AZ.  You may know that for many days in advance and up until 11 PM the night before last (shown here), our best models had O practically passing right over us with prodigious rains indicated.

Unfortunately, we meteorologists often “go down with the ship” when this happens due to model forecast consistency.  Only in the last minutes, so to speak, did the model runs get it right (but too late to be of much use) and finally indicated that the true path of the heaviest rain was NOT going to be over us, as was already being discovered via obs.  O was such a cloud mess, the mods may have been off in locating where the center was.  Not sure.  Will have to wait for the panel report.

Seems to be preciping on the Cat Mountains right now, though doesn’t show up on radar, so its likely a RARE “warm rain” event here in AZ where the rain forms by collisions between larger cloud drops to form rain drops and the cloud tops are low1.  Maybe that’s O’s legacy;  tropical air and a warm rain day sighting.

BTW, whilst Catalina and most of Tucson didn’t get much, it has continued to rain steadily in our mountains over the past 24 h with Dan Saddle, up there in the CDO watershed, leading the way with 2.09 inches in 24 at this hour (5 AM) and its still coming down lightly, as noted.  Its been a fantastic rain since it was steady and soaking up there over that whole 24 h period, much like in our winter storms.  Below, some totals from the PIma County ALERT gauges.  You can see more totals here.

Gauge    15         1           3          6            24         Name                        Location
    ID#      minutes    hour        hours      hours        hours
    —-     —-       —-        —-       —-         —-       —————–            ———————
Catalina Area
    1010     0.00       0.00       0.00        0.00         0.16      Golder Ranch                 Horseshoe Bend Rd in Saddlebrooke
    1020     0.00       0.04       0.04        0.04         0.20      Oracle Ranger Stati          approximately 0.5 mi SW of Oracle
    1040     0.00       0.00       0.00        0.00         0.12      Dodge Tank                   Edwin Rd 1.3 mi E of Lago Del Oro Parkway
    1050     0.00       0.00       0.00        0.00         0.16      Cherry Spring                approximately 1.5 mi W of Charouleau Gap
    1060     0.00       0.00       0.00        0.00         0.16      Pig Spring                   approximately 1.1 mi NE of Charouleau Gap
    1070     0.00       0.00       0.00        0.00         0.04      Cargodera Canyon             NE corner of Catalina State Park
    1080     0.00       0.00       0.00        0.00         0.20      CDO @ Rancho Solano          Cañada Del Oro Wash NE of Saddlebrooke
    1100     0.00       0.00       0.00        0.00         0.08      CDO @ Golder Rd              Cañada Del Oro Wash at Golder Ranch Rd

Santa Catalina Mountains
    1030     0.00       0.04       0.04        0.08         1.73      Oracle Ridge                 Oracle Ridge, approximately 1.5 mi N of Rice Peak
    1090     0.00       0.00       0.04        0.04         0.75      Mt. Lemmon                   Mount Lemmon
    1110     0.00       0.00       0.00        0.00         0.43      CDO @ Coronado Camp          Cañada Del Oro Wash 0.3 mi S of Coronado Camp
    1130     0.00       0.04       0.04        0.04         0.31      Samaniego Peak               Samaniego Peak on Samaniego Ridge
    1140     0.00       0.08       0.28        0.35         2.09      Dan Saddle                   Dan Saddle on Oracle Ridge
    2150     0.00       0.00       0.04        0.08         0.71      White Tail                   Catalina Hwy 0.8 mi W of Palisade Ranger Station
    2280     0.00       0.04       0.12        0.16         1.02      Green Mountain               Green Mountain
    2290     0.00       0.04       0.04        0.04         0.47      Marshall Gulch               Sabino Creek 0.6 mi SSE of Marshall Gulch

BTW#2, true CMJs (cloud maven juniors) will want to photograph the rain from these shallow clouds, this rare, Hawaiian-like rain event2,  lining the Catalinas this morning as soon as its light enough.   It would be like photographing a parakeet on your bird feeder here in Catalina, one migrating from South America.  I think that’s where they come from.  Anyway, your cloud-centric friends from other part of the world would be quite interested in seeing your photos of this.

Is the summer rain season over?

No way!   (But you already knew that, though it sounds more exciting to put it that way, in the form of a question like the TEEVEE people do)

Now we get into some interesting weather times as we go back into the scattered big thunderstorms feeding on the moist plume that accompanied O.   That moist plume will be around for the next few days.  These coming days, with their thunder squalls,  may well be the most “productive” ones for rain here compared to the piddly output of O here in the Heights.  We have upper air goings on that are likely to make storms cluster more into big systems a time or two during the next few days instead just the one over here and over there kind of days, the ones you hope you get lucky on to get truly shafted.  So, “fun times at Catalina High” ahead, to paraphrase something.

