What an amazing and “productive” little rainband that was just after midnight! And more rain is likely with weaker bands just upwind here at 4 AM. Could we really approach an inch? Amazing. Didn’t seem possible in this small mind that we could amass that much. For a full regional rain table, go here to the ALERT gauge records.
Now, after this ends, a long dry spell has to be endured, at least until around the 20th of Jan, at which time we hope the troughs and rain threats at least, will begin to barge in every few days, namely, and pattern more typical of winter sets in.
The weather ahead
After the last drops fall today, we’ll suffer through another dry spell and warm up though about the 20th when a major trough passes by.
Oops…. Have cameras ready for a great day of cloud shots once the sun breaks through.
Doesn’t happen every November, thunder, but it sure pounded away at times yesterday. Seemed louder than usual thunder a few times even with the lightning over there by the Tortolita Mountains. Of course, that’s where the heaviest rain fell as several T-storms tracked along a similar path over there just a little to the W through N of us, Bio2, in one of the heavier cloberations receiving 1.17 inches.
Here, in The Heights, we received a disappointing, but nevertheless welcomed final total of 0.24 inches. This brings our total here in Sutherland Heights for November up to 0.60 inches. Average is 0.96 inches1. Here, the regional totals as the storm was coming to an end:
As is proper, let us begin examining the nubilations of our storm by looking at those clouds that preceded the actual rain day yesterday.
Moving ahead to yesterday…..
The great thing about yesterday was that because the upper trough lagged so much behind the cold front, you could be sure it wasn’t over, that is, the rain chances. In fact, as the wind turns aloft from a southerly or southwesterly direction to a more westerly one, we here in Catalina have a better chance of having the clouds pile up over us, even if they’re not full fledged Cumulonimbus clouds, they can still reach depths where they precipitate while upwind, they don’t because they may not be deep enough. The Catalina Mountains provides the lift that helps do this, and we saw that happen later in the afternoon and evening when it began to rain again long after the cold front and it so-so rain band went by.
The End, FINALLY!
1If we don’t get more rain by the end of November, I will delete the sentence of a week or so ago stating that November would have above average rainfall. No use having people see that.
We’ve waited a LONG time for a rain day. It was so nice, so photogenic as well. I hope you enjoyed it as much as I did.
Also, you may have seen the Froude Number1 in action as Cumulus congestus and Cumulonimbus clouds developed and went around the sides of the Catalina Mountains instead of developing over them and dumping big shafts of rain on them. The heaviest rains yesterday were due to streamers of showers and with an OCNL TSTMS that were north and south of us, Oracleville, Bio2 area, and Marana, Avra Valley where over half an inch was logged in some places.
Still , we managed a third of an inch here in Sutherland Heights, the first appreciable rain since I don’t know when, though, I could look it up. Too long, though, even for Catalina.
Some regional totals, 3 AM to 3 AM: Precipitation Report for the following time periods ending at: 03:19:00 11/04/16 Data is preliminary and unedited. —- indicates missing data Gauge 24 Name Location ID# minutes hour hours hours hours —- —- —- —- —- —- —————– ——————— Catalina Area 1010 0.08 Golder Ranch Horseshoe Bend Rd in Saddlebrooke 1020 0.12 Oracle Ranger Stati approximately 0.5 mi SW of Oracle 1040 0.08 Dodge Tank Edwin Rd 1.3 mi E of Lago Del Oro Parkway 1050 0.16 Cherry Spring approximately 1.5 mi W of Charouleau Gap 1060 0.16 Pig Spring approximately 1.1 mi NE of Charouleau Gap 1070 0.24 Cargodera Canyon NE corner of Catalina State Park 1080 0.20 CDO @ Rancho Solano Cañada Del Oro Wash NE of Saddlebrooke 1100 0.16 CDO @ Golder Rd Cañada Del Oro Wash at Golder Ranch Rd
