Part I: The Making of a Cloud Seeding Activist

A Personal Sojourn through a Murky Scientific Field Filled with Confirmation Bias, Vested Interests

and Skewed Literature


Art Rangno

Retiree, Research Scientist IV, Cloud and Aerosol Research Group, Atmospheric Sciences Department, University of Washington, Seattle.

Author Disclosure

I have worked on both sides of the cloud seeding fence, in research and in commercial seeding projects.

My main career job was as a non-faculty, staff meteorologist for almost 30 years (1976-2006) for the University of Washington’s Cloud and Aerosol Research Group (CARG), Atmospheric Sciences Department, with Prof. Peter V. Hobbs as director of CARG. I was part of the flight crew of the research aircraft we had, and directed many flights.

An overview/introduction to Peter Hobbs’ group’s work in cloud seeding, as it was presented at the American Meteorological Society’s Peter Hobbs Symposium Day in 2008 can be found here. Since Peter V. Hobbs has virtually no wikipedia presence, unlike his peers of comparable stature, he deserves at least a review of his group’s work (and our collaborations) in that domain, hence, if anyone says that anymore, the link.

After retiring from the University of Washington I was a consultant and part of the airborne crew for a National Center for Atmospheric Research (NCAR) test of cloud seeding in Saudi Arabia during the winter of 2006-07. That research involved some randomized seeding of Cumulus clouds.

I also worked in commercial cloud seeding programs in South Dakota (twice), India, in the Sierras, and for a CARG seeding program for the Cascade Mountains in the spring of the drought winter of 1976-77. I also worked for North American Weather Consultants, a provider of commercial cloud seeding services, as a summer hire in 1968 while a meteorology student at San Jose State College.

Confirmation bias? Yes, I have some. You can make supercooled, non-precipitating clouds precipitate (see ppt in Part II) for examples). But since those clouds are almost always shallow, the amount of precip that comes out is small. Is it economically viable? I don’t know. EOD.  (End of Discussion).

For a modicum of credibility regarding what you will read:

The director of the Cloud and Aerosol Research Group, Professor Peter V. Hobbs and I got a small monetary prize for our work in the cloud seeding arena. The award was adjudicated by experts with the United Nations’ World Meteorological Organization. Peter had done mainly constructive work in this domain before I arrived. My portion of this prize was really for tearing down accepted structures within the cloud seeding literature via reanalyses of prior cloud seeding experiments, once deemed by the scientific community as the best we had done in this field, along with other published commentaries.


Thanks in advance to the two of you who actually read this whole thing! It’ll take a couple days. Its not a happy story about science, but rather one about how it sometimes fails to catch perverse literature. My hope is that my path through this field was “anomalous” or we’re in deep trouble.

Table of Contents

  1. Prologue
  2. Where it all started: How unsettling experiences regarding journal literature during a large Colorado cloud seeding experiment laid the groundwork for an eventual trip to Israel as a super skeptic
  3. The “documercial” movie about the huge Colorado River Basin Pilot cloud seeding experiment
  4. Scientific idealism begins to slip away in Durango
  5. 1974: I am the recipient of the Archie M. Kahan “Resident Skeptic” Award, my first “accolade” for exceptional skepticism of cloud seeding papers!
  6. The decay of idealism accelerates in Durango
  7. Conflict of interest on part of those chosen to evaluate the CRBPP 🙁
  8. The informational “black hole” during the CRBPP
  9. The 1973 NAS panel report on Climate and Weather Modification reaches Durango in 1974
  10. The final blow to idealism in Durango
  11. A regrettable personal media eruption in Durango that required an in person apology
  12. The apology and the Durango Herald’s article after effects
  13. 1979: my first conference presentation is going to be addressed by the Colorado experimenters before I give it
  14. 1983, a real no-no: a request for an investigation
  15. Tension highlight at Park City, UT, weather mod conference
  16. Intermission and “get a life!” note
  17. Not trusting the cloud seeding journal literature was a “fruitful perception”
  18. Peter V. Hobbs and his group’s work
  19. Anecdotes about my life outside of these volunteer efforts in case it doesn’t seem like I had one (the only fun part of this “blook”)

