Cirrus clouds – Page 16

Weather 10 days from now remains uncertain

Hahahahah. That is the funniest thing I have thought of in a long time, and its not that funny. Take a look at this “spaghetti” plot for 10 days from now based on last night’s global data. The map is for 500 mb, about 15,000 to 20, ooo feet above sea level.

“High predictability”, even as far as 1o days out, is indicated by those areas where the bluegreen and red lines are all close together. For example, in the upper left hand corner, or in eastern Asia and the extreme western Pacific Ocean if you can make those areas out through all the lines. Also, both the red and bluegreen lines themselves are pretty close together there, and that says the jet stream is extremely strong there, normal for that region in wintertime. That jet stream is geographically anchored in that region and so not much changes there, even from winter to winter.

But then look what happens to that compact jet stream as it approaches the middle of the Pacific! It comes apart, line a twisted speaker wire that’s been untwisted. The bluegreen lines, representing a colder portion of the jet stream, mostly head off to the NE, while the red lines, indicating a warmer portion of the jet stream, split off and continue more or less toward the east across the Pacific and into the Southwest. However, the details of both flows, the northern one and the southern warmer one, are pretty unknown, as evidenced by all the “scatter” in the lines, the “bowl of rubber bands” you see in the east half of the Pacific and into North America (and elsewhere). Note that the lines are tending to group that bit more over the eastern US, suggesting higher predictability, and the presence of an upper level trough (and cold in the East).

For the sake of contrast, here is the same kind of plot for just 48 h from now, showing high predictability. Of course, things always go to HELL in the longer term, but today’s 10 day vagaries are more than usual.

So, what seems to be ahead for sure is a split in the jet stream in the eastern Pacific with one of the branches coming toward us. That is the good part since that branch can be pretty wet if it is strong. But, as you can see, exactly where it is, and that’s crucial, is really anyone’s guess at this point. That warmer jet has to be south of us to have any rain with the disturbances that are shuttling along in it. And if you look over AZ, the red lines of the warmer jet are all over the map, literally.

Hence, to use an old word there, particularly uncertain times ahead. In fact the only thing that is certain, is with the southern branch of the jet in this area, there will at least be passing regions of clouds as upper air troughs go by. Will they, like yesterday, only be Cirrus? Or rainy Nimbostratus?

The second shot shows a nice “parhelia” or “sun dog” at the far right, caused by plate-like ice crystals falling face down, the normal mode. The final shot has some the rarely seen Cirrus castellanus, Cirrus clouds with little turrets or humps at the top.

Its not worth mentioning…

…so I wasn’t going to say anything, but last night’s model run based on the 5 PM LST global data went into a dry mode for AZ over the next two weeks, sucking up all that rain that was predicted in a run just SIX HOURS before the run last night (shown on the left), and all those runs before that one! Feeling like the model has punched me in the gut. It was like having your favorite’s team running back score the winning touchdown with a minute left on a 79-yard run, only to be called back due to a holding penalty. Or, in the World Series, the Cubs have just won the deciding game on a homerun in the ninth inning, but then it turns out that the batter hit out of turn and it was an out instead. Well, you get the idea.

Check the differences out between these two for the same time and day, Friday morning, January 20th from IPS Meteostar . Its incredible. That juicy, wet stream from the subtropics into California (right image) is completely gone in a forecast made just 6 h later!

Unfortunately, the new run with nothing but an upper ridge along the West Coast, and a deep trough in the East, is a favorite mode of the Great Southwest Rain Repeller, La Nina. In spite of the WILD fluctuations in model outputs over the past few days, you would have to give this latest one from last night’s global data some credibility. Its as though the model just woke up after all those predicted rainy scenarios in AZ and said, “I can’t do this, its La Nina time!”

However, with all these fluctuations, rainy scenarios for AZ may still come back. Standing by, if a bit grumpily. Maybe there’ll be some Cirrus clouds today to ease the pain. Let’ look at a national satellite view from the bowl record-setting University of Washington Huskies’ weather department here: Yep, a little band of Cirrus approaching from southern Cal. Should be here in time for a nice sunset.

