Altostratus clouds – Page 5

Stagflation

Meteorologists have called stagnant pressure conditions with inflated temperatures “stagflation” for as long as I can remember, which is not that long. Anyway, that’s what we have before us, pretty much the same old thing, day after day, except for some really nice Cirrus patterns in the sky to go with those 100-110 F temperatures we get this time of year. You can see the upper level moisture stream coming over us here, from the Huskies, if you’re interested.

Mind-starting to drift off center now….

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Weather extreme note

If you noted the record-tying “trace” of rain at Vegas back on the 25th and were pretty happy about it, well, you’re going to be put out by this NWS message, passed along by climate guru and mischief maker, Mark Albright, just yesterday. Apparently, the NWS has been concerned over this record tying event for some time:

“RECORD EVENT REPORT…CORRECTED
NATIONAL WEATHER SERVICE LAS VEGAS, NV
1059 PM PDT THU MAY 29 2014
…NO RECORD DAILY MAXIMUM PRECIPITATION WAS TIED AT LAS VEGAS
SUNDAY...
DUE TO AN EQUIPMENT ISSUE WITH THE PRESENT WEATHER SENSOR AT THE
MCCARRAN INTERNATIONAL AIRPORT ASOS, A FALSE REPORT OF A TRACE OF
PRECIPITATION WAS REPORTED ON SUNDAY, MAY 25TH. AFTER FURTHER
INVESTIGATION, THIS WAS DETERMINED TO BE INCORRECT. THEREFORE THE
FINAL PRECIPITATION TOTAL FOR SUNDAY, MAY 25TH, IS 0.00 INCH AND THE
DAILY PRECIPITATION RECORD WAS NOT TIED.
THE ABOVE INFORMATION IS PRELIMINARY AND IS SUBJECT TO A FINAL
REVIEW BEFORE BEING CERTIFIED BY THE NATIONAL CLIMATIC DATA CENTER.
$$”

Hope I didn’t spoil your morning.

On the other hand, you wonder what the NWS meant, “after further investigation…”? What might they have done to remove an extreme weather event, one that tied a record?

Let’s “jump in” and see what we can find out about this record-tying mystery. First, let’s pull up radar-derived precip maps for May 25th and May 26th and see if there is any chance it rained on the 25th. We have to do two maps since the end time of each radar precip map is for the 24 h period ending at 5 AM, whilst the record is for midnight to midnight of the 25th. Below, from WSI Intellicast are those two 5 AM AST maps in chronological order:

:

We can see that it DID rain in the 24 h ending at 5 AM AST on the 25th at McCarran Field, LAS, but not AFTER 5 AM ending on the 26th (map on the right.

But when did the weather observing machine think it rained?

By pulling up the hourly observations in text form below, we can see that the machine thought that rain began at 1519 Central Universal Time (8:19 AM AST) and rained for 11 minutes, ending at 1530 CUT. “RAB” means “rain began, truncated to minutes after the hour).

25 1456 SA KLAS >120 SCT   10        1011.1 77 45   0    0          29.92         1 10   0    0             AO2
25 1556 SA KLAS >120 CLR   10        1011.3 79 44 160    4        29.93                T                    AO2 RAB19E30
25 1656 SA KLAS >120 SCT   10        1011.0 82 43        3           29.92                0                       AO2
25 1756 SA KLAS >120 SCT   10        1010.6 84 42        5           29.91 85 70 8 04   0    T          AO2

Looking further, we can also see the text words “SCT” and “CLR” for the time periods in which rain was reported. Furthermore, the the “numbol”, “>120” , means no clouds below 12, 000 feet above ground level.

Can it rain to the ground from clouds higher than 12,000 feet above the ground? Its fairly rare, but it happens, as we Arizona sunbirds know from just the past couple of days when sprinkles fell from such clouds.

However, investigating even farther, we find that the machine is also indicating “CLR” or “SCT” conditions, meaning CLEAR or SCATTERED clouds above 12,000 feet.

Can it rain from CLEAR skies, too few clouds for the sensor to detect overhead? Or SCT skies? It has happened that the machine reports SCT conditions on a RARE occasion when a little Cumulonimbus is passing overhead. I think it was reported from Douglas last summer; thunder, too. Very odd, but not impossible.

But what we don’t see is any “VCRA” report, that is, the coding for “rain in the vicinity” that would be inserted next to the column of “10s” above if there had been any as detected by radar.

So, after a few hours of investigation, we have absolved the NWS of having improperly removed an extreme weather event: the trace of rain was, in FACT, erroneously reported from the McCarran Field weather observing machine.