Santa Catalina Mountains 1030 0.04 Oracle Ridge Oracle Ridge, approximately 1.5 mi N of Rice Peak 1090 0.16 Mt. Lemmon Mount Lemmon 1110 0.16 CDO @ Coronado Camp Cañada Del Oro Wash 0.3 mi S of Coronado Camp 1130 0.28 Samaniego Peak Samaniego Peak on Samaniego Ridge 1140 0.08 Dan Saddle Dan Saddle on Oracle Ridge 2150 0.16 White Tail Catalina Hwy 0.8 mi W of Palisade Ranger Station 2280 0.04 Green Mountain Green Mountain 2290 0.16 Marshall Gulch Sabino Creek 0.6 mi SSE of Marshall Gulch
Santa Catalina Foothills 2090 0.04 TV @ Guest Ranch Tanque Verde Wash at Tanque Verde Guest Ranch 2100 0.16 DEQ Swan Swan Rd at Calle del Pantera 2160 0.08 Sabino @ USFS Dam Sabino Creek at USFS Dam 2170 0.24 Ventana @ Sunrise Ventana Canyon Wash at Sunrise Rd 2190 0.16 Al-Marah near El Marah on Bear Canyon Rd 2200 0.04 AC Wash @ TV Bridge Agua Caliente Wash at Tanque Verde Rd 2210 0.00 Catalina Boosters Houghton Road 0.1 mi S of Catalina Highway 2220 0.04 Agua Caliente Park Agua Caliente Park 2230 0.04 El Camino Rinconado El Camino Rinconado 0.5 mi N of Reddington Rd 2240 0.04 Molino Canyon Mt Lemmon Highway near Mile Post 3 2390 0.24 Finger Rock @ Skyli Finger Rock Wash at Sunrise Rd
Except for a morning or afternoon sprinkle, no rain in sight, just a warm up back to above average temperatures. Dang.
1The young fluid dynamicist, Richard Penniman, fascinated by the flow around mountains, and who later became known as the rock and R&B entertainer, “Little Richard”, first brought the Froude Number to public attention in his song, “Tutti Froude-e.” The title, after an early release failed to capture the public’s imagination, was later revised for greater “accessibility”, to the song we know today as, “Tutti Frutti.”
2Who can forget “Max and the Storm Troopers” and that great song? I would submit, “everyone.” Of course, few know that after 1968 they changed their name to “Led Zeppelin.” And that, my friends, is “the rest of the story”, as Paul Harvey might say if he was lying about something anyway.
The day started with some nice Altocumulus “pancakus”, some lenticulars and breezy conditions, reminding one of fall day with a cold front approaching. Small Cumulus appeared quickly, but with the wind, you wondered if they would get enough heating to power upward into Cumulonimbus clouds.
By noon you had your answer as a large Cumulonimbus complex settled in just beyond the Tortolita Mountains west of Catalina. And it pretty much recurred there and over the Tortolitas all afternoon. In the meantime, passing light showers dotted this side of the Catalinas, but that was about it. No “Code 4” shafts on those mountains yesterday. Rain totals were less than a half inch, and most less than a third. On the other hand, would guess that parts of the Torts got well over an inch. The cores missed us again, with Sutherland Heights logging only 0.03 inches.
Developing showers passed over Catalina dropping occasional very large, sparse drops, but shafts generally fell out of those clouds after they had passed off to the northeast.
Late in the afternoon, the line of recurring showers finally approached Catalina, but as dry air encroached in the middle levels, at the same time, catching up to that standing line, all those great mushrooming clouds were no more. The cloud story board is below:
Some apocalyptic cloud scenes can be Cumulus that explode suddenly into Cumulonimbus, and Cumulonimbus clouds with their foreboding (unless you live in a desert) rain shafts, and their predecessor shelf clouds like “swirly dark Stratocumulus”, and arcus clouds, the latter, a lower line of clouds just above and a little behind the wind shift at the ground, usually just ahead of the main rain shaft. While we didn’t get to see an arcus cloud yesterday, we had some dramatic swlrly dark Stratocumulus clouds to scare us. I say “swirly” because if you looked up yesterday evening as they passed over, you would have seen rotation in them.
These can combine, as they did yesterday, to make you think someone might drop out of the clouds and fix the world1. See those scary photos below, way below as it turns out.
