Fall Festival of Rain

Tucsonans don't complain when it rains. Rain makes the actual festivals more fun, more reason to celebrate while packed under the tents. Tucson so far this fall has escaped any serious flooding such as has affected points south, west and north of here.

In a post two months ago, I noted the Climate Prediction Center's odds for El Niño during the upcoming fall and winter, and revisited my rant from three years ago regarding chatter about fall rain in Tucson related to El Niño. Since this fall's rains have been so good, I decided to present a fresh scatterplot for fall. For more explanation about the reasoning behind the scatterplot and for additional sources, follow the links in the previous post.

The Oceanic Niño Index (ONI) is defined and calculated by the Climate Prediction Center [CPC], and won't be available for October until the end of November. For now I'm forecasting 2018's October ONI will be approximated by the latest (mid-October) weekly Niño 3.4 region SST departure. As for this year's fall (September plus October) rain, so far for the period from 1 September through the morning of 16 October the airport has had 3.44 inches; that running total will probably increase by the end of the month. (I've had 4.76 inches for the same period, including 0.84 overnight last night.)

Considering just the last six years (2013-2018), there is a trend toward higher precipitation totals when moving from colder to warmer ONI. The decade of the 2010's has joined the decade of the 1970's in favoring above normal fall precipitation when the ONI is in positive territory. The exceptional years (fall precip well below normal but positive ONI) for those two decades were 2012 and 1979. Fall of 1976 was close to normal.

Considering the wet years appearing in the negative territory of October ONI, with the exception of the decade of the 1950's, in each decade there is one unusually wet fall. These wet falls have followed El Niño fall/winters by one (1964, 1970 and 1983) two (1996 and 2011) or three (2000) years. Certainly it's possible that the climate system sometimes stores somewhere a lingering effect of a previous El Niño, maybe even for a few years, and that that lingering effect influences Tucson precipitation in a specific La Niña fall. But most often any lingering effect does not appear to have an influence. As a specific example, most recently the fall of 2016 does not appear to have been influenced by a lingering effect of the previous fall/winter's strong El Niño. It is as much nonsense to call the fall of 1983 an El Niño year as it would be to apply the same label to the fall of 2016.

Missing Middle of the Monsoon

Every year in Tucson people complain about the current monsoon—not like the ones they remember. That's an accurate perception; it isn't just a matter of recalling only the spectacular days. Each monsoon has a different variety. Some years feature squall lines that roll across the metro area between 3 and 5 pm, others chaotic distributions of evening storms, others organized nocturnal systems, others breaks when the monsoon completely shuts down—each of these more frequently in some years and less in others. So judging this year is not like the others is usually justified.

It's generally recognized and understood that during the shoulder seasons of the monsoon, early July and the weeks around Labor Day, rain totals can be erratic. Erratic is even better understood for the off-seasons, late June and mid-late September. Intrusions of tropical moisture if they happen in the off-seasons are appreciated; if not, oh well. But usually over a four week period near the middle of the monsoon, the last half of July and the first half of August, one way or another the idiosyncrasies of that year's monsoon generate a rain total that meets expectations. That did not happen this year. (My house is 12 miles north of the Tucson Airport.)

2018 Period	# days	My house, inches	Airport, inches
June 15 and 16	2	1.76	0.91
July 5 to 15	11	0.98	1.77
Jul 16 to Aug 13	29	1.01	1.15
Aug 14 to Aug 25	12	1.26	2.05

Until two weeks ago this year the usual quips about the non-soon had given way to bitter comebacks, What monsoon?!, or as someone on my community's listserve wrote sarcastically on August 11, Our trees/shrubs are just loving it!! G RRRR!

Since the current official definition of the monsoon includes June 15, as well as all of September, and since September is expected to be above normal, it's likely that the official rain total for this year's monsoon will look reasonable. But no matter how much rain arrives in September, it won't wash away the reality of a missing (less than 0.04 inch per day) middle of the monsoon this year.

Elusive Effects of El Niño

Seems only yesterday, but it's been three years since everyone was talking about expectations for the then upcoming 2015-2016 winter. That summer of 2015 the Oceanic Niño Index (ONI, defined and calculated by the Climate Prediction Center [CPC]) had already run past plus one, and was expected to (and did) exceed plus two during the winter of 2015-2016. This year the latest Diagnostic Discussion by the CPC places the odds for El Niño at 60% this fall, and 70% during the upcoming winter. The CPC's consensus of forecasts takes the ONI to around 0.6 by this October and to about 1.0 during the winter.

