Cirrus clouds – Page 13

Low temperature records galore

Here a very nice site if you want to look at what weather records were being set around the country, with an example for the past few days below. The one below were set as a gigantic blob of cold air (high pressure region) plopped down into the US, one bigger and colder than usual for this early in October. There are a ton more low temperature records being set today. As you know, this cold air event was well predicted in the computer models many days in advance and was blabbed about here.

Does this exceptional cold air in early October presage a cold winter?

Well, to know for sure, sort of, we go to the Climate Prediction Center to get their best guessestimate, and then look at natural phenomena, used by folk long range weather predictors, like the height of ant cones, length of horse’s hair, etc. The CPC’s outlook, the best info around, beats Farmer’s Almanac by quite a bit, kind of like the way my former employer’s sports football team was beaten down by Nike Team One in Duckville, Oregon last Saturday evening, 52-21; wasn’t close. Let’s see what the CPC sees for the next few months:

Wow! This is not what I expected to see for October, November and December because of the current weather regime with all that record cold in the very areas where warmth was expected.

This CPC prediction suggests that the cold air now in the East is a fluke and a quite comfy, energy-conserving fall season should be observed where the low temperature records are falling today. This CPC longer range prediction would go with an El Nino-influenced winter, but so far, the overall pattern has not looked much like one. Of course, phenomena like the El Ninos/La Ninas, when they are strong, are the best hat racks to hang our climate prediction hats on these days. The El Nino we have now is pretty marginal, barely made the criteria for one; a crummy hat rack.

The above seasonal forecast by CPC was issued on September 20th and a new prediction will be issued shortly. Usually, though, they don’t “yo-yo” much, that is, change much from one month to the next in what is foreseen for the next three months; there’s some inertia involved.

BTW, and oddly, one of the severest winters in the East was associated with a very weak/marginal El Nino in 1976-77, a year also that included extreme drought along the entire West Coast through February.

————————————–

Folk weather predictions; ant cones (are they really better?)

Now lets look at ant cones and see what we can make out of those. Perhaps ants know something about the coming winter since they’ve been around for about 10 billion years¹. Maybe there was something in our summer temperatures and rains that “spoke to them” about the coming winter. Below, a typical ant cone of the size around now.

You know, I’m not getting a lot out of what these ants are trying to tell me about this coming winter, though, its very nice.

So, for the present, and with no strong climate signal anywhere, we have to assume that the early cold is a fluke, not an indicator of a whole winter.

———————————-

A little rain is but a few days ahead, Thursday. In the meantime there have been some nicely patterned Cirrus, Cirrocumulus, and Altocumulus streaming out of the very same system that moves over us Thursday evening.

There will be more of these photogenic clouds today and in the days ahead of the storm. Keep camera ready!

It will be fun to have more dramatic skies and some wind with a “storm” finally. Mods have another one a week or so later, too.

—————————————

¹I’m exaggerating here since the entire universe, one that began with a spec smaller than the head of a pin and yet had everything in it, is about that old.

Yesterday’s “be-a-moths”; what’s ahead in August and early September

Nice sunset yesterday, one consisting of_______, _________, ________ clouds, ones that always give us one of those “glad to be here” in Catalina, CDP, feelings. I might give the answers tomorrow, but please try to name these clouds and maybe get that, “Its fun being a cloud-maven, junior” T-shirt you’ve always wanted. It has clouds all over it, maybe even ones you’ve seen and logged!

Only got a trace of rain here in Catalina, though there were a few “be-a-moth” (as we used to say as kids) Cumulonimbus clouds here and there yesterday. Check the U of AZ time lapse movie at about 2:30 PM yesterday for a giant. A couple of examples from around here below:

SONY DSC — 3:55 PM. Now if we were talking pancakes, this would definitely be a “tall stack.” It was quite a sight, and I hope one of you out there got under this and have a rain report for us today. I would estimate, as you would now, in view of the little movement of the storms yesterday, bases about 8 C (pretty warm), that this giant gave someone 1-2 inches in the peak core.

There were several reports of more than an inch yesterday in the ALERT raingauge network.

What’s ahead?

