Windy; slight rain foretold overnight

Doubtful to me, but a tiny amount of rain (less than o.10 inches) is foretold by the  massive U of A Weather Department Beowulf Computer Cluster for Catalina overnight.  Check this out.  Would be very nice, even if just a dust settler.  BTW, you should wipe down your rain gauge collector funnel since all the dust from the past few weeks might prevent some drops from rolling from the outer collector into inner magnifying tube.  Hey, maybe some WD-40 on the collector funnel would really get those drops in there!  Hmmmm.   Never done that.

Below, this morning’s Tucson sounding showing a bit of moisture at 550 mb or about 12,000 feet above Catalina (where the two heavy lines pinch together some).  The one on the right is the temperature and the one on the left, the dewpoint temperature.   This suggests their may well be some “flying saucer” clouds, Altocumulus lenticularis today, one that hover in place while often expanding and shrinking in minutes as the incoming air moistens and dries.  There are also indications for clouds at Cirrus levels, above 300 mb or 30,000 feet, and down around the tops of the Catalina Mountains; those would be Cumulus fractus, humilis, then later fattening up to mediocris as afternoon and evening wear on.  They will be marginal for producing ice during the day (which would mean virga), but, if the model is correct, they would deepen upward farther so that ice does form in them (tops colder than -10 C or so) and cluster into groups with appreciable virga and some rain overnight, probably looking more like Stratocumulus, a sky-covering layer  by morning.

You can also perhaps see that the winds are pretty strong over us already.  Not much now, but as the sun heats the air at the ground, and that air rises, compensating downward motions occur as the air above takes the place of the air that is warmer and gets lofted.  So, as we usually see, the wind will be picking up drastically this morning as both that happens, and those stronger winds above us are “mixed downward” in turbulent blobs we see as gusts.   Also, that that Tonopah low pressure center strengthens as it passes by to the north.

You can follow the development of this “Tonopah low” now located, of course, near Tonopah as of 5 AM AST today, here with the University of Washington Huskies’ surface map loop.  This former Husky employee notes that the Washington Huskies had a great basketball and softball weekend.   Oh, also, the loop will update automatically.  Here is the NWS detail on wind and stuff today for Catalina.

 

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.