Don’t forget, too, those Cirrus clouds are usually the way the tops of winter storms appear, one with vast layers and produce hours of rain at a time, if you could slice off the topmost 1-2 km (about 1,000 to 2,000 yards, or about the same amount of yardage as given up by my former company’s (i.e., Washington’s) football team in the Alamo Bowl this December 30th).

Remembering that about Cirrus representing the tops of storms if we could only see them will help us get through today’s model disappointment I think.

Some more of that Catalina climo

Here is a 35 year record showing what days have had measurable rain in January. Sometimes “singularities” in weather show up in these kinds of charts of tempearture or precipitation, such as the “January thaw” that seems to occur with some regularity in the East but is “unexplained.” You would be looking at our chart for Catalina for example, a cluster of days with higher or lower precipitation and it MIGHT be a singularity, something that Nature likes to do at that time of the year rather than a statistical fluke that represents nothingness. Here’s January, a month that averages 1.65 inches in Catalina. These data are almost totally due to the careful measurements made at Our Garden organic orchard here in Catalina–only the last few years here are from measurements on East Wilds Road.

Not much to see here. That peak on the 6th looks more like a fluke rather than a singularity. You would never say that one day represents a singularity, but maybe 5-10 days.

The reason why I wanted to see this was because of the striking changes that were foretold by the “WRF-GFS” model 36 h ago and were shown here yesterday. Was there a singularity that might support a greater chance of rain in SE AZ in mid-January, and therefore, cast that bit more credibility on such a huge model change?

I would have to say “no.” And, not surprisingly, that huge change has gone bye-bye in the models. Nothing like it is shown now, though they do have a rain situation developing for here by the end of the 15 day run (around January 20th and beyond). But this rain comes out of the lower latitudes of the Pacific, a completely different direction than was shown just yesterday, and if the models are correct in this pattern breakdown, it means flooding in California as the flow breaks through to the coast from the Pacific.

Below, what the models came up with based on last night’s global data, again, from IPS Meteostar, whose renderings I favor.

These are exciting times for those of us who peruse the models.

Why?

These vast changes indicate that there is something far, far upwind, perhaps a data sparse zone, errors in reported measurements that is causing a problem for the models and that more changes in their outputs may come down the line until that problem is better “resolved.” (They are never perfectly resolved.)

So, every 6 h update of the models is a “must see”, with the persuser (me) holding his breath with excitement. In these cases, its all “good” because a rain situation is foretold for us. Take a look at where the jet stream is compared to where it is now, up around British Columbia. You can see it barging into southern California and major rains ALWAYS accompany this pattern. Also, you can probably count on at least two storms breaking through before this pattern changes much. The reservoirists in Cal will be very excited to see this pattern develop since most of their holdings have much below capacity. And these kinds of storms usually produce significant rain in Arizona, too, though here we would be a little far south to get the brunt of those storms in this scenario.

Pretty clouds yesterday

Can’t leave without a little cloud excitement. I wonder how many looked up and saw this little beauty go by (shown below)? So pretty and delicate-looking, as unusually thick virga (snow) fell from this little cluster. It would be called, “Cirrus uncinus” at this stage.

That snowfall probably began developing one-two hours before it came over us, and the cloud patch would likely have been fluffed up on top that bit and as a mostly liquid water cloud, that is, an “Altocumulus castellanus” before becoming this “uncinus.”

Below we saw the dying remnants of that patch, the snow to finally stop falling out with the parent cloud mostly gone, and that snow continuing to dry up on the way down. Lots of nice cloud sights yesterday, in fact.

Enjoy.