(Actually the point of this rather tortured writeup is to expose you to a little of our weather reporting language called, METAR. You can read about it here pretty good. You can get those METAR reports from many places, here’s one.

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A hodge-podge of cloud scenes from the recent trace of rain rainy day

(Counted over 100 drops on a wide area of pavement during the many, many sprinkle episodes two days ago; each one, I noticed, dried up in about two seconds, too.)

The End.

‘Manda rain

BTT you read this, rain oughta be falling or near by as the remnants of ‘Manda hurricane dribble into Arizona today. Looks like there’s just enough rain upstream right now (4 AM) to produce, hold your breath, a MEASURABLE amount here in Catalina! Likely will be just a few hundredths, though, as much as two tenths is about the top potential from this. At this point, anything measurable is a fabulous rain!

Mods have been oscillating on whether it would rain here for many days, but last night’s run ended pleasantly with a “correct” forecast of measurable rain. See green pixelation over Catalina below:

Valid for 11 AM AST today. Heart of rainband over us then, mod says. — Valid for 11 AM AST today.
Heart of rainband over us then, mod says. From IPS MeteoStar.

Your Catalina cloud day

(Also, another great cloud movie from the U of AZ here....)

5:15 AM. Cirrus, leaning toward “spissatus”, heavy dense patchy Cirrus.

7:42 AM. Cirrus fibratus/uncinus. “Cirrus” will do it.

4:35 PM. What would a day be like without Altostratus? Here, “translucidus” because the sun’s position is visible. When the sun can’t be seen, its “opacus”, like a lot of science can be.

5:27 PM. Walkin’ doggie and this seemed like a nice shot of the rustic neighborhood streets, the Catalinas, and up top, some glaciating Altocumulus, castellanus on the right side; hasn’t gone through the ice forming stage yet, or the ice hasn’t fallen out that’s in it.

7:18 PM, Crepuscular rays show up as the sun sets due to smoke and haze under the clouds. The clouds? A mix of flakes of Altocumulus and Altostratus (the solid blob), some Cirrus on top of it all.

The weather way ahead…

Not a lot showing up here for mid-June, so won't say anything about that. — Valid for June 12, 5 PM AST. Not a lot showing up here for mid-June weather, so won’t say anything about that. I suspect it will be warm, though.

As close as it got

Like you, my heart started pounding when that bank of thick clouds on the horizon got close enough to see that there was a rainshaft to the ground with a minor Cumulonimbus on top of it (ignoring the fact that you could’ve been hanging out by the radar all day).

6:47 PM. Cumulonimbus with rainshaft to the ground slowly approached near sunset yesterday. Big dust plume also visible to the right of the shaft a little later.

Today, the heart of the cold air and best moisture are over us and TODAY we will get those local icing-out Cu and small Cbs with sprinkles here and there. Measurable? Not so sure. Will be lucky. LTG in the area likely today, too.

If you’re a low temperature anomaly centric person at this time of the year (in texting, “LTACP”, or just “LTAC” for short), you will likely enjoy today’s 10 degrees or so below normal afternoon maximum, chillier even with outflows from virga and the scattered light showers around.

More later, photos, too… Behind on animal chores now.

Yesterday’s clouds

I thought it was a pretty nice day for you, though a little disappointing due to the late arrival of the minor rain threat mentioned above. You had quite an array of clouds to discuss in your cloud diary, which was good.

Below, I reprise them for you:

6:30 AM. Altostratus, the State Cloud of Arizona I think; Altostratus. We see a lot Cumulus, of course, but sporadically in the winter following a storm or trough like today, and in our summer rain season, but Altostratus we see year round.

DSC_0087-1 — 8:49 AM. Mostly Cirrus uncinus (hooked, or tufted at the top).

10:03 AM. Accas: Altocumulus castellanus. According to my cloud chart, it could rain with 6 to 196 hours after you see these clouds.

After the rain, the oven

First, pretty nice sunset yesterday evening, which is redundant because sunset always occurs in the evening.

7:18 PM. Altostratus with slight amounts of virga, underlit by the evening sunset. Haha, "evening sunset." — 7:18 PM. Altostratus with slight amounts of virga, underlit in the evening sunset. Haha, “evening sunset.”

7:19 AM. Only the virga is highlighted over here. Liked the way was splayed over a house in the foreground. — 7:19 AM. Liked the way was splayed over a house in the foreground. Sort of perty.

