Cloud-maven – Page 62 – About real clouds, weather, cloud seeding and science autobio life stories by WMO consolation prize-winning meteorologist, Art Rangno

Water, water everywhere in the sky, but not much fell on the ground

Yesterday was a disappointment. Oodles of water up there above us, as represented by cloud bases somewhere around 15 Celsius (59 F) yesterday morning, early Cumulonimbus activity–one was up toward Oracle by 10:37 AM–Oracle got 1.06 inches yesterday, but while the skies darkened over Catalina several times, they didn’t “unload.” Maybe only once or twice before in six summers have I seen this darkening to the level we had yesterday, without a rain shaft soon falling out of it. A couple of examples from yesterday:

1:29 PM. A Cumulus congestus takes shape over Cat State Park, and heads toward Catalina. Only sprinkles fell.

2:40 PM, looking toward Charoleau Gap. It doesn't get more "portenful" than this. I was SURE a shaft would crash down, and with it, the WIND from the north, the clouds then building over ME to the south, as happens so often when heavy rains pour down on the Gap. Didn't happen, at least not until too late, long after it had moved farther north. — 2:40 PM, looking toward Charoleau Gap. It doesn’t get more “portenful” than this. I was SURE a shaft would crash down, and with it, the WIND from the north, the clouds then building over ME to the south, as happens so often when heavy rains pour down on the Gap. Didn’t happen, at least not until too late, long after it had moved farther north. Got pretty dejected.

So, what went wrong? Why were the clouds SO DARK, even shallow ones like Stratocumulus, let alone the Cumulus congestus, but with so little “emitting power”?

The darkness of these clouds was surely due to the high smoky aerosol content of the air that led to unusually high droplet concentrations in these clouds. The higher the droplet concentrations, the darker the bottom of the cloud, say holding cloud depth constant. So, a moderately deep cloud, but one too shallow to rain, can look like these, like the normal darkness on the bottom from which blinding shafts of rain fall. So, most likely we were looking at smog-laden clouds, the kinds of ones in our future around the world because that’s what we do, produce smog and smoke, well, us and lightning.

And, as we recall from Squires and Twomey (1967), smoke inhibits the formation of rain in clouds. I am sure most of you remember that article about smoke and sugar cane fires in Australia, and how those smoked up clouds did not rain like the ones around them that were “clean.” This phenomenon has been reported on numerous occasions since, like how in LA it helps reduce drizzle (mist rain) occurrences.

However, as we know, even smoked up clouds can rain IF they get high enough to reach the -10 C level here because then copious amounts of ice, soft hail and snow will form aloft, and down it will come! That only happened in isolated places, like over Oracle where they got that inch of rain (at least around here). So another cause of dark clouds lacking in downspouts was that they were not QUITE deep enough for the tops to reach -10 C. up around 20,000 feet above the ground yesterday–those tops were SURELY so close, though!

Back to smoke effects. With bases as warm as 10-15 C yesterday, there should have been rain formed without ice, and almost certainly a little did (these eyeballs detected some yesterday afternoon on the Catalinas). However, this is the type of rain that smoke inhibits most. This is because with so many cloud droplets competing for a given amount of condensation, they all stay too small to collide and stick together (requires drops bigger than 30 micrometers in diameter (let us not forget Hocking and Jonas (1970)…. So, we lost some rain due to smoky skies there, too,

Next, it can be relatively cool with tremendous amounts of rain IF there is a good disturbance to cluster the clouds together, forcing converging air near the ground, taking it away at Cirrus levels. We didn’t have a “disturbance”, a trough or a low to help out.

Finally, without the help aloft, we needed, as you can all guess by now, that bit more heating at the ground, maybe just a few degrees was all to launch some really large but isolated storms.

Today?

