Fall Rain

Nice rainbows from about 5:30 - 5:45 PM last evening, near the end of and just after a dump of about half an inch. A faint secondary bow can be seen near the furnace exhaust stack. A short time before this photo, while it was still raining, both bows extended fully off to the northeast.

Tucson airport (misspelled Tuscon at the weather.gov site) has now had 1.29 inches so far in September. (Mine now stands at an even 2 inches.) My post last year discussed the September-plus-October rain for TUS. I won't repeat that, except for a short listing of a few data points already plotted in that post, limited to just the years where the previous winter had been a strong El Niño. The numbers (October Oceanic Niño Index; September plus October Rainfall, inches) are the same as described and plotted in last year's post.

Year	ONI	Rain
1958	0.5	1.42
1973	-1.7	0.00
1983	-0.6	9.26
1992	-0.1	0.97
1998	-1.2	1.34
2016	-0.5	1.29+

This year's October ONI is based on the CPC consensus forecast--currently expecting borderline neutral through the fall and winter. The year 1983 did in fact see a lot of rain in September-October, and it did follow an El Niño winter, but by October of that year the ONI was about where it is now expected to be this year. Nevertheless, it has become a legend about September-October 1983 that it was an El Niño year.
Given that history, it's a bit surprising that so far this fall there have been no Tucson sightings of El Niño laggings. Although it's very unlikely that we could get a significant tropical system over the next ten days, after that there is a period of a few weeks when the potential is high for another tropical system to affect Tucson. If that were to happen, I predict an outbreak of laggings that will quickly escalate into a full epidemic of El Niño year!

Monessen

Though overshadowed by other news yesterday, there was a speech given in Monessen, Pennsylvania. The scene was bizarre, with Donald Trump standing amongst bales of scrap aluminum. I guess that making America great means bundling more scrap. Yesterday's event was held exactly thirty years since steel production in Monessen ended. (If there was a betrayal of workers' loyalty, it happened on Ronald Reagan's watch.) I don't know much about Alumisource, but I do know that the coke plant portion of the old steel mill is operated today by ArcelorMittal, is manned by United Steelworkers, and is fueling steel production (not scrap processing) in Cleveland. The Clinton campaign should counter by pledging continued bipartisan efforts to protect today's steel-producing jobs from foreign dumping.
Long ago I twice belonged to the United Steelworkers union, including a summer at Monessen's coke plant. Some memories about times that will never return:
There were about 14 of us college students hired for that summer. (Probably everyone had some connection. My connection was that my Dad served in the Air Force Reserve with the Human Resources manager for the steel mill.) We were hired to replace about 7 regular workers (including union leaders) who had been dismissed for organizing a work slow-down. I was worried that the year-round workers would resent this. But one of them assured me it was not a problem. An eventual ruling would reinstate the dismissed workers with back pay (he was right about that). In the meantime, they got the summer off, we had jobs, and the union had made the point that more workers were needed to safely satisfy production goals. I'm not sure it wasn't a game that all sides were playing all along.
There was extra pay (about 40 cents per hour) for laboring on top of the coke ovens. Staying cool up there meant moving fast, and I wasn't good at that. But on hot humid days, the older guys would decide that job wasn't worth it. So it passed down to the guy with the lowest seniority. Hot humid days outside here in Tucson feel like those days on top of the coke ovens, except that here there is always air-conditioned comfort to look forward to inside.
I was working the evening that Richard Nixon delivered his resignation speech. We were taking a scheduled break, in a space at the center of the coke-oven batteries. There was a radio. The music stopped, and a news special report was being introduced. One of the regular workers, a younger guy not much older than me at the time, looked at his watch and noted that it was time to get back to work. He was right. But the crew chief saw my disappointment and said, No, this is important. We have to listen to the beginning of this. So we listened to the first few sentences of the speech, and then got back to work.
I imagine that the guy who was looking at his watch may be voting for Trump in November. But his wife will be voting for Hillary.

Will Tucson Get Beyond The Middle?

