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).
DSC_0132
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.
DSC_0135
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.

Author: 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.