Western drought status: before and after the Big Niño erupted

“BN”, sometimes referred to in the media as the,  “Godzilla Niño” of 15-16.

Before, one year ago, the drought status as presented by the National Drought Monitor folks there in Cornhuskerland, Lincoln, NE:

First, a legend, no, not a story, though we could write one,  “The Legend of the Ghost Niño of 2015-16“,  but rather a guide to the colorful drought intensities on the maps below:

Drought intensity legend

One year ago


Western drought status as of April 7th, 2015.
Western drought status as of April 7th, 2015.

Now let us look closely below–you’ll have to–to see what the Big Niño has done to ameliorate drought so far THIS  water year (since Oct 1):

Western drought status as of April 5th, 2016!
Western drought status as of April 5th, 2016!

Of course, the giant low centers spinning around in the central Pacific sent a stream of large waves over and over again that blasted the Cal coast. That was expected, and verified. But not much else did. Drought should have increased in the Pac NW–recall it was forecast to be drier and warmer due to Niño conditions.  Instead, the Pac NW had record amounts of winter rain!

Cal, especially, central and southern were to be slammed. Southern Cal residents were advised to consider purchasing sandbags in one media story last fall.  And, of course, we here in AZ are profoundly disappointed; conditions have only improved some in the north part of the State.

Well, of course, there’s not one dry meteorological eye in the house after a bust of this magnitude.  And when our best models predicted giant West Coast storms that looked like the kind we were expecting due to the Niño, even though they were 10-15 days out, they seemed sure to happen.  CMP, bloated with confirmation bias,  was sucked in several times this past winter.

Sure, we knew that Niño correlations with weather are not 1.00, that is, perfect, still, the “signal”,  the size of the Niño, was so huge we figured it had to come through with those mighty storms striking the lower West Coast as happened in 1982-83 and 1997-98.    Those correlations, as strong as they were, of course, were limited in number since these large events are rare.  Those correlations will, let us say in place of cuss words,  “degrade.”

Oh, me, what will we say when the next Big Niño appears?

The weather ahead

You’re probably pretty excited about the wind and very cold air just ahead.  CMP is.  And, with the jet stream at 500 mb (18, 000 feet or so–5.5 km above sea level) eventually circumscribing us with its charateristic moist lower region of air, we should just enough moisture for some isolated very light showers, probably just in the Catalinas, during the period of low freezing levels that hits late Friday and continues through  Sunday.  Low freezing levels mean even moderate Cumulus clouds could form ice, leading to virga.

Amounts could, at the most,  only be a few hundredths here, and most likely we will be missed; precip just limited to snow flurries on Ms. Mt. Lemmon and thereabouts.  The U of AZ mod sees the cold blast arriving late Friday after dark.

On the other hand, Saturday and maybe Sunday as well,  will be good days for you to practice your ice in clouds detection skills in smallish Cumulus clouds.

The weather way ahead

Still looking to see at least two more troughs and chances of rain during the last two weeks of the month.  NOAA ensembles suggest so.  Best chances, 23rd-25th, and again around the 28th or so.

Some cloud shots from our little 0.01 inch rain day on Tuesday:

6:02 AM, Tuesday.
6:02 AM, Tuesday.  A summer-like scene, complete with thunder frames the post dawn hours.
10:35 AM. After the morning excitement cleared off, a pretty Cumulus congestus erupted north of Saddlebrooke town. There’s a hawk in the photo.
12:12 PM. That Cumulus congestus and its sisters, were able to reach the level of glaciation, and wind shear, send a plume of ice downstream toward the east, and rain below that overshooting turret.
2:36 PM. Pretty much the perfect cloud for ice in cloud studies. As the air warmed aloft and capped the Cumulus clouds, this one just poked up high enough to form some ice. It would have been a great sample to determine the temperatures and cloud conditions at which ice onset in clouds on Tuesday.
4:16 PM, Tuesday. Those shadow and sun highlights that make our mountains so darned pretty. I just never will be tired of these views!

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.


  1. Hi Art: Thanks for replying to my previous post. The cactus I was referring to is called “Astrophytum capricorne”. The flower is a big yellow one with a red ‘throat’. Quite stunning to see. Anyway, you probably are too far west or NW from it’s normal habitat in the mountains of Mexico. Meanwhile, just a brief comment on the E.N. maps you showed in this post; not all that much has changed! I was hoping to see a lot less of that dark area. I’m glad the PNW is no longer as close to it, but we may still see a dry warm summer here. April so far has been relatively dry, and next week we are expecting more above normal temperatures in the sun. It might get near 80F here.

    1. The Pac NW had an awfully warm summer last year, many thought it the best ever. It would be amazing if those folks had two in a row, but, as you know, Niñoes tend to produce warmer summers in the Pac NW, while here summers can go either way, with a slight tilt toward drier (*ugh”). Thanks for the additional info on that cactus.


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