Cloud-maven – Page 24 – About real clouds, weather, cloud seeding and science autobio life stories by WMO consolation prize-winning meteorologist, Art Rangno

Forgetting about our mud for a moment; thinking of the danger to others as seen in future weather maps

Have had 1.75 inches here in the Heights last few days. Horsies are tromping around in significant mud.

But, to resume a theme about others from the prior entry, those in California, they’d better be paying close attention to the weather a week and more out. In this weather watcher’s opinion, which should count for something, California may be in for an unforgettable January.

Why?

Recall how those “ensemble-spaghetti-Lorenz” plots had an unusually constrained (contours of flow, red and blue lines that were unusually bunched together all the way from Hong Kong to ‘Frisco even 10-15 days out? That indicated a high confidence forecast of where the jet stream would be.

USUALLY, the contours are pretty wild, scattered all over the eastern Pac after about 10 days or so, and Cloud Maven Person got overly excited about this esoteric part of weather forecasting, and decided to write a partially decipherable tome on it.

Well, that constrained jet, blasting into Cal from the subtropical latitudes with a terrible ferocity, has continued in model run after model run now, and CMP’s excitement has been further elevated, maybe to penthouse level now, hard to elevate it more.

Way below are a few examples from just last night’s model run based on global obs at 5 PM AST, showing a few sample of the jet stream predicted pattern at 500 millibars, or around 18, 000 feet (from IPS MeteoStar, as usual).

THESE are extraordinary maps, and extraordinary maps mean extraordinary storms, AND they are appearing with extraordinary consistency.

They are also compatible with what we saw in those ensemble-spaghetti plots of a few days ago. So, like the “Frankenstorm” of 2010 that hit California, this series of strong storms hitting Cal in just over a week, will be considered to have been “well-predicted” by those crazy plots.

Is FEMA ready?

I think they will be involved at some point.

But, too, this is a forecast series where we (those in Cal) have lots of time to get ready for big, destructive events.

Like what?

For Cal, the usual.

1) Huge waves smash the coast, some home roll into the ocean. With a jet having a gigantic fetch from the Pac, huge waves are a certainty, surf will definitely be up, if that’s what you do because the surface winds will ALSO have a huge fetch to build those giant rollers.

2) Winds. At some point, hurricane force winds blow stuff around in one of more of the low centers generated by such a powerful jet stream. Looking at the pattern, I think one within this storm series may produce 100 mph winds or more somewhere in Cal.

3) Flooding. Can the nearly empty Cal reservoirs we’ve heard so much about be filled up in a series like this, something that might go on for one to two weeks? I think so, some anyway. But this is a truly wild thought, and as you can see, CMP is kind of out of control here.

It is certain that the rains with one or more of the low centers that slam the West Coast during this series will produce rains of 10 or more inches in a day in the hill and mountain regions of Cal.

Also, the series begins with a strong, but maybe not exceptional storm about 8 days from now, this after a pretty good rain has already occurred, so the ground is going to be pretty wet when the Big Series hits.

The jet stream pattern strengthens and shifts farther south with each day after this first major storm, and that’s when the real onslaught will hit.

I don’t want to get people overly excited like I am, but I am terming these, and the whole recent series of unbelievable jet streams bashing into Cal, and even Baja!, “the California calamity maps.”

2016010900_WST_GFS_500_HGT_WINDS_240 — Valid, Monday, January 18, 5 PM AST.

Skipping ahead:

2016010900_WST_GFS_500_HGT_WINDS_312 — Valid Thursday, January 21st, at 5 PM AST. EGAD! WHAT a monster!

2016010900_WST_GFS_500_HGT_WINDS_336 — Valid 5 PM, January 22nd. One blast is finishing up, but look at the jet entering on the left/west side. Once again, “egad!”

Skipping ahead some more….

2016010900_WST_GFS_500_HGT_WINDS_384 — Valid at 5 PM AST, January 24. Upper cut to jaw of Cal from the Pacific. This one would be quite bad in rain, wind, floods.

Now the timing of these things WILL VARY as the mod runs keep churning out results, but in CMP’s view, the pattern that will cause CA havoc is locked in now, promulgated ALMOST without doubt by our Big Niño.

Here is another amazing map from a prior run, that just makes your jaw drop due to what the models are sensing is “out there” for Cal and the West Coast:

This is looks like it was for another planet, the jet SO POWERFUL and heading into Baja!

Crespuscular rays due to light rain from precipitating Stratocumulus (i.e., “praecipitatio.”, if you want to impress your friends.)

