Another big Cirrus streamer from the Equator heading our way!

Well, when there’s no rain in the model predictions for 15 days, you have to get excited about something….

Like a solar flare, there has been another massive ejection of high clouds from the equatorial region and its heading toward Catalina, AZ.   Here, from the Washington Huskies Weather Department1,  is a 24 h loop of the event.  Hope our cell phones still work.  Here’s the latest still image:

Satellite image for 3:30 AM AST supplemented with various interesting annotations, some of which are correct.

 

What are the ramifications of ejected Cirrus coming all the way from the Equator to Catalina?  Pretty skies, sunsets and sunrises, which is quite important to us humans.  Also, when it starts arriving today, we’ll have milder nighttime temperatures.  Yes, even Cirrus clouds cut down the outgoing longwave radiation leaving the earth’s surface at night, and of course, moderates the incoming visible (shortwave) radiation (sometimes called “sunlight”).  We don’t want to dumb this down too much.

After 9-11,  when all the aircraft stopped flying for a week some guys at a small university, one so small I don’t think it even had a football team,  found that the daytime and nightime temperatures were affected by the lack of contrails.  Daytime temperatures were a spec higher and nighttime temperatures a tiny bit lower, suggesting that even CONTRAILS have an effect on the weather and climate.  It was an important finding.  Of course, without a football team I am clueless, as are you are,  concerning what university those findings came from.

You know what gets a lot of us scientists about that contrail study after 9-11, is that something simple and important was done that I (we) could have done had only we thought of it.  We’re kind of bitter about it.  Might have got a raise, too, got the name out there.   Citation index fluffed up some.  We’re dealing with a lot of loss here.  Heck, you probably could have done this, too, it was that easy.

The study of contrails is a pretty big topic these days, though the effects are deemed small for the present.  Here’s a short article for you.  Here’s an unrelated one, one about smog’s effects on clouds, but one you should read, anyway.  Might be true.  Reading the second one is like doing an extra pushup.  Its good for you.  And me since one of the authors of the second article (Danny Rosenfeld) criticized me (and Pete Hobbs) royally in print in the late 90s only because we said his work was invalid.  Show’s I’m magnanimous, following the ideals of science meaning that as scientists we have no personal feelings about our detractors.

Yeah right.  Check the climate blogs and those ones who refuse to allow other scientists to even comment on their work!  Its a hideous situation out there now, far from the ideals of science where one WELCOMES criticism.  But, I diverge….getting worked up when I should be concentrating on clouds.

BTW, that little blob of clouds north of the ice cloud mass coming at us, is due to a little disturbance that will hit the coast of Cal in a few days.  With it, the clouds here will get pretty thick, probably as will happen later today or tomorrow with the ice clouds, causing the optical depth to exceed 4.00000000000 (4).

What does an optical depth of four mean?

That means that the sun’s position is not discernable.  (Also, can’t be a Cirrus cloud, BTW, but rather Altostratus if its an all ice cloud).  Optical depth is usually something used by the smog folks.  A really clean sky has an  optical depth of 0.05 or even less.  Smog laden skies, such is the coastal areas of southern California, or back East on humid days in the summer, have optical depths of 0.2-0.5 at times, horizontal visibility might only be a mile or three; the leaves are gray and the sky is brown, as the song says.    Aren’t we happy we don’t have that kind of smog?

Looking way out, just now, I saw this in the ensemble of spaghetti, thought you should see it, too.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

While no weather beyond warm breezes and high clouds is portended here, where would you really like to be in the West in two weeks or so for some really heavy rains?  Can you tell?   What’s a place I mention too many times when comes to Cal rains?  Yes, the King Range around Shelter Cove, between Frisco and Eureka.  This plot gives high confidence to major flooding in northern California in the 10-15 day window.   Why?  Because so many of the blue lines (564 dm height contours) dip down toward the tropics in the eastern Pacific in support of the actual forecast from last night (represented by the yellow lines). Remember that the blue lines result from small errors put into the model runs at the beginning to see how robust a forecast is.  The wilder the spread of the lines, the less reliable a forecast is.  The more they group together, the more robust, more reliable a forecast is. They look fairly bunched up in the eastern Pacific, and this is the reason for having this plot here today.   I suspect we’ll be reading about heavy rains in Cal during that 10-15 day window.  It will be fun to see if we can make such a call so far in advance!

The End.

