6:05 AM. Pretty ripples in Cirrocumulus below some Cirrus. What a fantastic and subtle scene this herring bone pattern was!9:34 AM. Pretty much a whole Cirrocumulus morning, punctuated by a few Cirrus clouds. Why isn’t it Altocumulus? Granulation is too tiny; no shading. BTW, no ice evident though this layer was colder than -20 C (-4 F).10:30 AM. An aircraft has punched this very thin Cirrocumulus layer and left a tell-tale ice trail that looks like natural Cirrus. Same cause for that second, white ice patch farther to the west. Its almost impossible to detect something like this since the ice trail from the aircraft is almost exactly in the form of a Cirrus uncinus. The absence of natural Cirrus is a clue about what happened.10:34 AM. The aircraft-induced Cirrus is passing overhead, and if you look VERY closely you can see that tiny “supercooled” cloudlets of Cirrocumulus are still there around it. The ice crystals fell below the Cc layer and disappeared over the next 15 minutes.2:27 PM. Later that day….widespread natural Cirrus overspread the sky, with a very thin patch of Altocumulus on the right (granulation is a bit to large for Cc).3:44 PM. Those Cirrus clouds thickened and lowered some, trending (as we would say today) toward Altostratus (translucidus–the thin version).
Today’s clouds
Today our passing cold-core trough is overhead and in the middle of it, the moisture is low enough to trigger Cumulus and small Cumulonimbus clouds as the middle and high clouds exit “stage right.” Should be an interesting day since these cumuliform clouds will be so high-based (above the Lemmon summit) and cold that lots of ice will form, producing virga, and in some places, sprinkles. A hundredth or two is possible, but that’s about it. Heck, I guess there could be some lightning here in southern Arizona as well.
This will be the last interesting cloud day for awhile, as you likely know.
Below, your weather map for 5 PM AST when there should be plenty of ice action all around:
First, it behooves me1 to point out that there remains a considerable amount of uncertainty in the weather WAY ahead. This is demonstrated below by the map from the NOAA spaghetti factory from last evening, one that churned out a LOT of “spaghetti”, perhaps making the point about how chaotic weather is:
Valid at 5 PM, March 26th, two weeks from now. Doesn’t matter where Arizona is; although, although… when I look really close….I think I can see some rain for us. The lines are selected contours of the height of the 500 mb surface, after slight errors have been introduced to the initial state of the forecast model. The actual forecast of those contours is in their somewhere.
Yesterday’s Cirrocu
Late yesterday, a thin moist layer moved in and produced, where the air was lifted that bit more, a little patch of Cirrocumulus, our most delicate cloud.
5:09 PM. Cirrocumulus. No ice apparent, something that would blur the spaces between the tiny cloudlets. Height was about 17 kft above the ground, temperature, -15 C. So delicate!
6:28 PM. Line of Altocumulus enhances sunset. Too thick, elements too large to be Cirrocu, though they were both at the same height yesterday.
I think that covers just about everything.
The End.
——————-
1What an odd expression, to “behoove oneself” in effect, as in becoming a perissodactyla, while doing something you feel you must do as a responsible person. Imagine, before issuing a responsible statement, that it was normal for people to put on hooves, or to wear them when coming out to a news conference to announce something responsible, correct the record, etc. Perhaps, if it wasn’t that bad, you would wear only one hoof…
Rain beginning to pile up again in Cal as behemoth Pac storm moves in. See an actual, professional level weather map below, not a mickey mouse one. It will be good for you to see a complex weather map with all kinds of weather symbolia on it:
0.01 inches at Opids Camp, LA area mountain site, already (at 5:30 AM AST) out of predicted by C-M of 10 inches or so in the next 24 h; highest totals somewhere in central and southern Cal mountains likely between 10 and 20 inches for this one storm! California dreamin’1? Will keep you posted if I am right.
Here?
Really tough to forecast more than an inch in one winter’s day in a desert. Goes against the grain and the cactus, for that matter. Thought I would get some help from the great U of AZ Beowulf Cluster, but its still crunching the 11 PM AST data away as I write here at 5:30 AM. So, can’t wait for a really accurate answer. You should go there, though to get one….
