Aerosols, Climate issues, Definitions, Science stories, Smoke, Stratus fractus

Creepy Stratus fractus

Well, that cloud WAS “creeping” toward us after suddenly appearing on Pusch Ridge at dawn…  Looky here:

7:14 AM. It thinks we're not looking.
7:14 AM. It thinks we’re not looking.
7:25 AM. In only three minutes, a spurt toward Cartalina, hugging the mountains where its safe.
7:25 AM. In only three minutes, a spurt toward Cartalina, hugging the mountains where its safe.
7:44 AM. I wasn't watching for awhile, and suddenly, there it was across from me!
7:44 AM. I wasn’t watching for awhile, and suddenly, there it was across from me!
8:00 AM. By this time it was just sitting, pretending it was something innocuous, but I knew better.
8:00 AM. By this time it was just sitting, pretending it was something innocuous, but I knew better.
1:44 PM. By afternoon, it was gone... Or was it? You see, creepy Stratus fractus is afraid of the sun, writhes and evaporates when sunlight hits it, or it just warms up a little. It is truly cold blooded.
1:44 PM. By afternoon, it was gone… Or is it? You see, creepy Stratus fractus is afraid of the sun, twist and writhes in a death throe, evaporating right before your eyes when the sun comes out, or the weak light from the sun, as yesterday, warms the air up a little.  Stratus fractus is truly cold blooded and only strong light will make it go away!  The end.  Below, some apropos music and commentary…

 

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With Halloween only 10 and half months away, I thought I would “get in the mood” and make up a little creepy-ness for the little kids who read this blog. Hi, kids! Hope you didn’t get too scared reading this. “Uncle Artie” is sorry if you did get scared.

What you saw in that sequence of Stratus fractus movement is also demonstrative of what often happens to smog layers funneling out of the Tucson area toward Mark Albright’s house in Continental Ranch, Marana. Here’s an example of creepy morning smog (smoke and other aerosol junk), partitioned to the lowest layers near the ground by a radiation inversion, a temperature reversal that develops at night that results in a temperature rise as you go up. In the afternoons, after the sun has done its work for awhile, the temperature DECLINES as you go up and the smog molecules are dispersed over greater and greater depths. Got it?

7:32 AM, December 2, 2013. Maybe you remember this morning. Smog stays down there until the sun comes up, and then slowly creepy-creeps toward Catalina and our foothills as the wind changes direction and comes toward us in the late morning and afternoon. Happens during stagnant weather patterns, not much going on.
7:32 AM, December 2, 2013. Maybe you remember this morning. Smog stays down there until the sun comes up, and then slowly creepy-creeps toward Catalina and our foothills as the wind changes direction and comes toward us in the late morning and afternoon. Happens during stagnant weather patterns, not much going on. Fortunately, the heating by the sun disperses this goop into a greater depth so the smog seems less obtrusive, less visible, though its still there.  BTW, the second arrow pretty much point’s to Mark’s winter home in Continental Ranch.  Mark is a research meteorologist/climatologist at the University of Washington who got his feelings hurt when he corrected exaggerations of snowpack losses in the Cascade Mountains of the Pacific Northwest and people in his own department got mad at him for correcting those claims; happened back in 2005 or so. But, of course, it still goes on.  Mark and his colleagues were proved right in the ensuing years of mountainous snows in the Cascades.  Of course, a hundred years from now, well, that might be another story.  Tune in later, maybe around 2050 to 2100. It is interesting that when me and Peter Hobbs was correcting cloud seeding claims found in the peer-reviewed literature, ones made by people in OTHER universities, the people in MY department loved me for doing so!

Now, where was I after that big caption….?

Oh, yeah, the weather on deck

Sunday marathoners, achtung!

Looking more like a dry day now on Marathon Day, Sunday, though a cold front will have gone by just before it starts.  Looks like measurable precip will be partitioned to the north of Oracle on Sunday, but it will likely be cloudy with Stratocumulus clouds as the day starts, but those should gradually disperse into scattered to broken Cumulus clouds with virga by mid-day, some of those deeper Cu could produce a cold one; i. e., a sprinkle.

Jet core (at 500 mb, 18,000 feet or so) is well north of TUS as Sunday starts, and its really hard to get precip here until the core passes, which on Sunday will be later in the day.  But then, the cold front has long gone, and the tendency for precip with the jet core has diminished (subsiding air behind the front is moving in then) to just scattered deeper Cumulus clouds having some ice-forming potential.  Deeper clouds are stymied on the right side of the jet (looking downwind) overall in the Southwest in the wintertime by warmer air aloft and stable layers, the kind that produce lenticular clouds.

Below, what”m trying to say in words, is shown in this 500 mb forecast from IPS Meteostar with the wind velocities on it:

Winds at about 18,000 feet above sea level forecast for Sunday morning at 5 AM AST. No rain is also predicted by this latest WRF-GFS model run on Sunday in the TUS area.
Winds at about 18,000 feet above sea level forecast for Sunday morning at 5 AM AST. No rain is also predicted by this latest WRF-GFS model run on Sunday in the TUS area.

 

Since this is an analysis from a model output, one inherently containing error, there is that inherent bit of uncertainty.  So, you, as a weatherfolkperson,  imagine what can go the best (the most rainful error), and the worst, and make outlier predictions. Potential rain here in Catalina on Sunday:  max, a tenth (everything goes right); bottom, zero (or trace), in this case, as predicted by this model.

Way ahead

I will leave you with this.  I think its looking more promising for storms later in the month.   I think you’ll see what I mean:

Valid at 5 PM AST, December 20th.
Valid at 5 PM AST, December 20th.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The End

PS:  Lots of low temperature records falling in the West these days.