Pretty good sunset color. The clouds? Stratocumulus.

Weather station and mountain sunset color. You don't see that too often.... — Weather station and mountain sunset color. You don’t see those together too often. Mountains topped by non-precipitating Stratocumulus clouds.

How will SE AZ do?

Seems like passing rains will hit during this CA bludgeoning period, but floody weather not expected.

Since we’re pretty much at our average total for the month of January right NOW, CMP is going out on a limb and predicting an above normal total for the WHOLE month.

The End

What’s ahead, way ahead; some excitement for the West Coast

Been working on a talk for Feb 23, 1990…..at the U of WA, so not blogging too much. Will likely post “back to the future” talk in a few days. Its a science story, really, not quite a “talk.”

But enough of my blabbing, as Rob Reiner might say, lets move along to some INTERESTING spaghetti.

First of all, things rolling along pretty much as foretold in spaghetti at our last meeting, a week or so ago. Storms are rolling in on schedule now. Had 0.50 inches in the first one, here in Sutherland Heights.

Below, is the five day from now spaghetti or Lorenz plot. You may recall, though I doubt it, that spaghetti was foretelling a big ridge that would break off into the Arctic and help shunt storms into Cal and the West Coast.

Well, that was spot on because it is going to happen after a little break from the current storms. Of those, the rainiest one for us is tomorrow and the next day. Likely to see an inch or more here in Sutherland Heights from that one storm! Looks like a quarter of an inch will be the total for the current one.

All this is so great for the spring bloom, too, that time of year we all love.

But enough of my blabbing #2, as Rob Reiner might say again, lets move along to some INTERESTING spaghetti.

The weather pattern way ahead

But the real news I wanted to inform you about through excessive speculation is the spaghetti plots for about two weeks out, shown below. This ios amazing in my view.

I wonder if my one reader can detect the amazing part?

Its the grouping of the blue and red lines in the eastern Pacific that seems extraoardinary in a plot like this where “chaos” usually rules in this sector THAT far away in time.

Here, the grouping of red and blue, a coming together which can never happen in the political color realm, means there is a very strong signal in the measurements. The slight errors input at the beginning of the model runs leads to close to the same forecast even 15 days out!

So, what does it all mean?

This is no doubt in CMP’s mind that this strength in a medium range forecast is due to the constraining of weather patterns by the Big Niño now in progress. That feature is keeping the jet stream constrained to bash the West Coast and Cal, and that’s what you get out of this plot above. Very strong storms are now setting up to bash the West Coast, ones associated constrained to do so by the powerful El Niño.

The current storms, as you likely know from media weather folk, are classic in their El Niño appearance, streaming into Cal and AZ at lower latitudes out of the Pacific. So far this winter, in Cal and AZ, we haven’t seen much effects of a Big Niño until now.

That 15 day spaghetti plot is not one that we here can pin confidence on about a lot precip, but hang on in Cal, especially beginning about a week from now when this pattern really sets up and then crescendoes.

Below, just decided to add the 10 day spaghetti, kind of out of control due to excitement. The bunching of red and blue contours is astounding to me in this one, that in the east Pac resembling that of the geographically-forced bunching we see all the time in the extreme western Pacific off China. This bunching, with a dip to the south (trough) off the West Coast indicates a very reliable forecast of a huge trough bashing the West Coast about then (Friday, 5 PM AST, Jan 15th). Maybe, just MAYBE, those Cal reservoirs WILL be filled up in a single winter!

The End.

Soft underbelly, storm passageway, from the subtropics to Cal and AZ under contruction

Its never too early to talk about rain and storms in old AZy.

A couple are already on the move and will arrive here between the 3rd and 5th of January. Confidence is quite high, more so that on the last failed medium range forecast, which I think says something¹.

However, its after those first couple of storms that it gets really interesting, given the Big Niño in progress. Scrutinize this hint of future weather below, valid some two weeks from now:

Valid January 12th at 5 PM AST. Red lines represent tracks of the “subtropical jet stream. Blue lines more or less the Polar jet stream. Notice that the red lines are nearly ALL far south of the SW US, while the blue lines bulge northward into AK and the Bering Sea. This would be a strong split flow pattern, where storms coming out of the western and central Pacific are forced to stay at lower latitudes rather than move north. Yippee!

Cloud maven person admits that this is his very favorite pattern since he was a kid, the one that’s being suggested above, so subjectivity,, the enemy of science, could be creeping in.