U of AZ 11 PM mod run has Cbs developing over the Catalinas by noon, and during the afternoon some of those showers trail to the northwest over Catalina. I think one will. So, once again we have a day with rain around, and maybe today a little cell will bombard us with a quarter of an inch. Should be warmer, today and that will help since again we have no trough help. Still smoky, as you can see here at sunrise by that orange-brown layer below this morning’s Cirrus. So, once again, the clouds may look a bit darker than they “should” when we have clean air.

The End except for this nice morning shot of Ac perlucidus undulatus I would call it. Very nice!

6:54 AM. Altocumulus perlucidus undulatus, if you care.

Sign of a good rain day today after some disappointment yesterday (only 0.17 inches here)

Stratus fractus on the sides of the Catalina Mountains:

This tells you how wet it is out there, if per chance you haven’t walked around in it, and also tells you that moist air has some depth. These are the lowest clouds yet of our summer rain season. CUmulus cloud bases later this morning and this afternoon should also be lower than any prior day, and that means more rain gets to the ground, and likely the cloud clusters are large.

Fingers crossed for half an inch or more today here in Sutherland Heights-Catalina area.

BTW, some points in the Catalinas, such as White Tail, got 1-2 inches yesterday. Douglas way in the corner is already over 4.6 inches or about 160 % of their whole July normal. Excellent.

The End.

Catalina summer rain climo (again)

Running out of material, which is quite interesting because I haven’t been doing much, so am reprising these….

We had a little uptick in rainfall last year mostly due to that four and half inches in July. Very nice. No trend is evident in the summer rainfall here, global warming aside.

When it falls in summer….

Hmmm. Just noticed a discrepancy in the years of record. Huh. Must investigate later.

Some of yesterday’s clouds

One of my specialties is cloud bottoms, and there were several opportunities to photograph them. Here’s a quite nice one, hoping one day it might appear in a gallery, it’s that good I think. It was just starting to unload its watery burden onto the unsuspecting folks in south Catalina and Oro Valley (see next shot):

4:03 PM. From Sutherland Heights looking SW toward Oro Valley, just 19 min later.

Models chock full of moist days for at least a week ahead, so “let the games begin”. Certainly we Catalinans will get nailed one of those days. Extreme SE AZ has been pretty wet so far, with Douglas having almost 2.5 inches already. Will be green down there soon! Might be worth a trip to see how things are coming along.

The End, except for this shot of the prior day’s really dramatic sunset:

The L. A. suns

We begin today by not talking about sports as the title suggests, but rather examining pretty castellanus, Altocumulus castellanus, that is, from yesterday morning:

5:38 AM yesterday from Equestrian Trail Road.

The brighter regions at the top are liquid droplet clouds, below, snow virga as the drops quickly freeze into ice crystals. As they grow and collide, snowflakes (“aggregates of single crystals) develop. But the dry air below the clouds prevents them from falling more than a few thousand feet below those white tops. Too bad. This is also what the tops of many widespread rainy/snowy storms look like if you could cut away just the top few thousand feet, those situations where there is moist air all the way to the ground.

L. A. suns? No, the PHX team did not move to a cooler venue as might be desired on these record breaking hot days. But our orange suns of late, particularly in the late afternoon, are reminiscent of those sunsets seen in smoky, smoggy regions of which this earth has too many.

6:37 PM. The smoky orange sunset yesterday. Ugh.

Furthermore, smoke gets in the way of rain formation, something noted by experimenters as far back as 1957, and later when burning sugar cane in Australia in the 1960s. The burning there stopped the clouds, relatively shallow ones, from raining. This is because smoky clouds have more and smaller drops in them. Smaller drops are resistant to forming ice, and a cloud must become deeper to generate drops large enough to coalescence with one another to form drops big enough to fall out.

So, not only are the skies messed up by smoke, but the formation of rain, too, is interfered with. Fortunately, if deep thundery clouds form, as we expect today in our vicinity, this smoke effect can be overcome at least in those clouds and rain will fall out.

Also, because small drop clouds send more light back into space from their tops, even moderate-sized Cumulus clouds can look awfully dark on the bottom, suggesting they are deeper than they really are.