1. Prologue

This tome has four elements: my science work regarding the clouds and cloud seeding experiments in Israel; the earlier Colorado experiences that led to being an activist in this domain with a strong distrust of the cloud seeding literature; discussions about the difficulty of getting a review of Israeli cloud seeding published in the American Meteorological Society’s Bull. of the Amer. Meteor. Soc. (“BAMS”), historically a repository of cloud seeding reviews, and finally; at the very end, the manuscript itself recounting the “rise and fall” of cloud seeding in Israel as it now stands following peer-review, the two reviews themselves, and my responses to the comments of the reviewers and to BAMS. Yes, its a slog.

Perhaps, as long as this account is, it will be seen as just a diatribe, a useless expenditure of energy on a cause that has little merit except to the author, me. I fear that’s how this will be seen, but I post it anyway.


No scientist working in a conflicted science arena where there are strong and diverse opinions, whether its on the origin of dogs, the degree of climate change ahead, or here, about cloud seeding, will be surprised by anything in this account.

“Filled with skewed literature”? An interesting provocation in the title that I now flesh out. “One-sided citing”, or “selective citing” is a frequent occurrence in cloud seeding articles. One-sided citing is when peer-reviewed article only presents one side of an issue or findings when there are more. It can only result from reviews of manuscripts by “one-sided reviewers” or ones ignorant of the body of literature of the subject they are passing judgement on in their review. It should never happen in honest, thoroughly screened-for-publication literature.

How often does one-sided citing occur?

A survey of cloud seeding literature through 2018 (article in preparation) found that 38 of 90 articles in AMS journals and in the Journal of Weather Modification Association’s peer-reviewed segment that concern two sets of once highly regarded cloud seeding experiments only cited the successful phase a year or more after those experiments had been discredited in the literature. The experiments were conducted in Colorado and Israel.

The number of instances that authors and co-authors signed on to articles that told only one side of the story was over 100 representing more than two dozen institutions from universities, to private organizations, certified consultants, and commercial seeding providers.

The institutional “winners” of one-sided citing?

Colorado State University, South Dakota School of Mines and Technology, and the Bureau of Reclamation, each having more than ten one-sided “events1.” These results tell you, not surprisingly, that institutions who have, or had, concentrated programs in cloud seeding as these did are the ones most likely ones to practice one-sided citing; omitting papers they don’t like, but should cite for their journal readers to balance the view of cloud seeding they presented.

What motive would there be for authors to only present the successful results of cloud seeding experiments that were overturned later? There are several possible answers some of which were addressed by Ben-Yehuda and Oliver-Lummerman (2017)1: “…such deceptions are, “…a deliberate attempt to create a false reality, persuade audiences that these realities are valid, and enjoy the benefits that accompany scientific revelations, whether those of prestige, money, reputation, or power….”

[1] Ben-Yehuda and Oliver-Lumerman’s book should be required reading for the authors of one-sided citing.

Foremost is to mislead journal readers by citing a success (that was later overturned, hoping that their readers don’t find out about it). This leads the reader to believe that cloud seeding has a more successful history than it really does, the probable goal of the authors. I deem this tantamount to citing Fleishmann and Pons (1989, J. Electroanalytical Chem.) in support of “cold fusion”, without citing the followup studies that showed their findings were bogus. What’s the difference here?

Added to this primary reason for one-sided citing would likely be: ignorance of the literature on the part of authors; authors who have grudges against scientists that have injured their home institution, or their friends’ work; and authors who don’t wish to cite scientists whose work threatens their own livelihood in cloud seeding.

Cloud seeding literature with only one side of the story presented can be considered, “skewed.” It should be considered a form of scientific misconduct or really, fraud, in my opinion. BAMS leadership disagrees with this strong position, stating that its too difficult to determine one-sided citing in declining a proposed essay on “one-sided citing” (“Should it be considered a form of misconduct?)

