Author: Art Rangno

Retiree from a group specializing in airborne measurements of clouds and aerosols at the University of Washington (Cloud and Aerosol Research Group). The projects in which I participated were in many countries; from the Arctic to Brazil, from the Marshall Islands to South Africa.

Timing of rain–go here

Hi, again,

Go here for as good as the timing on the incoming rain gets, graciously provided by the University of Arizona Department of Atmospheric Meteorology.  This model run, now in progress says that rain begins to move into the Cat Mountains by 3 PM tomorrow.  Exciting.   Also you will notice in this “total accumulation of precip” presentation, that we’re expected to get a very nice rain, looks like half inch to an inch by Friday, 2 PM, and even then it ain’t over.   Also you’ll see that by that time, areas to the north of us get SEVERAL INCHES according to this model.   However, those indicated amounts have to be used with caution since they originate with imperfectly known cloud and precip processes that we try our best to represent in models, but still come up short most of the time.  In this case, there is a “tendency” in this model to over-predict the precip.   And the onset timing could be off some as well.

Also, if you like to see time lapse of the clouds you might have missed yesterday, they have this U of A campus site with the roof cam pointed at the appropriately named Cat Mountains.  Us in Catalinaland are just behind Table Mountain, Pusch Ridge in that time lapse.  This time lapse will REALLY be interesting in the next few days.

You will also see, if you look closely, why we think of Cirrus clouds as “precipitating” clouds.  In the time lapse you will see trails of ice crystals falling out.  They are virtually dust like in size (well, they run 100-300 microns in diameter, those ones falling out), but if in it, you would hardly notice that kind of precip.   You would only see glints of crystals going by, and a dust like coating on the ground (if you were on Mt. Everest or K2).  So, once out of the body of the cloud they start to evaporate, fall even less slowly, and the trail becomes almost horizontal.   Sometime horizontal (flat) layers have precipitating Cirrus above them constantly dropping new crystals into the flat, constantly thinning layer in kind of a quasi-equilibrium.

Oops, enough of that.  Here’s is yesterday’s Cirrus-induced sunset, definitely more interesting than the above.

 

The End and waiting for the RAIN!

 

Double Vision

Who can forget rock band, Foreigner?   Remember that other hit song from that album about desert people like us, “Hot Blooded”?  I do.  But I was in Seattle then (1980s) at the U of WA, never dreaming I was going to be in hot blooded in Catalina, AZ, especially in the summers.

Today’s amazing progs with such wonderful sights maybe think of that song title because two of the same kind of upper cutoff lows are forecast to sit and spin over the Southwest in the next few days, with noticeable weather happenings,  like the wind picking up as early as Windsday (hahhaha).   What’s weather website without juvenile humor now and then?  But seeing this model output has made me quite happy, feeling good about myself and the world around me.

Again, I start with the Canadian’s (whom I sometimes tease since my relatives there might be reading this blog) model output (in totality here) from last night’s 5 PM LST global data.  The first panel is last night’s initial weather maps just to show you how drastic the change in the weather is going to be.  Look at how there is nothing but “high pressure” all over the West.

Then here’s what we see in just 60 and 132 h from that map, that is,  just this Friday morning at 5 AM LST, and Sunday morning at 5 AM (second and third maps).  Look in the upper left panels and note how similar Friday and Sunday are!  Amazing!  And the positions predicted are great for huge dumps of snow in the north parts of AZ and good rains here.  The aspect of this that really helps us is that the rains/snow won’t just come in ONE several hour spell, but should recur after they start because cut offs by their nature don’t move much but kind of wobble around like they look like on the upper maps, spinning tops, ones that initiate new bands and blobs of rain while they sit and spin.  And we will be dealing with TWO of those! Fantastic.

Now, for fun, the thing to do is NOT look at any more model runs, they could hardly be better than these, so why look?) and just watch the sky change over the next five days or so, dreaming about what will be, what COULD be.  Enjoy it all.  No matter what, the clouds will be great, the rain treasured, as will those sunrises and sunsets from time to time.