Low spin cycle continuing off Baja; water being added

That enfante terrible now dawdles over the coastal waters of California and northern Baja today, adding some water to its central system as seen here from IPS Meteostar. Note, too, a scruff of Stratocumulus clouds racing northwestward in the Gulf of Baja abouit the latitude of the border between north and south Baja. This is good. Still, this is a marginal storm as it trucks through on Sunday evening and I will be happy if we get a quarter of an inch. Mods don’t think rain will get here until the upper center is upon us later Sunday. Here is the whole map forecast sequence showing temperatures and winds aloft at 500 mb from the U of Washington unranked Huskies who play #12 Baylor in the Alamo Bowl –what a horrible bowl game that is for Baylor–on Dec 29th. Still, as a spin off myself here into the SW like all of our lows this year, but from the U of WA, I will be rooting, of course, for the “company team” along with my friends and former grad students with whom I worked. BTW, these are pretty maps with lots of color as you will see.

You will also notice in this 4 day series of forecast maps for 500 mb that yet ANOTHER low drops into the Yuma area replacing the current one that begins to move toward us later today. That new low develops via the back door from Colorado and nests over Yuma as a cut off at the end of the forecast cycle above. That ‘s an unusual trajectory for a low! However, mods think its too dry to produce any rain as you might imagine. But with another low center aloft ending up in the SW, it demonstrates again our characteristic pattern for this early half of the winter, having become something of a low magnet. It certainly has been strange to see so many cut off lows.

BTW, the longer term picture after our little rain is a dry one for the next two weeks; it may well mark the end of our cut off low fantasia. Hope not.

Today’s clouds…

The marginal amount of moisture circulating around the periphery of this Baja low, I think will spin out some spectacular middle and high cloud streaks and patches over us such as Cirrus, Cirrocumulus with its tiny granulations, and Altocumulus lenticularis here and there, ones that often break up into small and interesting cloudlets downstream. Get yer cameras ready! Some of this began to happen yesterday afternoon. Sometimes you see the most amazing tiny delicate patterns, very photogenic.

Here are a few shots from yesterday, beginning with that sunrise patch of Altocumulus and ending with a sunset shot.

Grandson of “Frankenstorm” knocking on Heaven’s door (Catalina, Arizona)

Well, I think Catalina, AZ, being next to the Catalinas, is “Heaven’s door”. I think, too, to have a second consecutive thought, that we’ll get more than an inch out of this Big Boy which is rare here in Catalina for a storm in the wintertime. Not close in areal extent to the original “Frankenstorm” that struck the West Coast in January 2010 with record setting low pressure, but a potent one anyway. In the January 2010 storm we received 1.41 inches the first day and 1.18 inches the second to “ice” a fabulous wildflower bloom that year. We sure seem headed to a fabulous bloom season this year, too.

BTW, there has been a lot of rain in droughty Texas. We are brothers/sisters in drought relief it seems these days. How nice; adds to the holiday cheer. Maybe the price of hay will go down.. It seemed interesting to throw something about Texas in there. Here is a map showing that great TX rain of yesterday from WSI Intellicast¹. These radar-derived amounts precipitation are pretty much spot on–I’ve checked ground gages a number of times. We should be seeing “green”, 1-2 inches) over much of AZ in the next couple of days, too. So, the map below is like a preview for AZ.

Speaking of green, look at the “green-for-rain” in AZ in the lower right hand panel of this forecast for this afternoon ending at 5 PM MST. During the prior 12 h, beginning at 5 AM MST, the entire State of AZ is virtually covered. I am just beside myself when I see a map like this! And look how far to the south of Baja California the circulation of the storm extends. Its gorgeous to see this. I guess there could be some flooding here and there, and some “snow birds” might complain about the “crummy AZ weather”, but….you can find people who will complain about anything. See the whole wonderful model sequence of rain and mayhem in AZ here, and in much more detail from the U of A weather department, here.

Look, too, at how excited the National Weather Service, Tucson is! They must have 50 bulletins out–be sure to keep reading them. They are really having a lot of “fun” down there, too.

Late breaking storm bulletin: We have sprinkles in the area (0425 LST). Check this radar-cloud map out from IPS Meteostar. What a great day this is going to be! Enjoy. Good chance we’ll see water in the CDO and Sutherland Washes, and maybe some snow mixed in with the rain as the storm closes out Tuesday evening now.

But is this storm the end of our “fun” weather? Oh, no, my friend. Another cut off low develops in our area after speeding down as a trough out of the NW in five days. Another round of significant rain is likely, though not as much as this one.