Being crude, then, and I mean using a model with a huge grid spacing compared to that of the U of AZ Cluster model, the Canadian GEM indicates about 36 h of rain, 5 AM AST tomorrow to about 5 PM on Sunday, and even at a average of 0.05 inches over that time, you get 1.80 inches! Good grief. So, maybe now that BIG forecast by a BIG atmos sci faculty member at Colo State, “1.5 to 2 inches”, might be right, closer than my dinky 1 inch max forecast of yesterday. Its great to be wrong when you under forecast precip, but that’s about the only time!
Higher resolution US WRF-GFS mod run from 5 PM AST last evening has fewer hours of precip, BTW, partly because it DOES resolve the forecast in 6 h blocks, not 12 h ones like the crude Canadian model.
Also, the winds above us, being more westerly than southerly during the coming storm, is better for us here in Catalina. Deep southerly flows have to go over Pusch Ridge, and rain can be diminished locally that bit due to the downslope effect off the Ridge. Won’t have that tomorrow and Sunday, so that’s a plus.
The cut to the chase: minimum from this typewriter now HAS to be much higher than 0,25 inches as was indicated previously. Will go to 0.75 inches as the LEAST we’ll get (things don’t go well, main bands just miss Catalina, etc), with 1.5 inches as max by Sunday evening 5 PM.
Will not mention this forecast again, of course, if the rain in Catalina is outside these limits.
Yesterday’s clouds
Nice patterns and nice small Cu yesterday with great visibility again.
1:53 PM Finely granulated, and with a bit of color (iridescence) Cirrocumulus. Here, the Cc is at mid-levels, not at Cirrus levels. In our cloud classification scheme, which is a little funky, its only the tiny granulations that make it Cc and not Altocumulus. Happens a lot.
5:13 PM. Delicate Cirrus uncinus (hooked Cirrus).
6:18 PM. Sunset Cirrus uncinus, so pretty.
The End, except for a little peak at Opids Camp rain just now… Wow, was just 0.01 when I looked at the 3 AM ob, and at 6 AM is already over an inch!
Hope, too, you caught the beautiful sunrise just now. Will reprise it tomorrow.
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1Some of you will instantly recall the initial words to this pop tune:
“All the leaves are brown, and the sky is gray, I went walkin’ for awhile on a winter’s day.”
These words were inserted after the “Mamas and the Papas” poke at LA smog in the original words were deemed by producers as less desirable in seeking a commercial hit. The original words that the song began with, before it was commercialized, were” “All the leaves are gray, and the sky is brown”, words that might offend Californians. Thought you’d like to know.
BTW, this video above is a PERFECT paradigm for this year’s sunny, warm and dry weather in the West, and the brutal winter back East. Take a look! Its great!
“Better” means wetter, of course. You don’t read this blog to read about DROUGHT! You read it to read about rain and moistness; clouds, too. Let’s leave drought for the other guys…
Here is the latest model permutation from the Canadians, one that successively, and successfully, I might add, jacks up the amount of rain for AZ as the real deal gets closer on the November 21-23rd. Take a lot at these two depictions from Canada for the 22-23rd (sorry about the small size; the Canadians are shy about their model outputs and don’t like to post large gifs or jpegs; also remote areas of Canada mostly have dial up so big files are a problem I’m guessing):
Valid at 5 AM Saturday, November 23rd. Note streamer of heaviest rain in central AZ, The colored regions are for those areas in which rain is forecast by the model for the prior 12 h.Valid at 5 PM, Friday, 22 November. Note streamer of heaviest rain in eastern AZ, and over our area with lots more ahead!
The colored regions are for those areas in which rain is forecast by the model for the prior 12 h.
Note round low near San Diego in the first panel, upper left:
“Round lows out of the flow; no one knows where they want to go.”
This old weather forecasting limerick I just now made up sums this situation well. Round lows sit, spin, wobble and jerk around for awhile, and so they shovel rain and clouds over the same areas for one or two days, sometimes longer.