What a life we have here!

Starts with the starting model map since that seemed to be a good place to start, then Friday and Sunday maps follow, respectively:

“Who you gonna call?”

Droughtbusters! (When you have a drought)

Kind of exciting today as another complex, hard-to-predict upper low center breaks off from the main jet stream and circulates down into the Southwest on Thursday and then sits and spins for a couple of days.  What so exciting to trigger a blog in the afternoon?

One of the enigmas has been that the Canadian model, often shown here because most of my relatives are Canadian, and the USA ! model have had large differences in where this upper low center will end up once in the Southwest and cut off from the main flow.   Once in place, it sits and spins for a while, which means that if you are in the right place, it might rain off and on for a couple of days. A cut off low in the SW is one of my favorites patterns of all time, not that you care.   Remember that low of December 1967 in Arizona?   The one that nearly buried the State in snow when it sat around for a couple of days in almost the same spot?

Well, this incoming one is not as gigantic as that 1967 one, but, it has potential to produce a lot of rain in the State for the same reason: sitting and spinning like a record player somewhere in the SW for a couple of days before moving on.

Today’s model runs were exciting because now the USA and Canadian models are in sync.   Previously the USA model had the low in a spot in which most of the rain would miss us, while the Canadian one had a pretty wet scenario for us.

Now, from this morning’s global data, they BOTH see the low ending up over southern California, drifting very slowly eastward, and BOTH have good rains predicted for the State!   Imagine a couple of days of good rains.  Wow.  Droughtbusters!  (in the plural because two models have this scenario now.)

Well, of course, it doesn’t guarantee it will happen just because both models are showing the same thing over several days, but it is very encouraging.  Fingers crossed.

Below, an example of this cut off low, well away from the main jet, sitting over about San Diego.  This depeiction is valid for Friday morning at 5 AM LST.  The whole loop can be seen here.  Enjoy.

The End.

 

Thankful for the 23 hundredths

Gorgeous day yesterday with lots of…Altocumulus opacus with castellanus clouds here and there.   But you knew what kind of cloud those were already.  And our upper trough and clouds situation closed out overnight with a decent 0.23 inches of rain here in Catalina.   “Nice”,  since it wasn’t a sure thing that we’d even get rain when the tropical plume from former hurricane Kenneth (R.I.P.) was slipping by to our SE across Douglas, AZ and into NM.  Dang.  So, it WAS a 24 h to be thankful for.

There was also, ever so briefly yesterday, the “flying saucer” cloud, an Altocumulus lenticularis, apparently hovering above but really a bit downwind of the Catalina Mountains.  This photo is one of the better of that cloud variety I have taken.  Also, while it may LOOK like its hovering over Samaniego Peak, its really quite a ways downwind from there. You’ll see that in the U of A time lapse movie for yesterday here.  It appears about one minute into the movie, or just after 9AM if you can read the time signature in the lower right hand corner.   Lenticular clouds usually form when the winds aloft are quite strong, and the air at the level of the cloud is “stable”, resists moving up and down so you get laminar flow instead of turrets and bumps on the top.  Below a couple of other shots characterizing the day.

Ahead?  A LONG dry spell.  Dang#2.

The End.



THREE times in a row, Canadian model wetting it up for us

This is great!  I thought sure that the Canadian model, which has been a bit of an outlier, would take that jet of moisture and rain emanating from the remains of Kenneth the Hurricane away.  But no, yesterday morning’s Canadian run had it cruising into us with a bountiful rain, and now overnight, once again as it first did on the night before last.  So, for three consecutive model runs, this torrent of moisture from Ken, ejects rapidly over us.  Stupefying!  Today we might call this small-in-length ejection of water vapor and clouds an “atmospheric flash flood” (too short in length to be called an “atmospheric river“, the new buzz phrase for West Coast flooding scenarios when long fetches of tropical air thousands of miles long in narrow bands ahead of fronts cause deluges).

