“Tom Thunder” strikes Catalina three times; rare contrail in video

Probably haven’t heard that name in a while.  It kind of went along with “Old St. Nick”, “Jack Frost”, the kind of thing that we kids called things.

Well, yesterday in the land of Catalina, we had three separate thunderstorms in about 8 h, all producing nearly continuous thunder, and when you could see it, nearly continuous lightning.  Oddly, there were few cloud-to-ground strokes.  The lightning, too, was odd, light bulbs going off in small areas of the thundering clouds, and when visible, was a fine, often curly cue thread, seemingly one third the width of “normal” lightning.  Thunder was heard at 6 PM, 11 PM, and 1 AM1 in those separate storms.  Was a pretty fantastic light show, as you know, since you likely got up to watch it as I did.

All in all, while not a lot of rain fell in Catalina (one core over the Golder Ranch Bridge at Lago del Oro Parkway, presented the gauge there last night with 0.43 inches, though friend, Rick Bowers of Bowers Photo over there on Trotter said he got 0.65 inches, the most in town.  Here in the Heights, just 0.24 inches.  Still, its ALL good, except maybe for the flying ant swarms that are beginning to erupt.

Here’s the quickest way to look at some rainfall numbers around the region:  Pima County ALERT gauges. And here fro the State, from WSI Intellicast’s rendering of radar-derived precip, usually pretty accurate.

The best way to reprise your cloud day, to make sure you logged all of them in your cloud diary,  is here, courtesy of the fine University of Arizona Department of Atmospheric Meteorology time lapse film.  It was so good yesterday, I put in two links to the same thing.  Really is a complicated flow day, one cloud maven person has not seen before.

To wit, there were two layers of ice clouds traveling almost perpendicular to one another.  Never saw that before.  The height difference must have been huge.  You will also notice some Altocumulus tufts at the SAME level as that

Big fat contrail leads to a “heavy” fall of ice crystals at about 9:30 AM, the aircraft flying in the lower ice clouds (where it was warmer, of course, and that means the ice content was higher than in the Cirrus clouds way up top that moved from the west).   That higher amount of moisture allowed bigger ice crystals to form and fall out so obviously from the contrail.

And it was an extraordinary event for another reason:  contrails aren’t supposed to form at the temperature this one did!  You won’t find contrails forming at -20 to -30 C in Appleman’s famous nomogram for contrail formation.  No, that’s right, you’re not supposed to get them until about -35 to -40!  Could be a publication in this….

IN FACT, what happened is related to the “Hole Punch” and “Ice Canal” phenomenon2 resulting more often from aircraft flying through droplet clouds like Altocumulus, ones that are also very cold, usually colder than -15 C.  So, the ground has been tread pretty heavily in this domain EXCEPT that there was NO DROPLET cloud where that strongly precipitating contrail was laid down!  Could be a publication, to repeat…some “sci glory” might be down the road….)

Here’s the Tucson sounding that tells all:

The balloon sounding for Tucson yesterday morning, valid at 5 AM AST.
The balloon sounding for Tucson yesterday morning, valid at 5 AM AST.  Note reversal of winds (west at 40,000 feet or so), then from the east at 25,000 feet or so (above sea level).


Well, got WAY behind in chores following the “vacation” in WA and OR lately, so will quit here.  Instead of a cloud shot, I will leave you with this public service reminder about dumping in others trash bins.

Putting stuff in other people's dumpsters can be financially ruinous.  Don't do it.
Putting stuff in other people’s dumpsters can lead to financial ruin.  Don’t believe me?  Read the bottom lines (see below).
You’ll need a second mortgage to pay the fine!  And, why don’t they just make it a million dollars…


More thundershowers on the way here as the Pac NW goes into a heat wave over the next few days.  Heat?  Hah!  They know nothing about HEAT. If its 85 F, they think its really hot!

Forecasting tip:  in the summer when the Pac NW gets hot, we’re usually wet.  So, lots of great days ahead, and more visits by “Tom Thunder.”

The End.


1Weren’t we supposed to drink Dr. Pepper at these times?

2Mr Cloud Maven person, yours truly, had his feelings hurt when his paper about his own research aircraft producing ice in clouds at below freezing temperatures, co-authored with Peter V. Hobbs, was rejected twice, but then accepted on the third try (way back in the early 1980s) and in the end, everybody was happy.  You can read the whole story here.  It starts out, so you can see how bad I felt, “…the reviewers are still unconvinced by these controversial claims.”