So, instead of a nice sharp frontal band passing by within a few hours and then its over, as happens most of the time here, bands rev up and keep spinning around the wobbling low, often hitting the same areas and the rain/snow keeps piling up. Remember the giant cutoff low in December 1967, and the MOUNTAINS of snow it produced back then in northern and central Arizona, stranding hundreds? Well, this ones not THAT big, but its big deal anyway with lots of water in it, and not so cold as the one in 1967 when “album rock” was emerging.
So, this could put a real dent in our October-November rainfall deficit throughout Arizona, a real “worth billions of dollars storm” to agriculture! I am pumped, as are you!
Great storm, too, if you’re planning on getting those spring wildflower seeds in the ground; do it just before the storm arrives and you’ll likely get a colorful return in the spring this year.
What are the chances of measurable rain here in Catalina? Oh, right now, I’d say anywhere between 100 and 200 percent. Now the NWS is NOT going to give you those kinds of percentages I might add. You only get them here.
Amounts?
Let’s go for it. I say the minimum (10% chance of LESS) is 0.40 inches, maximum (10% or less chance of more), is 1.50 inches (big top side due to stationary aspects of storm, likely thunderstorms in area). Median of these, which might be the best estimate for Catlanders (those domiciled in Catalina): 0.95 inches, all falling between the morning of the 22nd through the morning of the 24th, likely in pulses. Goodbye dust!
But in those central AZ mountains, with flow more or less perpendicular to them from the south, their best rain producing wind direction, 1-4 inches is very likely. Yay for rain and snow, maybe some TSTMS, too, comin’ right up.
Didn’t mention the US mods but they are “on board” for a major rain event in AZ. Canadian one saw it happening first, so am sticking with it.
Still another pretty good rain chance as the month closes, but a far colder situation than the one coming up.
Yesterday’s clouds
Small ones, Cumulus humilis, no ice, but pretty anyway. Also, a little smidgeon of Cirrocumulus late, with Cirrus, too, invading from the SW, and a pleasant sunset.
5:11 PM. Cirrocumulus blossomed overhead as a moist layer way up top encroached. No ice indicated.2:46 PM. Cumulus humilis dot afternoon skies. No ice indicated.5:32 PM. Cirrus clouds provide target for fading sunlight.
One of the best, really, never mind all that wind yesterday. No rain, of course, in our future, not even fantasy rain these days.
See usual rehash of yesterday’s clouds, the 60s, in case you forgot, below:
8:49 AM. This Altocumulus perlucidus cloud behaved like a lenticular, holding in place for at least 2 h, but did not have the classic pancake or sliver look of lenticularis clouds. Air likely too unstable (temperature dropped with height rapidly) and allowed tiny cumuliform elements to form. Only on the very right edge where it first formed, did this cloud appear “lenticular” in any way with its smoothness
10:15 AM. More classic looking, sliver Altocumulus lenticularis beyond the Catalinas. Cloud forms on the right edge, dissipates on the left as the air rises and falls slightly.
11:58 AM. Cirrocumulus (delicate granulation) on the fringes of Altocumulus (larger elements on the right). 12:01 PM. These clouds change by the second as the degree of moisture in the air jetting along up there ebbs and wanes. Look how much larger that fine granulation on the left got in just a couple of minutes. 2:09 PM. One of the many examples of iridescence seen yesterday in those Cirrocumulus clouds, or on the very thin upwind edge of Altocumulus lenticularis clouds. Its due to the formation of extremely tiny droplets, a few microns in diameter, that cause diffraction in the sun’s rays (see link for a more complete explanation and nice examples). Do you remember that white light has the wavelengths of all the colors in it? Here you can see some of them, and photograph them by performing a replication of the Black Power salute of Tommy Smith and John Carlos from my alma mater, San Jose State, one that beat the Wyoming Cowboys recently in fubball. I added a link in case you forgot and wanted to get worked up again. Yes I was at SJS when that happened down Mexico way, minding my own business doing weather forecasts with a political slant (left, of course, because that’s what made you popular during the rad lib days) for the college paper. Suddenly, I feel like going to San Francisco, putting some flowers in my hair.…
2:19 PM. Cirrocumulus and Ac lenticularis in the same layer. Recall Cc can’t have shading, not that it matters that much.