[Update March 30: Tucson didn't even make it to the middle.] Back at the end of September, I showed a scatterplot of the combined total November through March precipitation at Tucson airport for each of the previous 66 years versus the Oceanic Niño Index (ONI, defined by the Climate Prediction Center) for January, i.e. for the middle of each of those five-month winters. I noted back then that, of the eight previous winters for which the January ONI was greater than +1.0 (i.e., moderate-to-strong El Niños), all eight of those winters were in the upper one-third of the five-month precipitation totals. Below is the same plot, but now with an additional point, labeled 2016 so far.

What can be said for this strong El Niño winter is that at least this year's five-month total won't be in the bottom one-third (assuming that we'll get at least a third of an inch between now and the end of March). [Didn't happen! Only 0.11 inch from mid-February through March.] After the jet breaks under the West Coast ridge near the end of next week, it would not be too crazy to hope for an inch of rain in the last week of February, and then another inch in March. That would put the five-month total just barely above the middle 1/3—comparable to the 1957-1958 El Niño winter, but not even as good as last winter, and nowhere near the 1997-1998 winter that might have been dreamed of.
(The Tucson total precipitation since October 1, 4.59 inches, is still almost an inch above normal. But half of this year's since-October-1-so-far total fell in the month of October.)

Communicating Uncertainty

It's been a week since the heavy snows began. On Sunday, in a story about the Pennsylvania Turnpike reopening, a Turnpike official was quoted as saying that the situation worsened last Friday evening with the arrival of a storm that started earlier and farther west than initially anticipated. (Westbound motorists became stranded on the east side of the Turnpike's Allegheny Tunnel. This link to a wiki article about the tunnel includes a view from the final curve on what I remember as a grim uphill climb to the tunnel's eastern entrance.)
After reading the quote from the turnpike official, I googled "Louis Uccellini" because I remembered seeing a brief television clip showing the director of the National Weather Service cautioning uncertainty about the northern edge of the snow. Would that the local forecast offices in Pennsylvania had been echoing the caution of their Director. Instead, until the last minute, their public forecasts reflected a confident dismissal of the few models that were suggesting the possibility of a rapid northward advance of the heavy snow.
On Monday a Turnpike official clarified that, despite initial anticipations, their crews had reacted and had been doing everything they could to keep their road plowed and treated. On Tuesday the Turnpike officials and the Governor received new rounds of (undeserved, I think) criticism. Last Friday they were caught between a rock and a hard place. Even if an omniscient private forecaster had successfully urged closing the Bedford-New Stanton section of the Turnpike late Friday afternoon or early Friday evening, Turnpike officials would have been criticized by the high volume of travelers who had chosen to escape DC at the last minute, having timed their escape based on the increasingly confident and specific public forecasts, and so not expecting the possibility of being blockaded at Bedford or Breezewood. If I had been traveling west from Washington last Friday, I would not have cut it that close. But then, I'm a meteorologist.

Upcoming El Niño (continued), Tucson winter

In a post eight weeks ago, I showed a scatterplot of the combined total September plus October precipitation at Tucson airport for each of the last 65 years versus the Oceanic Niño Index (ONI, defined by the Climate Prediction Center) for October of each year. This year the airport has had 2.40 inches in September (and more to come next week), which already puts this year's September-October total well above the median for the last sixty-five years. So far this year's September-October total is in the middle of the pack relative to the eight years that had an October ONI greater than +1.0 (as this year is almost sure to have).

The plot in this post is similar to the earlier post's September-October plot, except that now in this plot the Tucson airport rainfall is totaled for the five successive winter months of November through March, and the ONI is for January (the middle month of the five-month period). Selected years are labeled (the year is for the end of the five-month period).

I'm still no fan of drawing a straight line through the data points. Instead, the important consideration for this upcoming winter is that, of the eight previous winters for which the January ONI was greater than +1.0, all eight of those years are in the upper one-third of the five-month precipitation totals. No matter who in the Southwest gets clobbered this winter, Tucson will at least get decent pieces of the action. It's easy to forget that last winter's November through March total (the point labeled 15) was already the 12th-wettest among the past 65 years. If this coming winter were only to match last year's total, it would still be a respectable showing for a moderate-to-strong El Niño winter.

