A rare mid-morning storm

Below, way below,  are the 24 h totals for yesterday’s storm from all of the Pima County ALERT gauges, in case you missed seeing them.  The south portions of Catalina got the most of that storm around here, while the north portion was “nil-ed”, as in recent, “one-nil”,  soccer talk. A real oddity is that the Catalina Mountain stations in this network saw no rain.

I’ve posted these amounts instead of the link to them because its a “rolling archive”, constantly being updated, and so before long, yesterday’s amazing storm will be disappearing as the hours go by while you’re still sleeping, making brain-clearing coffee, etc.

SH (Sutherland Heights got only 0.01 inches, an embarrassing and disheartening total when you think of how close the heavy rain was.  Just south of Golder Ranch Drive on Swan, an inch was recorded, and for a few minutes yesterday morning with that cold south wind blowing, low scudding clouds just above the mesquite trees, and frequent lightning strikes just to the east, it appeared the bottom was about to drop on us Sutherlanders.

It was a rare event,  not so much in the rain amounts, but rather the time that it exploded over the TUS region;  after sunrise through about noon, after which the forces of dissipation took over.  For a great look at this development, go here to the U of AZ time lapse film for yesterday.

As we know here, that period between sunrise and noon is USUALLY one of cloud dissipation;  nighttime clouds thin and clear, whilst new Cumulus clouds begin to arise over the high mountains. I am going to link to Bob Maddox’s analysis if this event when he is done with it later this morning.  You see, Dr. Bob is one of the world’s premier experts on convection and the organization of Cumulonimbus clouds into big clusters. It would be good for you to read what he has to say.  Saves me a lotta work, too.  Also, he has some great graphics.

On the other hand, Mr. Cloud Maven person’s experience, as a Pac NWesterner in airborne cloud research at the U of WA, is limited to a tremendous, I tell you, amount of flying into itty-bitty Cumulonimbus clouds that top out at or below only about 12,000 feet above sea level.  We especially liked them if their tops were not colder than -10 C1.  For comparison, yesterday’s powerful storms likely topped out at 50,000 feet and had top temperatures lower than -60 C!  Well, really, there’s no comparison.

Catalina Area
    1010     0.00       0.00       0.00        0.00         0.00      Golder Ranch                 Horseshoe Bend Road in Saddlebrooke
    1020     0.00       0.00       0.00        0.00         0.00      Oracle Ranger Stati          approximately 0.5 mile southwest of Oracle
    1040     0.00       0.00       0.00        0.00         0.00      Dodge Tank                   Edwin Road 1.3 miles east of Lago Del Oro Parkway
    1050     0.00       0.00       0.00        0.00         0.00      Cherry Spring                approximately 1.5 miles west of Charouleau Gap
    1060     0.00       0.00       0.00        0.00         0.00      Pig Spring                   approximately 1.1 miles northeast of Charouleau Gap
    1070     0.00       0.00       0.00        0.00         0.79      Cargodera Canyon             northeast corner of Catalina State Park
    1080     0.00       0.00       0.00        0.00         0.00      CDO @ Rancho Solano          Cañada Del Oro Wash northeast of Saddlebrooke
    1100     0.00       0.00       0.00        0.00         0.28      CDO @ Golder Rd              Cañada Del Oro Wash at Golder Ranch Road

Santa Catalina Mountains
    1030     0.00       0.00       0.00        0.00         0.00      Oracle Ridge                 Oracle Ridge, approximately 1.5 miles north of Rice Peak
    1090     0.00       0.00       0.00        0.00         0.00      Mt. Lemmon                   Mount Lemmon
    1110     0.00       0.00       0.00        0.00         0.00      CDO @ Coronado Camp          Cañada Del Oro Wash 0.3 miles south of Coronado Camp
    1130     0.00       0.00       0.00        0.00         0.00      Samaniego Peak               Samaniego Peak on Samaniego Ridge
    1140     0.00       0.00       0.00        0.00         0.00      Dan Saddle                   Dan Saddle on Oracle Ridge
    2150     0.00       0.00       0.00        0.00         0.00      White Tail                   Catalina Highway 0.8 miles west of Palisade Ranger Station
    2280     0.00       0.00       0.00        0.00         0.00      Green Mountain               Green Mountain
    2290     0.00       0.00       0.00        0.00         0.00      Marshall Gulch               Sabino Creek 0.6 miles south southeast of Marshall Gulch