4:39 PM. This dramatic scene amid the dust and wind. This would be an Altocumulus lenticularis, one that devolves into Altocumulus perlucidus (honeycomb pattern seen downwind from the distant leading edge).
As water year winds down, just a couple of weeks left, its worthwhile to see where we are. Pretty dismal. You can see why the spring wildflower bloom was minimal around here. Great December, though!
Can there be any rain before the official end of the month, measurable rain that might improve our dismal 10.83 inches, droughty total?
Not if you believe our own WRF-GFS model run from last night, but, “yes” if you like Canada and the Canadian GEM model. It has some rain in the area for us on Sunday the 22nd. Here it is:
Valid at 5 PM, Sunday September 22nd. Note green in SE AZ (lower right panel), and blue for moist air around 10,000 feet ASL in the left lower panel. Excellent model run.
In the meantime, our own model run has the moist plume WAY to the east at that same time, and so no rain here. Here is that map from the WRF-GFS , as rendered by IPS Meteostar, for moisture around 10,000 feet ASL. The blue moist plume in the Canadian model above (get microscope out) is the same as the green one below, except that the green moist plume is shoved off to the east and south. Dang.
Also valid for 5 PM AST, Sunday September 22nd. The green plume here across NM and into the Plains should be compared with the blue plume at this level (700 mb) in the Canadian run above.
Saw some clouds in the moonlight just now. Seems that drier air can’t quite get rid of our summer regime moist plume, one that even yesterday was close enough to us to have produced a thunderhead off toward Mt. Graham and vicinity to the NE. The chances are small we’ll get any more measurable rain, but as in sports, that moist plume seems to be hanging around, and you know that old sports saying that when heavily favored teams let underdogs “hang around”; don’t blow them out as expected, upsets can happen. Well, of course, that’s what I am hoping for, just that bit more rain to at least push us over the 11 inch mark. Its not a BIG hope, just 0.17 inches more before October 1st.
Here are a couple of cloud shots from yesterday:
7:34 AM. When it seemed the mid-level moisture should be gone, there it is, hanging around. These Altocumulus clouds meant that Cumulus were also likely to form in the above normal heating we have going on now. 9:38 AM. Some Cirrocumulus (fine granulation with waves in it). Since some areas have shading, not allowed for Cc, it would have to be considered a mix of Altocumulus and Cc (often observed) or just termed Altocumulus since the height is much lower for this complex of clouds than cirriform clouds. Gads, I doubt that’s clear. Oh, well. 2:09 PM. Thunderheads arose repeated in this area, then dissipated soon after this shot. 3:12 PM. A little patch of Cumulus humilis, kind of looks like someone leaping at something. No ice visible.
First about the rainfall around Arizona yesterday….
Jack is happy. Got 1.21 inches yesterday afternoon. Nice! No doubt some of our friends, fellow lowlanders, who can’t take Catalina-Sutherland Heights when the temperature rises above 82.5 F unlike you and me, experienced that cloud downspout that occurred at to Happy Jack Ranger Station in Pine, AZ, at almost 8,000 feet elevation.
For additional rainfall reports beyond those provided at “Happy Jack”, of course, we have to go to about 3 dozen other places because no one has managed to cull ALL of the rainfall reports we get into ONE daily list. Well, maybe the NSA has them all… Here are a few more links to rainfall data:
Not to mention the many “school net” and TEEVEE station-established rainfall reporting stations, and those folks who monitor rainfall at home but don’t report it to the rest of us who want to know about it. Maybe NSA can help out there, too. Hahahahaha, sort of. (BTW, I have nothing to hide to whomever is reading this; well, mostly nothing.)