Here, with gratitude to the Canadians, most of whom live with two miles of the US because they want to be as far south as they can get and are practically Americans anyway,  is last night’s model run, showing that fine, fine looking low pressure center encroaching on southern California in 24 h.  Its that low that starts to eject the body parts from  “Kenneth” at us.  I am just beside myself with joy!

They made me happy today with this sequence (extracted from here).  You’ll want to concentrate on the LOWER RIGHT HAND PANELS and those green to yellow and red regions where RAIN is expected in the 12 h PRECEDING the map VALID time.  Unless you click on these images you will have to have a microscope to see what I am talking about.

The valid times are, from left to right, Thanksgiving Day at 5 AM AST, Thanksgiving Day when eating turkey (5 PM AST), and 5 AM AST Friday morning.  What is remarkable is how fast the rain develops after just appearing on that first panel off southern Baja.  By nightfall, the model thinks rain will have started here!  Wow!  That would mean an awful lot of, probably middle and high clouds, are already in place streaming toward us ahead of the nub of that rain area shown in the first panel.

 

 

 

 

 

 

 

 

 

If we go to the University of Washington Huskies’ Atmospheric Sci Dept web site and this loop, you can see that it’s already happening, high clouds (shown as white regions in this loop) are already being torn from poor Kenneth down there.  Keep an eye (Kenneth’s is pretty much gone) on that bulge on the NNE side in the last couple of frames.  That’s likely where our  jet of moisture will originate.

Will be cleaning out rain gauge of dust and debris;  maybe will wax collector funnel so that those raindrops really accelerate into that inner measuring tube.  Hope you do, too.  You don’t want to leave anything out there, on the sports field, or on the funnel.

The End.

 

Ken might be bringing leftovers on Thanksgiving Day

Kenneth, that spinny thing with the eye hole, shown in this 24 h loop feasting on the warm waters about 500 miles south of Cabo,  seems inclined to drop in late on Thanksgiving Day with his leftovers.  How rude and wonderful at the same time!   Most of you (2 of 3 the three people who read this blog) will find this 24 h loop quite interesting and you might spend your whole day here questioning, “What does it all mean?”,  like the philosophers do.   So, be careful and don’t let your whole day slip away here.  I’m tempting you…

Check out these two snapshots for TG evening and Friday morning from this model run from the Canadians and the streamer of rain and moisture that comes in to SE Arizona on Thursday (lower two panels):

Of course, many of you may feel the Canadian model runs should be banned from this site based on some recent over-predictions of rain here.  And so you may wonder why I have gone back to a model that has let us “Catalonians” down so much recently.

Why, in fact,  DO I show this Canadian model output?

Because it has the most rain for SE AZ in it compared to other model runs, just like the last time it let us down!  I couldn’t help it.

Look at all that red coloring in the 2nd image, lower left panel for Friday morning (indicating the amount that fell in the prior 12 h while we were over eating and then trying to sleep on an overly full tummy but we might have a pounding rain to provide a “white noise” to help us get through that tough night)! (Stream of consciousness writing there).

Only yesterday, that same model showed the leftovers from Ken bypassing us for New Mexico.  Sure they need the rain, too, but this run from last night made me happier.  So, I am quite happy this morning with this model change showing more rain here in spite of set backs in other areas of life which I caused myself, dammitall, by not waiting to get more facts and instead relying on gossip in forming a key assessment that ultimately resulted in an inappropriate action that ruined a friendship.  (More stream of consciousness writing…) Oh, well, back to weather…

We have to remember that this model run is the LATEST run, and therefore is based on “mo better data” because its closer to the predicted event than those model runs that did NOT show so much rain here.   So, as a “scientist” I can show this latest run that shows what I want to happen and hold my head up as a truly objective observer since it was based on newer stuff;  it wasn’t just ME wanting rain.  On, the other hand, I hid from you those earlier model runs before this one that did not have much rain here with this “incoming” (trough).