Santa Catalina Foothills
    2090     0.00       0.00       0.00        0.00         0.20      TV @ Guest Ranch             Tanque Verde Wash at Tanque Verde Guest Ranch
    2100     0.00       0.00       0.00        0.00         0.20      DEQ Swan                     Swan Road at Calle del Pantera
    2160     0.00       0.00       0.00        0.00         0.00      Sabino @ USFS Dam            Sabino Creek at USFS Dam
    2170     0.00       0.00       0.00        0.00         0.00      Ventana @ Sunrise            Ventana Canyon Wash at Sunrise Road
    2190     0.00       0.00       0.00        0.00         0.00      Al-Marah                     near El Marah on Bear Canyon Road
    2200     0.00       0.00       0.00        0.00         0.04      AC Wash @ TV Bridge          Agua Caliente Wash at Tanque Verde Road
    2210     0.00       0.00       0.00        0.00         0.28      Catalina Boosters            Houghton Road 0.1 miles south of Catalina Highway
    2220     0.00       0.00       0.00        0.00         0.00      Agua Caliente Park           Agua Caliente Park
    2230     0.00       0.00       0.00        0.00         0.00      El Camino Rinconado          El Camino Rinconado 0.5 miles north of Reddington Road
    2240     0.00       0.00       0.00        0.00         0.00      Molino Canyon                Mt Lemmon Highway near Mile Post 3
    2390     0.00       0.00       0.00        0.00         0.16      Finger Rock @ Skyli          Finger Rock Wash at Sunrise Road

Redington Pass Area
    2020     0.00       0.00       0.00        0.00         0.00      Park Tank                    Redington Pass, 0.8 miles south of Park Tank
    2030     0.00       0.00       0.00        0.00         0.00      Italian Trap                 Redington Pass, 0.7 miles east southeast of Italian Trap Tank
    2040     0.00       0.00       0.00        0.00         0.00      White Tank                   Redington Road near White Tank
    2050     0.00       0.00       0.00        0.00         0.00      Bellota Ranch Road           Bellota Ranch Road near Redington Road
    2070     0.00       0.00       0.00        0.00         0.04      TV @ Chiva Tank              Tanque Verde Wash 0.5 miles south of Chiva Tank
    2080     0.00       0.00       0.00        0.00         0.00      Alamo Tank                   Redington Road near Alamo Well

Rincon Mountains
    4100     0.00       0.00       0.00        0.00         0.00      Manning Camp                 Manning Camp in the Rincon Mountains
    4110     0.00       0.00       0.00        0.00         0.00      Rincon Creek                 Rincon Creek at X-9 Ranch