 

 

 

 

—————————————————————–

1Nobody knows your university by its scientific accomplishments, but only by its athletic accomplishments.  Its been written up. I certainly wouldn’t.  If online universities could have football teams, it might be the end of “brick and mortar” universities.

In case you were wondering where those high clouds came from…

From down there, as seen here.

More of those high clouds, and we hope with some Altocumulus, will be dropping by from the deep tropics over the next week or so.

Camera alert: Sunsets and sunrises will be spectacular at times over this period and with more than one layer, there is more than one dominant color.

The saddest headline ever read re the coming winter?  From the Climate Prediction Center here:

“El Nino watch discontinued”

They’d been talkin’ up an El Nino this winter and spring for months!  And, as you know, El Nino occurrences tend to cause wetter winters here.  Doesn’t mean we still can’t have some good storms, but the odds are lower.

Yesterday’s clouds

3:38 PM: Pretty Cirrus/Cirrostratus from near the Equator.
4:37 PM. Cirrostratus thickening toward the horizon more than due to perspective. Where the shading begins, it is too thick be Cirrostratus (Cs), and is then classified as Altostratus (As) even though both are ice clouds. Typically As, from ground radar measurements, is more than 2 km (6,600 feet) thick. When flying up through As, the upper portion is exactly like thin CIrrostratus and haloes usually occur before exiting the top. Been there.  The bottom ice crystals?  Bullet rosettes.  Top, little itty bitty prisms, plates and stubby solid columns.

Miriam’s sunset

At least former hurricane Miriam gave us a nice sunset of mostly layer ice clouds (Cirrostratus; Altostratus (where thicker).  Note portion of halo, upper center, above pointy-top cedar tree on the horizon.  Looks a broken streak of droplet clouds (Cirrocumulus) just below that  bit of halo.

Today’s overcast of Altocumulus and Stratocumulus, also associated with Miriam, develops some light rain to the south of us now.  Wasn’t supposed to get here (from U of AZ model yesterday), but, there it is, SLOWLY heading this way.  Will it make it? Don’t think so. If it does, it won’t be much, a trace?  Dang.

Next rain here, sometime in October….  None now shown for the next 15 days.  Maybe summer stats later today or tomorrow.  (Correction, updated at 1:05 PM local based on the US WRF-GFS model run at 5 AM:  

the almost “usual” rain has shown up, 324 h from now, that is, Thursday afternoon, October 11th.  Below is the precip for the 12 h ending at 5 PM that day.  Also, as “usual”, don’t count on it, but its not impossible either.  There a tiny heavier rain blob over Catalina or so.

 

Didn’t get to a rain stat presentation yet due to being absorbed by former company team’s activities in SEA last evening where, at the conclusion of the match, there was a display of sport’s anarchy.  The attendees of this event, in some kind of euphoric riot, lost control of themselves, climbed out of their seats and advanced onto the floor of the stadium where only the athletes and their entourages are supposed to be.

Two curious friends were at that game, my friend Nate, who got a big check (250 K$!) from Al Gore at the Whitehouse a few years ago due to being a science star, and my other friend Keith, who made a LOT of money photographing the explosion of Mt. St. Helen’s in 1980 because he was where he shouldn’t have been went it went off.   Keith then quit the Ph. D. program in the geophysics grad school at the U of WA and started a company, Remote Measurements,  due to all the money he made from that poster of the explosion.

Nate and Keith now share season tickets now to the Husky football games, as Nate and I once did, which I think proves something about fans of college fubball.

What does it prove?

Maybe its that you can like college fubball and still get a big check from Al Gore (who later went on from being Vice-president to a star in the movies).

Or, it just proves that you don’t have to be THAT bright to be a success in science (hahahahah-its just long, hard hours, not brillance, that counts).

And, it may prove that college fubball fans are sometimes not be who we think they are.  Feeling defensive here about being so absorbed last evening, so let us not forget that the writer was thanked by the People of Earth with a small monetary prize, a “scroll”,  AND…a trophy (!) for his and Peter Hobbs’ body of work in the domain of weather modification, all these goodies being presented in Capetown, SA, in 2006.  So, there, IQ feels better now.

As a joke on that that latter thought, my friend and grad school officemate, Ricky, from Harvard U. no less, and I used to throw a  football around at lunchtime on the lawn in front of the 7-story department of Atmos. Sci.  Building at the U of WA.  Before we went out the door to play catch, I warned Ricky that his perceived IQ would drop by 30 points when people look down and see him tossing a football, and, forget dating any of the women in the Department…  :}  Just kidding!