 Yesterday’s clouds

11:15 AM.  The look of a stormy sky, Stratus fractus lining Samaniego Ridge, overcast Nimbostratus producing R-- (very light rain).
11:15 AM. The look of a stormy sky:  Stratus fractus lining Samaniego Ridge, orogrpahic Stratocumulus topping the Ridge, overcast Nimbostratus producing R– (very light rain).
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4:56 PM. By afternoon the deeper clouds were gone leaving Cumulus, a couple of distant Cumulonimbus clouds with their rain shafts, and an overcast of Stratocumulus or Altocumulus, no precip coming out of them.
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6:28 PM. The sunset, while OK, like O was a little disappointing since more clouds could have been lit up by the setting sun but weren’t.

 The weather way ahead

Cool weather alert:  based on model consistency, which I have already discredited earlier, there are cold snaps now appearing for the end of September and early October. They’ve shown up in a couple of runs now.   They have some support in the NOAA spaghetti factory plots.

 

The End.

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1There’s a nice description of  “coalision” , the warm rain process not involving ice, in Pruppacher and Klett (1998) if you really want a nice book about cloud microphysics in your library.

2Mostof the rain that falls in Hawaii falls from relatively shallow clouds with tops at temperatures above freezing, no ice involved, contrary to the usual situation here where ice is necessary.

Dial “O” for rain; Odile that is

Unless the younger folks watch Turner Classic Movies or something like that, they will be clueless about what ther the reference to “dialing” is in the title.  Oh, well.  Heck, who even remembers what a Walkman was these days?

The heavy cloud shield of TS Odile is moving in with some light, spotty rain hereabouts right now.  It will be interesting to see if today’s rain amounts to anything.  Seems it could be a very Seattle-like rain day with those heavy layer clouds over us (Nimbostratus/Altostratus) and intermittent very light rain all day.  Boring!  (Is “boring” with an exclamation mark an oxymoron of sorts?)

NWS is excited about Odile, as any meteorologist not having snow in his veins would be,  and have posted some daily rainfall records for this week. Of course, we’ve already set some rainfall records for September; can it happen again?  They seem to be concerned about that possibility.  Many of those September records, as many of you will remember I am sure, were associated with tropical storm Norma that busted into Arizona in early September 1970 as you will see1.  Workman Creek got 11 inches in one day back then.  You can read about Norma’s doings here and whether the NWS forecasts were adequate.

The meteorological situation was very different with Norma, and that may be why we precipophiliacs could be “disappointed” by rain amounts with Odile–Norma had help from the configuration aloft; Odile not so much.  However, in the days following Odile’s passage, that upper level trigger does fall into place over southern Cal, and we’ll have to watch out for some big thunderstorms in the couple of days AFTER Odile goes by when that upper level trigger (trough) still has some tropical air to work with. So, some really “interesting” weather ahead, the kind of weather we’ve forgotten can happen here in the many droughty years we’ve had lately.

Here, just hoping for some nice steady rains, not just sprinkles, that add up to something significant like a half an inch or more, keeping the desert green that bit longer, and maybe, some good scattered thunderstorms for a few days after the big cloud shield of Mr. Odile fades away.  That will pretty much do it for our summer rain season I’m afraid.

Now, since we don’t like to do work that can be done better by others, these ones and this one, for example, so on to yesterday’s pretty cloud pictures.  (Can’t get over the thought  I might be disappointed in Odile’s rain here, expectations not real high, so don’t want to express them and make you a little sad; keeping a lid on thoughts of a big Odile rain for Catalina, don’t want to get too manic, etc.)  Will just lay back and enjoy it…whatever comes.

Yesterday’s clouds2

10:00 AM.  Cumulus development looked promising in the mid-day hours, but none over the Cat Mountains produced ice.  Was surprised that didn't happen.
10:00 AM. Cumulus development looked promising in the mid-day hours, but none over the Cat Mountains produced ice. Was surprised that didn’t happen.  Note glistening rocks dur to the recent rains.
Ann2 DSC_000811:59 AM. Towering Cumulus and Cumulonimbus clouds begin lining the International border. Warning: adult commentary included in photo, the kind you see every day on TEEVEE.

 

DSC_0013

1:18 PM. High cloud shield from Odile’s advance creeps over Tucson from the south. Cumulonimbus clouds can be seen in the extreme distance.
DSC_0024

4:06 PM. Cirrus and Altostratus have overspread the sky, and the darkening to the S-SW looks ominous in view of Odile’s approach after wrecking southern Baja.

 

Followed by a great sunset, one deserving of more than one example.  No details, just enjoy.

DSC_0034 DSC_0035 DSC_0045 DSC_0052 DSC_0066

 The End

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1The present Arthur was in Durango starting his first job as a weather forecaster for the great Colorado River Basin Pilot Project, a randomized cloud seeding experiment,  when Norma’s remains hit and flooded the Animas River there.  I was inside a vaudeville theater listening to the rain pound on the roof, the audience of that melodrama, too, distracted a time or two, and also being distracted by Durango school teacher, Janet James,  whom I had taking a liking to.  She was there that night, too, but not with me.  Wonder what happened to her?

2 Caution: one photo is annotated with adult humor.