As we know, we are beginning the overall decline in chances of rain each day now; the summer rain season is winding down gradually. Doesn’t mean that in any particular year like this one that it will, BUT you have to give credibility to longer term models outputs that are on the dry side because we’re not dealing with an unbiased coin. The head on the quarter getting flipped for the choice of kicking or receiving in a football game is getting heavier; go for the tail since the heavy head might cause tails to come up more often.

Lately the model runs have had a complete break in the summer rain season around the 25th for a couple of days, then a slow return to wetter conditions alternating with breaks. Go here, to IPS MeteoStar, to see their rendering of the WRF-GFS outputs from last night’s global data, concentrating on the Arizona portion of these maps.

So, what are the chances THIS output, with a reasonable amount of “green” (meteorologists love to color areas of precipitation green; always have and always will) in Arizona at the end of August and the first day or two in September will have summer rains lingering on?

Go next to the NOAA spaghetti factory here. Examine the contours for the end of the month and the first of September…. And, there you have it! Eureka! The confidence level you’ve been looking for.

The End.

“Feint” rainbow

For a few minutes yesterday afternoon, it looked like some unexpected rain was trucking over the Cat Mountains from the east-northeast late yesterday afternoon. No one could blame you for getting your hopes up and misleading your neighborhood by saying it might rain in half an hour. Those clouds rolling in from the Catalinas (shown below) were great sights for soaring eyes, ones that look to the skies all the time for rain.

But within the hour, the clouds had broken up, and the shower they produced was reflected by a faint rainbow. Rainbows to the east and northeast are often precursors of rain and wind moving into Catalina. Here is the sad remnants of those albeit weak, Cumulonimbus clouds with their feint rainbow, one that was not followed by one drop of rain here.

A big patch of Cirrus kept the temperature down some during the first half of the day, and so our Cumulus were behind in development compared to areas around us. Here is that bad Cirrus spissatus in case you missed it, that which hung over us so long.

It was quite visible even in the visible satellite image all morning. When it shows up there, you can bet that the Cirrus in that image is thick enough to produce shading and mess up the development of Cumulus under and around it, particularly on marginal rain days like yesterday.

Much Cirrus is virtually invisible in visible satellite imagery; get it? You can see it from the ground (i.e., its visible), those thin wisps of Cirrus, but try to find it in a visible satellite image! This whole line of reasoning and befuddled exposition here reminds me of that Science knee-slapper of a few years ago; that article entitled, “Where are the invisible galaxies?”

Today?

Raining lightly now at 5:25 AM! Yay. A night stalker mass of rain is moving into TUS now as I write. They don’t usually like the daytime and fade as the sun rises in the sky. Sprinkles, very light rain showers (and as always pointed out here, quite emphatically I might add, “sprinkles is not DRIZZLE, dammitall”, to be a little colloquial there!).

Let’s hope this heavy cloud cover we have now (5:30 AM), which you could call, Altocumulus opacus and castellanus due to its height above the ground (its at about 11-12,000 feet above the ground and has turrets here and there). But, to get a little pedalogical you could label it in your log book as Stratocumulus, perhaps with the appendage, castellanus, since turrets are present–those are what’s causing the sprinkles/light showers.

Sunset was nice….

U of AZ mod shows this is our best day for a significant rain, some of that this morning, and some arises later with those afternoon and evening giants we get around here. Hoping so. Tomorrow is supposed to be drier.

The End.

Rainy days and Saturdays

Nice sunset yesterday….as some Stratocumulus spread over the sky underneath a pesky Cirrus cloud cover, clouds that announced the beginning of our next rain spell, now underway.

Light rain is falling this morning at 4:07 AM, and has been for hours, amounting to 0.01 inches. However, some places in Pima Land have gotten much nicer rains, around a third of an inch in the Cat Mountains overnight, for example; check here.

Progress of the real monsoon, since June 1st, can be checked back there at the beginning of this sentence. The coastal state of Karnataka has an average rainfall of about 70 inches since June 1st, a below normal amount, believe it or not. However, being a statewide average, that 70 inches doesn’t reflect the hill stations in the western Ghats, surely to have about twice that amount.