Greater Tucson
    2110     0.00       0.00       0.00        0.00         0.00      TV @ TV Road                 Tanque Verde Wash at Tanque Verde Road
    2120     0.00       0.00       0.00        0.00         0.00      TV @ Sabino Cyn Rd           Tanque Verde Wash at Sabino Canyon Road
    2300     0.00       0.00       0.00        0.00         0.24      Well D-37                    Rosewood Street west of Harrison Road
    2310     0.00       0.00       0.00        0.00         0.12      Well E-23                    Rancho El Mirador north of Broadway Boulevard
    2320     0.00       0.00       0.00        0.00         0.00      Beverly Well C-51            Beverly Avenue at Hawthorne Street
    2330     0.00       0.00       0.00        0.00         0.20      Kolb Boosters                Kolb Road at Golf Links
    2350     0.00       0.00       0.00        0.00         0.08      Rillito @ Dodge              Rillito Creek at Dodge Boulevard
    2360     0.00       0.00       0.00        0.00         1.22      Rillito @ La Cholla          Rillito Creek at La Cholla Boulevard
    2370     0.00       0.00       0.00        0.00         0.00      Alamo @ Glenn                Alamo Wash at Glenn Street
    2380     0.00       0.00       0.00        0.00         1.30      DEQ Ruthraff                 Ruthrauff Road at La Cholla Boulevard
    4160     0.00       0.00       0.00        0.00         0.24      E-8                          Irvington Road near Pantano Road
    4180     0.00       0.00       0.00        0.00         0.12      Pantano @ Houghton           Pantano Wash at Houghton Road
    6040     0.00       0.00       0.00        0.00         0.20      Santa Cruz@Valencia          Santa Cruz River at Valencia Road
    6180     0.00       0.00       0.00        0.00         0.59      ArroyoChico@Cherry           Arroyo Chico at Cherry Street
    6190     0.00       0.00       0.00        0.00         0.51      Arroyo Chico@Randol          Arroyo Chico at Randolph Way
    6230     0.00       0.00       0.00        0.00         0.51      Ajo Detention Basin          Tucson Diversion Channel at Ajo Detention Basin
    6240     0.00       0.00       0.00        0.00         0.63      DEQ Cntry Clb                Country Club Road near Columbia Street
    6250     0.00       0.00       0.00        0.00         0.00      Craycroft@Golf Link          Craycroft Road at Golf Links Road
    6260     0.00       0.00       0.00        0.00         0.08      Tucson Electric Pow          Irvington Road at Belvedere Avenue
    6270     0.00       0.00       0.00        0.00         0.47      Pima Air Museum              Valencia Road at Pima Air Museum

Southern Tucson Area
    6200     0.00       0.00       0.00        0.00         0.12      Summit Elementary            Summit Street at Epperson Lane
    6210     0.00       0.00       0.00        0.00         0.00      Franco @ Swan                Franco Wash at Swan Road
    6220     0.00       0.00       0.00        0.00         0.00      PC Fairgrounds               Houghton Road at Dawn Road
    6280     0.00       0.00       0.00        0.00         0.12      Wilmot                       Wilmot Road 2 miles south of Old Vail Connection Road
    6290     0.00       0.00       0.00        0.00         0.20      Corona                       Sahuarita Road at Sewage Treatment Plant

Altar/Avra Valley Area Area
    6370     0.00       0.00       0.00        0.00         0.00      Arivaca                      Las Guijas Mountains near Arivaca
    6380     0.00       0.00       0.00        0.00         0.08      Altar Wash @ Hwy 28          Altar Wash at Highway 286
    6410     0.00       0.00       0.00        0.00         0.12      Diamond Bell                 Diamond Bell near Stagecoach Road at Killarney Avenue
    6420     0.00       0.00       0.00        0.00         0.16      Brawley@Three Point          Brawley Wash at Highway 86
    6430     0.00       0.00       0.00        0.00         0.31      Vahala Park                  Wade Road at Los Reales
    6440     0.00       0.00       0.00        0.00         0.31      Brawley@Milewide             Brawley Wash at Milewide Road
    6450     0.00       0.00       0.00        0.00         0.12      Hilltop Rd                   Hilltop Road at Riveria Road
    6460     0.00       0.00       0.00        0.00         0.83      Picture Rocks CC             Picture Rocks Community Center
    6470     0.00       0.00       0.00        0.00         0.59      Michigan @ Calgary           Michigan Street at Calgary Avenue