This time three years ago I thought that the chatter about the upcoming effects of El Niño was excessive. This summer on the contrary it seems that excessive reticence has replaced overconfidence. Three years ago in an initial rant about the chatter, I posted a scatterplot of the previous 65 years of precipitation at Tucson airport, totaled for September combined with October, versus October ONI. Here are the final numbers for the last three years—an additional three points that can now be added to that scatterplot for fall.^*

Year	October ONI	September plus October Rain, inches
2015	+2.4	4.65
2016	-0.7	1.70
2017	-0.7	0.03

I won't rehash my old rants about fall; they can be read from three years ago here, and two years ago here. The point about expectations for this fall is that to the extent that an increased level of concern about the kind of thing that can happen in the fall because El Niño was justified three years ago, that level of concern is equally justified this year.

There will be a separate post for winter, including a fresh scatterplot^* for that season, as well as wonderings about why the scatter for that season is what it is. But that post can wait for a month or two.

* The plots three years ago were made with the previous version (v4) of the CPC's ONI's SST anomalies. The current version (v5) mostly differs by no more than 0.1 ONI (degree C), but in some cases the difference is 0.2 or even 0.3. Notably: October 1983 is now -0.8 (previous -0.6); and January 2010, which previously at +1.3 was right in the middle of the "moderate" El Niño category, now at +1.5 edges into the strong category.

Joe DeNardo

The Pittsburgh Post-Gazette this morning has a story that broadcast meteorologist Joe DeNardo died. Though the story acknowledges DeNardo's time with KDKA in the 1960's, the memories in that story are mostly from the time after I left the area.
Here are some memories from the 1960's. Joe was a star on both the radio and television sides of KDKA. In the mid-60's KDKA radio was trying to blend traditional public service news/sports with top-40 music. KDKA's morning radio show Pallan and Trow I was surprised to read started only in November 1965 and ran through April 1968. Pallan and Trow were talented comedian entertainers, not just ordinary hosts of a morning news/top-40 time slot. There was a certain time when I was getting ready for school when Joe would call in with the forecast discussion. Sometimes he couldn't stop laughing at the antics of the hosts, and he would have to call back later. I was a fan of Joe as much for being a straight man for Pallan and Trow as for being a serious meteorologist.
I was slow to give up completely on KDKA's blend. In the spring of 1967 I was taught to tune-in and turn-on to Chicago's upstart WCFL, which could be picked up after dark by tuning KDKA and then adjusting the dial slightly from 1020 to 1000. WCFL's weather forecasts were as brief as possible. It might be 89 in the northwest suburbs, 93 in the southwest suburbs, and 65 downtown at the lake. And of course as a good rule of thumb Chicago's weather today would be Pittsburgh's weather tomorrow.
So I credit WCFL as much as Joe DeNardo for my interest in weather. But Joe had the serious technical details, especially on the Sunday 11 pm newscast, when he would provide an outlook for the week ahead. At mid-week he would slide across the forecast 500-mb map, copied with grease pen onto a large clear plastic overlay. "Enhanced lake-effect snow showers on Wednesday/Thursday as this upper-air trough passes." The rest of the outlook into the following Sunday clearly communicated that his was a plausible scenario extrapolating into what was then for computer forecasts terra incognita.

Category Labels vs. Distinct Things

Suppose that it would be interesting, useful, or even important to categorize hot days for cities in the Northeast. A day when the temperature at the airport reached 95F or higher could be labeled Category 5 heat. Better yet, label that day a Scorcher. The Glossary of Meteorology would define Scorcher. Climate studies might draw conclusions about the number of Scorchers. To the question there would be a ready answer, What is responsible for this heat? Meteorologists say it is caused by something called a Scorcher. A simple report, Hot yesterday, a bit hotter today could be expanded into an earnest elucidation, Yesterday was not a Scorcher, but today we have a Scorcher because ...

Too often in meteorology an attribute of a thing is cast into a newly labeled category of that thing, and then in no time at all the name of that category is communicated as a distinct, peculiar thing, even though the new thing is basically the original thing, and the familiar label for the original thing adequately, succinctly and more clearly communicates the weather situation.

The jargon bomb is a subcategory of intense area of low pressure. Bomb does not categorize intensity, but rather the time rate of change of the central pressure of the low. If the question is, What is responsible for this wind?, then part of the answer is the large, ineradicable cold area of high pressure to the north of the low. Perhaps a sexy label could be devised for the high's stubborn persistence; anti-bomb? But no need for that. Already there is a long-established, familiar term that most everyone in the Northeast recognizes as labeling the overall pattern of extreme winter weather.