7:42 AM. Thicker Cirrus clouds are Cirrus spissatus, or "Cis spis" for short, though not in polite company. Should be the State Cloud of Arizona, we see so much of it, white or gray patches of ice cloud. Kind of fed up with just "Cirrus-ee" skies these days. — 7:42 AM. The thicker Cirrus clouds are Cirrus spissatus, or “Cis spis” for short, though not in polite company. Should be the State Cloud of Arizona, we see so much of it, those white or gray patches of ice cloud. Kind of fed up with just “Cirrus-ee” skies these days.

7:43 AM. Looking north-northwest from Catalina toward Mt. Humphries, a delicate blend of Cirrus uncinus fibers (upper half of photo) with thicker Cirrus spissatus in the distance (thicker appearance not due to perspective).

OK, enough great information on clouds and things we can see from Catalina/Sutherland Heights, now for the rain ahead….

Rainshowers, some thunderstorms wrap around this low that drifts from over San Diego to over Puerto Peñasco, Mexico (aka, Rocky Point) by Saturday. Here the Canadian version of what the weather configurations will be this coming Saturday morning:

As you can see, a little bit of tropical air gets whirled into this low from someplace down Mexico way, and, viola, showers and a couple of thunderstorms erupt. This could happen anytime between Thursday night and Sunday morning, maybe even a couple of days of scattered showers.

Rain here in Catalina? I think so. Likely range, not a lot, but from a low end of just 0.05 inches, to as much as a quarter of an inch by Sunday morning (10% chance of less; only 10% chance of more, as a first take on this). Gorgeous, dramatic skies are guaranteed, and likely some strong winds here and there emanating those high-based thunderstorms we can get this time of year.

BTW, not reporting on the US model forecast since it shows the low next weekend passing a little farther to the north, i. e., doesn’t take as favorable a track for rain here as the Enviro Can model shown above.

The weather way ahead

After the little “lowboy” goes by next weekend (producing some great, badly needed rains in NM and TX), the Arizona oven is turned on. Look for a string of 100+ days beginning in about a week.

Coming to weather theaters next fall and winter, “The Ninja (?) Nino.” Looks warmer and warmer down there in those key “Classic” and “The New Nino” equatorial ocean zones off South America to Hawaii. CPC’s (Climate Prediction Center) is getting pretty worked up about it, too. Check it out below and here:

Sea surface temperature anomalies from NOAA, valid for May 19, 2014. OK, here we go!CPC

Of course, as we know here, the effect on the summer rainfall season is not really well documented. But things can wetten up in late summer and fall due to tropical storms that drift farther north toward us, remaining a bit stronger because the ocean temperatures that maintain them are a bit warmer. This enhances the chance of a wet spell or two then. Mainly, with a good Nino, the chances of a wet winter go up a lot, particular the mid and later parts.

In the meantime, let us dream about September and October 1983, as the Great El Nino of 1982-83 was fading, but still was associated with colossal rains in Arizona those two months. In case you forgot, this recap about those days and TS Octave. During that water year of that Great Nino, October 1982 through the first couple of days of October 1983, just a year and a couple of days, Catalina recorded a Seattle-like 32 inches of rain!

The End

April showers and why

From your Pima County ALERT gauges, these 24 h totals ending at 3 AM this morning (covers the whole storm):

Gauge                        24                Name                        Location
    ID#      minutes    hours
    —-     —-       —-        —-       —-         —-       —————–            ———————
Catalina Area
    1010         0.04      Golder Ranch                 Horseshoe Bend Road in Saddlebrooke
    1020       0.20      Oracle Ranger Stati          approximately 0.5 mile southwest of Oracle
    1040                   0.08      Dodge Tank                   Edwin Road 1.3 miles east of Lago Del Oro Parkway
    1050             0.20      Cherry Spring                approximately 1.5 miles west of Charouleau Gap
    1060         0.55      Pig Spring                      approximately 1.1 miles northeast of Charouleau Gap
    1070         0.08      Cargodera Canyon             northeast corner of Catalina State Park
    1080           0.08      CDO @ Rancho Solano          Cañada Del Oro Wash northeast of Saddlebrooke
    1100             0.04      CDO @ Golder Rd              Cañada Del Oro Wash at Golder Ranch Road

Santa Catalina Mountains
    1030         0.75      Oracle Ridge                 Oracle Ridge, approximately 1.5 miles north of Rice Peak
    1090       0.00      Mt. Lemmon                   Mount Lemmon
    1110         0.75      CDO @ Coronado Camp          Cañada Del Oro Wash 0.3 miles south of Coronado Camp
    1130         0.24      Samaniego Peak               Samaniego Peak on Samaniego Ridge
    1140         0.83      Dan Saddle                   Dan Saddle on Oracle Ridge
    2150            0.12      White Tail                       Catalina Highway 0.8 miles west of Palisade Ranger Station
    2280          0.20      Green Mountain               Green Mountain
    2290          0.24      Marshall Gulch               Sabino Creek 0.6 miles south southeast of Marshall Gulch

The absence of precip at Mt. Lemmon is not because the storm went around it, but rather because it fell as snow.

