Category: Sunrise

Smoke and mirrors in the models; fire in the sky

For those of you who have forgotten that heavy metal pioneering band, Deep Purple, and their hit, “Smoke on the Water”, to which this post sort of alludes to, straining really, take this.    It was kind of fun to see this “songumentary”, because it was about something that really happened.  In a line out of Spinal Tap, the parody heavy metal band, one review considered Deep Purple, “the globe’s loudest band.”  How funny!

Here’s the “fire in the sky” at sunrise yesterday, and in case you missed it.  Fabulous blaze of fire underlighting those Altostrastus clouds with their snow virga.

Then, in the afternoon, we had these sky gems; Altocumulus clouds, mostly of the floccus and castellanus varieties, some shedding ice in what up there would have felt like snow flurries.  For those three of you who follow this page, you can guess immediately how cold those ice-shedding Altocumulus clouds were:  colder than -10 C, and probably colder than -15 C without even looking at a temperature sounding.

The weather ahead; discouraging.

The models have been gradually reducing the chances of rain since the last blog about rain ahead, and when they do show rain on or around February 7th, its been reduced from what was once going to be a substantial period of rain to a minor event.  Hence, the models have truly come up with “smoke and mirrors”; looks real but its not.

 

Low spin cycle continuing off Baja; water being added

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

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

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

Today’s clouds…

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

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

Sunrise and Cirrus splendor; the rarely seen Cirrus castellanus floats by

Gee, three days with a cloud or two over droughty Catalina!   Yay! Here’s yesterday morning’s nice Cirrus uncinus (icy clouds with long trails).

Then, later that morning, the RARELY seen Cirrus castellanus sporting some mammatus (downward protuberances at the bottom) showed up.  (I should note that some of the female atmos sci students at the U of WA preferred to call “mammatus” varieties, “testicularis”.)   I mention this in defference to their preference.

These icy Cirrus clouds, whatever you call them,  are probably the rarest of all Cirrus.  The noticeable cumulus-like shape shown in the second photo is rare up there.   Mainly a steep drop in temperature with increasing height up toward the top of the troposphere (the earth’s blanket of air that contains our clouds (moslty).

Turrets, or cumulus-like shapes in clouds like the “puff” of Cirrus in the middle of the second photo, are also thought to be driven by the release of the latent heat of condensation (in lower, warmer Altocumulus clouds) and latent heat of deposition in ice clouds).  When condensing droplets or as an ice crystal, heat is released to the atmosphere.  This is a HUGE factor in thunderstorms (a lot of heat is released during condensation in updrafts), frequent in cooler,  mid-level clouds such as in Altocumulus castellanus, but,  because there is so little water vapor at Cirrus levels, very unusual way up there.     Yesterday’s cloud were likely forming around -40 C,  at about 33-34,000 feet above the ground.

Below the Ci cas photo is a sounding from the folks at the U of WY.  It hints at a steeping of the lapse rate just above the 250 millibar level (between the 200 and 300 on the left side), and also just below a stable layer  or sideways “v” in the temperature trace up there.

I was quite pumped to see this rare display.   Out of thousands of cloud photos, I have but a dozen or so of Ci cas.   Unfortunately, it seemed, passersby in the Basha’s parking lot when this was about to go overhead, were non-plussed when I pointed out the unusual cloud.  They were mostly polite,  but generally said something like, “Huh?”  It made me wonder what is happening to us if we can’t get excited about a Ci cas?  I started to feel sad.

Later, in the afternoon, when the heavy ice clouds moved in (Altostratus translucidus and opacus) in the late afternoon, you probably were guessing that a good sunset was on tap.  And you were right.   Below an example of that Altostratus, followed by another neat sunset.   Likely to repeat all this today.

Hey, get excited!

 

 

 

 

 

 

 

 

 

 

 

 

 

The End

Sunrise and sunset heaven: Cirrus and maybe Altocumulus on the way

Yep, a cute tiny little upper air low with just a dollop of high clouds is going to be spit out of the eastern Pacific off Baja Cal today and tomorrow and toward AZ, and along with that will come some Cirrus and probably Altocumulus floccus and castellanus clouds, maybe with virga.  The first Cirrus cloud is likely to get here by late afternoon or evening today, and the sky should be full of high, icy Cirrus clouds tomorrow morning.   So charge your camera batteries now for some of the “everyday-but stupendous” AZ color at sunset today and at sunrise tomorrow.  You’ve been warned.

Below a map of the air flow and pressure patterns at 300 mb, or about 30,000 feet, the domain where cirriform clouds like to reside, valid at 5 AM LST this morning.


“Send in the clouds”….then the wind, the rain, the cold front, the snow

Too bad Steven Sondheim wasn’t a meteorologist.  He might have written some great weather songs.  Instead, he chose to write about “clowns.”

Hmmmm.  Perhaps he WAS thinking about some weatherman in those days when he used the word “clowns.”  Who can forget that the LA Times  headline about weather forecasting in 1981;  the headline that declared that weather forecasting in the media consisted of,  “Clowns and Computers.”   Personally, I think humor has no role whatsoever when talking about weather….   Oh, well, I digress.

Today will be really exciting for us weather buffs (buffoons?)  We WILL be excited as mom Nature gives us a reprieve from the steady diet of glorious days, sunrises, and sunsets (this morning’s at left), paradise really,  with a blast of wind and then cold, likely to inflect more damage on our probably dead palms here in Tucson-Catalina-Saddlebroke.  Also this will be punctuated by a really exciting cold front passage, one where the temperature is likely to drop at least 10 degrees Fahrenheit within minutes as the wind shifts to the W  then NW after those bruising S-SW winds.  Probably here on the knob, we’ll see 40 mph or more in momentary gusts. Good-bye dead palm fronds.