I disagree. Its rather easy to determine one-sided citing. The numbers above indicate an awful lot of misleading literature is reaching the journals, something that publishers/editors of journals don’t want to hear about. Ask Stewart and Feder and their experiences with Naturein getting their 1987 article, “The Integrity of the Scientific Literature” published.

Moreover, one-sided citing damages authors like myself (I am frequently a “victim”) who lose citations they should reasonably have, and thus one’s impact in his field as measured by citation metrics is reduced. Surprisingly, one-sided publications have originated from such well-regarded institutions as the National Center for Atmospheric Research, the Hebrew University of Jerusalem, and Colorado State University, among many others that could be named, thus compromising their integrity as reliable sources of information.

That so many occurrences of one-sided citing reach the peer-reviewed literature points to a flawed peer-reviewed system, one populated by “one-sided reviewers” and/or ones ignorant of the literature they are supposed to know about in the role of a reviewer.


My whole cloud seeding story, more or less, is about these kinds of lapses due to one-sidedness; scientists presenting only part of the actual story, as happened in Israel regarding a key experiment, again pointing to a weak peer-review foundation in journals.

Moreover, this “Readers Digest Condensed Book” is only a partial (!) autobio and should be considered one in development. I know changes/additions will be made over time as comments come in… I’ve tried to constrain myself for the time being to just those important-to-me science highlights/”traumas”/epiphanies that I experienced in this realm rather than present EVERY detail of my experiences in this field (though it will surely seem like I am discussing every detail).

This is also a story, too, by a person who only wanted to be a weather forecaster ever since he was a little kid, but ends up working in and de-constructing cloud seeding experiments, the latter almost exclusively on his own time due to an outsized reaction to misleading literature.

I joined the University of Washington in 1976, btw, long after my disillusionment with the cloud seeding literature was underway. With Prof. Peter Hobbs support at the University of Washington when I brought in drafts concerning cloud seeding, I had a strong platform from which to rectify misleading and ersatz cloud seeding claims. I don’t believe another faculty member at the U-Dub would have taken the interest that Peter did in cleaning up my drafts. Thank you, Peter Hobbs.

In fact, my distrust of the cloud seeding literature, developed in the early 1970s, was so great that I hopped a plane to Israel during the winter of 1986 relatively sure the published cloud reports that supported rain increases in cloud seeding experiments were not slightly, but grossly in error. And someone needed to do something about it!

Most of this “blook” will be about this chapter of my life because it seems so characteristic of the compromised literature in this field that somehow seems to escape the attention of reviewers, and for those who report in this field, demonstrates the powerful seductive forces that the thought of making it rain has on otherwise good scientists. Nobel laureate, Irving Langmuir, comes to mind.


1An author or authors on a one-sided article are each counted as an “event.” A single author can comprise several “events” if he repeatedly “one-sides” the issue, and a single article that “one sides” with several authors can be several “events.” It was observed that several authors repeatedly one-sided their cloud seeding articles.


For a comprehensive, informative, and entertaining read about early cloud seeding experimenters, crackpots, sincere, but misguided characters, and outright footpads in this domain read, “Fixing the Sky: The Checkered History of Weather and Climate Control” by Prof. James R. Fleming. I highly recommend it. (Coincidentally, James R. Fleming was a crew member of Peter Hobbs’ research group when I was hired in 1976, before he became the illustrious Prof. Fleming). You will read about Nobel Laureate, Irving Langmuir, in his book and how he became obsessed with cloud seeding effects and his critical faculties got diminished. The “Langmuirs” in this field persist to this day, willing to throw up specious arguments to recoup lost cloud seeding efforts, or create ersatz publications “proving” an increase in precipitation due to seeding had occurred. And they’re still leaking articles like that into the peer-reviewed literature due to inadequate peer-review.


The experiences described here also deal with a “checkered history of cloud seeding,” but one that emanates from academic settings in the modern era in form of peer-reviewed literature. One will be able to confidently conclude from my account that putting on an academic robe did not end the kind of cloud seeding shenanigans described by Prof. Fleming, though they are far more subtle, sophisticated and crafty. So “crafty” has been such literature, it has persuaded national panels of our best scientists (yes, and consensuses have been formed) to declare that what were really ersatz cloud seeding successes, true and valid in several cases. Namely, bogus papers have misled our entire scientific community!