Here in the Heights, 0.08 inches fell between 1 PM and 3 PM. Clouds accompanied the rain.

But what kind? That’s why I am here for you. See way below.

First, some techno-babble. Rain was an on and off event for Catalina and environs in the models run after run. A forecaster friend sent many e-mails that went from “looks good for rain” here, and just about as many that said, “doesn’t look good for rain.” In fact, the (WRF-GFS) model run for just 12 h before it rained, had no rain here, but just a bit to the north. What happened?

Extra sag.

Here’s the amount of trough “sag” (“amplitude”, as we would say) over Arizona predicted just 14 h before it started raining in Catalina yesterday afternoon:

12 forecast valid for 11 AM yesterday morning. Note that the wind maximum is NORTH of Catalina, and over central AZ.

Areas of rain forecast to fall in the 6 h ending at 11 AM AST yesterday morning. Rain just a tad north of Catalina.

A computer analysis of the actual winds at 5 PM AST yesterday showing that the trough had more amplitude (sag, droop, etc.) as it crossed Arizona yesterday than was forecast just a day or so in advance. That meant we in Catalina were more embedded in the deeper, and colder clouds with this trough. The jet stream circumcribes those clouds during the cool season here in AZ and most of the SW US. See rain totals at top of blog.

In case you think I am lying again, just because I am a meteorologist and say a lot of wrong things, below is the REAL map for last evening with wind data from rawinsonde balloons on it.

From the Huskies, this 500 mb map over satellite imagery. Strongest winds in our trough run from San Diego, Tuscon, to El Paso, with the tightest spacing of contours and strongest winds at this level in extreme northern Mexico

I hope you’re happy now.

Here’s what the temperature did as the windshift and rain began, in case you missed it:

Yesterday's temperature trace for Sutherland Heights. — Yesterday’s temperature trace for Sutherland Heights.

Yesterday’s clouds

The sequence: cloudy, sunny “sucker hole” (one of Biblical proportions), cloudy, raining, sunny, dusty.

6:06 AM. Altostratus and Cirrus combine to produce a gray sky. — 6:06 AM. Altostratus and Cirrus combine to produce a gray start to the day.

9:44 AM. Lower level moisture layer produces an Altocumulus lenticularis just beyond Pusch Ridge. Seems sky will cloud up real good at this point.

Also at 9:44 AM. Looks real bad off to the N, too, in dense Altostratus and lower Sc or Ac.

10:57 AM. Sucker hole! Its real sunny, warming up. You're thinking as you ride your horse as I was, "What a bad weatherman we have! Said would be windy, cold, and might rain, and yet here is the sun and warmth. What a bad weatherman we have!" — 10:57 AM. Sucker hole! Its real sunny, warming up. You’re thinking as you ride your horse as I was, “What a bad weatherman we have! Said would be windy, cold, and might rain, and yet here is the sun and warmth. What a bad weatherman we have!” (Weatherman is laughing in the background.)

11:44 AM. Sucker hole starts to fill in... Haha! — 11:44 AM. Sucker hole starts to fill in… Haha! “Dreamer” is the horse there.

12:10 PM Sucker hole filling in! — 12:10 PM Sucker hole filling in more and more! You’re starting to feel real bad that you made fun of your weatherman, but he’s still laughing at you.

1:17 PM. Rain showing up to west-southwest, upstream. Wind shift hits and ten degree cool off begins. You're glad you finished your horseback ride none too soon. — 1:17 PM. Rain showing up to west-southwest, upstream. Wind shift hits and ten degree cool off begins. You’re glad you finished your horseback ride none too soon.

3:54 PM. A remarkable thing is happening. While there's plenty of dust in the air. it is also still raining slightly, almost from drizzle-sized drops. Eyeballig the cloud depth of the backside of the raining clouds from which the drops MAY have fallen from, CM opines that these drops are comprised of melted aggregates of needle or sheath ice crystals that were, as single crystals before aggregating as they do when in high concentrations, were really in high concentrations in those clouds, implying a strong ice multiplication phenomenon was at work. Was really a weird scene to have so much SUN and drops falling from clear sky overhead. I would be very proud of you if you noticed this few minute event at the end of our little rain. — 3:54 PM. A remarkable thing is happening. While there’s plenty of dust in the air. it is also still raining slightly, almost from drizzle-sized drops. Eyeballing the cloud depth at the backside of the rainband clouds from which the drops MAY have fallen from, your CM opined that these drops originated with melted aggregates of needle or sheath ice crystals that, as single crystals before aggregating, were in high concentrations (10s to 100s per liter) in those clouds, implying that a strong ice multiplication phenomenon was at work inside them. Was really a weird scene to have so much SUN and drops falling from clear sky overhead. I would be very proud of you if you noticed this few-minute event at the end of our little rain.