The Big Fat Ridge (representing a blob of deep, relatively warmer air compared to the air hundreds of miles around it) has overextended itself into the Gulf of Alaska and Arctic. It looks like too much of it has extruded into the Arctic areas.

What always happens when the BFR extends to the north over thousands of miles is that the westerlies, with their series of storms moving along in them, “break on through to the other side”, as Jim Morrison might say if he had been a meteorologist. But they are shunted by the BFR “underneath” and travel at relatively low latitudes north of Hawai’i toward the West Coast.

That means those low pressure centers carried along in the westerlies travel over warmer water than usual, arriving along the Cal and Baja coasts with Hawaiian style wetter clouds. Some of the great rainfalls in Cal and AZ occur in these situations.

How much can it rain from storms like those, should they materialize with vigor? Check this 24 h rain table out for Cal for January 21-23, 1943. These are all just 24 h amounts for a storm that gradually shifted southward along the West Coast. Broke 24 h precip records from Cal to Colorado:

The storm that produced these prodigious totals originated near the Hawaiian Islands a few days before the rivers of atmo water struck the West Coast. The above table was typed by the writer (hah, “typed”, then “writer”²) on a Hermes 3000 typewriter in about 1962 or ’63. Only those amounts over 10 inches in a day are shown. Shows you what can happen when storms barge in from warmer waters, and when they are strong (have deep low centers with them that produce strong winds against the mountains.)

So, while the first coupla storms are pretty much (he sez, in the bag, will be watching to see if the above “Lorenz plot” (aka, spaghetti plot) has seen something two weeks out. Usually only the strongest signals show up that far out, and what is shown above is darn strong for a ridge, trough underneath in the eastern Pac.

Add a pinch of veracity, too, due to the Big Niño we have now. Niños are phenomena that enhance the southern portion of the jet stream/westerlies in the eastern Pacific and SW, and that means stronger lows out there, too.

Exciting days ahead in old AZy!

The End.

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¹In a sense it was quite accurate for so many days ahead. While there was NO precip, it WAS, in fact, quite a storm of cold air.

²Another silly-ism. There’s a real quarry of them here in this blog. But I hope to indulge listeners not only with an occasional “silly-isms”, but I also hope to educate the listener with one or two facts, one of which is often correct. Are you listening?

Boffo Christmas time storm

A possible great storm has been able to make it through all the model calculations intact for a few model runs now. Spaghetti tell us its in the bag that something big is coming to all of the Southwest around Christmas Day and just after. Check it out:

Valid 5 PM AST, Christmas Day. Giant SW trough then guaranteed. If it stays in a "U" pattern, like will be cold enough to snow here on the 26th. If it cuts off and becomes spinning top, as the latest models are suggesting, may not snow, but likely would produce a lot precip, maybe an inch or more because it would take so long to go by. — Valid 5 PM AST, Christmas Day. Giant trough in the SW guaranteed. If it stays in a “U” pattern (as shown above), likely will be cold enough to snow here in Catalinaland on the 26th. If it cuts off and becomes a spinning top, as the latest models are suggesting, may not snow, but likely would produce a lot precip, maybe an inch or more because it would take so long to go by. Spinning top formations tend to dawdle, have a mind of their own.

Wild in the West TG weekend ahead; astounding December tropical storm prediction just in

There it is, laid out for you:

Valid Thursday evening, 5 PM AST, November 26th — Valid Thursday evening, Thanksgiving, 5 PM AST, November 26th. SE Arizona is presently on the edge of the action, just windy and mostly dry. But progressing W through N of here, the weather will deteriorate. Likely heavy precip, for example, over this weekend in NW Arizona, especially mountainous areas. Exceptional cold dominates the Pac NW. This weather pattern develops and holds for a few days beginning on Wednesday, November 23rd as a trough from the Pac NW collapses soutward along the Pac Coast, then drifts inland, taking its time before it exits the Great Basin. Will be fascinating to see how the details emerge.

For those who enjoy spaghetti, the above was a real exciting dish to see this morning, one based on last evening’s global data.

Those two people that come here regularly and read these discussions about “Lorenz plots” from the NOAA spaghetti factory, which I have named for the MIT weatherman that first proposed “chaos theory”, Prof. E. N. Lorenz, who noticed that slight changes in initial conditions can make huge difference in stuff later on. That a “butterfly flapping around in Brazil” can affect a storm in Texas kind of exaggerated paradigm. But the idea is correct, if ludicrous in that example, one that seems to recur from time to time.

