Canadian model wetting it up for SE AZ on the 10th; US mod just says “no” to AZ rain

Hot off the Canadian presses from last evening’s global data from 5 PM yesterday, this exciting depiction (from Enviro Can) for Friday afternoon, the 10th.  Note green and yellow regions in all of the SW, lower right panel!  Note big upper trough over Vegas, upper left panel.  Its all good, and, this being the 5th, its only a few days away!

00_054_G1_north@america@zoomout_I_4PAN_CLASSIC@012_144

Valid Friday afternoon at 5 PM AST. Note “tropical river” emanating from a tropical storm or depression off the tip of Baja (colored regions in lower left panel).  No reason to be depressed if this happens.

But let’s look deeper….deep into the heart of the US WRF-GFS model for the exact same moment in time, shown below:

Also valid at 5 PM AST on October 10th.  Perhaps the US model is sequestering rain for Arizona.... NONE, and in nil, is indicated from a model run generated from EXACTLY the same data as the Canadian one above and it shows no rain for much of anywhere in Arizona.  How bizarre is that?
Also valid at 5 PM AST on October 10th from IPS MeteoStar. Perhaps the US model is sequestering rain for Arizona…. NONE, as in nil, is indicated from a model run generated at the same time as the Canadian one above!   As you can see from the arrow, there is NO RAIN indicated for most of Arizona as a very strong upper level trough goes by. How bizarre is that?  Something’s goofy here and its not just me.

What caused this model bifurcation?

For one thing, the US mod sees no tropical depression off Baja, and our hurricane center is very skeptical that any tropical development will take place south of Baja, one that would move NW or N and send a moist plume up into a trough positioning itself over southern Cal on the 9th.    US mod has NO tropical moist stream coming out of the eastern Pac ahead of a trough over southern Cal at all, whether there is a low down there or not.  Boohoo.

So, any rain here in Catalina would be with the usual passage of the jet core and in the cold Pacific air behind the cold blast headed our way on the 10th-11th.  And that rain would be very light, likely less than a tenth of an inch.

The Canadian model, sadly,  has to be considered a little goofy right now with its copious SE AZ rains, and widespread rain/snow over the rest of AZ, too.  It would be good to inform your neighbors that you are thinking the same thing about the Canadian model, i.e. that its a bit looney as well in case they saw it and are touting a lot of rain on the way without really looking into things.  Embedded editorial note:  A lot of people vote like that, too, I think;  also read health claims in magazines without looking at the peer-reviewed literature, taling with their doctor, examine the results of double blind,  randomized trials, that kind of thing on which we base the whole edifice of medicine on.  No, they’d rather read on the side of a health pill food, “these claims have not been evaluated by the FDA” and then take the stuff anyway and enjoy the effects of a placebo, which, if you believe in it, can be pretty good.

No doubt the reports of low temperatures in Arizona with this coming big upper trough on the 10th-11th, and snow in the high mountains, will spur a flock of snowbirds to migrate south.  It’ll be windy and dusty, too, as it usually gets ahead of the passage of the cold front with these big troughs.  That will be interesting, as well as all the cloud forms that start to show up with it.

Note:  I’d show you some NOAA spaghetti so that we could get a little more on this model discrepancy, but its been sequestered from me, as you will see here.  In the meantime, will hope for Canadian vindication in the days ahead.

The End.

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.