Now, as a further aside, Karnataka, Kerala, two Indian west coastal states would be a great place to go for a vacation now! There you could REALLY absorb a REAL monsoon, where passing rains, heavy, pounding, thick with drops, visibility down to less than a mile, go on hour after hour with brief interruptions. Its really pretty amazing and worth experiencing, at least once.

But, not much lightning there, like we have, because the rain develops mainly through a process not requiring ice, much like the rains in Hawaii where lightning is also rare. The rain develops largely through the collisions of drops, ones that stick together after they collide, and get bigger on the way down through the cloud, sometimes called the “warm rain process” because ice is not involved, and that causes most of the rain in that Indian coastal region. Cloud bases are right on the deck, and are typically 20-25 deg C, very, very warm.

In contrast, to continue a pedantic stream, “warm rain” is rare here in Arizony because cloud bases are relatively cool (less than 10 deg C in the summer as a rule), and droplet concentration are moderate to high (hundreds per cc). Higher cloud droplet concentrations make it harder to grow cloud droplets big enough to collide and stick together inside our clouds.

But, we do get that kind of rain, “warm rain” here once in a great while in Arizona as part of the rain that forms in our Cumulonimbus clouds when their bottoms are especially warm, higher than 10 deg C. Seems to happen about once or twice a summer in my experience so far.

What’s ahead?

Now that afternoon and evening rains around the area are back for the foreseeable future (5 days), what’s way ahead, beyond the foreseeable future?

There, as you know, when we start thinking about beyond the foreseeable future we start thinking about spaghetti! What do those crazy northern hemisphere-wide plots produced by NOAA with their dizzying numbers of lines mean for us here in Arizona?

First, I present a map of the 500 millibar contours as produced in the Haight-Asbury hippie district by San Francisco State–I mention this because the lines on this 500 mb map look a little nervous and maybe it has something to do with that map origin, being from a cultural area whose norms are “anomalous.” I have pointed out on this map, “Our Big Fat Anticyclone”, one whose position is critical for decent summer rains here. In this map, as you can see, its not really OUR “BFA”, but rather belongs to Amarillo, TX, as of last evening.

Nevertheless, it is well positioned to fan humid air from the southeast into Arizona, as is happening now. Remember, the circulation around a big fat anticyclone is clockwise. When it sits on top of us, things are not so good; upper level temperatures are high, humidities are low up there, stifling convection and preventing tall Cumulus clouds.

But when the high is away on holiday, temperatures are lower above us, its more humid up there, and those factors allow for deep convection; huge Cumulonimbus clouds. It only takes a few degrees difference to go from those dry days we just had with their Cumulus pancakus, to the kinds of days ahead for us now, where clouds stand tall!

Continuing, finally, Here’s is today’s plot for 15 days from now, the afternoon of August 11th, based on global data taken at 5 PM AST yesterday. What do you see? You see an arrow pointing to something of a void in all the “spaghetti.” That void represents the most likely position of our BFA some two weeks from now, and that position is pretty darn good for summer rains here. And it is in that region, to the north of us, almost the whole time from now!

So, based on this “most likely” position, one would venture that the rich summer rain season we have had thus far, will continue to be active. Of course, this doesn’t mean rain everyday, but that breaks will likely be short through almost the first two weeks of August.

Can you imagine how tall those desert grasses and weeds will be by then if this is the case?

The last couple of photos document our fabulous re-greening now in progress. If you haven’t been out in the desert, you should get out there and experience this wonderful event. Doesn’t happen every year, as we know!

More nice clouds

Another nice day of high heat and high, patterned clouds. at times. Here are a few shots of the latter, beginning with another flaming sunrise shot. The U of AZ time lapse movie for yesterday is really informative. The clouds shown in the second shot go by just after 6 AM, soon after the movie begins and you can really see the ice/snow falling out of those guys.

They’re not zero, but the chances of rain twixt now and the end of the month are pretty small. However, a tremendous surge of humid air is indicated as the month closes from the remnant of a tropical storm-hurricane along the Mexican Gulf of Mexico coast. Of course, that’s so far out it can’t be TOO reliable, but its something that would bring substantial rains. Here’s what it looks like in green (moist air) and brown (dry air) from IPS Meteostar. All that “green” air to the east of us is heading our way.

