Some more of that Catalina climo

Here is a 35 year record showing what days have had measurable rain in January.  Sometimes “singularities” in weather show up in these kinds of charts of tempearture or precipitation, such as the “January thaw” that seems to occur with some regularity in the East but is “unexplained.”  You would be looking at our chart for Catalina for example,  a cluster of days with higher or lower precipitation and it MIGHT be a singularity, something that Nature likes to do at that time of the year rather than a statistical fluke that represents nothingness.  Here’s January, a month that averages 1.65 inches in Catalina.  These data are almost totally due to the careful measurements made at Our Garden organic orchard here in Catalina–only the last few years here are from measurements on East Wilds Road.

Not much to see here.  That peak on the 6th looks more like a fluke rather than a singularity.  You would never say that one day represents a singularity, but maybe 5-10 days.

The reason why I wanted to see this was because of the striking changes that were foretold by the “WRF-GFS” model 36 h ago and were shown here yesterday.  Was there a singularity that might support a greater chance of rain in SE AZ in mid-January, and therefore, cast that bit more credibility on such a huge model change?

I would have to say “no.”  And, not surprisingly, that huge change has gone bye-bye in the models.  Nothing like it is shown now, though they do have a rain situation developing for here by the end of the 15 day run (around January 20th and beyond).    But this rain comes out of the lower latitudes of the Pacific, a completely different direction than was shown just yesterday, and if the models are correct in this pattern breakdown, it means flooding in California as the flow breaks through to the coast from the Pacific.

Below, what the models came up with based on last night’s global data, again, from IPS Meteostar, whose renderings I favor.

These are exciting times for those of us who peruse the models.

Why?

These vast changes indicate that there is something far, far upwind, perhaps a data sparse zone, errors in reported measurements that is causing a problem for the models and that more changes in their outputs may come down the line until that problem is better “resolved.”  (They are never perfectly resolved.)

So, every 6 h update of the models is a “must see”, with the persuser (me) holding his breath with excitement.  In these cases, its all “good” because a rain situation is foretold for us.  Take a look at where the jet stream is compared to where it is now, up around British Columbia.   You can see it barging into southern California and major rains ALWAYS accompany this pattern.  Also, you can probably count on at least two storms breaking through before this pattern changes much.   The reservoirists in Cal will be very excited to see this pattern develop since most of their holdings have much below capacity.  And these kinds of storms usually produce significant rain in Arizona, too, though here we would be a little far south to get the brunt of those storms in this scenario.

Pretty clouds yesterday

Can’t leave without a little cloud excitement.  I wonder how many looked up and saw this little beauty go by (shown below)?  So pretty and delicate-looking, as unusually thick virga (snow) fell from this little cluster.  It would be called, “Cirrus uncinus” at this stage.

That snowfall probably began developing one-two hours before it came over us, and the cloud patch would likely have been fluffed up on top that bit and as a mostly liquid water cloud, that is, an “Altocumulus castellanus” before becoming this “uncinus.”

Below we saw the dying remnants of that patch, the snow to finally stop falling out with the parent cloud mostly gone, and that snow continuing to dry up on the way down.  Lots of nice cloud sights yesterday, in fact.

Enjoy.

 

 

 

 

 

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.