Were the cloud seeding experimenters responsible for such acts in the modern literature just misguided, deluded but sincere people?

Or were they “chefs” that “cooked and trimmed” results to present their journal readers with ersatz successes that they benefitted from? You’ll have to decide. The evidence is clear in one case.

This, too, is written as I near the “end of my own road” and thinking that the events I experienced might be useful for others to know about and, especially, to be vigilant about.

Since its a story with dark elements, it’s also one where the scientific community (like doctors who loath testifying against malfeasant doctors), has tended to “circle the wagons” in misguided efforts to protect the reputation of science and scientists rather than being concerned with the “victims” of scientific misconduct/fraud. I am treading in this world now with in a manuscript submission to the Bull. Amer. Meteor. Soc. (BAMS) and the American Meteorological Society, discussed in considerable detail later.

Having never been a faculty member, only a staff person at the University of Washington, I suspect that it is easier for me than for authors like Prof. Fleming to address malfeasance and delusion as seen in the peer-reviewed literature by well-credentialed faculty members; “the club,” as it were.


The organization of this piece is somewhat suspect. Its not my forte, as Pester Hobbs would know. It will jump around a bit; you will able to as well via “jump links” in the Table of Contents. Discussions about Israel’s clouds, cloud seeding, and the battle to get my review that published has a light gray background for some sorting of topics!

The references to technical literature mentioned colloquially here, are mainly in the submitted manuscript itself, which is found at the end of this piece, and on my “Publications” blog page, linked to later. I didn’t want to overwhelm non-technical readers with numerous inserts of citations. The “Rise and Fall of Cloud Seeding in Israel” manuscript that I will discuss relative to BAMS, consists of a distillation of more than 700 pages of peer-reviewed journal literature scattered among various journals and conference preprints. Its an account that has not been told before, and needs to be heard by a wide audience because of the lessons contained in it.

I start with the Israeli experiences before I tell you how I got to this degree of skepticism from experiences in Colorado, the second phase of this “blogzilla”…

2.  Durango, Colorado: Where it all began so long ago

How an idealistic view of science decayed into cynicism-followed-by- activism during a large randomized cloud seeding experiment in Colorado, eventually leading to a trip to Israel to evaluate their clouds

This section is kind of a slog about my Colorado experiences….but, I wanted to hit a FEW highlights of what was an epiphany about science for a rather naive person just out of college, me, that occurred in Durango, Colorado. This was my very first job as a weather forecasting meteorologist after graduating from San Jose State College.

(Skip if busy….though if you do, you will miss some personal ridicule, a movie, accolades, a possibly libelous newspaper headline caused by me, and details of a monetary science prize from the United Nation’s World Meteorological Organization that me and Peter Hobbs received for our work in weather modification. Yes, in 2005 I became, “Prize-winning meteorologist”, Art Rangno… 🙂

It is sad for me to have to point out something about the above “prize”, however. Like my HS and college baseball career, (all 2nd team this; all 2nd team that), the prize described above was really a consolation one, to insert a truth-in-packaging note. Other workers got lots more than we did that year. On the other hand, 32,000 Chinese weather modification workers got the SAME amount as Peter and I got that year; hah, less than a US dollar each!

OK, back to serious text…

…that Durango job was a dream come true for me, since I only wanted to be a weather forecaster since I was a little kid (even, somehow, forecasted weather for my 5th grade class–had an aneroid barometer in the “cloak room”). And there I was in the beautiful little town of Durango, Colorado, right out of college, forecasting weather for an important scientific experiment! My life could not have been better!

How I got to the point where I would be so skeptical of peer-reviewed cloud seeding literature that I would travel thousands of miles in question of cloud reports from the world’s leading cloud seeding scientist, however, began here during the huge Bureau of Reclamation randomized cloud seeding experiment called the Colorado River Basin Pilot Project (CRBPP). Read on.