Spectacular cloud day yesterday

Probably most people didn’t notice much yesterday, but at times, especially in the mid-afternoon it was spectacular up there due to delicate little patterns within Cirrus and Cirrocumulus clouds. Some examples below.

5. The after life of those Cc and Ac clouds was Cirrus! 6. Oddity: extremely thin Cirrocumulus with holes. The Tucson rawinsonde sounding indicated that these initially liquid droplet clouds (Cirrocumulus and Altocumulus) were at 26,000 feet (at the 330 millibar level) above Catalina at -30 C (-22 F) . So, being that high, its no wonder those delicate Cirrocumulus clouds (Cc) became fuzzy masses of ice. Long ago it was noticed that nature liked to produce a droplet cloud before it froze to become ice, even at these low temperatures. Only around -35 to -40 C does ice form directly without going through the water phase, though liquid drops have been reported at -44 C! To watch some of this transition happen before your very eyes, go to the University of AZ time-lapse and, about 1:02 from the finish (about 15:35 PM if you can read the time on this movie!) before the end of the movie, a really nice patch of Cc appears on the left, but by the time its about to exit the field of view, it has magically transformed into a thin patch of ice cloud. This little patch of Cc in the movie is likely the same one I shot at 15:32 PM in photo number 4. Just ahead, our upper air anticyclonic summer regime And with that big mound of hot air over the Southwest US, the first onset of summer rains are now indicated in the models twelve days from now, around June 25th. Too far in advance to bother showing, but am very hopeful of an earlier onset of the summer rain season, and we hope, a LONG, juicy one! In the meantime, we will be in a trough for a few days, but, as tantalizing as that is, the models still see insufficient moisture for rain in AZ when the trough peaks over us this weekend. However, rain is shown in Sonora near the AZ border this weekend so its not impossible that a few Cumulus might get overly enthusiastic and bust those model predictions of complete dryness this weekend in the mountains. If rain did unexpectedly develop over the weekend from our little trough, it would probably fall from very high-based Cumulonimbus clouds producing mostly virga. The End.

Clouds!

Something in the sky to look at, Cirrus! And more!

Some Cirrus, Cirrocumulus, Altocumulus clouds from the tropics have floated over in time for a nice sunrise presentation. Some of these clouds should be around all day. From this morning:

Also, let me reprise our June rain frequency chart for Catalina. “Upon further review”, I have altered some text box wording to reflect a more accurate picture. In reviewing some Tucson rain days in early June, where I had asserted that they were associated with “cold troughs”, I learned from an review of old weather maps that, while those rains were associated with troughs in the upper levels, they weren’t nearly so cold and strong as I had believed. And those troughs had tapped the tropics for the rains that fell, and I had not indicated that. It bugged me that I had got that wrong and so here is the corrected version of that chart.

Also with “only” 35 years of data here in Catalina, the “transition” zone below could be a statistical fluke. In checking the Tucson 100 year plus record, there has been rain on days in this “transition” period, so its not impossible. No rain is indicated during this period in the models right now, either, but there is a threat of rain developing. More on that below.

Looking troughy enough for a rain threat in a few days

From our Canadian friends, this four panel prog chart for the afternoon of June 16th. Note “trough” (upper left panel) extruding southward from Montana all the way down to Cabo San Lucas. The models have had this figured out for many days, but the magnitude of the trough, the strength of the winds around it, and how much cool air it would contain way down here in the SW US, has been subject to some wild variations. Now it appears that the trough will be pretty weak, not much cold air in it, BUT, with the amplitude it has (how far south it extends) makes it possible to fetch us some tropical air. None of the models have much in the way of moist air reaching us YET. Take a look at the lower left panel for moisture at 700 millibars, or around 7,000 feet above the ground here in Catalina. That blue shading shows that the moist plume drawn northward will mainly be in eastern NM and west TX, which will be good for them, but not us. Still these kinds of things are dicey and one of those rare days with rain in mid-June is not out of the question. What is life without hope?

The End.

Little low goes by at 30,000 feet

While working on a climate issues rant due to an article in the latest issue of Scientific American (May 25th), we had an interesting cloud day yesterday. I needed a cooling off period anyway, so I thought I would point out some interesting things from yesterday, June 3rd.