——-EDITORIAL OUTBURST——
How strange it is that we cannot go to ONE friggin’ site and get all of the rain reports for the whole State! Would it be due to a lack of…….inter agency cooperation and competition, even among non-profit organizations???? (Insert creepy organ music here)
——-END OF EDITORIAL OUTBURST——
Back to rainfall observations…..
Douglas, AZ, if you haven’t heard from your favorite TEEVEE meteorologist who makes a lot of money1, has experienced its wettest June through August ever, with 13 plus inches, with about two weeks to go! This is for the purpose of generating a thought about a trip, a weather vacation, for you. That whole area down there, with its historic heavy rains this summer MUST be seen! Your weather diary will be sadly lacking without some notes about the vegetation, ponding and stream flows in that area. Damn well know I’m going again. There is a treasure of scenes, maybe new lifeforms, down thataway that won’t happen again in our lifetimes. The specifics below from the NWS:
SXUS75 KTWC 130105
RERTWC
RECORD EVENT REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
605 PM MST MON AUG 12 2013
...DOUGLAS ARIZONA RECORDS WETTEST METEOROLOGICAL SUMMER ON RECORD...
RAINFALL OVER THIS PAST WEEKEND AT BISBEE-DOUGLAS AIRPORT PUSHED
THEIR 2013 METEOROLOGICAL SUMMER TOTAL TO 13.23"...WHICH ECLIPSED
THE OLD RECORD OF 13.07" FROM THE SUMMER OF 1964.
METEOROLOGICAL SUMMER IS THE PERIOD FROM JUNE 1 TO AUGUST 31ST.
THE 13.23" IS ALSO THE TOTAL FOR THE 2013 MONSOON. THIS RANKS AS 2ND
WETTEST MONSOON ON RECORD...STILL WELL BEHIND THE RECORD OF 15.90"
FROM 1964.
LASTLY...THE 2013 CALENDAR TOTAL OF 14.10" CURRENTLY RANKS AS THE
19TH WETTEST YEAR ON RECORD.
$$
On to clouds, yesterday’s:
As a CMJ, you should have noticed the harbinger of better things ahead for late yesterday afternoon and evening when we had “thunder on the Lemmon” beginning at 2 PM, about 4-5 hours earlier than the two prior days. Earlier is better.
Also earlier were the first scruffs of Cumulus clouds forming over the Catalinas, in this case about 2 h ealier than prior days, another “earlier is better” scene for rain here in Catalina-SH. Here are some scenes; hope you seen’em. Oh, my, another outburst of creativity.
First, before Cumulus, these “strangers”:
8:11 AM. Billow clouds, Cirrocumulus undulatus, if you want a tech name. They weren’t around very long, just a few minutes, hope you scene’em. Best seen as action figures in the U of AZ time lapse film for yesterday.
11:13 AM. Cloud street streaming off the Lemmon is pretty advanced for this time. Cloud bases, too, a bit lower than the day before. Lower is better (for rain amounts).1:43 PM. First ice on top of Ms. Mt. Lemmon. Should be in your diary. Can you see it? Answer in next image. I’m trying to learn you up on these things…dammitall. Note lack of a rain shaft at this time1:43 PM close up of glaciated turret showing above the cloud mass above Lemmon. There’s some writing on it. Thunder b
While this early TSTM fabove aded quickly, dropping only 0.28 inches on Mt. Lemmon, the “Dump of the Day” (say, those within 5 miles of here) erupted suddenly just after 5 PM over and to the south of the Golder Ranch development at the foot of the Catalina Mountains. The cloud-to-ground strikes came within seconds, not minutes from this dynamo, though like its predecessor, it did not last long. Still, parts of it moved far enough north to give SH (Sutherland Heights) 0.12 inches. Here it is:
5:16 PM. “Dump of the Day”, looking toward the Golder Ranch development from the parking lot at the top of Golder Ranch Drive. LTG was too scary to leave car.