The End.

 



Five days of rain ahead; interpreting probability forecasts

Five consecutive days of afternoon and, or, evening rains are ahead.  If you don’t believe me, go here, to the University of Washington’s model run from last night‘s GLOBAL data, showing where the rain areas will be (in color!) every three hours for the next FIVE days. You will see that EVERY afternoon and evening has regions of color in our area.  I hope you’re happy now.

Instead of dwelling on yesterday’s drab conditions;  all that water up there, and in the air around us as measured by those high dewpoint temperatures, air that produced almost no rain here in Catalina, I thought I would instead liven things up today with a learning module for you, delimited by a string of dashes for excitement.

————————————————

Below, is a link to the Environmental Science Services Administration (ESSA) pamphlet that tells you how to interpret today’s probability forecasts (10%, 40%, etc.,  chances of rain).

How to interpret precipitation probability forecasts

While I have provided this information as a public service, if you would like to obtain one of these pamphlets for yourself, you can get them for ten cents from the Superintendent of Documents, Government Printing Office, Washington, D. C.

Alert:  there may be some questions in the days ahead to make sure that you read and understand this information.  A sample test question:

“There is a large Cumulonimbus cloud on the Catalina Mountains but you can’t see them through the rainshaft coming out of that cloud.  There is a flash flood warning for the CDO wash.  The chance of rain is 10%?

True or false?

(The answer to this sample question will be provided in an upside down font when WordPress is able to to that.)

 End of learning module.  (I hope you’re happy now.)

——————————————————–

OK, here’s is a tiny sample of clouds from yesterday.  I hope you recorded them correctly in your log book.  Here they are, in case you miss them on some hot day ahead:
12:36 PM  Sprinkles are around.  Altocumulus opacus, could be labeled Stratocumulus underneath.  Above the Altocu, Altostratus, the three layers helping to provide that Seattle drab look.

 

4:35 PM. Can you spot the Cumulus fractus under this Altostratus translucidus layer?

“Curve ball” of a Cumulonimbus strikes out Catalina again

It looked like it was coming straight down the middle. I didn’t see any rotation on it.   It was coming toward ME… and to Catalina.  We were going to get “shafted”, rain shafted that is, at last!

I started taking video, shooting numerous still shots of the mammoth-behemoth, churning, tropical-like, boiling-roiling Cumulonimbus cloud rolling in from the southwest toward Catalina, lightning sparking every minute or two at one point.  Pileus veils appeared and disappeared as the tops shot upward through moist layers.  What is a pileus?  Hint:  Its not Latin for somebody who flies an airplane.  But, continuing about airplanes….

If only I had a plane, I dreamed, to go inside them, fully explore and experience them in a quantitative way, those voluptuous turrets!  To penetrate their depths with instrumentation like we would used to do in the olden days at the University of Washington, recording the hail/graupel bursts on the pilot’s window, ones where it was like someone had thrown rice at the window, the huge amounts of supercooled liquid water piling up on the airframe, the plane trembling, rocking in turbulence, turbulence whose effects could only be mitigated by Marezine, the lightning strikes on the fuselage, the white knuckled, almost euphoric, glad-to-be-alive feeling afterward.

Yes, those were the good old days.

While our dogs were cowering, made restless by the approaching thunder,  I dusted off my rain gage collector, looked inside it, as you all should do, for telltale signs of recent bird visitations, droppings that might hinder the rush of water into the inner collector, or even block it all together.   Once having cleaned it off, I sprayed the outer collector with WD-40 so that the drops would roll quickly into the inner collector without the least resisitance, allowing the tipping bucket of the Davis Vantage Pro II Extra Deluxe Mark IV rain gage and weather station system to report rain as rapidly as possible.

This was going to be a great rain, it would make up for the prior two day’s of disappointments and sadness, really. BTW, its quite normal for meteorologists to feel like they live in a “hole” where the best rains hardly ever hit.