Some cloud notes from yesterday, including some chat about the unusual streaks.

In that warm afternoon yesterday, it was so great seeing sheets of Cirrus and Altostratus (ice clouds, Altostratus with heavy shading) massing on the horizon, knowing that this time it was NOT just going to be a sky decoration for a nice sunset, but were clouds filled with stormy portent. You probably noticed the lack of sunset color due to the extensive coverage of those clouds upwind. No break allowed the sun to under light them, a sign of extensive clouds upwind to the southwest.

Also, unless you were blind you saw some unusual events in the thin Altocumulus (translucidus) layer yesterday: ice canals and splotches of ice produced by aircraft that flew in them. When so many happen as did yesterday mid-day, its a good bet those Altocumulus clouds, though comprised of liquid droplets, are terribly cold. While the TUS morning sounding did not pick up this mid-day layer, one can be confident that it was likely colder than -20 C or -4 F.

What you also saw was examples of how the presence of ice within a droplet cloud, causes the droplets to evaporate, and the ice crystals to grow and fallout, something that happens on our rain days. However, because there were so many ice cyrstals produced by these aircraft (almost certainly all jets) they compete for the tiny amount of water available at -20 C and form small crystals with little fall velocity.

So the trails of precipitation are very fine and don’t go very far. Here are some examples of that rare phenomenon, rare because for us to see it, takes a thin, cold water droplet cloud, and it has to be high enough so that aircraft are frequently penetrating it. One wonders why, in some of these cases, the trails yesterday were so long with an aircraft probably could have climbed or descended a couple of hundred feet to avoid flying in a light icing producing cloud (the Altocumulus layer composed of supercooled droplets)? Note “ice optics” in ice canal in the first photo, a weak sun dog so I didn’t just make it up that the canal was ice. I you wanna know more about this phenomenon, go here and/or here.

On schedule for major AZ storm beginning Monday

Now that the models have reconciled, “come together”, to show a large storm affecting Arizona and us here in Catland beginning later Monday, it seemed interesting to ME to show you how this one gets here. This is where our numerical models do things that in the olden days before them we could never anticipate.

Here is a loop from last night’s global data on how a large, vigorous low center forms over San Diego within about 84 from right now. This loop of the high and low pressures in the middle troposphere (around 15,000-20,000 feet above sea level) from the University of Washington’s “WRF-GFS” model for the West Coast and environs:

Watch what happens in the Gulf of Alaska. Everything is rolling along FAR to our north, going toward the east, looks like it’ll stay up there with those waves moving one after the other into Canada. There is no hint of anything moving this way. Then suddenly, the wave rippling along in the Gulf turns south bound as it hits the West Coast, part of it ripped off and becoming a spinning center just off California and the rest continuing on into central Canada! Really, its amazing to see such a drastic change like that shown in this sequence.

This type of sequence has been very much like this winter’s past storms have gone through, rippling along in the northern Pacific Ocean, and then suddenly part of those waves shearing off from the main jet, making a right turn toward the SW US, becoming an isolated, spinning, wobbling center away from the steady strong westerlies of the jet stream. Some years have had lots of these “cut off” lows, and it seems we are headed in that direction this winter, at least through the first 6-7 weeks.

One of the keys to this happening is how vigorous is the storm immediately upwind of the one that plunges south, oddly. This influence of upwind storms in perturbing the jet stream downwind was discovered WAY back in the 1950s. In the current situation, an extremely intense low developing in the central western Pacific sends huge amounts of heat and clouds northeastward behind, upwind, of “our storm” and that heat and moisture (see here protruding into the Aleutians in this loop) helps amplify the jet stream downwind where our storm wave is by causing the winds shift more to the north downwind of the warm air plume at the backside of our wave).

