Oh, well. Was expecting at least 0.25 inches a few days ago, and thought maybe a heavy shower last night might pull that expectation out of the trash bucket. Monthly total now up to 0.70 inches (updated after reading NWS-style and CoCo gauges here), still significantly below average (0.96 inches). Not much else elsewhere, either. Double dang.
Mostly Cumulus humilis and flat Stratocumulus yesterday. Was looking for ice as the temperatures aloft cooled during the afternoon and evening, and only as the sun went down was a slight bit of virga visible to the west. That Stratocu deck over us was deepening upward, and began reaching the magic point where ice begins to form, probably around or a little below -10° C (14 °F) in clouds such as yesterday’s. Let’s look at a sounding from the U of AZ (as displayed by IPS MeteoStar) and see what it says about those evening clouds and see if the above is just a bunch of hooey (I haven’t seen it yet, either):
Still looks like a chance for some light showers before the month closes out, but will be hard to get enough to bring the total to an above average value. Dang.
Will update my reader on December’s early cold outlook as new information that agrees with my assessment comes in. Right now, that information is not available.
A horse photo will always enhance a blog about clouds. Expecting a little uptick in readership due to this ploy, maybe will break out of the single digit column.
Not much happened early on, a thin film of Cirrostratus covered much of the sky, delaying the expected development of convection, as would be evidenced by the formation of Cumulus clouds, until mid-afternoon.
But they did form, mostly to the S through W of Catalinaland, upwind of us, and eventually rumbled in on their last legs as weak thunderstorms with gushes of sprinkles and gusty breezes, maybe ones over 15 mph!
Over there in Marana and Avra Valley, those places upstream of us, some spots got more than half an inch. But, i it seems this year that storms die when they move toward Catalina, and especially, toward MY house and its many raingauges (3).
Still, it was nice to feel cool breezes, air chilled by falling rain, even if elsewhere.
Here are a few dull and disappointing cloud shots from yesterday, including one with a horse:
Still have rain chances last few days of Oct into early Nov.
Many of you probably were gasping for air after having seen the WRF-GFS model outputs from last evening’s 5 PM AST global data.
A large hurricane, really more the size of its typhoonic big brothers in the western north Pacific, and one that also dwarfs the late tropical remnant, “Newton” , that came through here a week or so ago, is shown to move along the SAME path as Newton into Arizona in about 13 days from now.
For those few of you who did NOT peruse the 00 GMT, CUT, Z output, here are the fantastic fantasy hurricane depictions that this model, with all of its calculating power, shows entering AZ on the 26th. Kind of fun to see even if it is bogus because it indicates that such a strong tropical cyclone could come through here one day.
Below, from IPS MeteoStar, these, maybe the best fake AZ hurricane depictions I have ever seen. Note all the isobars, i.e., lines of equal pressure with this tropical cyclone in AZ, and then remember for all its rain, little Newton had virtually no signature on pressure maps! Hell, the pressure didn’t even fall at Nogales as Newt approached. Pitiful.
But it wouldn’t be like that in this fantasy hurricane. Tremendous pressure falls would occur as it entered AZ giving your microbarograph quite a workout as the pressure plummeted and then went up as the center passed by.
You do have a microbarograph don’t you? If you don’t, think about it.
Next, you’re curious, though, about what steering pattern caused this hurricane, previously shown to stay far offshore and dissipate over some jellyfish and plastic particles way out in the Pacific in the models.
Let’s look, again from IPS MeteoStar at the steering situation at 500 millybars, or in around 20,000 feet or so:
What you need to have any confidence is a big trough along or just offshore as we had with Newt, not a slight little itty bitty eddy aloft that has to be in exactly the right location at EXACTLY the right time. I mean, its like a ball that goes for a home run after it bounces of the center fielder’s head1 …
Hold your cash on the sand bags.
Finally, there’s really nothing from the spaghetti factory that supports this. Boohoo. What you need in spaghetti is strong support for a trough along the coast, not the below:
Spectacular Altocumulus castellanus and floccus (no virga) passed overhead during the morning. I hope you documented them with a few photos.
Have to depart from clouds and weather to tell this tale. Yesterday I stopped here to let the mighty Zeus rest a little. I let him graze “off leash” on some of the still-green nettle grass in a gravel parking area next to our cottage. I then went to get a pail of water for him, the pail being on the north side of our house. When he saw I was leaving, he immediately followed me like a dog. It was kind of cute.
But as we got to the gravel outside the north porch of our house, our two dogs, Banjo and Emma were going nuts at the sight of a horse outside the north windows.