This monster collection of Cumulonimbus clouds (“mesoscale convective system” or MCS in weather lingo) with swirly shelf clouds preceding it barged over Catalina later yesterday afternoon after it appeared that not much was going to happen all day. Heck, there wasn’t even a decent Cumulus over the Catalinas until after 2 PM!
The result of this system slamming Catalina was the usual strong preceding winds roaring down from Charouleau Gap way and points north or northeast. The winds were not as damaging as three days earlier.
Then the rain! So nice! Got 0.55 inches of rain here in Sutherland Heights, an inch and half on Samaniego Ridge, and 1.65 inches on Ms. Lemmon.
Worth watching is the U of AZ weather departments time lapse video, especially beginning at 2 min 50 s into it. That’s when the big group of Cbs begins to make its presence known from the east. What is interesting, and what I have not seen before, is that you will see the tops of a thunderhead farther west, that icy part up around 30,000 to 40,000 feet, shoved backwards (back toward the west) by outflow at the tops of the huge incoming system. Very dramatic.
Detour: detecting ice in clouds….some practice shots
As the burgeoning cloud maven junior person you, of course, know how important the appearance of ice in our clouds is. You got ice; you got precipitation, which is snow up there, soft hail, hail, frozen drops.
Only the largest hailstones up there can make it to the ground as such here in Arizona due to our high summertime freezing levels. The rest melt into raindrops, some of which are large enough to reach the ground. Those downpours that suddenly emit from cloud bases were always hail or graupel (soft hail) aloft.
Sometimes in deep stratiform clouds attached to clusters of Cumulonimbus clouds, and with especially moist air from the base of the stratiform layer to the ground, clusters of ice crystals we call snowflakes make it to the ground without evaporating as steady light or very light rain.
Last night as our storm was coming to an end, it is likely that THOSE drops were once snowflakes rather than soft hail or graupel.
The End (finally)
1Huh. Maybe that wouldn’t be a bad thing. I am very concerned about microplastics (particles 5 millimeters and smaller) in our oceans, resulting from the breakup of larger plastic items we’ve been throwing in the oceans for decades. Seems those tiny particles are getting into everything, including the fish out there! It would be great if someone could get rid of them.
Back to weather and yesterday’s microburst with three minutes of sheets of unbelievably heavy rain with rice-sized hail, 50-60 mph gusts, blazed across Sutherland Heights between 4:06 PM and 4:13 PM. It was a memorably violent storm, comparable in those worst 2 minutes or so to anything we see in the summer, and it was completely un-predicted for Catalina the day before (0% chance of rain here) though showers WERE predicted for the higher terrain of eastern AZ yesterday). For the full story, see Bob M’s excellent discussion. For just clouds and stuff, here is OK.
Stuff blew everywhere and I felt lucky not to lose some branches of trees in the yard. Here’s yesterday’s cloud diary. First the background about what was happening, the TUS balloon sounding of the atmosphere:
Too dry today for rain. Next chance for rain around the 17-19th as that bigger (but maybe drier) cold trough settles in. Temps will be nice, though. Lots of intermittent trough action indicated in 06 Z mod run through the rest of May, so May should continue to be pretty interesting and likely devoid of never-ending heat month as sometimes happens here. This scenario pretty well supported in those crazy NOAA spaghetti (or Lorenz) plots.
Photos not loading in WordPress now, so quiting here, dammitall! Must go on to other chores now. Not happy!
OK, photos finally went in. Happy now, though too many photos as usual.
1I doubt that happened…. Really, this was a song about people who don’t like to go to work, kind of anti-capitalist which is ironic because it was that system that allowed the boys to make their millions (billions if they had invested wisely into Microsoft in the early 1980s) and gone on to help the world with their billions like Bill and Melinda.
Truly LATE breaking news, untimely really, but Augustober 18th was too special a day to ignore:
Giant clouds, dense rain shafts, frequent lightning in the area throughout the afternoon, dewpoints in the high 50s to 60 F; can it really be after the middle of October? Or, is this some kind of preview of climate change we can look forward to in the decades ahead, that is, if you’re thunderphilic?