3.  The movie explaining the Colorado experiment; a tribute to its size and importance

To depart for a second, it was a project so huge that it had its own movie, the cloud seeding “documercial,” Mountain Skywater, with a soundtrack by a local Durango artist, Clarence “Gatemouth” Brown!

Departing even further from serious text, it is with extreme modesty that I point out that I was the STAR of this 28 minute movie; I never dreamed that I would be a STAR in a movie (!), but there I am, as was declared by the Commissioner of Reclamation in those days, Ellis Armstrong. He attended the 1972 release of the film in Durango and gave me an autographed photo of several of us with him in which he proclaimed on it that I was the STAR. I only speak maybe two sentences in the whole thing! It was a pretty humorous take. I do cite it in my filmography, however. 🙂

Watching this movie you will get a sense of that cloud seeding era and how it was thought that a cloud seeding success in this randomized experiment was going to be a slam dunk in the San Juan mountains around Durango. There wasn’t a lot of questioning in those days about the work that this massive project was based on; namely, several stunning randomized experiments conducted and reported by Colorado State University (CSU) scientists in the late 1960s–contracts were being signed in 1968 for the CRBPP work about when the Climax II experiment was only about half completed! (And that, my friends, was a gigantic goof, as you will read.)

Also from the movie you will get a sense of the CRBPP’s scope and how well-planned it was overall. The precip measurements were made by those who didn’t know what the experiment day call was, seeded or not seeded. It doesn’t get better than that, and the BuRec deserves some mighty big accolades for that; trying to do it right. They were so confident, too, that they said that in spite of randomization (in which only half the days are seeded), that the CRBPP would produce an extra 250,000 acre-feet of water from the target watersheds.

Also in “doing it right”, and before the CRBPP began, the BuRec proclaimed in its PR literature that they would hire an independent statistical group to evaluate the results of this mega-experiment. It doesn’t get better than that, either. It was a display of confidence about the outcome of the experiment.

Aside: For the other seeding operators out there whose films you might see, this admonishment: “Randomize, baby, randomize”. Prove your claims the right way. Also, to seeding funders: employ independent panels to evaluate what you’ve been getting from commercial seeding as the Israeli’s bravely did.


4.  Scientific idealism begins to slip away in Durango

However, during the CRBPP I lived through journal peer-reviewed literature (J. Appl. Meteor.) that many of us knew was bogus but no one challenged. I, too, participated in a “Code of Silence” that kept our outside peers in the dark about important discrepancies that were being discovered in the CSU cloud and cloud seeding hypotheses during the CRBPP. These discrepancies turned out to cause the undoing of an otherwise well-planned experiment by the Bureau of Reclamation’s Atmospheric Water Resources Management Division, as it was called then (just “BuRec” in this piece). “Management” of atmospheric water was a word that also spoke to overconfidence.

At the same time, while in awe of the BuRec’s planning, it was strange to me that the personnel with them were immune from learning from those of us in the field about problems in their interpretations of the CRBPP’s results.

An example: BuRec personnel submitted a paper to a Florida conference in 1974, several years after the CRBPP had started, purporting that “carryover seeding” effects (those days when a control day followed a seeded day) had compromised the CRBPP because heavy snow often fell on that second “control” day. They then assumed that any heavier snow on the 2nd day MUST be due to seeding effects from leftover seeds that didn’t get blown away. They then grouped such carry over days, or portions of such days, into the actual days chosen for seeding and got better suggestions of increased snow due to seeding for the CRBPP overall.

However, no seeding effects were being detected in the first few years on single days that were seeded. Therefore, it was a crazy idea that somehow the seeding agent, silver iodide, turned into super-seeds after we turned off the seeding generators.

Of course, there was a natural explanation for this phenomenon when two days in a row were selected for experimentation.

I wrote a long letter in 1974 explaining why the findings in that BuRec preprint were bogus. When we randomly selected a second day in a row for experimentation, it was because an incoming storm was so large and heavy that it took two days for it to go by, or it was just beginning on the last hours of the first day. Not surprisingly, the heaviest part of the storm was on the second day, and usually early on.