Zeus got distracted by all of the commotion in the house and went onto the porch to look in one of the windows to see what was up, or maybe he saw his own reflection and thought it was another horse? Here is the hilarious scene:
1This actually happened in South Dakota, at Mitchell’s Cadwell Park, during a baseball game I played in ’72. I was catching in those days for Mitchell Commercial Bank. Our center fielder, a track star, ran to get a scorching line drive to medium depth center, and racing to his left, reaching up to grab it, the ball instead bounced off his noggin and went some 40 or 50 feet over the fence! He was OK. We had no “concussion protocol” in those days. Had a chance to bat against the legendary Canova, SD, pitcher, Lee Goldammer in that game. Whiffed on three pitches; was maybe at bat for 30 seconds.
0.02 inches of it, anyway, as the core of the jet stream at 18,000 feet or so passed by Catalina yesterday afternoon. Keep your eye on the orange and reddish streak in these progs from IPS MeteoStar yesterday morning beginning at 5 AM AST and how it slides over us as the clouds began to ice up:5 AM yesterday. Jet at this level races across central AZ.
11 AM yesterday. Maximum winds getting closer! Tiny Cumulus clouds begin to appear over the Catalinas and on the west to north horizon.
The jet separates deep cold air on the left side, looking downwind, and deep warm air on the south side. The deep warm air prevents Cumulus clouds from getting very deep due to inversions and stable layers where the temperature does not change much with increasing height, or even rises. The temperature at 500 millibars or 18,000 feet above sea level dropped from -17.7 °C to -21.1° C over TUS yesterday between 5 AM and 5 PM, while the temperature about which ice begins to form in our clouds dropped about 400 meters during that time. With the temperatures at the ground rising into the mid-70s as the colder air moved over us, Cumulus clouds deepened, reaching the ice-forming level between 1 and 2 PM.
Also with patterns like this, the cyclonic rotation (vorticity) in the air above us is increasing like mad, and that leads to a gentle upglide motion in the atmosphere, one that also helps cool the air aloft and usually produces sheets of clouds like Cirrus, Altostratus, Altocumulus and NImbostratus. But yesterday the air was too dry for sheet clouds to form.
First ice was noted just after 1 PM. Can you find it?
5 PM yesterday. Just passed! B y this time, Sutherland Heights had 0.02 inches as the tops of Cumulus and Stratocumulus complexes continued to cool and ascend. The sounding from TUS at 5 PM AST (launched about 3:30 PM AST) indicated the coldest tops had reached -20 °C or so, plenty cold enough for ice, virga, and light rain showers. Too bad the bases were so high since we could have had some real rain if they had been lower.
But, we were “lucky” to get that. Even the great U of AZ model had no rain anywhere near us late yesterday afternoon when it fell! THAT does not happen very often.
Nice Cu, ice, too.
Substantial rains, maybe half an inch or so, still on tap between May 6th-8th as previously foretold here. Yay! May averages 0.38 inches here in Catalina. More rain likely after that episode, too. So an above normal May in rain is pretty much in the bag now. Could be an especially great May, too.
I was really happy for everyone out there when the skies were dotted with so many perfect examples of Cumulus humilis. It was like a numismatist finding a perfect Indian head penny. If you were like me, and I suspect you are, you were just going CRAZY taking pictures of those flat little pancake clouds. Those clouds were pretty much limited to about 1,000 feet (300 m) thick at most
Not cold enough for ice in them, of course, since the temperatures at Cumulus cloud tops were only around -3 ° to -5 °C (28 ° to 23 ° F, respectively). Around here, ice USUALLY does not appear in clouds until the temperature is lower than -10 °C at cloud top.
Yesterday began with some light snow falling on Mt Lemmon…well, it was falling downward TOWARD Ms Lemmon, actually. Fell out of some thick Altocumulus clouds up there around where the cloud top temperature is… what? OK, silly question for you, probably lower than -15 °C (5 ° F).
Let’s check the sounding to be sure, remembering that the launch site (University of AZ) was downwind of air flowing from the NW yesterday that went over the Catalinas, so a sounding at the U of AZ might suggest higher temperatures than this cloud was actually at since the air was probably descending before it got there.
Indeed, as just seen by me, the TUS sounding indicates that layer, up around 14 kft above sea level, 11 kft or so above Catalina, not a city, but rather a Census Designated Place or CDP, was “only”at -10 ° C.
I reject that as the temperature of the virga-ing cloud over Ms. Lemmon! Its a little too warm IMO.
By afternoon, the skies over Catalinaland were spotted and dotted with spectacular Cumulis humilis examples. (The littlest shred clouds are Cumulus “fractus.”)
I’ve left the time of the photos off today. After all, there was only one true time yesterday, “perfect humilis time!” or as we like to say, “PHT.” Immerse yourself.