In case you didn’t call in sick yesterday as was suggested here so that you could see the those majestic Cumulonimbus clouds roll in, and in paritcular, missed this one below that literally rumbled toward Catalina from the direction of Twin Peaks, here is a sequence of shots taken at 12:53 PM, 1 PM, 1:07 PM, and 1:28 PM.  Rain seemed imminent.
Of course, it fizzled out.  Three strikes!  Three days in a row of near misses!
This one got SO CLOSE!  And as you see below, there were flanking bases even as it neared, absolutely necessary for continued life of the storm.  Without those flanking clouds, a Cumulonimbus can have a shockingly short life span, maybe 20-30 minutes of rain to the ground.
As you can see below, those dark bases sans rain shafts (flanking dark cloud bases) were a good sign that the approaching storm was going to continue propagating into Catalina with gusto, and gusts as well, as the flanking clouds piled up into new Cumulonimbus clouds, riding on top of the outflow winds of the rainshaft.

But no, the flanking clouds disappeared in minutes, leaving only the sad stratiform remains of that once proud Cumulonimbus.  Below, 2:57 PM, one of the saddest cloud sights of all, Altostratus cumulonimbogenitus, orphaned from their parent Cumulonimbus cloud, set adrift, and adrift, without being fed from below, well, they die.  Light, ever so light, rain was falling when this photos was taken.
Eventually the steady, very light rain added it up to 0.02 inches.  I felt like I was back in Seattle because the way that rain was falling yesterday afternoon, was EXACTLY like the rain that Mr. Cloud-maven person experienced year in and year out in Seattle, Washington.  Yep, that’s how it rains in SEA most of the time and you experienced that right here in Catalina yesterday afternoon.
The day ended with a remarkable clearing of all the low clouds, not a Cumulus could be seen from horizon to horizon.  But we did have “pretty Cirrus” (spissatus) clouds, also orphaned from Cumulonimbus, to make a nice sunset.
Today, after the early morning rainbow, one that I didn’t get a photo of?
Gee, the dewpoints are still high, we have a surprising amount of mid-level clouds this morning, some with turrets and showers, yet the U of A weather model suggests no rain later today based on what it sees.   Hmmmm.  Its usually correct in these matters, though I hope some surprise is waiting for us late this afternoon anyway.
The End.
Kind of upset I missed getting a shot of that unusual morning rainbow because the camera had no SD card again, so I think instead, out of spite, I will put in a recent photo of some kind of beetle.


Catalina traces out while flooding occurs nearby again

Flash news:  Nearly CONTINUOUS lightning from a localized spot at 3:30 AM just NW of the Tortolita Mountains.  Amazing for this time of day.  Continuous lightning is a rare event, especially here, mostly seen with big complexes of thunderheads.  And this small thunderstorm just erupted at that time “out of the blue”,  according to its radar history.  Thunder was barely audible, and most of the flashes seemed aloft, toward its top.

Well, quite an exciting way to get started today.  What the HECK caused that small cell to explode like that?  Now, at 4:08 AM there’s just a sad remnant moving toward PHX.  Probably dumped an inch or more on somebody out there at its peak, a real “flashflood” event I’d say for somebody, one that happened before the NWS could even react.   Very unusual.

Rehashing yesterday, which produced only a sprinkle here just before 5 PM (trace of rain).  Pretty tired of reporting traces all the time.  OK, here goes:

2:43 PM. Disappointing as only Cumulus fractus, humilis, and mediocris have formed in the immediate area.
4:07 PM. Now this is exciting! A ROW of building Cumulus mediocris and congestus stream off the Catalinas toward Catalina! Very promising sky.
Caption function fails again in WP; so here is the caption for #3:  4:31 PM.  Row of clouds above fizzles out; none produced a shower (reached high enough for tops to form ice).  But, here, a base seems organizing practically right overhead! If this one sprouts a top high enough to glaciate, there could be a real localized dump of rain!  Will watch for strands to begin emanating from this base.
Caption 4:  4:47 PM.  The awful sight of a broken up cloud base has occurred after the promising solid base.  (Many of you know that as a professional photographer, I specialize in photographing cloud bases, its niche I have filled)   A few raindrops fell out at this time, suggesting the top may have just crossed the ice-forming threshold height above; but no strands, no shaft developed.  Dang.
 Caption 5:  In the meantime, the dark layer seen in the second photo from a giant complex of Cumulonimbus clouds far to the S has overspread the sky, killing all the remaining Cumulus buildups.  This layer, completely composed of ice crystals and snowflakes, would be termed, Altostratus cumulonimbogenitus.  Its an awful sight sometimes.
Caption 6:  While overspreading the sky during the evening, that layer provided some nice background lighting for this row of Altocumulus castelanus.