So, in our weather models today, we alter the initial conditions, at lot more than a butterfly can do, but still slight ones that are reported by our global data network slightly and see what happens to the forecast of the positions and strengths of highs and lows, and where the jet stream will be as the model crunches ahead in time. There might be a couple of dozen trials like this (23?)

In the plot shown way below this harangue, only two of the flow lines around 18,000 feet above sea level are shown from the different forecasts that have arisen from these many model runs. The farther away from the start you get, in general, the more the weather forecasts go to HELL (or do they?)

OK.

Now, where the lines are bunched up is where the model forecast is highly reliable; where they are spread apart a lot indicates cluelessness.

Now if there is an somewhat clearer understanding of this “ball of yarn” plot as one reader put it, you can see with all the bluish lines gathered together in the western US, those that are deep inside the jet stream labeled “552”, that the whole West will be dominated by a gigantic trough or cold air by Thanksgiving Day! Wow.

The red lines, labeled “582”. are on the periphery of the south and warm side of the jet stream. Notice how those lines are “bunched” across the whole Pacific from the troubled fake islands in the South China Sea to Hawaii and eastward into Mexico.

Compare the red lines in the whole Pacific Ocean with the spread in the Atlantic Ocean, the former is indicating more forecast reliability; the latter less.)

It may not seem like it, but these “Lorenz plots” have been a VERY POWERFUL development in forecasting, only recently permitted when computers became so powerful that we could run our models many times in a short time. Weather models require the most powerful computers made in the world, those by China, of course, and not here, which is kind of embarrassing, really¹.

All of this is very interesting and indicates a wild Thanksgiving weather weekend! Tell your western friends to watch out!

But, it will be an innervating TG weekend for us cloud and weather-centric folk!

Some rain is indicated in southern AZ due to, hold your breath, the remnants of a tropical storm that filter in Tuesday night and the Wednesday before TG. Aren’t tropical storms supposed to be gone by now? Maybe this is the new climate! Tropical storms all year long!

————————knee-slapper domain————————–

Bursting-out-laughing moment just now after the ludicrous sentence above about tropical storms all year…

The above weather discussion was based on the 00 Z model run, which was, tropically-speaking, pretty staid.

But as I was closing out today’s blog, and smiling at that ludicrous statement about “tropical storms all year long”, I looked at the 06 Z model run, just off the press and when I got to the last few panels, I burst out laughing. You might, too.

It has a remnant hurricane coming into Arizona on December 2nd, low center still intact as it passes over Phoenix! This is so funny!

Here are the knee-slapping panels from that 06 z run from IPS MeteorStar for your own amusement. Its REALLY uncanny:

A remnant hurricane hits Baja and comes into Arizona in DECEMBER? Wow. No doubt this is due to that Big Niño down there stirring things up, turning the weather world upside down.

2015111806_CON_GFS_SFC_SLP_THK_PRECIP_WINDS_348 — Valid at 11 AM AST DECEMBER 2ND! Note tropical storm center is over PHX, and look at all the rain the model thinks will have fallen in AZ!

BTW, We seem to miss out on any major rains, however, with the TG situation.

The End

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¹Those great big Chineses computers can really hack stuff, too! (Hahaha, just kidding, sort of.)

Similar maps…

When some of you were weather browsing this morning, and you saw this forecast map from IPS MeteoStar, valid for next Tuesday, which shows a very late in the season tropical storm off Baja heading toward the Southwest US, while a vigorous winter storm bashes the West Coast, I had a feeling that it reminded you immediately of one of your early weather memories of a similar situation. First, the IPS map.

2015111700_WST_GFS_SFC_SLP_THK_PRECIP_WINDS_186 — Valid at 11 AM AST, Tuesday, November 24th. This from last evening’s 5 PM AST global data. The green and blue areas are regions where the model thinks it has rained during the prior 6 hours.

The map below is from an era when you were a little child and maybe you, too, were clipping weather maps out of the Los Angeles Daily News, if that’s where you lived:

Sandwiched between storms 002 — Actual map from the Los Angeles Daily News, November 30, 1951, clipped by the present writer. Note that with isobars the Daily News was not afraid of challenging its readers with a non-Mickey Mouse weather map. The tropical storm on this map is down there to the lower right where the scale of miles is. Like this winter season, 1951-52 was a Niño year, though not of the great magnitude of this one.

Looking back, but a little closer, like yesterday and the day before…..

Nice storm we just had. 0.65 inches fell in Sutherland Heights. Would not have predicted that much over these past couple of days to be honest. Total for month now 1.10 inches or a little above the 38 year average of 0.97 inches.