So, in sum, you ARE getting a selective presentation of OBJECTIVELY produced data.  I wonder if anybody else does this?

Also, yesterday was truly stunning in clouds, with some honest-to-goodness Cumulonimbus clouds sprouting up yesterday morning.  They were so pretty.  And you got to see great examples of cloud tops “glaciating” (turning to ice) right before your eyes.  Didn’t hear any thunder, but there could have been some.  And then we had the late afternoon sun and those dramatic cloud shadows (produced by those much shallower Cumulus clouds) on the Catalinas.  Here are some examples for your visual pleasure.  BTW, we didn’t get hit by the cell cores.  So, rainfall here was only 0.02 inches; 0.03 inches, at Sutherland Heights (last photo).

The End except for this part.  Many of you have asked, “What was that recent quote by Mr. Cloud-Maven person in the Wall Street Journal about, anyway?”  Maybe they had the wrong Cloud-Maven person…

Well actually no one has asked that question…    But its an interesting story (I think) for those who write about science probably than for those who do science (he sez).  Maybe, in a display of particular grandiosity–after all, only the great scientists of our day are asked his/her opinion about a matter of scientific import in the WSJ!–explain what that was all about one of these days. Smiling very megalomaniacally here.   Hahahahah, sort of.



A 35 year record of Catalina rainfall and what it reveals

Thanks to our friends at Our Garden just off Columbus Blvd. here in Catalina, about 1 mi northwest of my location, we have a rainfall record that goes back to the later 1970s.   This is fantastic because there are no official reporting stations nearby that reflect our rainfall climate, one this close to the Catalina Mountains.   The closest to us in rainfall is Oracle Ranger Station, but that’s at 4400 feet elevation.    We’re about 3000 to 3200 feet here in Catalina.  The long term climate stations, ones under the aegis of the government, are also at lower elevations, and more importantly are farther away from the Catalinas than we are.  Those lower, farther away stations have annual or “water year” (October 1st through September 30th) totals of only around 12 inches.   So, they don’t reflect our wetter Catalina climate.

Our Catalina average rainfall since the 1977-78 water year?  17.04 inches!  Median, 16.59 inches.  Oracle, at 4400 feet elevation for comparison, 21 inches; Mt Sara Lemmon, 30 inches. Too, you could have guessed that we receive much greater rainfall than stations farther away from the Catalinas by our more “lush”, and, being from Washington State,  I use that word advisedly, vegetation hereabouts.  Here is a chart with the water year rainfall values from Our Garden plotted on it:    (Discussion continues below)

Most of the two of you who read this blog will find this 1) quite interesting, and 2) upsetting since there is a clear downward trend in water year rainfall since the folks at Our Garden started maintaining records. Perhaps, you will wonder,  “will it become too dry to sustain life here? Maybe we should sell now and move to a wetter locale like Mobile, AL, before the bottom drops out of the real estate market in the dessicated conditions ahead.”  (Oops, the bottom has already has dropped out of the real estate market.)

But, following the words of Douglas Adams’ in Hitchhiker’s Guide to the Galaxy, “Don’t Panic” .

Let’s look at this a little more closely, shall we?  First, let’s see where this godawful decline in rainfall is located in the records.   Summer?  Winter?  Or both?

Here is our summer rainfall in Catalina (June through September) that will be VERY illustrative of where the decline is taking place because….its not here!

(Discussion continues below)

Yay! As you will plainly see, our summers are the same as ever over the past 35 years or so!  FANTASTIC!   The same number of great storms, lightning, molasses-like dense rainshafts and colorful summer skies are likely still ahead for us between June and September.  No indication here of any “climate change” over the very period in which the earth’s temperature began a noticeable rise following the coolness of the late 1940s through mid-1970s.  As we all know, that rise in temperature since the mid-1970s has been attributed to CO2.  Until recently, global temperatures and the rise in the atmospheric CO2 fraction have been in lockstep.  (Not so over the past 10 or so years for reasons that are “not well understood.”)