Here is yesterday’s cloud movie pointed at the Catalinas, and courtesy of the University of Arizona‘s Atmos Sci Dept. This is interesting because you will see the Cirrus moving out of the west in the morning, with some Altocumulus, Cirrocumulus underneath, then by afternoon, you will see the Cirrus moving from the east! Hardly ever see that much change in wind direction at 30-40 kft in such a short time.

Also in the movie you will see a couple of great examples of Cirrus uncinus, tufted Cirrus with trails of snow coming out, actually more like single, tiny ice crystals maybe only a few human hairs in diameter (say 300 microns or so). What type of crystal? Of course, toward the bottom of the trails, you always want to guess, “bullet rosettes.” Toward the top of those clouds they are likely simpler crystals, like short hexagonal columns or tiny hexagonal plates, not that you would care THAT much.

24 h satellite loop of water vapor channel showing itty bitty low that went just to the south of us yesterday. Look hard in SW Arizona in the beginning and you’ll be able to just make out a little swirl in the wind.

Height of clouds above us? About 25,000 to 30,000 feet.

Along with that low going overhead, is this strange event: almost no wind between 25,000 and 30,000 feet, indicating that the exact center passed almost overhead. It would be like having calm winds on Mt. Everest; just doesn’t happen very often. Here is the TUS sounding for 5 PM AST yesterday. And, if, like me, you thought you were looking at the same blob of Cirrus for hours, you just about were! That due to the winds coming to a virtual halt. Where the lines (temperature and dewpoint) pinch in together in the sounding below is where the clouds were located, and in the first column to the right of the box are the winds. Notice what they were at the “400” and ” 200″ levels (millibars, between 23,000 and 40,000 feet above sea level): “light and variable.”

It was about this time, 1 PM AST, that I began to notice that something was “wrong.” When I came out of the gym an hour later, this patch of Cirrus, the one I had taken a picture of going in, was still there in pretty much the same spot. By 4 PM AST, it had drifted ever so slightly to the north, but there it was, still hanging around, as was the case at 5:40 PM and 6:51 PM, shown in the the next two shots. Even at sunset, those Cirrus clouds were still around.

BTW, these would not be the same cloud particles up there, since the crystals are always falling out and have to be replaced by newly formed cloud. Those tufts and compact specs at the top of these clouds (well, that’s where they are if you can’t tell) in these photos represent that process. In those tufts the concentrations are tremendous, but once formed they gradually spread out, much like a plume of smoke.

“Los Angeles” Catalina

Got a little homesick yesterday looking at the white sky, the barely visible mountains in the distance, like Twin Peaks, eyes a little teary, not from sadness so much, but from smog and smoke. Grew up in the San Fernando Valley you know, Reseda. Lots of smog there at times, though not as much as in Burbank, thank heavens, where it banked up against the San Gabriel Mountains.

Reseda, as you know is quite famous from the Karate Kid movie and was even mentioned by Frank Zappa in his Tinsel Town Rebellion album so I like to tell people that I grew up there, went to Reseda High School, played some sports. Maybe I should add a sports highlight to convince you that I went to such a famous high school, and maybe, too, mention that overpowering, incapacitating crush I had on Rozzi R. when I was 15 years old, since a story like that would titillate your interests more than a sports story, or maybe even stuff about weather. I think I know the people who read this blog pretty darn well.

Below is that “nostalgic” LA sky we had yesterday, thanks to fires in New Mexico, the second one of the yellowish-orange sun typically associated with smoke particles. Of course, the “white sky” is common on humid days back East, and in the global warming domain, is our friend.

Yes, that’s right, smog is our “friend”, because, as was likely yesterday, in spite of record heat, the temperature would have even been a tad HIGHER without that smoke layer!

In fact, one of the conundrums in foretelling climate in the coming decades, is how much smoke, our “friend”, will offset the warming due to trace gases like CO2. Imagine, a world of never-blue-but-always-white skies and no more worries about global warming!

As the cliché goes, “Beam me up, Scotty” if such a world came to pass! So, lets knock off the fires, all smog, in fact, and untoward gases!

More clouds, less smog today

In case you missed it, some sunrise Cirrus today! Finally a cloud. Who cares if its at 45,000 feet above the ground! It shows there can still be humidity in the air.