After a long dry spell though at least the next week, November will close out on a dry or wet note, which is pretty encouraging.

Yesterday’s clouds, ice and sun: a soliloquy on ice

Fair amount of ice yesterday in our low clouds. As you would guess on your way to becoming a cloud maven, bases AND tops were especially cold for AZ. Afternoon cloud bases were running about -8° to -9° C, whilst tops were about -15° C. Still ice was not plentiful. How’s come? Well, it seems the amount of ice in clouds is dependent on both the cloud top temperature and the droplet sizes in the coldest parts of the clouds (see Rangno and Hobbs 1994, Quarterly Journal of the Royal¹ Meteorological Society) (Hell, no one’s going to read this, though it is now available without having to go through a “pay wall” and the page linked to above has been updated with new pdfs!)

In sum, a cloud with a base of -10° C and a top of -20° C will have LESS ice than a cloud with a base of 0° C with the same cloud top temperature (-20° C) because with a warmer base, the drops near the top of the cloud in second example will be larger.

That seems to be the way it works. So, yesterday’s thin cloud with cold bases had smallish drops, and ice production was a little limited.

Also, if you monitored Ms Lemmon, and the Catalinas in general, you probably were thinking, “Where’s the ice?”, in those cold Stratocumulus clouds as they piled up against them.

Well, when you have strong winds at cloud level as we did yesterday, and with ice crystals taking a little time to appear from some of the droplets that freeze in the cloud stream, grow, and eventually fall out, you’re not going to see much evidence of ice on the windward side of the mountains in these kinds of situations. The ice is going to appear and fallout as snow or virga downwind a good distance downwind, and that’s what was happening yesterday to nearly all of those deeper clouds (with slightly colder tops and larger cloud droplets in them) that formed over the Catalinas.

If you don’t believe me, yesterday’s time lapse movie from the our great weather resource, the University of Arizona, shows this. You’ll see a lot of precip and virga falling of those clouds as they stream eastward from the Catalinas. So, we didn’t get to SEE much ice from those Stratocu clouds but it was there.

Lastly, the sun, as it appeared yesterday at sunset in the dust-haze kicked up by that powerful low that brought us our rains. The jet stream, as was pointed out by a friend, was about 200 mph overhead of TUS at 40 kfeet. Wow.

5:21 PM. The sun. Stratocumulus sans virga at top. Droplets too small, temperature too high at cloud top apparently. Sun seems to be free of blemishes, too. Are we still in a sunspot minimum, thought to drive cooler climates, one that might rival the Maunder Minimum? I don’t know. I am a weatherman, not an astrologist.

The End.

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^1″Royal”–that is so funny; “hey”, guys, wake up, its the 21st century!

Tired of winter

Winter began, meteorological speaking, yesterday with mid-afternoon temperatures in the upper 50s to low 60s with the wind driving the wind chill down to, I don’t know what, something really low . In other words, winter began here in Catalina about 18 h ago.

Enough already! Retired to AZ for warm air and low house prices. Pretty bad, too, out there this morning, with the temp at 44° F right now here in Sutherland Heights; colder yet in low spots of course. Only 36° F now in Black Horse Ranch.

More worse cold expected in about nine-ten days. Precip somewhat doubtful in that a more better cold slam that hits around the 20th¹. Pretty strong support in the Lorenz plots (aka, “spaghetti plots”), too, for that cold slam, so get ready. Those crazy plots help us to discern whether a predicted pattern in the model output is an outlier or likely to occur.

In the meantime, going out of chronological order here, THIS coming week end’s lesser cold slam is DRY in Catalina in USA WRF-GFS model run from last evening’s run.

The Canadian GEM, however, based on the SAME global data as the US model, has rain a plenty here in Catalina and all of AZ, Sunday and Monday! The Canadians see a lot of tropical air feeding in from the sub-tropics over much of AZ ahead of the cold front that hits us later Monday, and that’s the reason for all the rain in that model. The US model doesn’t see the moist sub-tropical stream getting much out of Mexico.

Note the large separation between rain in Cal and rain in AZ in the panel below.

Valid Sunday afternoon, 5 PM AST. Lower right hand panel has rain amounts that have accrued over the prior 12 h in the model. As you can see, quite a bit is predicted over SE AZ. Yay! — Valid Sunday afternoon, 5 PM AST. Lower right hand panel has rain amounts that have accrued over the prior 12 h in the model. As you can see, quite a bit is predicted over SE AZ associated with the system coming out of the sub-tropics ahead of the cold front going across Cal.

