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…)

By Art Rangno

Retiree from a group specializing in airborne measurements of clouds and aerosols at the University of Washington (Cloud and Aerosol Research Group). The projects in which I participated were in many countries; from the Arctic to Brazil, from the Marshall Islands to South Africa.