But our summer graph is foreboding.  Panic now!

No change in summer rainfall means that ALL of the decline in rainfall over the past 35 years is going to be contained in the “cool” season rainfall records for October through May.  Those cool season rains are due to disturbances in the jet stream; “troughs” that pass over us.  They must be decreasing in frequency over this period.   Furthermore, such a “trough” in the westerlies must have its maximum wind (i.e.,  at the 500 mb level) sag to the south of us to get rain1.

Here is the awful graph which you have now anticipated from the summer rain graph; take a deep breath:

(Discussion continues below)

As you will see, this graph is so shocking I considered calling a news conference about climate change after I plotted it, even though I am not really a climatologist, but rather, a nephologist2.   So, it wouldn’t be quite right to do that.

However, my claim in such a bogus news conference would be that it will likely stop raining in the wintertime in southern AZ within 40 years, if the downturn continues.   I will assign this decline to global warming, since almost all negative-bad news trends are these days.  And, I might have widespread credibility, perhaps a headline.  “Arizona to go dry by 2040!”  The media are, as we know, primed to accept these kinds of claims today it seems without really investigating.

But it will be poor science, an outrage, really.  It should be taken to the Catalina refuse transfer station.

What’s the truth here about our downward trend?  Its certainly a REAL decline over this time span, and,  “what does a longer record show?”

The fact is, Jenny and Wayne at Our Garden happened to start their rainfall record during one of the wettest regimes of the 20th century, and even longer!  Remember how the Great Salt Lake was filling up in the early 1980s?  Remember the huge rains in Cal and AZ in the late 1970s and early 1980s?  Well, of course, IF you DON’T have a good 100 years of experience here, you can’t recall the similar big wet spell in the SW after the turn of the century (1904-05 to about 1920) and the drying that took place afterwards, too.  Those that have been here since 1945 or so are thinking, “If you think its dry now (last ten years), you shoulda been here in the 1950 and 1960s!”

So you can begin to appreciate that our shocking trend since 1977-78 is not one that will continue forever, is not associated with global warming, but is fortuitous because of the starting and end points of our available record.   Our climate in AZ is always oscillating from dry to wet regimes and back again, even in the slightly warmer years likely ahead in the coming decades due to “global warming.”

An example of this oscillation can be seen in the 30 year STATEWIDE averages for rainfall in Arizona.   Check these out from our friends at the Western Regional Climate Center (here). They are shocking and illuminating.

As you will see, the mostly droughty 1941-1970 statewide AVERAGE for Arizona is a ghastly TWO inches LESS (11.69 inches) than that for the frequently rainy era of 1971-2000 (13.59 inches).  Incredible.   That is a HUGE difference when you average over the whole state!   That change to wetter conditions would likely be attributed to the Pacific Decadal Oscillation change in 1977-78 that rolled on for the next 20 years or so.

So, without a grand picture, even 30 years of data can be misleading, produce spurious trends.

Gee, kind of lecture-ish here, boring.  Oh, well.

So, what’s really ahead for Arizona?

Of course, nobody knows for sure, and the climate models with global warming are dicey on long term regional precip changes, such as in southern AZ.

However, I’m one of those (remember, though, not really a climo) who feels that a prediction of just the opposite conditions in the winters ahead might be a “buzzer beater”, a correct one, a winning one; that we are likely to experience a phase shift into wetter winters in the decade or two ahead rather than dryer ones as a projection of the trend line would suggest.

Enough!

The End

__________________________________________________

1 If you still have a copy of Willis and Rangno (1971–Final Report to the BurRec, Colorado River Basin Pilot Project, Durango) you of course will already suspect this because that is also the case in Colorado as we reported.

2 Nephologist:  one who studies and has reported stuff in peer-reviewed journals about clouds, but not climate).

 

 

 

 

Wobbly storm drenches Catalina with 0.62 inches of rain!

