Rain piling up; total 0.35 inches at 3 AM! Now its 0.48 inches at 6 AM!

Sounds more exciting if you title like that…and that’s what I’m here for, excitement, weather and cloud excitement!

Pima County ALERT 24 h precip totals, some around here below,  as of 6 AM:

Gauge             15         1           3          6            24         Name                        Location
    ID#      minutes    hour        hours      hours        hours
    —-     —-       —-        —-       —-         —-       —————–            ———————
Catalina Area
    1010     0.00       0.04       0.08        0.08         0.43      Golder Ranch                 Horseshoe Bend Road in Saddlebrooke
    1020     0.00       0.00       0.04        0.08         0.43      Oracle Ranger Stati          approximately 0.5 mile southwest of Oracle
    1040     0.04       0.08       0.12        0.12         0.47      Dodge Tank                   Edwin Road 1.3 miles east of Lago Del Oro Parkway
    1050     0.04       0.04       0.08        0.08         0.47      Cherry Spring                approximately 1.5 miles west of Charouleau Gap
    1060     0.00       0.04       0.08        0.16         0.71      Pig Spring                   approximately 1.1 miles northeast of Charouleau Gap
    1070     0.00       0.00       0.08        0.08         0.35      Cargodera Canyon             northeast corner of Catalina State Park
    1080     0.00       0.04       0.08        0.12         0.51      CDO @ Rancho Solano          Cañada Del Oro Wash northeast of Saddlebrooke
    1100     0.00       0.04       0.04        0.08         0.28      CDO @ Golder Rd              Cañada Del Oro Wash at Golder Ranch Road

Santa Catalina Mountains
    1030     0.00       0.00       0.00        0.04         0.20      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       0.04       0.12        0.24         0.71      CDO @ Coronado Camp          Cañada Del Oro Wash 0.3 miles south of Coronado Camp
    1130     0.00       0.00       0.00        0.00         0.04      Samaniego Peak               Samaniego Peak on Samaniego Ridge
    1140     0.00       0.00       0.00        0.04         0.24      Dan Saddle                   Dan Saddle on Oracle Ridge
    2150     0.00       0.00       0.00        0.00         0.04      White Tail                   Catalina Highway 0.8 miles west of Palisade Ranger Station
    2280     0.00       0.00       0.00        0.00         0.31      Green Mountain               Green Mountain
    2290     0.00       0.00       0.00        0.00         0.24      Marshall Gulch               Sabino Creek 0.6 miles south southeast of Marshall Gulch

As you can see, a couple of stations in the Catalina Mountains were virtually missed by the storm (ZERO total, for example,  at Ms. Mt. Lemmon) or it snowed on those low total precip gauges and the snow has not melted and is sitting in the gauge’s funnel.  Select choice number 2.  Mountains just becoming visible; looks like snow down to 6,000 foot level.

Didn’t see any precip/virga before dark yesterday, started raining just before 10 PM, nicely, and continued through midnight when it quit.  However, the main event, lasting about 6-8 h is supposed to start happening about now, but rain mostly lighting up in TUS.  That means we should see some clearing around mid-day, but leaving enough low clouds stacking up around the Catalinas for some nice quilted sun and shadows on those mountains, one of our prettiest sights I think, along with our now snow-capped mountains.

FROPA, or “frontal passage” in weather text speak, occurred late yesterday afternoon.  I wonder if you noticed the wind shift and dropping temperatures?  However, was a very shallow depth of wind that shifted, and temperature took about 3 h to drop 10 F, (58 F to 48 F) not exactly as sharp a FROPA as was anticipated from this microphone yesterday.  Also, a bit unusual, the rain band was displaced far behind the wind shift that occurred around 4:30 PM.201312041900 fropa

Yesterday’s clouds

I thought yesterday was quite an interesting day for you.  Lots of cloud types to log in your weather and cloud diary.  Let us begin our retrospective with Sunrise on the Equestrian:

7:05 AM.
7:05 AM.
7:17 AM.  Splayed Cirrus display, racing at you at over 100 mph.
7:17 AM. Splayed Cirrus display, racing at you at over 100 mph.
7:52 AM.  Orographic Stratocumulus top the Catalinas, a very good sign that the incoming front will produce rain.  Indicates reasonable lower level humidity.
7:52 AM. Orographic Stratocumulus top the Catalinas, a very good sign that the incoming front will produce rain. Indicates reasonable lower level humidity already in place.
9:34 AM.  Small Cumulus form over the Oro, Cirrus above.  So pretty a sight, I thought.
9:34 AM. Small Cumulus form over the Oro, Cirrus above. So pretty a sight, I thought.
12:17 PM.  Micro-snowstorm (Cirrus uncinus) passes past the Catalinas.  You can see this cloud from the U of A here in their time lapse movie.
12:17 PM. Micro-snowstorm (Cirrus uncinus) passes past the Catalinas. You can see this cloud from the U of A here in their time lapse movie.
12:58 PM.  Seattle-style Stratocumulus overcast.  Got a little homesick there for a second.
12:58 PM. Seattle-style Stratocumulus overcast. Got a little homesick there for a minute.
DSCN6773
3:38 PM. Atop horsey Jake now, looking for signs, knowing that front is getting closer. Here those darker, lower line of clouds were atop the windshift that was about to occur, marking the leading edge of the front. This colder air has lifted and chilled the moist air from the southwest to help create that lower base, the sure sign of a wind shift. Looking north toward Saddlebrooke from near The Chutes on the 50-year trail .

toward

 

4:27 PM.  Cloud bases lower significanty as the cooler air rushed in.  But look, no precip in spite of the heavy cloud cover?  What's up with that?  No ice, cloud tops still too warm in FROPA area.
4:27 PM. Cloud bases lower significantly as the cooler air rushed in. But look, no precip in spite of the heavy cloud cover. What’s up with that? No ice present in them; cloud tops still too warm in even FROPA area1.
Also at 4:27 PM, looking toward weak sun producing the lighting break on the Catalinas.  Note haziness likely due to dust.
Also at 4:27 PM, looking toward weak sun producing the lighting break on the Catalinas. Note haziness, likely due to dust.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Your next storm:  due in  Sunday morning.  Likely just something around a tenth of an inch.  Nothing showing up beyond that, but lots of mod fluctuations re storms.  I suspect the one that showed up a few days ago for the 20th or so will arise again in some future run.  Just a gut feeling since there’s no evidence in the spaghetti plots yet to support that hunch.

 

The End.

 

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1The TUS balloon sounding yesterday afternoon about the time of the next to last photo.  Shows tops WERE warmer than -10 C, in case you didn’t believe me because the clouds looked so dark yesterday afternoon.  They were pretty dark because there was a higher ice cloud overcast (Altostratus) and when droplet concentrations are high, clouds are darker on the bottom.  We usually have pretty high droplet concentrations here in old Arizony.

2013120500.72274.skewt
Note that the temperature of the air (blue) lines slope upward to the right.

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.