And, of course, the day finished out with another one of those dramatic sunsets, and the lighting on the clouds at that time of day that makes us so happy to be here, that we can take temperatures above 82 F without having to depart for higher ground. Last evening, this beauty:
7:03 PM. Looking north beyond Saddlebrooke, and along with it, another fabulous evening of lightning. Doesn’t happen like this as a rule in that colder, high terrain that our “temperature refugees” head for. Much better down here for evening and nighttime LTG.
——————
1I dream about being a TEEVEE weatherman making a LOT of money. I could then take those weather vacations I’ve dreamed of, never mind the State Department Travel warnings, to Cherrapunji, India, where they once measured over a thousand inches of rain over 12 months; to the Island of La Reunion in the southern Indian Ocean where tropical storms have sat and dropped, and your jaw will also drop, 72 inches of rain in ONE day, and 66 inches in 18 hours in a DIFFERENT storm–before that one let up.
At sunset yesterday, this rarely seen optical display called a “sun pillar”:
6:58 PM. A sun pillar sprouted from the horizon due to a few plate-like ice crystals falling from those Altocumulus clouds.
Waited for a cute bird or bat to fly above or through the pillar, making it a more popular, valuable photo; instead a helicopter came by. But it “works” as shown below. You’ll have to look hard, but its there.
Also at 6:58 PM. “Sun pillar with helicopter” $975. But, if you call now, you’ll get TWO of these exact same photos for $1,950.
Some of yesterday’s other interesting cloud formations:
4:25 PM. Patch of CIrrus spissatus with flanking Cirrus uncinus.
5:30 PM. CIrrocumulus (center, left, fine granulation) and Altocumulus (larger more separated elements) right side. The whitish veil to the left of these droplet clouds are ice crystals that likely formed within them.6:38 PM. The fine and extremely delicate patterns in Cirrocumulus clouds still amaze.
Today’s clouds
Weak wave/trough passing to the south of us has some great middle and high clouds in it, splotchy ones that are sometimes incredibly spectacular, clouds like Altocumulus castellanus/floccus with virga. Just looked outside now and some of those are to the southwest of us at 5:35 AM. You can see how complex the cloud coverage is at IPS MeteoStar’s sat-radar loop here. They’ll be gone later today so enjoy them while they’re here.
The Weather Ahead
There are many troughs foretold for the Southwest and Great Basin area over the next two weeks. That the good news; it also goes with long term climo patterns that troughs like to nest in the Great Basin. But none extrude far enough southward, that is, the jet stream racing around the trough bottoms does not reach us, to bring precip to southern Arizona. Occasionally precip hits northern Arizona over this two week period, which is good, of course, for them and water supplies. In fact, its not even likely that we’ll see a cloud below 10,000 feet above ground level here if this pattern holds. And with troughs and low pressure centers nearby to the north, periods of windiness and dust will occur as they go by.
Fortunately, I guess, there’s little confidence indicated in these forecasts beyond about 11 days, NOAA spaghetti says, and so there are surprises that can pop up yet.
Low forming in AZ. Jet stream (at 500 millibars) goes by/strengthens to the SE during day; therefore, expect rain to begin before 5 PM, but not before 11 AM. It should continue off and on for about 24 h afterwards (in case you don’t watch TEEVEE where YOUR weatherman/gal will be telling you much of what is below. But to make it that much more interesting for you, this: (Cloud pics way at bottom in case you want to skip all this.)
Let’s play, “Beat the Model!”
Kind of a “fun” day for us amateur and highly paid media forecasters since rain will develop where there is none upstream of us; clouds will thicken downward from the Cirrostratus/Altostratus with Altocumulus as the day progresses, with light rain beginning from that process, heavy layer clouds with virga that eventually reaches the ground as the atmosphere moistens up. For example, at this hour (4:50 AM AST) there are NO radar echoes from precip in all of Arizona, somewhat surprisingly.
As part of the “game”, and AFTER laying this out this rain onset timing (rain beginning after 11 AM and before 5 PM in Catalina, that is, best guess, first drops in mid-afternoon), its then fun to see what the very latest super Beowulf Cluster model of the U of AZ says, the best of the best. Its a test of how well you and me are “learning the territory”; “don’t need no model” if you truly understand our SE AZ patterns (when rain occurs relative to air flows aloft like jet streams), know the local and upwind terrain effects because you’ve lived here long enough, can read satellite imagery, etc.