The End

Jackpot

“If its 110 degrees, can thunder be far behind?”

Nope.

Here from IPS Meteostar, a favorite place to look at weather, this.

Only 13 days from now. Heavy rain shown for SE Arizona! — Valid only 12-13 days from now, July 9th at 5 AM Local. Heavy rain (blue region) shown for SE Arizona during the preceding 12 h ending at 5 AM! (More simply: “overnight.”

Sure, could be illusory as we know, but it does demonstrate that we are deep into the summer rain season by July 9th, as predicted by the seasonal outlook from the U of AZ. After the past desiccating months, fingers crossed.

Also, let us consume some spaghetti to see if there is any truth to this rain at all:

Yes! I love spaghetti! Upper high in correct position for good rains here, around the Four Corners area (area lacking lines), so that heavy rain COULD actually happen!

BTW, hope TV Weatherman George comes back. He is very, very good. I know I tease about TEEVEE weathermen, but maybe its only jealously, and also I don’t think I could do their job, too much (non-atmospheric) pressure! I might say something awful, in a happy talk context:

“Too bad about those people in that plane crash, but, ‘hey’, how about those Wildcats!”

No, it really does take some real explanatory and graphics skills to do TV weather these days, plus be likeable on top of those. George has those skills and attributes.

In case you missed them…these stunning skies

Cirrus uncinus. Started out looking like radiating lines of Cirrus, but this look is due to perpspective:

1:10 PM. Much later.... — 1:10 PM. Much later…. Well, in cloud time its much later because these guys will gone in a just a few minutes jetting along at 25,000 feet or so. Note those tufts at the top suggest momentary liquid water followed by ice formation and fall out (in LONG strands).

Cis fib and Cis spis lead to nice sunset; big trough, big wind ahead

Cirrus fibratus and Cirrus spissatus, of course. Here they are from yesterday.

2:56 PM. Cirrus fibratus, straight or gently curved elements.

7:28 PM. CIrrus spissatus (thick, patchy Cirrus) with other varieties.

The weather ahead

Troughulent weather is ahead as you can plainly see here from the NOAA spaghetti factory:

Here’s what it looks like on a regular 500 millybar map (IPS MeteoStar):

No rain in it for us, but if you missed having wind yesterday the 21st, well this situation will make up for it. Likely to be gusts over 40 mph in these here parts when it actually peaks out in about a week. In the meantime, a West Coast trough ahead of this violent jet streamer from the Pacific will keep the air moving long before this unusual event slams into Cal.

The End for now.

Pretty castellanus

5:29 AM. Ac floccus and castellanus with virga. Cloud bases (sans virga) were at -10 C (14 F) yesterday.

Along with Altocumulus “floccus¹” as well, many with ice virga. Some clumps got so enthusiastic that they went into sizes that we really can’t name, too large to be Altocumulus elements, and too small to be what we normally would call Cumulus or Cumulonimbus. Here are some more examples of yesterday’s clouds:

5:49 AM. ????? Mostly glaciated, though little virga shows out the bottom. — 5:49 AM. ????? Mostly glaciated, though little virga is coming out the bottom.

6:14 AM. "Micro-cumulonimbus"??? Its got all the ingredients, little anvil. fully glaciated here, and a few drops fell all the way from 13,000 feet about the ground. — 6:14 AM. “Micro-cumulonimbus”??? Its got all the ingredients, little anvil. fully glaciated here, and a few drops fell all the way from 13,000 feet above the ground, but there is no real shaft something you like to see when you call a cloud a Cumulonimbus, Highest tops above 30,000 feet, colder than -40 C (-40 F).

6:22 AM. Off to the south, this classic example of regular Altocumulus castellanus and floccus. So pretty. Note ice plumage beyond Pusch Ridge.