There are many other local labels that succinctly communicate a familiar pattern of wind, temperature, humidity and/or sky condition; examples include Santa Ana, Bora, Blue Norther and, in Arizona, Monsoon. These locally familiar labels are effective precisely because they resist being defined precisely. Instead they are learned as a pattern—know it when you see it. Conversely, when a subcategory of a thing is defined by numerical threshold(s) of attribute(s) of the original thing, it has to be wondered what is intended when using that jargon term for communication since use of the unfamiliar term requires a redundant reiteration of the threshold(s).

The term derecho is like the term bomb in that both terms could be termed second-generation categorizations. Derecho does not categorize the magnitude of the severe winds accompanying a fast-moving line of thunderstorms, but rather the time during which the line remains severe, or equivalently the area swept out by the line during that time. Certainly it is important for forecasters to recognize and for both forecasters and the public not to dismiss an unusually long-lived line of severe thunderstorms. But why not communicate the attributes unusually long-lived for the thing and unusually high confidence for the long-lead-time warning? (What's worse, earnest elucidations about the term derecho these days invariably short-circuit the history, butchering the fact that when the Spanish word for right translates to English straight it is not as a direction but as not evasive, honest.)

Polar air is a thing. It is defined by the climate system, not by an arbitrary numeric threshold. For the same reason, polar front, polar jet stream and polar vortex are all things. Arctic air is a distinct thing, generated by absent sun during the arctic winter. The labels Polar and Arctic are arbitrary jargon, but they are long-standing and deserve to be respected and elucidated. Arctic air—whether stationary, displaced or on the move—is both Weather and Climate, and, because it is generated by minimal sun where absolute humidity is very low, it will always be with us, no matter how much manmade greenhouse gases continue to increase and no matter what schemes may be instituted to reflect a portion of incoming solar energy.

[I acknowledge that at least part of this rant was inspired by the Air Weather Service Back to Basics program of 40 years ago.]

Republican Disgrace

In a few days I'll be back to posting about weather. But first, a follow-up to my previous post (about Collusion). Yesterday Senator Dianne Feinstein released a pdf-file of testimony, putting discussion about the famous dossier (prepared by Christopher Steele, the guy who's father had been a weather forecaster) back on the table. I'll quote from Josh Marshall's summary at Talking Points Memo:

... this is a testament to what can happen when the GOP unites behind a campaign of willful disinformation at the country's expense ...

I've read the first 140 of the 312 pages of the released pdf-file, and I would say that so far the contrast in questioning by the committee's majority vs. minority staff is striking, if not disgraceful.

Collusion

I'm about halfway through the book Collusion: Secret Meetings, Dirty Money, and How Russia Helped Donald Trump Win, by Luke Harding. Along with events from the title, Harding presents a bio of Christopher Steele, the man who prepared the famous dossier. For me it's interesting to read that Steele's father had been a weather forecaster, and his grandfather a coal miner.
The book's sixth chapter is, among other things, about Paul Manafort's relationship with the Russian aluminum oligarch Oleg Deripaska. There is a quote from a Manafort email to an intermediary on July 7, 2016, in which the campaign manager offered to provide the aluminum oligarch with private briefings about the campaign. (The book expands on close ties to Putin.)
Whenever I have been hearing aluminum oligarch in connection with the ongoing investigations, I have been thinking about the Trump campaign appearance in Monessen, Pennsylvania, last year. Comedians at the time had fun with the bizarre scene of Trump standing amid bales of scrap aluminum prepared for recycling. A day after that event I commented in a post (mostly workplace memories from a long ago summer). Unsure if I remembered correctly the exact date, I later found an online news story, dateline MONESSEN (KDKA/AP). The Monessen speech was on Tuesday, June 28, 2016.
According to the news story, the appearance was a policy speech on free trade, where Trump outlined a seven-point plan to restore America's trade position. I don't recall or see in the news story any points of a plan, just the usual platitudes. In my earlier comment, I thought it odd to be celebrating bundling scrap for shipment to somewhere else. There were 200 invited guests according to the news story, with another 100 outside, half of them protesters (some of them from my hometown). The town of Monessen itself is not a Trump stronghold. In fact the mayor, who acknowledged inviting Trump to Monessen, was defeated for re-election this year.
There are so many odd things about that appearance in Monessen. It was as if the campaign manager's main objective was to have the candidate seen in a photo op with the bales of scrap aluminum. Perhaps that visual message was intended for a certain foreign country.