Another fireball over Tucson! Backwards halo seen, too! Rain on tap

Check these out in yesterday’s “Olympics of optics” where all kinds of goofy optical things were seen:

3:19 PM. Fireball crosses Tucson skies.
3:19 PM. Fireball crosses Tucson skies leaving long plume of “smoke.”  Photo not touched up in any way shape or form because that would be wrong.  Note: always carry your camera with you since you only have seconds to capture something like this.
3:19 PM Fireball crosses Tucson skies 2.
3:19 PM Fireball crosses Tucson skies 2.

 

DSC_0438
3:57 PM. Then there was this “wrong way1” partial halo a few minutes later.  Could it be another  sign of climate change, as almost everything that happens is? The sun is below the bottom of the photo; haloes are supposed to go around the sun not around nothing.  When a partial halo around nothing occurs like this, its called a “circumzenithal arc”  caused by tiny, pristine ice crystals like hexagonal plates.   If you want to read about optics of all kinds, go  to the University of Washington Huskies weather department where they have optics chapter online.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4:10 PM. Contrail passes through or above Cirrus uncinus. Yesterday was one of the top (worst) days for contrails above and in view of Catalina IMO.
4:10 PM. Contrail passes through or above Cirrus uncinus. Yesterday was one of the top (worst) days for contrails above and in view of Catalina IMO.  Note lines of contrails above and behind weather station. We hope it was due to an unusual confluence of conditions such aircraft flying a heights different from normal due to a peculiar wind profile, Cirrus moisture at the level of the airways, that kind of thing since we rarely see as many as yesterday.

 

 Today’s clouds

Thickening and lowering, ho hum, the usual as a trough aloft (bend in the jet stream winds up there) off southern Cal and Baja approaches today.  Ahead of the bend in the winds, seen in the map below, the vast layers of air rise ever so gradually, something like cm per second.   But, its enough to produce sheets of clouds.

What kind of clouds?

Heavy, dense and gray ice clouds we call Altostratus (As), with thicker and thinner spots should dominate the day.  Then as the moist layer lowers,  that is, as the As  “bases”,  really just comprised of falling snow that only looks like a solid bottom, get lower, patches of virga will start to reach the ground later today.  Altocumulus ought to be around, too, water droplet clouds not cold enough to be completely iced up.  Expecting those layer clouds, or undercutting layers to be low and lumpy enough to be termed Stratocumulus late in the day.

Rain?

The strongest winds at 500 mb (around 18,000 feet above sea level) will be to our south beginning today, a necessary condition for virtually ALL wintertime rain here.  CM is expecting some rain to fall in Catalina later today, or tonight as this bend in the winds aloft goes by.  Expected amounts in this first wave,  trace, minimum to 0.25 inches max by mid-day tomorrow.

Its really dicey situation since its not clear how deep the moisture is off Baja now, but looks potent enough for as much as a quarter inch from this keyboard, though less is more likely.  Sorry the range is necessarily so great.

BTW, the WRF-GOOFUS model didn’t have ANY rain predicted for this time frame period in both of the 5 AM  AST and 5 PM  runs of yesterday.   So, we’re out on a bit of a limb.

After tommorow….

After 5 PM AST tomorrow,  all peoples and models see more rain for Catalina as two waves/troughs barrel in right behind the first one that goes over tonight.  The 2nd and 3rd ones produce a couple of rains through Thursday with big breaks likely in between.

The total amounts for Catalina between now and Friday morning still look like they will be contained within the range of  0.25 inches (things don’t go so well;  disappointing really) and an inch (things go really well).  Best guess is average of those, for a few day total of 0.625 inches.

The End

———————————

1Remember “Wrong Way Corrigan”? Picked up that fumble and scored a TD for the other team?  Maybe it was an early sign of the effects of concussions in fubball.

 

 

 

By 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.