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