So, what’s a weather forecaster to do?

Lean on the Canadians! Their model was ahead of the game on our half-incher rains early in the month compared with the US mod, so they deserve that bit more credibility here, too, I think.

BTW, the two models were identical in not predicting rain in the passage of the cold front yesterday.

The End.

PS: Would post photos of yesterday’s gray, non-precipitating Stratocumulus, lacking ice in it², of course, for you to review, but in transitioning to a new OS in the past two days, some things have gotten wrecked, don’t work anymore. SOS, as they say.

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¹Let’s see if any english teachers are reading this blog….

²Cloud lesson/pop quiz for cloud maven juniors: What cloud top temperature range would you guess for those non-preciping Stratocu. Recall it was a cold day, so you know they were at below freezing temperatures…..

Answer: Guess that tops must have been warmer than -10° C (14° F, in plain speak)!

In fact, the TUS afternoon sounding suggests they were about – 5 ° C (or only 23 ° F), way to warm for natural ice to form, hereabouts, anyway³.

³In really clean conditions, ice does form in clouds with tops as warm as -5° C^4.

⁴These would really be a great factoids to pass along to your neighbors, ones that would enhance your weather esteem in their eyes. Memorization is recommended.

“Tweener” era begins today after pre-dawn sprinkles; one photo has birds in it

We’ll have to suffer through a few days for the next storm, i. e., experience sunny weather with pleasant temperatures. Its amazing that people all over America come to Tucson to experience sunny days with pleasant temperatures!

0.45 inches total in The Heights of Catalina in this latest round of rain, sounds of rain. Actually, there was also some tiny graupel/soft hail in the rain yesterday, too.

Graupel indicates a lot of cloud droplet water overhead, and that ice crystals were colliding with them until they lost their identity and became little snowballs. In regions where there are very few ice crystals, graupel and the harder version, hail often form. Its likely that nearly all those rain drops that came down with the little baby graupel were melted graupels.

Graupels….. Makes me think of that rock group, Led Graupelin, didn’t have the impact of Led Zepelin. But I have LG’s one and only album entitled, “Compare to Led Zepelin.” Was only $2.99, too! Where’s my guitar? I think I will play, “Stairwell to Heaven” now…

When graupel or hail occur, there’s a pretty good electric charge up there in those Cumulonimbus clouds. Its best to be indoors when its hailing until you know if a strike might occur (if there hasn’t been one already). Besides, its not comfortable being out in hail. And if you were listening to the rain, you heard a few blasts of thunder toward Lemmon around 2 PM that came out of one of the more enthusiastic Cumulonimbus clouds that went by. Got 0.12 inches total to add to the night before’s rain of 0.33 inches.

Yesterday in clouds; a sojourn in clouds from morning to evening, in that order with no times noted

I know how much you like to see pictures of rain, so here’s one. You’re not like the “others” are you those people around you every day?

Then the piston of atmospheric subsidence slammed down to squash our Cumulus cloud tops to levels and temperatures where ice could not form….

Two picures in a row of a NWS-style rain gauge. Probably has never been done before. Has been getting a workout lately. Everyone should have one.

The weather ahead

Kind of funny to see the Canadian GEM model internally plagiarize itself. Compare last night’s panel at 500 millibars (below) with that same level’s panel foretold for six days from now.

Yep, its the same thing over again in six days, though with less rain IMO:

ann 6 days from now — Valid on Tuesday, November 10th at 5 PM AST. From the Canadians.

In another interesting model development, the best USA model, the WRF-GFS is having an internal CONFLICT of major proportions. Check these progs out generated by data only six hours apart. The first one, showing a big trough coming into Cal, was generated by global data taken at 5 PM AST last evening. The panel below it was generated by the same model based on global data taken just six hours later, at 11 PM AST (so it the most recent WRF output available) and has a big ridge along the California coast.

2015110500_WST_GFS_500_HGT_WINDS_384 — Valid at 5 PM AST November 20th.

“Which one will the fountain choose?”, to quote old song lyrics¹:

2015110506_WST_GFS_500_HGT_WINDS_384 — Valid at 11 PM AST November 20th. From IPS MeteoStar.

Of course, spaghetti tells us which one is right, mostly.

The End

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¹Except that here we present only two “coins” not three.

0.33 inches so far; more rain on way! Dense blog contains annotated photo!