When will the rain/front hit?

Well, lets say you don’t have a supercomptuer, a Cray, a Fujitsu, or access to thousands of PCs for parallel computing purposes to solve all the euqations in your 57-layer nested grid model using GFS-WRF outer boundary conditions, etc.,  for your subdomain.  What the HECK would you do, besides peruse the internet for answers, which can take a LOT of time?  Besides, we know that the internet is loaded with bad information…

Here’s what I do in this “bind.”   You get out a little piece of paper or Hollerith card (2nd photo), and you use the technique of “extrapolation.”  You got to the internet and check out the recent movement of the cloud band feature upwind of you by marking where the leading edge was, say, 4-6 hrs ago, then where it is currently, and move the two marks forward so that the back one (the old edge) is at the front of the feature and look at where that 4-6 hrs of past movement puts it  4-6 hrs from its present position.  Presently, the middle of this mass of Altostratus clouds (last photo) we have over us, will be around Noon to 1 PM using that technique.   However, there is no precip in that fat band of clouds, though one would think they would be thickening up as they approach us due to the Cat Mountains and overall effect of the Mogollon Rim.  So, maybe there will be some sprinkles around.  Our best models suggest the main rain band and front will not arrive until well after dark., and “extrapolating”, using the past 13 h,  suggests the front won’t hit until dawn tomorrow!  So, it”ll be a long time comin’, but “a change gonna come, yes it is.”

In the meantime, the biggest conundrum in today’s forecast is is what are these Altostratus layer clouds going to do (last photo), the ones at presently  zooming above us in winds of nearly 100 mph, bases at 20-22, 000 feet?  There are no radar echoes in Arizona to the west of us here in Catalina, yet as you can see they are drooping precipitation down at us in the form of virga.  As the air moistens below these clouds, as it should given the approaching system, that virga will tend to hang down lower and lower.  I would guess with this scenario that some very light rain or sprinkles will start reaching the ground this afternoon into this evening in Catalina ahead of the main rain area, the one due in well after dark. Our best model for this area is, of course, at the U of A, right here, and you can see the precip creep in then.  I think I would use them (U of A and NWS since the last time I used the “extrapolation” technique described above was in 1989 I think.  However,  you’d be surprised, when timing fronts coming in off the Pacific (where I was forecasting then), how well this simple, simple technique worked.)

Don’t be surprised if a bit of a clearing comes up toward later this afternoon to sunset.  Its not unusual to have a vast amount of quasi-threatenbing cloud go overhead all day, maybe with a few sprinkles, and then have a thin slot or brief clearing before the heavy clouds and rain move in later in the evening.  That appears to be suggested in the satellite imagery today.  We shall see! What an interesting two days ahead!

Still looks like a little snow in Catalina Sunday morning.  U of A mod indicates that the total amount of precip will be around half an inch.

 

BTW, while you’re digesting all of the above, here is where the weather records that were set for yesterday are.   You can see that a LOT of records were set yesterday!  Generally low temperatures and record snowfalls for the day in the northern half of the US beginning in the Mid-West and “thence” westward to the Pacific Coast.

 

OK, enough rambling!

 

 

 

Colorful announcement of a storm

This glorious sunrise today about 7:30 AM announces in its way that a strong storm is on the way.

Why?

First of all the clouds, “altocumulus lenticularis” are the lower, rippled clouds, combined with a higher,  solid layer of altocumulus and altostratus clouds demonstrates that the air is moist to saturated over a great depth above those lowest clouds.

The lenticulars highlighted by the rising sun just above the Catalina Mountains generally occur when the wind speed at their level is at least 30-40kts.  Thus, lenticular clouds have always been a sign of being around and under strong upper level winds we sometimes call the “jet stream.” While lenticulars might hover over the same spot for minutes to hours, watching how fast the elements in it move, or other cloud movements can tell you something about how strong the jet stream is over you.  Today, the clouds were racing across the peaks, consistent with the very strong jet stream and storm systems that is about to pounce on us.  The NWS balloon sounding from Tucson this morning, a couple of hours before this shot, indicated the winds were 30-35 kts at the level of the Ac len clouds.

The second photo, kind of dull compared to our glorious sunrise, has something to say in it, too. The wind at cloud level is at the photographer and its strong,   What happens in these “pre-frontal” situations is that the air ahead of the cold front can be relatively stable, that is resistant to moving up and down, and in resisting doing that when hills and mountains are present in the path of the air movement, something akin to gigantic ocean swells are produced.  Here you see darker bases off in the distance that are PERPENDICULAR to the wind just like huge ocean swells might be.  A time lapse camera would show the movement of these “swells” beautifully as they peak and die, going through ridges and troughs, that is, slight rises and falls of the air in its movement toward the camera.

At the same time, those clouds, due to the Catalina Mountains and the higher terrain downwind from Catalina, also forces these cloouds to deepen, a process that will continue as the upper low pressure trough approaches.  As this happens, clouds such as these that are not precipitating now, start to precipitate.  The rain often doesn’t move in, but begins to fall from these deepening layer clouds overhead.  I think that is going to happen here in the next couple of hours (its about noon now).

Here in Catalina, AZ, the rainfall (17.5 inches per year) is considerably more than that in and around Tucson (12 inches per year), and this difference largely comes in winter storms like these that are subjected to the lift zone described above out ahead of the higher terrain here in Catalina,  and downwind of us.