Measurable rain to fall in November (!)

That’s it.  Its a kind of news release, best released on the 1st.  Its news, of course, you won’t find on other weather sites because maybe they’re chicken, or prudent.    Check back on November 30th, and if its rainless again, there will be no mention of this forecast.

But, after the rainless October (we average about an inch here in Catalina), you probably won’t believe me.  Check this out from the NOAA spaghetti factory.  I got pretty excited when I saw it.  I think, you will, too, maybe mention it to your neighbors over coffee this morning,   having been pretty convinced yourself after seeing this that storms are a brewin’ for Catalina and vicinity (all of Arizona) in November:

Valid for November 10th at 5 PM AST.

Valid for November 10th at 5 PM AST.  Originates with global data obs made at 5 PM AST last evening, and represents a few key 500 millibar height contours after DELIBERATE little errors have been put in and the computer model rerun with them in it.  
























Thank E. N. Lorenz, a meteorologist for Chaos Theory and maps like the above that show how little tweaks in the original data can change stuff a lot if things are fragile, but not so much if the signal is robust, and things not so fragile.  Here a deep trough along and off off the West Coast on November 10th is virtually guaranteed by the blue and red lines that plunge so far to the south off the West Coast.  A trough out there, as you know, gives us the best chance for rain as it progresses to the east.  The bunching of lines indicates where the forecast, with baby errors, is strongest, like off Asia, and hereabouts, off Baja.  Those red lines are pretty much where the south edge of the jet stream will be at this time of year.  As you know, we have to be on the north side of the jet during the winter here in old Arizony to get precip, so it looks good for that to happen as we move forward in the month.

BTW, here’s your official forecast for the whole month of November from the Climate Prediction Center (CPC). As you can see, this November is a tough month for them, no real signals showing up for the month as a whole as indicated by the HUGE areas of “EC”, i.e.,  “equal chances” of above or below normal precip.  We’re kind of on the edge of “we don’t know what’s going to happen” (in the popular lexicon, “clueless”) which is good.  The signal for continued drought here is not so strong,  though it is there.  Poor New Mexico, though.

November precip forecast for North America made on Halloween by the CPC.
November precip forecast for North America made on Halloween by the CPC.














Cloud photo op coming up

A weak trough ejects from the Pacific and over us beginning tomorrow, and it should bring some great photogenic  Cirrus and Altocumulus clouds tomorrow afternoon and evening, likely some “castellanus” if you care.  Likely to be some virga (snow falling from the Ac) too, so could be a great sunset shot coming up.  With the virga, always a slight chance of a sprinkle-its-not drizzle.

The End.