Looks like CMP is low AGAIN on his prediction! Thought a third was the most that could fall in our present storm chapter (10% chance of more, that is), and best estimate, 0.165 inches. Now it looks like met friend and professor at a major university will be much closer with his half an inch prediction. Very painful. Kind of like Stanford with their brainy team beating the Washington Huskies in fubball . It really hurts.

Let us begin today with a look at desert grasses from this summer and falls rains. Pretty deep, knee high in some areas, but as we know here, full of nettles. Kind of a cool look though.

Was heading out to see, what from Google Space, appeared to be a new meteor crater near me, one maybe the astro boys missed. Turned out it was just a house under construction, pretty much underground as well. Kind of a cool thought to build like this, lots of energy saved, which is always good. Cell phone service likely compromised.

8:11 AM. An earth house under construction. — 8:11 AM. An example of an earth house under construction here in the Catalina area.

Yesterday’s clouds

…and a dense discussion of detecting ice in them. I am hoping that my followers noted the time of the first appearance of ice in those Cumulus and Stratocumulus clouds that began to fill in during the middle and late afternoon. As that happened, a few raindrops sputtered down here just after 3 PM as that happened. You should have logged both these events, the first visual appearance of ice, and when those drops fell in your weather diaries.

The whole point of this blog is the detection of ice in clouds by layman and laywomen, or “laypersons” I guess it should be now days. This is because if you see ice developing in lower clouds, something will be falling out of them soon. Ice grows in water clouds at below freezing temperatures at the expense of droplets. Therefore, if they stay in a water cloud long enough, they will get heavy enough to fall out. Poor droppies disappear, unless the air is really rising fast.

An interesting side note is that the air FLOWS THROUGH clouds, exiting on the downwind side. A cloud does not just float along as is. It is moving slower than the air, even itty bitty Cumulus clouds the cloudy air is being replaced constantly. The cloud is really moving upwind relative to the air! The POSITION of the cloud moves downwind, but SLOWER than the air that goes into it.

However, if ice crystals form in a small cloud then, they will fall out as single crystals at the downwind edge; they are not going to reach the ground unless you’re on a mountain top. You saw a fair amount of ice exiting the downwind end of clouds yesterday, falling out and evaporating in the dry air there. Where the cloud is wide, then they can gain some mass, collide with droplets, or other crystals and fall to the ground.

2:38 PM. No ice nowhere. Windy conditions not shown.

2:38 PM. Cumulus and Stratocumulus clustering to the south-southwest of Catalina, but no sign of ice.

You need clusters of crystals locked together, called “aggregates” or ones that have gone through riming, collisions of ice crystals with drops at below freezing temperatures that freeze on the ice crystal making it more massive to get rain drops to the ground. Riming is what leads to graupel (soft hail) and hard hail (the latter to crystals impacting larger, often precipitation-sized drops that freeze on them).

For air travelers, or those who examine tree icing after storms, rime ice is white and produced by small cloud drops; clear icing is caused by much larger drops, usually drizzle or rain drop sizes. If the drops are too small (much less than about 20 microns) they are too small to hit anything and rather go around solid objects. Let’s say you’re on the top of Ms Mt Lemmon, say at 8.000 feet in the fog. The temperature is 24° F. Its windy. You look around and you see no icing on the pine trees trees up.

Where are you?

Ans: at cloud base.

That’s because itty-bitty drops, too small to hit on pine tree needles are flowing around the needles. Some great comments to make that would enhance your stature as a cloud maven junior is to offer your companion the information, “Wow, look at those trees! Here we are ing the freezing fog, and yet they have no ice sticking to them! That means the cloud droplets are pretty small, smaller than about 20 microns! I guess we’re at the base of this cloud system above us.”

These would be really great things for you to say. Of course, as you drove up to Mt. Lemmon, you would know already how far above cloud base you are, but, what the HECK.

You’re at Ms. Mt. Lemmon again, You like it up there when its in the fog. This time the temperature is 25 ° F. Its windy. The pine trees are loaded with rime icing, the ice juts out in the direction from which the wind is coming.

Where are you?

Answer: At LEAST a few hundred feet, more likely a thousand feet or more above cloud base. Drops have reached sizes above 20 microns in size, as they usually do at these heights above cloud base in old Azy. Later, you notice that the clouds are topping Sam (Samaniego) Ridge at the 6500 foot level. Now, they can’t be disconnected layer clouds, but rather SOLID from base to where you are. Drops are tiny again at the bottom of each layer.

