So big, so little; in potential to realization

The U of AZ models got pretty excited about yesterday’s rain potential, even the WRF-GFS run AFTER the one I looked at and got me excited about yesterday’s rain potential.   The model one that followed the one I saw when posting yesterday’s blog, one that comes out around mid-morning based on 5 AM data, also had a big rain day in these parts.  (Sometimes the two runs don’t agree so well, so when they did, it seemed like a “done deal.”)   Take a look, for example, at the total rain predicted in that later model run that came out yesterday morning, and take a look at what it thought Mt. Lemmon, would receive in the 24 h ending at midnight last night in this pdf:

U of AZ WRF Precip

Yep, 3-4 inches (!) was to have fallen from the skies on Ms. Lemmon in the 24 h ending at midnight last night.  You can also see that we here in Catalina were supposed to see at least half an inch (that greenish area to the west of the orangy area).  We got 0.14 inches.  Better than zero, though.

Pima County ALERT rain amounts?

Catalina mountains max: 0.55 inches, at White Tail, near Palisades Ranger Station (on the highway to Mt. Lemmon).

Probably as much as half an inch fell “over there” under this sudden late afternoon thunderstorm by Samaniego Ridge shown in the photos below.

Two places, though, one in the Rincons, and once again over in Avra Valley, did get drenched with more than 2 inches yesterday, so large amounts did fall in some areas.  Very appropriate for the really warm cloud bases and humidity we have these days.


That late night model run (based on 11 PM data) has another active day today, though not as active as yesterday.  The model thinks showers will roll off the Cat Mountains this morning.  Not so sure about that, but surely, there will be some giant clouds around and some tremendous falls of rain here and there with the humidity we have.  69 F dewpoint here now (5 AM) in Catalina.  Enjoy, as we know these spectacular rain days are numbered, and sooner or later, the westerlies will creep down here and wash all this humidity away with dry Pacific air, and we’ll start to feel those cooler mornings associated with drier air overhead, that dry air that lets all that night warmth escape into space.

GW moisture factoid

One possible cause about why global warming has pretty much halted over the past 10-15 years (well, up to 2010, anyway, when this paper I am going to mention was published), was that the moisture in the stratosphere (the layer above where clouds and precip form) had declined over the period when the temperature stopped rising.   With less moisture up in the stratosphere, more heat was escaping into space from the earth since water vapor is the biggest greenhouse gas of all, and when it changes a little, a lot happens to the radiation characteristics of the earth.   This decrease in water vapor “topside” since the late 1990s was enough, it was calculated, to offset the effects of increasing anthropogenic greenhouse gases since then.  Whether such a drying will continue, or why it happened, is not known.

This finding was from Susan Solomon’s group, work that appeared in the illustrious journal, Science.  Solomon is the scientist that did so much work on explaining the ozone hole in the 1980s.

4:21 PM. Veil-like rain with little gradation  (just above trees in foreground) falls from soft-looking bases along Samaniego Ridge.  I’m thinking “warm rain” process.  With those low (and very warm bases) the scene looks “Hawaiian” to me, a location where ice is rarely involved in the production of all that rain they get there.

4:39 PM. After the rain over there being “veil-like”, a shaft suddenly emerged announcing that a top has shot up at least 10 kft more than the tops around it, has reached the ice-forming level. Lightning is now immiment.
4:48 PM. A wall of rain moves slowly off the Catalinas toward Catalina. Only remnants of a once proud line of heavy rainshafts arrive, leaving us with just 0.14 inches.