6:53 AM. Lesson. Some liquid water drops reach the highest, coldest point in this buildup. On the right, they're all gone, only ice remains. The droplet part is brighter because the droplets are smaller and reflect more of the sun's light than do the larger ice crystals. — 6:53 AM. Some liquid water drops reach the highest, coldest point in this buildup; that brighter part peaking out on the left. On the right, and at the top, the droplets that were present earlier in this part of the cloud have all evaporated; only ice remains (except in those partly shaded cloud rags). The droplet part is brighter because the droplets are smaller, they’re are more of them, and reflect more of the sun’s light than do the larger ice crystals at the top.

Taking a bite out of drought in the Plains States

Here the Drought Monitor for May 7th. Looks pretty bad in the central and southern Plains States and the central and southern Rockies.

But here’s what’s happened according to WSI’s radar-derived rain totals over the 7 days ending since this map. Makes you fell that bit better for our drought-stricken brothers even if we didn’t get anything. And it looks like rains will continue off and on in droughty Plains areas now for another two weeks. Excellent. Nothing in sight here, sadly.

The 7-day rainfall totals ending on May 14, 2013.

The End (still putting life together after moving; posts will be a bit sparse).

—————-

¹“Floccus” has a ragged or lofted base, one higher than the other ones around.

Big trough coming

In case you missed it, and a note about missing cold air reports

SONY DSC — 7:01 PM Virga from Altostratus clouds is illuminated by the setting sun.

Took time out from a bazillion chores concerned with moving to a new house here, and other doings for a U of WA archive project to savor another great sunset here in Catalina:

The weather way ahead

Before looking ahead, look outside now (6:20 AM) There are some gorgeous patterns in Altocu and Cirrocu!

The models have gone real bad on us, taking away rain that was once predicted here in early May. Sure, its unusual, but it could have happened. Now its pretty much gone (for now).

In the meantime, sometime very unusual is forecast for the central and southeast US. Can’t remember seeing a pattern like this so late in the winter where in really cold upper low center just goes down to Natchez, MS as in this loop. Lots of low temperature records likely to be set for early May if this pattern comes to pass.

: Valid for mid-day, Tuesday, May 7th.

This continues a trend, too, this spring of well below normal temperatures in the Plains States in the middle portion of this forecast loop. They had one of the coldest springs ever in the northern Plains, and the latest measurable snowfall ever just happened in Wichita, KS. Just yesterday, the latest freeze date in the 91 years of records was established at Wichita Falls, TX, when the temperature dipped to 29 F, nine days later than any prior freeze day.

Here are some additional details, as provided by climate issues troublemaker Mark Albright, former Washington State Climatologist, and friend, who has been complaining lately that if these were high temperature records, they’d be all over the news, but low ones get swept under the media rug.

Here’s Mark’s statement from a few days ago:

“The coldest baseball game in major league history was played yesterday in Denver where the game time temperature was 23 F. It breaks the record set just last week in Denver. You can watch the video here to see the conditions at Coors Field.

“This story echoes my thoughts exactly. Why aren’t we hearing from the news outlets about the historic spring cold wave gripping the US and Canada in 2013. When it was warm last year we heard all about it.

In Fargo ND 45 consecutive days (10 March – 23 April) have passed without a single day of above normal temperature. In fact, they have yet to record a temperature warmer than 43 F this year through the 23rd of April. March 2013 averaged -10.5 F below normal and April 2013 is even colder at -12.6 F below normal so far in Fargo ND. This sets up a major risk of severe flooding in a week or two when the Spring thaw finally arrives.

To the north of Fargo, Saskatchewan is reporting their coldest spring in over 100 years:

Unusual cold has also been seen in interior Alaska where Fairbanks is running -14.9 F below normal in April 2013.”

While it will likely be getting warmer over the next 100 years, we seem to be afraid of reporting low temperatures and cold; that is, while it gets gradually warmer, we seem to be afraid or mentioning that weather will be pretty much doing what its always done, being abnormal a lot of the time, too. Even I get worked up if I think there is a news bias against reporting cold air! It ain’t right.