This morning’s sky and what we can get out of it:
Well, we STILL have our “stratiform” overcast up top, above at least two other layers of clouds.
The lowest of these was topping Ms. Mt. Sara Lemmon, which are the lowest bases we’ve seen in the current surge.
Going along with that is that the lower air continues to be extremely humid, knocking out the effectiveness of evap coolers, with dewpoints in the mid and upper 60s all across southern and central AZ.
But, one aspect we have to get rid of:   the overcast on top of all this.  It won’t get hot enough to spawn good storms until we do.  But this one is thick and composed of ice.  Ice takes longer to evaporate, burn off, unlike Altocumulus droplet clouds, which by definition, are quite thin and burn off readily.  These were taken at 5:20, 6:09. and 6:23 AM, respectively.
So, a slow start but one would think, major rains in the area, maybe here, are in the bag.  Take a look at the huge amounts that fell to the S of us in the 24 h ending at 5 AM AST this morning, 1-4 inches over a vast area of southern Arizona (from Intellicast.com).  The day before yesterday, those kinds of rains were to the N of us.
Our turn today?

Cold one on tap for Catalina; tubes in Cal

First, this is not about BEER!

Usually when you get carried away and expect something unusual to happen, it doesn’t, like that girl I thought liked me but didn’t (there have been a number of those…)  Yesterday, carried-away Mr. Cloud Maven person mentioned the possibility of tubes in Cal.  Here’s the report in the Big Valley near Merced, CA, from yesterday.  Big hail, too.  I am pumped!  Spiking fubball now!

0535 PM     FUNNEL CLOUD     ATWATER                 37.35N 120.60W
04/12/2012                   MERCED             CA   PUBLIC

3 DIFFERENT FUNNEL CLOUDS IN THE ATWATER AREA

0605 PM     HAIL             ATWATER                 37.35N 120.60W
04/12/2012  M1.75 INCH       MERCED             CA   AMATEUR RADIO

Official name of tube-producing clouds?  Oh, something like, “Cumulonimbus capillatus incus (has an anvil) tuba.”

Actually, its not terribly unusual to have tubes in Cal when the air is extremely cold up top over Cal in April and May, and that’s what we have now.  Take a look at this nice, compact map from San Francisco State Former US Hippiedom Capital Weather Department for last evening at 5 PM AST. At San Francisco, its -29 C at 500 mb, very unusual for mid-April.   (Actually, they got some real nice maps there.)  Combine that with the strong sun on land surfaces, and voila, Cumulonimbus galore!

Also, if you look carefully, you will see that where there is no data, over the Pacific Ocean, the 500 millibar pressure contours are nice and smooth .  But notice how “nervous” they get once crossing the coastline where there is data.  I think really it has something to do with the interpolation scheme that try to place the contours exactly at the right spot between the real data; that algorithm may be a little primitive.  Kind of funny in a way.

That cold core of air is heading for Arizona, and no doubt some April low temperature records will be set, such as lowest maximum, and likely a few minimum temperatures before this passes on into the Plains, with no doubt true severe weather there the result of that.  And we, too, will have some Cumulonimbus clouds, lightning here and there around the State.

Below the SFO State map is the forecast from IPS Meteostar showing where this mass of cold air will be later Saturday at 5 PM AST, northern AZ.  U of WA WRF-GFS mod thinks rain will be occurring here just about ALL DAY on Saturday after beginning around dawn!  That would be a heckuva cold day, winter-like, with temps in the 40s-50s here at 3,000 feet and we’d have those pretty white Catalina Mountains afterwards.  Sure seems like 0.20 inches is in the bag for the bottom of this rain event, with maybe 0.50 inches being at the top here in Catalina.

Yesterday’s line of enhanced virga in As deck at sunset

Now here’s an odd feature. Looked at first that it might have been due to an aircraft passage in that streak of Altostratus, but then I rejected that thought, as I can do.  I came to believe somewhat confidently, odd as it is, that it was natural.  Natural linear features in clouds are fairly common.  Here it is, in case you missed it:

Rain today, clouds yesterday


Yep, that’s right, rain IS imminent!  In case you forgot what they looked like, there’ll be a display of “hydrometeors” before 7 AM here in Catalina.  Should last the whole morning at least.  If you don’t believe me and think I just made this up, go here.

BTW, “hydrometeors”; what real meteorologists, well, maybe pretentious ones, call rain drops; remember, we’re METEORologists, we like to see things falling out of the sky.