What it is doing is building, for a time, a high pressure ridge aloft within and just ahead of it. In response to that “ridge building” plume of heat and moisture caused by that intense storm upwind of “our wave”, the jet stream downwind begins to head more to the south, IN our wave. The intense storm behind our wave is building “amplitude” in the jet stream. Amplitude in “synoptic” meteorology generally means the jet stream winds go more to the north and south rather than just east and west. And that’s what you see happen for a time in this loop, and its this greater amplitude that causes a part of the once steadily progressing wave across the Gulf of Alaska to go, “Oops, must go south now” as the winds from the north increase tremendously on its backside.

The assymetry of the winds in these waves tell you where its going next. If they are stronger on the backside, it will go south or southeast. If the winds are strongest on the front side, or east side, it will go north or northeast. If you can see the winds in the above loop, you’ll see that they reach 120 mph from the north on the backside as it plunges S, but the winds on the east side are only about half or less of that.

Hope this is somewhat intelligible. Still rewriting…!

Personal predictions? I think we’ll get at least 0.50 inches, probably see some more snow mixed in with the rain by Tuesday morning. Think about a great wildflower bloom this spring. In the meantime, enjoy the warmth and cirrus of the next couple of days. One thing that might help is that disturbance SE of the Hawaiian Islands feeding moisture into the jet stream (seen here in this loop again). I thought at first that bunch of clouds might be related to the MJO (not a coffee brand, but the “Madden Julian Oscillation” which can have a profound effect on US weather). But it wasn’t. The MJO is in the area of the Maritime Continent now. Go here for the latest NOAA details on this subtle wind regime that travels around the globe toward the east.

Last evening’s “cirrus-ee”, (ice crystal clouds), sunset.

The End.

“Come together, right now, over me” in Arizona with some rain

This song and refrain by Lennon and McCartney, amended a bit in the title for local interest¹ was actually a reference by them to a striking “divergence” in weather model predictions of that day during a droughty time in England; the models did “come together” eventually to predict the same thing, and that was for a lot of rain in droughty England in the days ahead. By the way, you won’t find this kind of historical background information in Wikipedia or in some biography.

As we saw yesterday, one model can show a lot of rain in AZ a few days, and another not. So, we, too, as did Lennon and McCartney, wanted those models to “come together” and show the needed rain over us; not one model doing this and another one doing that, as they can do. I know a lot of you were fretting all day about which one was going to be right, the dry one or the wet one for Arizona? Well, we have seen them “come together” over the past 24h.

Expect rain and snow!

And a goodly amount of it, in AZ, including Catalina, beginning late on Monday and then continuing off and on for a couple of days! Wildflowers, here you come! Maybe you should get that better camera before the spring bloom, and also help the economy along while doing so.

And as you might have speculated, the Canadian wet model run for Arizona, the one one showing a storm pattern similar to the ones we have had intermittently in November and early December, was the one that won out over yesterday’s model “diffugulty.” This is great news unless you’re chauvenistic and just that bit peeved that the Canadian model won this event in the “weather model Olympics.” Oh, well. The US model, while now predicting storminess for us is a bit drier than shown here. Still, its all good.

Here’s last night’s juiciest Enviro Canada panel for AZ, that for Tuesday morning at 5 AM PST showing the storm barging well into AZ (lower right panel). Exult! The entire sequence can be seen here.

On a cloud note, we had for a time yesterday, some of the rarely seen Cirrus castellanus, icy clouds with turrets. Usually its too cold and too “stable” for turrets at heights above about 30,000 feet above the ground, but there they were. See below.

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¹In the early original drafts of this song, the reference was to “England”, not Arizona. As you can see, those part of the lyrics referring to location and rain were a bit awkward and were eventually dropped.

Yep, its gone; all that model predicted rain in just the next 12 h run!

Dammitall! Of course, being quite jaded, and knowing drastic changes in model predictions from one run to the next are usually bogus, this disappearance of all that predicted rain in 10-15 days ahead of us on yesterday morning’s National Center for Enviro Prediction “GFS” model has hurt. People don’t realize how hard it is to be a weatherman/meteorologist. You get hurt like this a lot. I already was thinking about the headlines. “Farmers beg for dry weather!” “Tucson becomes sister city of Venice!” Sign in downtown Tucson: “Water skiing rides, $10.” “Tucson surf report: 1-2 feet with a slight chop. Winds NW 5-10 mph.” “NWS, police caution Tucson boaters about drinking and boating.”