Marana/Oro Valley Area
    1200     0.00       0.00       0.00        0.08         1.06      CDO @ Ina Road               Cañada Del Oro Wash at Ina Road
    1230     0.00       0.00       0.00        0.00         0.04      Oro Valley PW                Calle Concordia at Calle El Milagro
    1240     0.00       0.00       0.00        0.00         2.17      Moore Rd                     Moore Road at La Cholla
    1250     0.00       0.00       0.00        0.00         0.24      Pima Wash @ Ina              Pima Wash at Ina Road
    1260     0.00       0.00       0.00        0.00         1.89      Big Wash                     Big Wash at Rancho Vistoso Boulevard
    1270     0.00       0.00       0.00        0.00         1.26      CDO @ Big Wash               Cañada Del Oro Wash near Oracle Road
    6020     0.00       0.00       0.00        0.00         1.02      Santa Cruz @ Ina             Santa Cruz River at Ina Road
    6110     0.00       0.00       0.00        0.00         0.67      Avra Valley Airpark          Santa Cruz River 0.5 miles east of Sanders Road

Vail Area
    4220     0.00       0.00       0.00        0.00         0.08      Rancho Del Lago              approximately 1.8 miles northwest of Vail
    4250     0.00       0.00       0.00        0.00         0.00      Pantano @ Vail               Pantano Wash 1.5 miles southeast of Colossal Cave Road
    4270     0.00       0.00       0.00        0.00         0.08      Salcido Place                6 miles north-northwest of Mescal
    4280     Site temporarily removed due to road construction        Cienega Crk @ I-10           Cienega Creek at Interstate 10
    4290     0.00       0.00       0.00        0.00         0.04      Mescal                       2 miles northwest of Mescal
    4310     0.00       0.00       0.00        0.00         0.00      Davidson Canyon              Davidson Canyon Wash 0.25 miles south of Interstate 10
    4320     0.00       0.00       0.00        0.00         0.00      Empire Peak                  Empire Peak
    4410     0.00       0.00       0.00        0.00         0.00      Haystack Mtn.                Haystack Mountain

Green Valley Area
    6050     0.00       0.00       0.00        0.00         0.04      Santa Cruz@Continen          Santa Cruz River at Continental Road
    6060     0.00       0.00       0.00        0.00         0.00      Santa Cruz@Conoa             Santa Cruz River at Elephant Head Road
    6080     0.00       0.00       0.00        0.00         0.00      Santa Cruz@Tubac             Santa Cruz River at Tubac
    6310     0.00       0.00       0.00        0.00         1.26      Keystone Peak                Keystone Peak
    6320     0.00       0.00       0.00        0.00         0.51      Tinaja Ranch                 near Caterpillar Proving Ground
    6330     0.00       0.00       0.00        0.00         0.12      Anamax                       Mission Road north of Continental Road
    6350     0.00       0.00       0.00        0.00         0.00      Elephant Head Butte          near Elephant Head Butte
    6390     0.00       0.00       0.00        0.00         0.00      Florida Canyon               Florida Canyon Work Center

After 7 AM, you will also be able to round up totals from the University of Arizona rainlog.org site, and also
the CoCoRahs site for Arizona.

The USGS 24 h rolling archive is here.

Our NWS data are here; click on Regional and State Summaries (“latest”).

Since, like me, you have neighbors in the area that measure rainfall, but don’t report anywhere,  you’ll want to call them up and list those amounts as well.

Now that we’ve rounded up about as much rainfall data as we can, its time for some cloud photos, a lot of them to tell yesterday’s  story:

DSC_0280
8:12 AM. Nothin’ much going on, two layers evident. A higher layer of Altocumulus perlucidus (top right), and a lower deck of scattered Cumulus, not likely formed from rising currents from the ground, but triggered by a general upward motion of the air, enhanced over the mountains.
DSC_0281
8:12 AM also, looking SSW toward Tucson and Pusch Ridge. The two layers are evident here as well, and towers in the lower layer are evident. Still, not much going on in the radar at this time.
DSC_0286-1
By 9:24 AM, the “explosion” was well underway as those turrets began to group into a huge cluster spewing heavy rain and lightning. But would it make Catalina? It seemed to be moving parallel to us and not toward Catalina, spreading westward toward Marana and the south part of Oro Valley.  Notice the difference between this shot and the one above.
Ann DSC_0295
10:10 AM. The storm continues to march across west Tucson and toward Marana. Just a hint of a cloud bank on the side toward us, something that might be fueled by outflow spreading north and northeastward that might cause the storm to grow in our direction.