1:56 PM. Anvil of the Cumulonimbus over west Tucson, drifts overhead of Catalina, and in three minutes, rain drops started to hit the ground. This is amazing because those drops had to fall from at around 20, 000 feet above the ground (estimated as bottom height of this thick anvil) and could only have happened if those isolated drops had been hailstones ejected out the anvil, something that also only occurs with severe storms with very strong updrafts in them. So, if you saw those few drops fall between 2 and 2:05 PM you saw something pretty special.
The weather just ahead, and this might be it for precip for the rest of October
A nice-looking upper level trough is ejecting over us from the SW this morning but the computer model says its going to be a dry event. A second low center forms just about over us in the next day. AZ model doesn’t see much rain for us throughout these events, and rain doesn’t begin here until after dark today.
I think that is WRONG; bad model. Watch for some light showers this morning, then a break and rain overnight (which the models do predict). Due this quite bad model forecast, as seen from this keyboard, I feel must interject for the blog reader I have, an improved rain prediction for Catalina over that rendered by a computer model.
Feel like guesstimating a minimum of 0.25 inches between now and Thursday evening, max possible, 0.60 inches, so the median of those two, and maybe the best guestimate being the average of those two, or 0.425 inches here in Catalina. When you see a prediction of a rainfall total down to thousandths of an inch, you really know that the person predicting it knows what he is doing…..
Below, your U of AZ disappointing, but objective, take on the amount of rain based on last evening’s data and one that is the result of billions of calculations. One must remember that cloud maven person’s calculation of the rainfall amount for Catalina is only based on three.
Morning thunder, evening thunder; 0.84 inches of rain, 1-2 inches in the mountains, with some of the most dramatic skies and shocking cloud changes ever seen (by me). “But, hey, enough of ‘me’, lets get on with the ‘shockumentary'”, as Rob Reiner might say.
Scene 1: Its morning. A horsey ride has been planned with an important, published friend. You’re thinking, “It will be good to be seen with someone important.” No one’s paying attention to weather. The weather is cloudy, quite nice really, but nothing threatening can be seen.
Scene 2. Heading out.
Scene 3. On the trails.
Scene 4. Ooops
Scene 5. Dramatic skies and a few close strikes.
The storm passed dropping 0.22 inches. And, compounding error, as we know, when potent upper air disturbances bring morning thunder and rain, its pretty much always the case that the rest of the day will be dry as a subsiding couplet of air follows a rising one, the the strongly rising couplet of air that forced our morning clouds and storm.
So, was kind of looking ahead to a disappointing rest of the day , but was thankful for the unusual morning storm.
You won’t have to go to New Mexico, Sonora, or the Indian State of Kerala to find great summer rain. According to this model output from last evening, its only a bit more than a week away!
The last time we saw a model prediction like the ones below, was for the 24 h ending today, made a whopping 12 days ago. When you consider the great rains we had ending YESTERDAY morning (2-7 inches in the mountains, and inch here in The Heights, that far out prediction was only a day or so off. So, there’s hope that the paucity of summer rain that has left our desert so brown will be rectified a bit more in the near future.
Below, from 5 PM AST obs, the WRF-GFS 12-h rain totals predicted for August 20 and beyond as rendered by IPS MeteoStar. Normally, these are pretty useless predictions, but since that last one with so much rain foretold was close to what actually happened, maybe there’s something to watch out for around the 20th.
Clouds got more enthusiastic than expected here yesterday, reaching sizes big enough to produce light rainshowers to the NE of Catalina, and THUNDER just after 6 PM up toward Oracle town! Nice. Looks like a small Cumulus, postcard day today in Catalina. Cloud tops marginal for ice, holding around -10 C, capped by subsiding, dry air. (Except for the light showers this morning between 7 and 9 AM; this note added at 7:32 AM when I saw a shower developing to the west over Oro Valley!) This, from the U of AZ model. Since the air is colder aloft to the N today, ice will likely be seen in some clouds up thataway.
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