Here’s another example. You get up in the morning after a cold winter storm to see “iced trees” on Ms Lemmon. Another comment you could be making is that, “Wow (always begin with “wow”), those clouds must have really been low based last night, way down on Sam Ridge!”

Riming on trees is analogous to the collection of fog droplets by trees and vegetation along the west coasts of the continents in onshore moving banks of Stratus and Stratocumulus clouds that intercept hillsides. These can be significant sources of water. Some studies of droplet collections by trees have found that under the tree, something like 20-40 inches of “rain” can be collected by a tree in northern California.

Wow, I can’t believe all the information I am providing today! Its really incredible.

OK, to first visible ice yesterday, 3 PM:and

3:00 PM. FIrst ice begins to eject out the end of that Stratocumulus complex upwind of Catalina. When the body of the cloud began to be overhead, a few drops reached the ground!

3:00 PM. Close up of ice ejecting out the downwind end of this Stratocumulus complex. — 3:00 PM. Close up of ice ejecting out the downwind end of this Stratocumulus complex (that hazy stuff).

3:30 PM. Classic example illustrating the air flow through a cloud that's producing a little ice. What kind of ice? Looks like colder crystal types, plates, stellars, maybe some dendrites. — 3:30 PM. Classic example illustrating the air flow through a cloud that’s producing a little ice. What kind of ice? Looks like colder crystal types, plates, stellars, maybe some dendrites; defintely not warm crystal types like needles and hollow columns that form at temperatures above -10° C.

5:21 PM. Wind shift clouds, those lowest ones on the horizon, begin to appear to the north-northwest horizon, toward Casa Grande.

5:31 PM. The sun going down amid Cumulus or could be called, Stratocumulus castellanus.

5:32 PM. OCNL LTG DSNT NNW at this time. Again you see those wind shift, frontal passage type clouds here. A wind shift to the NW didn’t hit here until about 1:30 am when the rains and temperature drop hit.

The End

Looks like we’re having wind today

But will it rain?

Stay tuned until tomorrow evening to find out!

Range of amounts in Catalina, given kind of a marginal moisture situation:

Goose egg to 0.33 inches max, median 0.165 inches, CMP’s best forecast. A friend and met man/prof predicts 0.50 inches here, FYI.

Looking backward

Have felt a little guilty not posting cloud photos from the last storm, Oct 30th, leading my reader into some sadness, maybe even despair the following day when she didn’t see her cloud day reprised. Here are a couple of the characteristic scenes from that day, which includes a shot of a rare drizzling cloud. You will love that shot! Also reprised here is the pioneering technique of novella-sized captions.

8:07 AM. Note how the deteriorating Equestrian Road draws your eye to the bank of Stratocumulus. Quite artistic I think. Think of Bob Dylan’s mournful line, “If today was not an endless highway…¹.” Equestrian Trail Road actually ends in Sutherland Heights., just so you don’t lose focus here.

8:59 AM. The easy to read sign of a windshift, one that pushed up the tops of the innocuous Stratocumulus to a thickness where drizzle drops began to form. — 8:59 AM. The easy to read sign of a wind shift, one that pushed up the tops of the innocuous Stratocumulus to a thickness where drizzle drops began to form.

9:12 AM: "Drizzle, der it is", as might be phrased in old TEEVEE show, In Living Color. — 9:12 AM: “Drizzle, der it is”, as might be phrased in old TEEVEE show, In Living Color. Shape of lower cloud tells you that the wind is blowing from right to left.

10:33 AM. Let's quote Bob Dylan again, this time in one of his most famous incomprehensible songs, Subterranean Homesick Blues: "You don't need a weatherman to know which way the wind blows; a horse will do." — 10:33 AM. Let’s quote Bob Dylan again, this time in one of his most famous incomprehensible songs, Subterranean Homesick Blues: “You don’t need a weatherman to know which way the wind blows; a horse will do.” Well, CMP added those last few words. Bob couldn’t think of something as good as that. The clouds and horse tell you the wind is blowing from right to left. Btw, ome people were so amazed by the words in that Dylan song quoted above that they began to call themselves, “Weathermen.” How crazy was that? Who in the WORLD would want to call himself a “weatherman” that wasn’t one?

1043 AM. The perfect Cumulus congestus? I think so.

4:11 PM. Rainbow. Indicates raindrops are falling over there.

Still windy outside, 6:03 AM to be exact. Looks like the observation of windy is going to be correct. Expecting some nice lenticular clouds to show up today. Have cameras ready. No rain before 7:15 PM. Overnight, watch out!

The End

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¹Best sung by Judy Collins