Not raining now at 4:38 AM, but its on the radar here for the Catalina area from a great weather provider, Weather Underground.  Amounts here likely to be around an inch in the next 48 hours.  Still looking for a drop in temperature enough to bring our current (5: 1o AM) mid-fifties temperatures into the upper 30s in the rain as the cold front goes by, maybe tomorrow morning as well as a second little pulse of clouds and precip keeps things going for a second day.  That temperature drop should lead to a little snow in the heavier periods of rain.

Second pulse?

Racing from the north central Pacific is a little blob of clouds down the “backside” of our humongus trough.  Here, from the University of Washington Huskies, still playing basketball in the NIT tournament, is a 500 millibar map.  The blob of clouds that will extend our rainy spell is located, on this map, a few hundred miles west of San Francisco.  It is CRITICAL to us to get that second day of showers after the current front goes by with its strong rainband today.

The green lines on this map are contours along which the wind blows.   Here you can see a HUGE fetch from the north central Pacific to Oracle Road, Catalina.  To demonstrate this more clearly, click on the map below to get the full version, and place a finger on one of the green lines in the north central Pacific, say, just south of the Aleutians.  You might want to pick the one labeled, “5580”.   Then with your finger on that line, follow it southeastward (“down” toward the lower right), maintaining contact with the montior screen, until you exit the right hand side of the map.  I hope you haven’t had a peanut butter and jelly sandwich before doing this.

If this map pattern was stationary, that’s where the wind would go,  forever, “down” and then “up”.  Where your finger reached the point farthest to the south on this map, and where the wind makes a sharp turn around San Diego, is what we call a “trough”.  And, if you were to see a map at a LEVEL in the atmosphere, there would be a long extension of lower pressure from the Pacific Northwest to San Diego at the time of this map.  But no, we meteorologists complicate things by using constant pressure surfaces which go up and down in height all over the map instead of constant level surfaces instead of an easy to understand constant level map with highs and lows on it.  Oh, well.

 

 

This “second pulse” of clouds and precip is moving so fast, it will get to the “bottom” (south end where the wind curves to the north) of the trough before it has a chance to exit Arizona.  That will add a whole second day of showers and rain with a very low freezing level tomorrow. Its a bit rare to see something like that catch up so fast to the main trough and, in a sense, delay its passage.

 Yesterday’s clouds

Okay, you had yer flying saucer clouds here and there during the day, that is, in proper cloudspeak, Cirrocumulus (Cc) lenticularis (first photo), Altocumulus lenticularis (second photo, is lower, has shading, compared to Cc–that short flat cloud below the Altostratus layer), you had yer Altostratus band (3), followed by yer clear slot, beginning at 4 PM -hope you planned a picnic around it, or trip to the beach (4), then quickly followed by heavy, dense Altostratus layer, (see second shot with saucer cloud).

No sunset color due to the solid cloud banks to the west.  Should be enough breaks in “post frontal” low clouds for sunset color today, however.

Boffo storm bops Burbank before belting Benson

…and the rest of Arizona tomorrow.    Actually, at this hour, 5 AM, the storm coming here has not yet gotten to Burbank.   Its only close.   But, people get excited when you say things like that in the title, and that’s what we’re about here, weather excitement, not accuracy excitement.

Weather excitement?

Take a look at the NWS site here.  They are beside themselves with excitement, issuing what appears to be hundreds of warnings for the entire State of Arizona, and not one drop of rain/snow has fallen yet!  Imagine how excited they will be at the NWS when something actually happens!  (hahaha, just kidding; you’re doing a great job down their guys and gals.)   They just want to WARN us about this well-predicted, STRONG storm, one having the unusual characteristic of being well-predicted in the models more than a week in advance.  Hardly ever happens.

So, with the NWS all worked up about winds and rain and snow and cold and stuff like that in our IMMEDIATE Catalina future (next few days), here at this keyboard we will try to fill in a cloud appearance niche, or try to.

Examining the AZ station and cloud plot here posted by our friends at the University of Arizona Wildcats Weather Department, this nice map.  
You can see a sheath of clouds (whitish area) extending southward from southern NV and UT down past Yuma AZ.   There is no radar echo with it now, or will there be.  Your interpretation:  must be Cirrus and Altostratus (thick ice clouds), maybe with some Altocumulus at the bottom toward the back (west side).  You’ll notice, too, that it is COMPLETELY separate from the main frontal band that has not yet (5 AM AST) gotten to Burbank, CA.