The above could be a headline in the Catalina Cryer; but that erratic storm that sent sheets of middle and high clouds over us everyday for a week it seemed, finally came through with a stupefyingly good rain.  I just could not believe how that storm kept “giving” all day and into the evening yesterday, ending with a dramatic sunset while rain still fell (see below)!  This is where a meteorologist can be in awe and excited all day, commenting over and over again to those in his presence about how amazed he is about dank and dark skies producing ANOTHER splurge of light to moderate rain!  I’m still excited.   (Very odd behavior, especially when you have visitors from Seattle.)

But recall, at times, and on some models, no rain was in the numerical crystal ball on some runs just before this happened, while on the other hand, a few days before it happened, this kind of drenching rain was predicted several times in some model runs.  All these model fluctuations due to the erratic nature of the upper level configuration, main jet stream to the north, our storm like a spinning top, wobbling around out there in the eastern Pac.  And that scenario was giving the models and us AZ  “precipophiles” headaches and hope, but ultimately, wonder.  This storm will be emblazoned in this writer’s mind forever because of how great it “came through” for us here in SE AZ.  Take a look at the map below for last evening just as the rain was concluding, where you can see a frontal rain band is about to drench Cabo San Lucas, and the upper low center is positioned off central Baja; pretty darn unusual.  (Note: the air is flowing along the greenish “height contour” lines, so it goes from the north on the west side of the low, and usually descends, while on the east side it curls around and goes NEward, with rising motion with sheets of clouds produced, as shown here.)

Combining this rain with our other two November drenchers of just under half an inch each, we have finally had a month with ABOVE normal rainfall at 1.45 inches, at least for us in Catalina where the November average is 0.97 inches.   Sometimes it seems like above normal rain can’t happen anymore here with the droughty spell we’ve had.  But more on that and climo maybe tomorrow.  In the meantime, the latest 24 h regional totals will be here when the site is back up. Before the site crashed, Mt. Sara Lemmon had already gotten over an inch of rain as of late yesterday afternoon.

 

PS:  That next rain, only yesterday predicted for Sunday, November 20th?  Its gone.  Like the endless “puddle” seen on the highway on a hot day, that  “puddle” of rain like the one on the highway that always moves farther away, has now also been moved farther away to November 22-23rd in the models.  Don’t count on it!

Below, our dramatic sunset of yesterday.  Streams of rain off the AZ room frame the sun in front of a messy backyard.  But I will straighten it up today, I promise!

The End.

A pleasant 0.03 inches

Not sure even the dust noticed, but we had a brief shower around 8:30 PM that actually measured with 0.03 inches!  After the spectacular sunset, indicating a large clearing to the WSW, it seemed doubtful we would even get that.  But, what do I know after these past few days?

Below, an example of a nice sunset due to Altostratus clouds (overhead);  “file footage” really, since I had a rare missed shot of that one last evening).

With rain still out to the west and north of us right now (go here to see this 12 h loop of clouds and radar echoes from IPS Meteostar) there is still a chance of more measurable rain later today or overnight.  Still, the configuration aloft will not be favorable for anything of consequence; likely we’ll just a few more hundredths.  But, what do I know#2?

Also, you will see something dreadful regarding that possibility of rain.  A blast of clouds riding on a high level north wind coming out of Nevada and Utah, heading straight for our little system around northern Baja, that will try to keep any rain to the south of us.  The models, such as this one from the University of Washington, have us just on the north edge of any precip.

As so often happens, our models seem to always see another rain in the future, rains that so often fail to materialize.  This time the rain “mirage” is for Sunday, November 20th.  Oh, well, something to think about.

Have some climo data for Catalina, about 35 years worth and will be posting that in the next day or two.  Past records help you dream about what could be in a winter or summer.  Can you imagine that little ol’ Catalina has had almost 30 inches of rain in a year a couple of times? Imagine how the washes ran!

The End.