Probably had some….OK, your guess… on the ice crystal type up there in those Cirrus clouds.

Yes, that’s right, bullet rosettes, would be an excellent guess, crystals with a solid “germ” center from which columns radiate outward like these ones below captured in Cirrus clouds over Barrow, AK, some years ago.

Update on “dusty coolsnap”, foretold many days ago for around June 5th.

Here, from the NWS Tucson, you will see that “dusty coolsnap”, foretold by the models many days ago, has been evolving into “breezynotashotsnap”, if you can call that a “snap”, a word that implies more suddeness that what will likely happen. Still, a trough brushes by to the north, just doesn’t have the amplitude it once did in the models; we’ll see only some moderation in temps. How can they not “moderate” after record highs, so that was an easy thing for me to say.

Still no rain in mods for hereabouts, but some close calls from afternoon thunderstorms in New Mexico every now and then.

The awful indications is, just beyond a week from now, more record HIGH temperatures lasting for a few days! Yikes.

The End

Spinning on down from Glasgow to Rocky Point, a low

This is pretty interesting; don’t see this happen too often where a lobe of low breaks off and spins from Montana, back toward the south-southwest to pretty much over Rocky Point, MX, as you will see in this past 48 h water vapor loop. In a water vapor loop, you pretty much see all that the movement that is taking place in the atmosphere and here you can begin to understand why it takes biggest computers on earth to model it. Here’s a close up from IPS Meteostar.

Note, too, those white puffs exploding in west Texas as our little low spins thisaway. Those are massive thunderstorms that our low has and will be triggering in west Texas and eastern New Mexico over the next few days. This is great to see that happening due to the drought those poor folks have been experiencing over the past couple of years. This little low, as tiny as it is, will make a huge dent in those conditions in some areas. It really would be great to be there in some little town, like the well-named town of “Plains”, TX, and see how happy the folks are getting as the rains hit. It would be like the end of a Hallmark movie where everyone is quite happy about how things have turned out.

Here are two shots showing what its like now in Plains-Floydada, TX, area, First, you can see that the earth is quite flat there.

DSCN1514 — Note green along highway. It has been raining off and on in these areas for the past month, so things are perking up. There were occasional bursts of wildflowers, too.

DSCN1525 — These aren't horses. What are they?

But while Texans are getting happier and happier (and I hope they don’t complain about flooding because that would be just plain WRONG), what’s in it for us?

Well, the quality of moisture is less here toward the center of the low, maybe about 1/3 as much in the air over us as in Texas. So, what does that mean we will see? Maybe a few Altocumulus in streaks, maybe finely patterned Cirrocumulus, and then as afternoon comes on, some Cumulus with high bases because its so dang dry. I better predict some Cirrus cuz I see some now! Also, I think I will forecast that the low temperature this morning will be about 62 F here in Catalina because that’s what it is now. Maybe some ice optics, too, now in progress! Continuing, these clouds, too, mean some great opportunities for sunrise/sunset color and ice optics now that I see one (parhelia).

But with those high bases goes low temperatures, likely well below freezing, and you know what that means. The tops are likely to be colder than -10 C to -15 C, 14 F- to 5 F), an ice-forming threshold hereabouts for small, high based Cumulus. With the formation of ice, VIRGA, snowflakes and ice crystals come out the bottom. You can see this by the hazy look around the clouds where it is evaporating–ice takes longer to evaporate.

In the higher terrain, the virga will melt into rain and reach the ground, and the clouds will likely get tall enough to produce lightning, but not here today, but to the north of us at least early in the afternoon and evening. Our best chance of rain with thunderstorms in southeast AZ will be tomorrow as the moisture gradually increases over us from the backflow around the north of the low. The low is forecast to pass to the south of us tomorrow and Thursday. You can see all this happening in our local U of AZ weather model here. (Note the local time is in the upper left hand corner. You will see the precip is only forecast to occur in the afternoon and evenings with this system.

So, finally, some weather excitement in the offing!

What’s ahead?

What’s ahead?

Just ahead, our upper air anticyclonic summer regime

Looking troughy enough for a rain threat in a few days