 

11:01 AM. Looking more promising as SW wind heading from storm causes new Cumulus bases to form on its northeast side! Gettin' closer, hopes beginning to rise.
11:01 AM. Looking to SW toward Marana and more promising as SW wind blowing out from storm causes new Cumulus bases to form on its northeast side!   But, with the overall coolness of the morning, will those bases grow up to be Cumulonimbus clouds?    Gettin’ closer; hopes risin’.
11:14 AM. SW wind has hit, temperature dropped by about 5 degrees into the low 70s (!). Oregon visitor next door says he feels COLD! But, look at that base! So nice, so firm, so fully packed! Bound to cut loose with a big dump, and those bases like that are propagating in this direction, borne on that SW push of wind. Note scruffy Stratus fractus clouds lining the Catalinas, brought about by that surge of cooler air near the ground that resulted in condensation at the top of that wind layer. The cloud base above it is due to the lower wind layer lifting en masse, the air its undercutting. Not described so well me thinks.
11:14 AM. SW wind has hit, temperature dropped by about 5 degrees into the low 70s (!). Oregon visitor next door says he feels COLD! But, look at that base! So nice, so firm, so fully packed! Bound to cut loose with a big dump, and those bases like that are propagating in this direction, borne on that SW push of wind. Note scruffy Stratus fractus clouds lining the Catalinas, brought about by that surge of cooler air near the ground that resulted in condensation at the top of that wind layer. The cloud base above it is due to the lower wind layer lifting en masse, the air its undercutting. Not described so well me thinks.
DSC_0333
11:20 AM. Sure enough, a cloudburst results from the new firm bases! Something around 2 inches in an hour fell in Marana at this time, and, overall, its getting still closer to Catalina!
DSC_0335
11:32 AM. Frequent cloud to ground strikes are occurring east of Catalina, and the low, scudding clouds of the outflow winds have covered the sky. This was such a dramatic scene. Looking S, the heavy rain, from yet another new cell that formed above the cold outflow wind over and just east of the south part of Catalina. The pounding rain that produced an inch only about a mile and a half south of Sutherland Heights is falling now.

Well, we here in Sutherland Heights know what happened next. As quickly as the sky had deteriorated to a low overcast with plenty of lightning, the low clouds disappeared and the rain area began to recede to the south and west, dissipating slowly as it did.   It was a truly horrible sight, not worthy of a photo.

Ironically, something in the way of the little Cumulonimbus clouds CMP flew in developed late in the afternoon, and presented an example of ice formation at temperatures only a little below freezing (tops likely around -10 C). Here is that pretty cloud over the Catalinas.

4:45 PM. A small Cumulonimbus capillatus cloud over Catalinas. At least the storm had cleared out the hazy air of the prior day.
4:45 PM. A small Cumulonimbus capillatus cloud over Catalinas. At least the storm had cleared out the hazy air of the prior day.

 

 

 

 

 

 

 

 

 

 

 

 

 

The day concluded with all the Cumulus clouds having disappeared, but leaving enough residual middle and high clouds for a decent sunset photo.

DSC_0384
7:30 PM. A dramatic, if ultimately disappointing day for us here in the Heights, finishes with a nice sunset.

 

 

 

 

 

 

 

 

 

 

 

The End.

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1Had to do with long-term studies of the theories and lab results concerning the mystery of ice formation in clouds with top temperatures higher than -10 C.  Its common, but is quite complex, and not yet completely understood.  So, we avoided bigger, colder-topped clouds as much as we could.  BTW, while it may seem incredible that ice formation is not completely understood, but let us remember that the so-called Standard Model of particle physics is also incomplete.  How many years have those guys been studying that?  Its embarrassing, really.

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.