Of course, you can’t really do this except when the weather is at hand. The models are just too good when it comes to beyond a day or so.
Rain amounts?
Here’s how to make an educated guess from “patterns and such”:
First, determine the outliers, those least and greatest amounts “possible”: bottom of precip amount (if things really go bad) here now looks like 0.20 inches (estimated 10% chance of less), top amount (if things really go well) up to 0.80 inches, (estimated only 10% chance of more than that, i. e., everything appears to be falling into place for a substantial desert rain here. The best guess, now that you’ve figured out the top and bottom amounts in kind of a mental “ensemble”, the average of those two outlier forecasts, 0.50 inches by mid-day tomorrow. That’s it.
Since I have busybeelabored these weather points for some time now for the two of you that read this blog, we should all be making the same interpretations today sans model outputs; just eyeballing stuff, doing our own thing, getting a handle on this storm by really THINKING about it, not just soaking in some model output quite yet. Don’t peak yet! This is better than Sudoku, Angry Birds, bajan, facebook, etc.
NOW let’s peak at the U of AZ model from 11 PM AST to get the latest, best prediction for Catalina and see how it matches up with our own forecast based on perusal of a few simple model charts, sat imagery, dewpoints, etc.
Here are the U of AZ Beowulf Cluster outputs, run from 11 PM AST data. The rain arrival in Catalina is shown in the panel below and its between 5 and 6 PM AST, moved up from 10 PM on the run 24 h ago, but a few hours later than our SOP (Seat of the Pants) forecast above.
This is so great! I love this competition! Its weather sports! Its great to tweak the model’s nose, the model with its billions of calculations when maybe you’re own grades in calculus weren’t so great! I am pumped about rain before 5-6 PM!
Now for a comparison of our amounts….
Beowulf predicted amount: between 0.10 and 0.50 inches from this map below by noon tomorrow (when most of it should be over), which shows the heavier rains to the SE of us, ones up to 0.7 inches.
These Beowulf model amounts are often on the HIGH side, and so this is of some concern for us and our prediction, since this model foretells a tenth to a quarter inch or so by 1 PM AST tomorrow when the precip is over except for spotty light passing showers. If that is an amount pushed to the high side, egad!
So, we’re (I’ve roped you into this) a bit on the high side of a model prediction that is known to push rainfall amounts already toward higher than observed. Hmmmmm.
Those lower predicted amounts in the model are probably due to all the low dewpoints we have to overcome with a nice Gulf of Cal/subtorpical influx, and that influx, the model thinks, will end up arriving to the southeast of us. Uh oh. Too late to back off rain amount guess, will ride out the storm; Riders of the Storm Amount, you might say to break up the boredom here a bit.
Now, if you were going on TEEVEE with a forecast after all this investigating, you might, after your educated guess, tweak our own forecast some; somewhere between the original one, which was pretty original, and these model ones. Works out for the best that way. We used to call this, the “man-machine mix”. We still do it.
What can we learn from this exercise?
If those green areas (those having more than 0.50 inches) are farther to the west and over us, we might be detecting a slight eastward bias in the model in these kinds of situations when the moisture roars out of the south-southwest as it will today. No doubt about it, we will be on the edge of the major rains! Fingers crosssed.
I have to admit that due to an internal pro rain bias, I am often on the high side of rain amount predicting.
Wouldn’t it be great if newspaper stories about political events had bylines like, Joe Blow, Democrat, “disclosures” so we might read between the lines some, etc?