I showed the BuRec data that control days that followed a control day, the second control day also had heavy snow, especially in the early going just like they were inferring was due to inadvertent “carryover” seeding of a control day after a seeded day. You could claim in a similar way from my examples that not seeding on a control day caused heavy snow on a following control day; silly. I had much more argumentation as well.

My explanation fell on deaf ears.

I concluded my commentary to them in 1974 about their ersatz findings with a line they couldn’t refuse to act on: I said they needed a “Resident Skeptic” at their headquarters in Denver.

A couple of weeks later, the CRBPP Project Monitor from the BuRec, Mr. Bill Douglas, presented me in person with a framed, Dr. Archie M. Kahan “Certificate of Honorary Resident Skeptic Award.” The presentation, in which he read the words on the Certificate, got a lot of chuckles from our staff who gathered around to see it. Archie Kahan, whose signature appears in the lower right, was the head of that BuRec cloud seeding division.

5.  My Well-earned Resident Skeptic Award from Dr. Kahan and the BuRec

Here is that “Certificate”, one really meant, I thought anyway, to ridicule someone they didn’t take seriously. Well, there were some at the BuRec, like the late Olin Foehner, who did take me seriously. I was only trying to help, guys…. You’ll have to zoom in to read the text.

Note the upside down Bureau of Reclamation logo in the lower left hand corner. It was to be prophesy for the division that sent me this “award.” Due to various missteps, of which the CRBPP was one, and a wetter period of years in the later 1970s into the 1980s, interest in cloud seeding virtually disappeared and their office was shutdown.

6.  Decay of idealism accelerates in Durango

More disillusionment with the BuRec and journal literature came when their preprint about carry over effects in the CRBPP was published in 1975 in the peer-reviewed, J. Appl. Meteor. There was no mention of the synoptic situation that I had described that compromised their findings. To them, inadvertent contamination of CRBPP days was too good an argument to let go of to help boost the results for a failing 10 million dollar experiment. Nor did I comment on it; I had no experience in journal matters and it never occurred to me to do so.

7.  The choice of the evaluators of the CRBPP 🙁

Another decline in confidence about the science of the CRBPP occurred when the BuRec, instead of choosing an independent group to evaluate the CRBPP as they said they would do before the project started, hired a cloud seeding group to evaluate it! While the group they hired went under the company name of Aerometric, Inc., most of the team of evaluators were really from North American Weather Consultants, led by Robert D. Elliott, President of NAWC. NAWC was largely a commercial cloud seeding company with many seeding projects and at one point was seeding commercially so enthusiastically in Utah that it contaminated some control days of the CRBPP! “Aerometric-NAWC” was chosen as the evaluator when it was clear, after just two years of random decisions, that the CRBPP was NOT going to replicate the CSU seeding results.

Perhaps the BuRec needed a friendly bailout, someone to put a happy face on a science disaster. (Footnote: I had worked for NAWC as a summer hire in 1968 and loved it and the great people there. Tor Bergeron stopped by! Still, it wasn’t a good choice by the BuRec to have them evaluate whether cloud seeding worked.)

8.  The informational “black hole” during the CRBPP: important findings came in from the field but never went out to peers

In mid-stream of the CRBPP, the BuRec called a meeting in July 1973 to try to understand what was going wrong with it. Why wasn’t it going to replicate the CSU work? Mainly, it was due to a few critical CSU assumptions that were not supported by data, such as the 500 mb temperature being an index of cloud top temperatures, and therefore, as it had been assumed, a reliable index of seeding potential. After all, the CSU experiment seeding effects were stratified by 500 mb temperatures repeatedly in the published literature; they had no data on actual cloud tops. Neither of those parameters, 500 mb temperatures or cloud top temperatures, are reliable indicators of seeding potential.

Nor were there widespread non-precipitating, reasonably deep clouds ripe for seeding ahead of and behind periods of natural precipitation, clouds that CSU scientists had inferred existed because the claimed increases in snow they reported, were solely due to the greater duration of snowfall on seeded days. Seeding had no effect on natural precipitation they concluded.