OK, now those potential headlines and story lines are gone. Not a drop of rain is shown in all of Arizona over the next 15 days in the model run executed last night. That run was based on global data taken just 12 h after the Wet One yesterday morning (that is, around 5 PM LST). Not a drop in the next 15 days, just like the Dry Ones had before the Wet One! Its too depressing to show them so I will just blab some.

However, here’s is another secret about models. They don’t always “forget” an outlier prediction like yesterday completely. As new data comes in this morning, and in the days ahead, one should not be surprised to see SOME rain start creeping back into Arizona in those later predictions for that wet period, now 9-14 days ahead. So, as in a relationship in which you’ve been spurned because of a tempest in a cloud bottle, really not that much, i.e., if it was a rainstorm it would only be a trace; it might be rejuvenated, though it might never be the same (that is, the model runs will never show as much rain as the Wet One did).

What is always interesting to meteorologists is to ferret out the region of the globe that was in error, what measurements caused the Wet One to appear?

Consolation: at least the cloud drought is over with some pretty Cirrus this morning. Should be a nice sunrise. Remember, too, that Cirrus clouds, composed of tiny ice crystals that fall out, is considered to be a precipitating cloud though those ice crystals are too small to show up on radar. “Hey”, if you were on Mt. Everest you’d think it was snowing that bit (dust-like snow, which we can identify with here in the SW because we have dust).

Maybe a trip to Mt. Everest would be something you should check out, though personally I would like the Cherrapunji region of India-Bangladesh during the real monsoon, the one in Asia. Why? “Factoid”: Cherrapunji once had over ONE THOUSAND inches of rain in a 12 month period! Still reigns as the world record for that amount of time.

The End

Calming Cirrus

Feeling better now after some calming Cirrus uncinus and spissatus moved in yesterday. Wasn’t sure we could have clouds anymore here above Catalina, AZ. Really, there’s nothing like some uncinus and spissatus to make you feel better after you get worked up over some global cooling stuff you thought was wrong. And that nice sunset later on didn’t hurt either. Its great to get stuff out after stewing over it for a few years, too. Next, will certainly have to correct that National Academy of Sciences report on cloud seeding that came out back in 2003. Still upset over some stuff in there…. Got our (Hobbs and mine) work wrong! Unbelievable. What were they thinking?! Don’t think they read some of the things they cited! They will be scolded royally after I have thought about it some more…

Oops, hope we have some more calming Cirrus today.

The End.

Cirrus show

Just a couple of photos of yesterday morning’s glorious display of Cirrus (OK, “uncinus”) clouds, those high, icy white ones that were so fantastic enhanncing the desert and Catalina mountain background, taken from on top of a horse.

As you know by now, those Cirrus clouds are composed of tiny ice crystals, but, as tiny as they are, they are generally far larger than droplets in clouds. So, when ice clouds form, they are essentially precipitating clouds. Those ice crystals are too heavy to stay aloft and the larger ones settle out producing these extremely fine, delicate strands. Sometimes those trails extend thousands of feet below the “head” of the cloud where they were generated, and as they fall, go into regions where the wind is slightly different in velocity and direction, and so you get interesting twists and turns.

If you could fly up there, you would find tiny snowstorms of simple ice crystals shaped like little bullets (a crystal type), triangular prisms, stubby columns, or plates, crystals that would sparkle as they went buy and showed their pristine faces to the sun. Seen’em do that many times when with the U of WA and their flight research program. They look like daytime shooting stars, or fairy dust, as they rush by the pilot’s window, and also where I was, viewing from a dome atop the fuselage of our various aircraft. You would not know you were in a “cloud” except for those displays.

The last photo is of a droplet cloud, Cirrocumulus, composed of extra tiny cloudlets. It was a higher altitude one, pretty cold up there, maybe -30 C. Went off the “screen” before it may have crystalized into a Cirrus cloud many do. I thought it was a nice view, taken on the Canyon Loop Trail near Green Rock yesterday.

The End.