Yesterday’s clouds
In a word, phenomenal. So many gorgeous patterns up there in those Cirrus and Cirrocumulus clouds yesterday afternoon, I could hardly take enough photos of them. Like etched glass, this beauty:
3:40 PM. Cirrocumulus transitioning to Cirrus (left to right). Cirrocumulus are nearly always droplet clouds. Here, at an estimated -32 C from the TUS sounding, and at 22,000 feet above Catalina, those droplet specs of Cirrocumulus clouds quickly froze, and as ice crystals in them grew they began to trail gently downward. If you were up there in an aircraft, flying those those ice crystals, you would see something akin to tiny sparkles of light, like diamonds glinting in the sun. When the wind decreases in velocity and changes direction some below the parent cloud, you’ll get these beautiful, delicate strands (as at right), each strand representing the remains of one of the droplet cloud specs that froze. So pretty!
4:20 PM. The young (left) and the old (right) , side by side.
7:09 AM. Altocumulus, trending toward perlucidus. Height? Aout 13,000 feet above the ground, from reading the TUS sounding. Temperature? -10 C (14 F). No ice trails visible.12:13 PM. Nice, high-based small Cumulus (or Altocumulus castellanus) with snow virga moved over the SE part of the sky in the early afternoon. Bases were around 11, 000 feet above the ground at -5 C (23 F). Sprinkles (very light rain showers-its not drizzle) reached the ground in a few isolated areas.2:02 PM. A somewhat rare example of Cirrocumulus and Altocumulus probably at the same level in proximation with one another. Cirrocumulus (Cc) is defined by a very fine granulation and no shading. The fine granulation gives the impression here that its much higher than it really is. Altocumulus clouds are defined as having much larger elements, shading allowed. Well, even if the Cc was at a slightly higher level, this is a good example of the difference between the two. Tell your friends.5:10 PM. Mind drifted toward road runners for some reason…. This is Cirrus uncinus with long trails of ice crystals streaming back from the little cloudlet that originally formed, like an hour or two prior to the photo. The trails survive because its a bit moist up there below where the cloudlet formed.
The weather ahead
A huge buckle in the jet stream is forecast to form right off the West Coast in about a week, and its a pretty spectacular interruption in the pattern of a jet stream whizzing by far to the north of us that we have had now for sometime. Below is an example of ‘now” in the jet stream winds, and below that, a forecast panel (from IPS Meteostar) showing this striking change a week from now. There’s a big (“high amplitude”) trough in the eastern Pacific, a high amplitude ridge (hump in the jet stream toward the Pole) in the West and another big trough in the East.
Patterns like this are usually associated with extremes in temperatures; warmth in the West; cold in the East. It is certain when this pattern materializes in about a week, some high temperature records will fall somewhere in the West and some low temperature records will fall in the East. In the West, warm air is drawn far northward, aided by low pressure centers spinning around in the eastern Pacific, while in the East, cold air zooms down with high pressure centers from northern Canada.
Why bother talking about a forecast a week in advance?
Because it has a lot of “credibility” in our ensemble (spaghetti) plots. Here is last night’s “ensembles of spaghetti” plot produced by NOAA for one week in advance. Look below at these “ensemble members” the different blue lines, ones that are loaded with slight errors at the beginning of the model run, to see how strong the forecast a week ahead is.
Those bunched blue lines in the eastern Pacific (see arrow) inspired this whole spiel about the coming change because its a nice example of when the plots show something reliable in the way of a longer term forecast, and in this case, a forecast that also shows a big change in the weather patterns over thousands and thousands of miles, from eastern Pacific to the western Atlantic.
If you’re looking around this whole plot, you’ll see the lines are also very bunched in the extreme western Pacific and westward across Asia. Those blue lines are always bunched over there because there is little variance in the flow in that region; its locked into a pattern by the geography, unlike in the central and eastern Pacific and into the US where the jet stream is MUCH more variable. A simile: imagine a fire hose turned on at the hydrant, the part of the hose at the hydrant stays in place while the end of the hose flops wildly around. Its something like that; western Pacific to eastern Pacific.
Our weather?
Well, after all that gibberish, not much change will occur here; its everywhere but here! Seems we’re doomed to another dry seven to 10 days ahead with occasional periods of high clouds and great sunsets as weak disturbances from the sub-tropics pass by, ones that can only produce Cirrus clouds.