Rawinsonde balloon temperature and dewpoint profile near the time that it rained in clear air from the backside of our rainband. As you can see, cloud tops were around -10 C or a little cooler, pretty warm for raining clouds here. The main part of the rainband likely had somewhat cooler cloud tops. Thought you like to know. This sounding supports the idea that an ice multiplication process was at work, at least on the back shelf of these clouds that rained. I wanted to confirm prior ground speculations with more speculations from the sounding at rain time, though it was launched around 3:30 PM AST way over there by Davis Monthan Airbase. Wondering now if I will finish this blog today….

4:34 PM. Shelf of rainband exits the Catalinas. Nice lighting, though.

6:32 PM. While the rain may have washed a lot of dust out of the air, more dust invaded the area as soon as the rain ended.

The End, finally.

Late morning cold slam

Its not a breakfast at a restaurant chain, but a sharp cold front passage later this morning, say between 10 AM and Noon. Should be pretty interesting. Temperature will drop about 10 F in an hour. Expecting/hoping, too, for a little measurable rain with this “FROPA” (frontal passage in weatherspeak). The brisk winds, as they always do, have activated a lot of the nighttime wind detector lights in the neighborhood.

The usual post-frontal clearing in the afternoon and a pretty cool day, maybe 20 F cooler than yesterday afternoon which got to 88 F here in the Heights, the Sutherland ones, that is. Of course, our media weather stars are all over this weather situation, so nothing much to be added here.

Still have plenty of higher ice clouds overhead right now at daybreak, but look for an invasion of Cumulus and Stratocumulus within the couple of hours after daybreak. They should appear first on the Lemmon, topping it, then fill in after that as the cold slam gets closer.

Yesterday’s clouds

The full complement of expected clouds was not really observed yesterday. Missing in action for the most part locally were Altocumulus lenticulars downind of Ms. Lemmon. Cirrocumulus clouds were also pretty much a no show. You can see some of those high lenticular formations that did occur WAY downwind of Ms. Lemmon and the Catalinas if you view the U of AZ Weather Department time lapse movie for yesterday between 11 AM and 1 PM, then another pile of Ac len just at sunset (7:15 PM) in their movie.

Below, what we did see, various varieties of Cirrus, and eventually those thickening to Altostratus ice clouds. And a hole was out there that allowed a brief colorized sunset rather than a gray one.

9:20 AM. Main feature is Cirrus spissatus, with Cirrus fibratus (lines at upper right) and some uncinus (center left) also present.

1:13 PM. Looking at incoming Cirrus to the WSW… More Cirrus spissatus (patches) in the distance with some hooked Cirrus (uncinus) upper center.

1:14 PM. Looking N at the traces of Altocumulus lenticularis clouds (e.g., sliver cloud above road in distance), possible Cirrocumulus top center of photo.

6:21 PM. By this time, the leaden look of Altostratus pretty much dominated the sky; dosen’t look good for sunset color at this point.

7:03 PM. Sunset bloom began as bottom of Altostratus got lit up. Note how similar the cloud bottoms are in this photo compared to the one just above.

7:06 PM. Heavy line of Altostratus with a higher overcast of CIrrostratus adds interest to the fading sunset.

Sprinkles in area overnight!

Some sprinkles/radar echoes passed overhead early this morning. Will check, as you will, for drop images in dust on solid outdoor surfaces to possibly report a trace due to drops that reached the ground. Going out now with flashlight, to heck with that coyote over there. Result: looks like there were a few isolated, larger drops that fell last night. Below, confirmation of echoes overhead from WSI Intellicast’s 24 h radar-derived rain for AZ:

Radar-derived precip ending at 5 AM this morning from WSI Intellicast

Nice sunset with late sudden bloom after looking like there might not be any color at all.

6:54 PM. Mammatus shaped virga hangs down from heavy patches of Altostratus providi — 6:54 PM. Mammatus -haped virga hangs down from heavy patches of Altostratus providing sunset highlights. Dimly seen are flakes of Altocumulus clouds, as seen below as well.