I'm a contrarian in going with a 5-month winter, but that's the way it is in Tucson. Freezing temperatures can occur in November and March, although they are more common from December through February. Winter weather patterns can bring rain to Tucson in November and March, although on average they do so more often from December through February. It's important to bear in mind that even El Niño winters are feast or famine—there can be periods lasting weeks, even a month or more, when the jet stream gets locked into a pattern unfavorable for rain in the Southwest. During the 1972-1973 El Niño most of Tucson's winter rain, 3.5 inches, came in November and March, while only 2.27 inches came in December through February. Similarly, 1957-1958's November plus March outperformed December through February. Conversely, and more typically, of the 10 inches in the five-month winter of 1965-1966, 9 inches came during December through February.

Budapest Flooding

On Monday evening Budapest received over three inches of rain in one hour. The results are characterized in online news articles as apocalyptic and tsunami-like. Those Budapest scenes look a lot like Tucson at this time of year in most years, although not so much so far this year. Hopefully in Budapest they've recovered in time for Hungary's national holiday today. Coincidentally, today is also Tucson's 240th birthday.

Upcoming El Niño Seasons

Here in Tucson the rain for the past week finally met expectations. But already, even before the monsoon begins to wane, attention is turning to the upcoming El Niño seasons. It will be interesting to see if the consensus outlooks hold for a strong El Niño to develop and persist through the winter. Whatever the strength of El Niño may turn out to be, the evolution of the weather patterns will be fascinating.
I was preparing to update a five-year-old plot and accompanying rant concerning winter precipitation variability here in Tucson, which I had made back when a La Niña was on the way. But a few days ago the local paper had a tantalizing story discussing the prospect of an active tail-end to the monsoon this year, because El Niño.
So I decided to see what the actual numbers look like. Traditionally September rains would be considered the tail-end of the monsoon, and a tropical system in early October would be beyond the monsoon. Actually, that's still the official definition. Instead of trying to separate the two, I totaled the precipitation for the two months of September and October. The precipitation data are from the Western Regional Climate Center. I used the latest, official definition of the calculation of the Oceanic Niño Index by the Climate Prediction Center. There are a total of 65 years on the plot. Selected specific years are labeled.

I hope that nobody tries to fit a straight line through the plotted points. If this year's October ONI is greater than +1.0, as present trends and most projections suggest, what does history tell us about what to expect? On the plot, there are eight years with an October ONI greater than +1.0 (the right one-third of the plot). For seven of those eight years, the combined total September-October precipitation was at least 1.7 inches. In contrast, the left two-thirds of the plot contains 57 years with an October ONI less than +1.0. Of those 57 years, nearly half had less than 1.7 inches, and two of those years had no measurable rain in either month. So this year, bet on more than 1.7 inches in September-October, because you will have a very good chance of not losing that bet. But another way to summarize the right side of the plot would be to say that in six out of those eight years, precipitation was within plus or minus one half inch of the 65-year mean, which is 2.21 inches. On the other hand, one might choose to go with a persistence forecast, imagining that whatever factors contributed to last year's, i.e. 2014, September-October precipitation performance, those factors are only better this year, and thus the decade of the 2010's might join the 1970's as star contributors toward the upper right quadrant of the plot.
Citing 1972's disastrous tropical system Joanne as the kind of thing that could happen this year would at least be the right analogy--both years with oncoming strong El Niños. Citing 1983's September-October disastrous sequence of events as an example of what can happen in an El Niño year, while discussing this year's high and rising ONI's, is mixing apples and oranges. The 1983 data point would support imagining a big September-October next year. That data point is the only big year making the argument for a lagging effect in September-October from the previous winter's El Niño. But then 1972 is the only data point arguing for a big September-October this year. Certainly the possibility of disastrous flooding triggered by tropical systems in September and early October is a concern, but it should be a concern most years. Dangling the notion that that concern should be higher in Tucson this year because a strong El Niño is developing is not supported by the data.