Note cloud empty area or slot behind (to the west) this sheath of middle and high ice clouds over the Colorado River Valley.  A very common sequence in the Southwest interior in late winter and spring is to have a completely separate slice of high clouds, even thickening up to look quite gray, maybe with some virga, give a false impression that the storm is imminent, much closer than it really is, followed by a spectacular clearing from western horizon. Often, this sequence, as is possible today, leads to astonishingly colorful sunsets here if the timing is right. You won’t read about possible colorful sunsets at the NWS today! This why I am here, to warn you about a nice sunset while they warn you about winds and stuff.

However, at the current rate of movement, this band of high clouds will pass overhead in the middle of the day.  Drat.

What next?

After the high clouds go by, there is enough moisture around for middle clouds, though not decks of them.  So in the hours after the ice shield goes by, that is this afternoon and evening, we should see some Altocumulus and patches of Cirrocumulus.   As the winds increase over us, almond shaped clouds (flying saucers) are likely.

Update at 6:13 Am AST:  “Lenticulated sunrise” in progress now!  Check toward Mt. Sara L.  Here it is, in case you missed it.  Gorgeous.

Continuing….   Those kinds of clouds are good harbingers of storms.    Some small Cumulus are likely to start showing up in the afternoon as well I think, but will be high based and too shallow to produce precip.

It will be, I think, one of our most photogenic days so get yer cameras ready for some interesting, and finely granulated Cc, or Ac lenses.

The main slug of low based clouds, rain/snow, cold air, windshift to the NW, graupel, lightning, etc., comes in after mid-night with the front.  Temperatures are likely to drop 10-20 degrees as the front goes by tonight and the rain begins.  Check it out here from the great weather calculator at the University of Arizona.  And here for even more detail!  Even the Great Beowulf Weather Calculator at the U of AZ is excited about this storm, predicting more than 3 inches of water-equivalent snow on the upper regions of the Catalina Mountains, which is clearly too much!

But how great it would be if it was correct!

Hang on.  Breezes already at 6:37 AM, and you know what that means:  one heckuva windy day this afternoon and evening, dusty, too.

I think I need to rest now, maybe lie down for awhile, let the weather excitement dissipate.

The End.

 

 

 

 

Cirrus, maybe some lenticulars, and dust ahead

In case you missed it, the thin layers of Altocumulus clouds provided a bit of a sunset “bloom” around 6:30 PM AST yesterday.   Here’s what yesterday looked like, and I am doing this because I have a strong feeling some of you like to live in the past, like I do when I think about my best sports days in high school and JC R’s bat, and maybe a coupla others after that, so that’s why I am reprising yesterday below):

Here’s what we are looking at, in order of their appearance: 1) encroaching Cirrus (its not a cloud name, its what it was doing), 2) later, the Cirrus thickening (usually downward) into a nice example of Altostratus, a cloud normally composed of only ice crystals and snowflakcs, 3) Altocumulus perlucidus translucidus (honey-comb pattern, quite thin), with traces of ice falling out if you look VERY carefully, and 4) and 5), the Altocumulus as it was briefly (you only had a few minutes) underlit by the distant setting sun (its 93, 000, 000 miles away).

Moving on to the future, such as the rest of today

Its great, weather people can really do that, look to the future and say things that will actually happen with a great degree of confidence, like for the rest of today.  (HELL, an economist can’t even predict what will happen in the next few hours!)

What will happen in the hours ahead?  Cirrus clouds, patchy ones here and there,  and a good chance of some Altocumulus or Cirrocumulus lenticular clouds as the jet stream powers its way down here, shooting from the southwest over us by late in the day.  Sometimes, and I have predicted this before without a lot of success, you get these tremendously fine grained clouds (Cirrocumulus) that suddenly pop out of the blue overhead.   There’s an awfully good chance of seeing those today, too, with the strengthening winds aloft.   Of course, I’ll be watching for you if you miss them, and will replay anything “exciting” tomorrow.

Also, as the low in southern Nevada strengthens tremendously during the day, the winds will pick up as you all likely know by now, and the blue sky will start to wash out in a brownish dust haze.   Twin Peaks may not  be visible from Catalina late in the afternoon due to dust.  You can track the development of that low here, from the University of Washington.  Right this moment, 5:50 AM, there is not much there, so a lot of the development excitement in southern Nevada is ahead.  The NWS, Tucson is quite excited about all the things that might happen, as you will see here!

Enjoy and interesting day!

 

The End