6:18 PM. Doesn’t look like much of a sunset will get through this solid-looking cloud cover of Altostratus, Cirrus, with flakes of Altocumulus below.

10:13 AM. Bright patch of CIrrus is from an aircraft; the Altocumulus flakes with virga hanging down are natural. Only a greatest of the Cloud Maven Juniors would be able to make such a discernation, if there is such a word.

10:12 AM. Over this way, a mix of Cirrocumulus and Altocumulus (larger globules).

Expect another middle to high cloud cloudy day with nice breezes. Weak jet stream to south (see map below) as upper level trough passes today, the main criteria for cool season rain in AZ (some 90-95% of all measurable rain in AZ falls only when the jet stream in the middle troposphere (about 18-20 kft above sea level) is south of us. However, while that criteria is met today, just not enough moisture has leaked in over the Baja and southern California mountains for clouds low enough to produce rain. So while its a virtually necessary condition, its not always sufficient.

Forecast winds at 500 mb (18.5 kft ASL) at 11 AM AST. Strongest winds at this level coming onshore in Baja, Cal.

The End.

The cloud streets of Oro Valley

3:53 PM. Three little rows of clouds are emitted from the Tortolita Mountains to the west, drift over Oro Valley. These kinds of “streets” are there, and usually emit form the same spots, every time we have a moist, but shallow layer of air, and there’s a bit of wind. We met men would call this situation a “cloud-capped boundary layer” where air rising to form these clouds doesn’t get any higher, usually due to a stable layer like an inversion. The visual divergence, where one of the streets looks to be going to the left, and the one on the right going to the right, is due to perspective. Cloud streets are virtually parallel to one another. The flow at cloud level was toward the photographer, me. You got Cirrostratus on top of these Cumulus/Stratocumulus clouds. (Where clouds like these are more isolated, we call them, Cumulus, when the same clouds group together into masses, we start calling them Stratocumulus. Its kind of a fuzzy area in our fuzzy classification system (see Catalina cloud maven’s cloud classification article in the Encyclopedia of the Atmospheric Sciences, 6 vols., yours for $2258.20, “only one left in stock”, Amazon says, and the great Judy Curry, is Ed.–better get it before its gone!

5:03 PM. That little zone on the Tortolitas is still pumping out the clouds. Compare the back edge of this larger mass (which now would be Stratocumulus) with the origin point of the previous photo. The cloud street is the one on the left that goes off the screen. — 5:03 PM. That little zone (center, here) on the Tortolitas is still pumping out the clouds. Compare the back edge of this larger mass (which now would be Stratocumulus) with the origin point of the previous photo. The cloud street is the one on the left that goes off the screen.

5:32 PM. That Cirrostratus steadily thickened as the afternoon wore on, almost making it look like another storm was moving in. Cumulus filled in, too, becoming large areas of Stratocumulus, adding to the anticipation of a rain. — 5:32 PM. That high Cirrostratus layer steadily thickened, becoming Altostratus here, as the afternoon wore on. Seemed like another storm was moving in. Those isolated Cumulus clouds and their “streets” filled in, too, becoming large, dark areas of Stratocumulus, adding to the false anticipation of a rain as a storm skirted Arizona.

The weather way ahead after the upcoming heat wave

I have been staring at this weather Rorschach test for a few hours now, and there’s not much to say about it, except that there seems to be two eyeballs near the North Pole, and maybe one of the yellow lines forming a jaw down there toward Greenland, possibly a tilted drivers cap toward Russia.

Clearly the global patterns are “unsettled”, to use one of our favorite forecasting words. (“We will have ‘unsettled’ weather over the next few days”, as one might say in Seattle most of the year.)

Below, “troughing” is suggested in the SW, but not much. The Asian trough, anchored along the coast of Asia, is shown moving offshore here as it should during the spring, and that in turns helps form a trough downwind in the SW US, as we see happen in the spring over the long term (in climatology). So we can only hang our hat on climo, that these uncertain times shown below in the plot below will resolve into something better than more drought.

We can also ponder the larger question of, “How’s come we can put a man on the moon and various space junk on Mars and can’t forecast the weather beyond about a week?” Its crazy.

Or even the vastly larger question concerning chaos theory, a theory that rests on the phenomenon that small perturbations in the initial state of unstable systems are able to make huge changes over time, thus:

“Will a space probe, going off into deep space, as is happening now, an artifact that’s not supposed to be there, unsettle the unstable Universe?”

Pretty thoughtful blog today, I thought. Usually don’t go this deep, but it just kind of happened.

The End, or is it?

Dull Altostratus-ee day yesterday, but big Pac storm continues to move toward Catalina!