No such thick, non-precipitating cloud was found to exist in the CRBPP. This was largely due to the fact that cloud tops during storms were almost always colder than -15°C in storm situations, and usually considerably colder. Those cold tops naturally produced substantial ice concentrations without being seeded. High natural ice concentrations in clouds pretty much decimates seeding potential.

In closing that 1973 meeting, consisting of a who’s who in weather modification from universities and companies around the country, the Chief of the BuRec’s cloud seeding division, Dr. Archie M. Kahan closed it by observing that the CSU physical hypotheses, “were not as strong as we had been led to believe.”

It was an understatement.

But these important findings presented at that BuRec conference remained husbanded with those at that meeting. The “Code of Silence” was in full operation. The discrepancies were not to be “outed” until 1979 in Hobbs and Rangno (J. Appl. Meteor.) and in my reanalysis of the CSU Wolf Creek Pass experiment that same year in that journal. (The former article was originally part of the draft manuscript I brought in to Prof. Hobbs, but he deemed it something that should be reported separately.)

9.  Another pivotal event in 1974

I remember how excited I was, too, when a National Academy of Sciences 1973 report, Climate and Weather Modification; Problems and Progress, came through the Durango office in 1974. The NAS Panel on Weather Modification (Malone et al.) stated that the CSU cloud seeding work had “demonstrated” cloud seeding efficacy on a “deterministic basis”.

What was exciting when I read that NAS report in 1974?

I knew by then that an assessment by our best scientists with the NAS, and that a scientific consensus on the CSU experiments, as we would say today, was wrong! It was interesting to me later that Peter V. Hobbs, for whom I was to work, was a co-author of that optimistic report concerning the CSU experiments.

10.  A final blow to idealism and of the credibility of the cloud seeding literature

The final straw, however, was a much-cited article in 1974 in the J. Appl. Meteor. titled, “The Cloud Seeding Temperature Window.” The two authors had used constant level pressure surfaces to index cloud top temperatures in several seeding projects to come up with a cloud top temperature window of -10° to -25°C for successful cloud seeding. This temperature range was thought to characterize clouds with tops this cold that were deficient in ice particles, but would have supercooled liquid water in them that could be tapped by cloud seeding. It turned out to be a too optimistic a temperature range as later research showed.

Moreover, the lead author of this article had been told by three different people on separate occasions in my presence not to use a constant pressure level as an index of cloud tops in the Rockies. Nature does not constrain cloud tops so that they can be indexed by a constant pressure level temperature in the atmosphere.

The other author of “The Cloud Seeding Temperature Window” was in the midst of evaluating the storm day rawinsondes of the CRBPP; he was the leader of the Aerometric-NAWC evaluations team chosen by the BuRec. He absolutely knew that stratifications by a constant pressure level was not a viable way to index cloud tops from our data. When I asked that 2nd author the next time he came through the Durango office about that article, “How could you write that?” He simply replied, sheepishly it seemed to me, that he had just, “gone along with” the lead author.

So that was it.

I never again trusted the cloud seeding published literature. Cynicism 1, Idealism, nil. It didn’t matter, either, how highly regarded the literature was. It still might be inaccurate, corrupt, I thought. I often wondered, too, why that “Window” article was cited so much. I presumed it must be by readers that did not know much about synoptic weather and cloud top fluctuations.

11.  A regrettable personal media eruption in late 1975 that required an apology in person at CSU

I remained quiet until the CRBPP experiment ended in 1975, which also allowed me to retain my great job in the nice little town of Durango, Colorado–ah, the plight of whistleblowers……

But then I erupted in November 1975 after the CRBPP ended when it was safe and I had no job. 🙂 Here’s that whistleblowing eruption as seen in the Durango Herald, one that I feel I have to disclose in this “blook” to give an idea of my potential biases:

You will notice that I referred to “Watergate” in the Herald headline. As I left the Durango Herald office with the reporter, Mike McRae, I muttered a mistake. I said, “if what I have begun to work on turns out, it could be the Watergate of meteorology”, meaning it would make a big splash. It was a poor, if current and accessible metaphor, but it implied wrongdoing on the part of CSU scientists. I was away when the article came out and was devastated to see what Mike had written after a careful 1-2 h recorded interview in his office. He had promised to let me examine the article before it came out, but called the evening before I left and said he wasn’t able to do that, adding, “trust me.”

