Cooler hot air riding in from the West later today

Should arrive by later this afternoon as foretold in models, unfortunately, in view of fires, with a lot of wind before and after a dry cold front gets here, too.  Check the NWS forecast for Catalina here.

The Cirrus clouds this morning?  The only trace of clouds we’ll see with this trough and “cold front” today, if you can call it “cold”,  with temperatures still in the 90s.  Those clouds will be gone by mid-day.Tomorrow morning we’ll notice a temperature difference!

The weather ahead, as you likely know, fiercely hot early next week, after our little cold front goes by today, followed by another dry, windy,  “cool” front around May 25th.

Of course, if you’ve had your NOAA spaghetti plot this morning, you probably already know about that weather change eight days from now.   Here’s a chart from last night’s spaghetti run.

What do you see in the map below?


Except here at this blog, you have NEVER seen a weather map like this before!  Imagine your TEEVEE weather presenter showing you something like this!  Heck, where’s the land?  Well, you can see Florida and Communist Cuba in the lower right hand corner.  Just remember that Arizona is somewhere to the west of Florida.  The outer dotted line is the Equator, where the date changes.  (Just kidding, want to see if you are paying attention.  Eyebrows should be raised on a couple of counts because TWO things are wrong in that ONE sentence.)  OK, on to the map and no silliness….

First, those yellow lines are where the actual weather map contours of 576 and 552 “decameters” at 500 millibars pressure are predicted to be in last night’s run, on the afternoon of May 25th.   When those yellow lines bulge southward, as they do in our domain in the West, a trough was foretold in that run.   All the other red and turqoise lines help determine how reliable where those two yellow lines will be.

Look at all the red lines pushed down toward the Equator in our sector!  There is nowhere in the northern hemisphere where so many red lines (576 decameter contour) extrude so far toward to the south!  These red lines are from the same model, but run with slight changes in “initial conditions” (you might think of it as with a couple “bad balloon” readings) to see how robust the “signal”, the predicted features in the model are.

So, when all the lines, as wobbly as they are, do the same thing (extrude to the south, or bulge toward the north as they do northeast of the Hawaiian Islands) then the “signal” is quite strong, and the foretold feature more reliable.  So eight days from now, a pretty long time in model predictions, we can be pretty darn confident there’ll be a MAJOR trough in the West that will affect Arizona.   See how the turqoise lines also dip southward for the most part.

And what does that mean as far as Catalina weather?   Dust, wind, and cooler weather for awhile; “dusty cool snap.”

No rain is indicated at this time, though the summer thunderstorms will be close prior to the dusty cool snap.

OK, I think I have confused things enough.


The End.