That thick (likely more than 3 km, or more than 10,000 feet) and steady gray sky diet of Altostratus opacus clouds didn’t provide a lot of visual highlights most of yesterday, in contrast to the many Altocumulus flocculations of the day before. An example of yesterday’s sky for most of the day:

3:50 PM. Altostratus opacus. Or is it? Not much going on here¹.

Virga hung down here and there, and some radar echoes during the day suggested a sprinkle here and there reached the ground, but none here.

Later, as usually happens, the tops of the clouds lowered, as did the bases, and we had some pretty Altocumulus again, some with long trails of virga, indicating a deep moist layer below cloud bottoms. For a time, as dewpoints rose, it looked like Ms. Lemmon might be topped with Sc, but those lowest clouds did not get quite low enough.

5:14 PM. Two layers of Altocumulus are present, the lower one having spires (Ac castellanus). Nice lighting on mountains.

5:08 PM. Two layers of Altocumulus are present, the lower one having spires (Ac castellanus), to repeat.

6:23 PM. Heavy virga issues from an old Altocumulus cloud, its once higher, pyramidal top has collapsed as snow developed in it and in essence, hangs down in an upside down version of what it once was — 6:23 PM. Heavy virga issues from an old Altocumulus cloud, its once higher, pyramidal or mounding top has collapsed as snow developed in it and in essence, hangs down in an upside down version of what it once was (though not as tall as the virga is long here).

The Tucson balloon sounding (rawinsonde) for 5 PM AST (launched about 3:30 PM, rise at about 1,000 feet a minute.) BTW, takes about an hour and a half to get the whole depth normally measured, to around 100, 000 feet. During that time, or even during the first hour, the atmo is changing, so when its at 40,000 feet, what is measured at 3,000 feet isn't the same anymore. Introduces slight error into models into which these data get fed. Models think its an instantaneous view of the atmo over Tucson. I think you should know this. — The Tucson balloon sounding (rawinsonde) for 5 PM AST (launched about 3:30 PM, and rise at about 1,000 feet a minute.) BTW, takes about an hour and a half to get the whole depth normally measured, to around 100, 000 feet. During that time, or even during the first hour, the atmo is changing, so when its at 40,000 feet, what is measured at 3,000 feet isn’t the same anymore. Introduces slight error into models into which these data get fed. Models think its an instantaneous view of the atmo over Tucson at 5 PM AST (00 Z time). I think you should know this. Note tops of that Ac with heavy virga were about -30 C (-22 F)! Notice, too, that some of those higher, colder Altocumulus flakes are not showing virga in the sunset photo above.

Weathering just ahead….

Rain One (“Little Bro”) is moving onto California coast as I write. Residents in towns like the very-expensive-to-live-in Monterrey rejoicing as drops patter on rooftops now! The negative news here is that the Canadian model has lessened the area of rain in Arizona as Rain 1 passes over us, confines the rain to central and northern AZ mountains now, still light, but not as widespread as before.

At the same time, the US WRF-GFS model has been adding rain in AZ from Rain 1; previously it had NONE. Now, these mods have now come together over us² to quote a song title from the last century, both showing about the same thing, so that’s probably what will happen. Just rain to the north of us. So, a little less of a close call to Catalina tomorrow as Rain 1 goes by. Just middle and high clouds for us, and probably some virga, nice sunrises and sunsets.

Rain 2, “Big Bro” moves into southern Cal tomorrow night, and still looks like a real and necessary pounder for southern Cal before moving on and drenching little Catalina. Will report on those SC amounts to see how big they get, too.

Rain should be falling here in Catalina by Saturday dawn and continue all day. Range of amounts, still a not-so-great quarter inch on the bottom (if things don’t go well), but top (if things go really well) still an inch! How great would that be? So, best guess about 0.60 inches here in Catalina, from averaging those two “extrema.” Later today, our U of AZ Beowulf Cluster model computations will start to have some quantitative amounts from actual calculations, not just a SOP guess from yours truly. Check here at the U of AZ later in the day for accumulated totals based on this morning’s 5 AM AST data.

Way out there

While our drencher on the weekend seems to be a one-shot wonder for at least a week after it passes, the longest view from our WRF-GFS, valid way out on March 13 at 5 PM AST, 360 h from last night’s model run, has another major storm moving into the SW, but this time it doesn’t come from the west, but from the NW. This is a climatological norm; storms tend to move from NW to SE during the spring months in the western US, and so there’s SOME climatology to hang your hat on that the rain forecast below for us may be a real event, not a fantasy storm, as so often happens that far into the future in our models. See the map below, from IPS MeteoStar’s rendering of the WRF-GFS to brighten your day that bit more, knowing one good rain is coming, and maybe, just MAYBE, the pattern is shifting to a normal one with an occasional rain here in Catalina beginning after mid-March.

Valid at 5 PM, March 13. Green areas denote those regions where the model thinks it has rained during the prior 12 h.

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3:50 PM. Actual Altostratus opacus. I've been talkin' clouds here for quite awhile, and in a clever kind of a test, wanted to see if you could tell the difference between the side of my gray car and an Altostratus cloud. — 3:50 PM. Actual Altostratus opacus. I’ve been talkin’ clouds here for quite awhile, and in a clever kind of a test, wanted to see if you could tell the difference between the side of my gray car and an Altostratus cloud. Its pretty important to me that you get this right.

Rain to fall in Catalina, March 1st and/or 2nd!

Very happy to post this breaking future news here on February 24th. Close rain call on the 27th, too, as the first of two significant troughs with their low pressure centers march into California, bringing a drought break there of some consequence. Likely an inch or two in the coastal areas south of SFO (“Frisco”; rhymes with Crisco), and maybe even LA area as well with the first storm. That first one continues across Arizona bringing widespread, though light rains the central and northern mountains on Thursday the 27th.

Valid at 5 PM Thursday, the 27th. Upper left panel shows little brother trough over Arizona, and most of State covered by a little precip *lower right panel). — Valid at 5 PM Thursday, the 27th. Upper left panel shows “little brother” trough over Arizona, and most of State covered by a little precip (lower right panel). Big brother on the move offshore of Cal, flow reaching deep into sub-tropics.

Then “Big Brother” hits Cal beginning on the evening of the 28th, gets here late on the first or early on March 2nd. The LA Basin rains in the second one look like they’ll amount to 2-4 inches, and maybe something from a quarter to half an inch here in Catalinaland when it arrives.

Model?

Canadian GEM (General Environmental Model). Sometimes, like their hockey team, it defeats the US models in weather forecasting, and I am riding the fence that it will this time. In the interest of disclosure, the US WRF-GFS model has virtually NO RAIN in Arizona on the 27th (!), whilst the Canadian one has widespread rains (both using global data from 5 PM AST yesterday). So, I reject the US model, one that takes the first storm too far north to affect AZ much. (This has sometimes been a problem for our US models.)

Second storm?

Both models have rain on the 1st-2nd, but the Canadian, much larger amounts in southern California where I grew up and, while having poor grades after puberty and the realization of girls (!) hit, nevertheless had some success playing baseball. Could be nearly a month’s worth of rain in one storm in the LA area, which averages about 3 inches in Feb and March, both, IF the Canadian model verifies. Those kind of amounts upstream would also mean more rain potential for us here, too. But, the fact that they BOTH have rain, is really great to see. One would think that some rain is pretty much in the bag. I hope they put rain barrels out in Cal!

After the storm…

Oh, me, look at this “Lorenz” (the chaos guy) plot:

Valid March 8th, 5 PM AST. Its awful as a graphic to begin with, but when interpreted its even more awful in the kind of weather it implicates for us as we march farther into March; in one word, Hot and Dry! — Valid March 8th, 5 PM AST. Its awful as a graphic to begin with, but when interpreted its even more awful in the kind of weather it implicates for us as we march farther into March: in one word, Hot and Dry! Easterners won’t like it, either, as the severe winter continues back there, Lake Superior might remain frozen over until April! Jet stream is flowing along the red and turquoise lines, so cold air brought southward where lines aim toward the southeast, as over the eastern US.

A pattern like the one above is hard to maintain in March since the climatology of March-May leads to a trough in the western US. So hoping the awful pattern above will give way by mid-March or soon thereafter, as do easterners I would bet. Below, likely fantasy, since its WAY out on the forecast horizon, but this historic forecast (would produce historically cold weather in the East if it did verify, chances probably less than 30% as a wild guess. I just now saw it and it was AMAZING!

Valid March 9th, 5 PM AST. — Valid March 11th, 5 PM AST. LOOK at that high pressure area and cold air slamming down east of the Rockies and strong low over New England. Good grief! Would be headlines if it happens.

Yesterday’s clouds

9:22 AM. Altocumulus perlucidus. — 9:22 AM. Great example of Altocumulus perlucidus.

1:47 PM. Later became blobby with heavy virga; Altocumulus opacus virgae if you really want to know.

6:22 PM. Skipping ahead, these formations led to another in a long series of nice sunset shots. Hope you got one.

The End.