I left the next day for Fresno, California. I got that Durango Herald issue about a week after it came out while I was there working briefly for Tom Henderson, and Atmospherics Inc.

After I returned to Durango from Fresno, I sped off to CSU to apologize in person for my lapse to the leader of the CSU experiments, Professor Lewis O. Grant. I had also submitted a “retraction” to the Herald clarifying what I meant. I did see that reporter Mike in the Durango supermarket, and, after I only shook my head at him, he said, “Never trust a newspaper reporter.”

Q. E. D.

But Mike’s article in which I stated I was going to reanalyze ALL of the CSU prior experiments, as you will read, was to have a profound effect that neither of us could have imagined at the time.

12.  The apology and the after effects of the 1975 Durango Herald article

I was able to meet with Professor Lewis O. Grant, the leader of the CSU experiments in his CSU office as soon as I got there, . I groveled and apologized for my possibly libelous newspaper gaffe. He was real nice about it, actually. And, moreover, even when I said I still questioned his seeding experiments and asked for data, like the list of random decisions, he did not hesitate. He was an idealist; questioning was a part of science and he understood that.

Professor Grant’s attitude was not shared by the leader of the experiments in Israel, I am sad to say as Sir John Mason’s letter illustrated.

I kept Professor Grant apprised of my work from Durango as I went along with it as I said I would. As the Wolf Creek Pass experiment began to fall apart in my reanalysis, he even wrote that I had found something important. He was a true scientist.

I also learned from Professor Grant’s graduate student, Owen Rhea, who had started out as the CRBPP’s lead forecaster in 1970 and, along with Paul Willis, had hired me, that the Durango Herald article got back to the National Science Foundation who asked of CSU, “What’s going on?”

According to Owen, due to that Durango Herald article in which I was claiming that I myself would reanalyze ALL of their work, CSU scientists began reassessing their Climax experiments at that time. Those, too, eventually fell apart “upon further review”; their own. Its always best if you find your own problems and report them first before someone else does.

First, in 1978, the earlier claimed evidence of inadvertent downwind increased snow due to seeding at Climax, was found to be due to a synoptic (weather pattern) bias on seeded days. Gone.

Then, in October 1979, at a joint conference of weather modification and statistics at Banff, Canada, Owen Rhea, Professor Grant’s graduate student, verbally withdrew the claims that seeding had increased snowfall in the Climax experiments. Paul Mielke, Jr., the lead CSU statistician, had already done this in a short commentary in the J. Amer. Stat. Assoc. in March of that year, also noting that the stratifications could not have partitioned seeding potential. Climax I and II, gone.

A lucky draw on seeded days had occurred in both Climax experiments; pretty remarkable, though Climax II was to receive some “help” as it turned out, exposed in later independent reanalysis in 1987 by yours truly, with Hobbs.

At that same conference at Banff in 1979, I presented my now published, “Reanalysis of the Wolf Creek Pass cloud seeding experiment” in the May 1979 issue of the J. App. Meteor.) It, too, like the Climax experiments, was the result of a lucky draw and favorable selection of controls by the experimenters, but ones chosen after the experiments had begun, a no-no for experiments because it opens to door to confirmation bias and cherry-picking.

That was my first presentation at a conference. The year before, I had played “center microphone” for a similar conference in Issaquah, Washington. That is, I ran around with a microphone for attendees that had questions for speakers. I was a real “gopher” just the year before.

All in all, the Banff conference was a devastating one for those involved in cloud seeding at CSU, and for those organizations such as the BuRec that had placed such big bets on the CSU experimenters’ original reports.

13.  Pre-1979 Banff conference palpitations and why; the human part of being a science worker in a conflicted environment

The Banff 1979 program that I was going to present in was published in the Bull. Amer. Soc. in May 1979. I was shocked to see that it indicated that CSU faculty would address my paper before I gave it. Thankfully this did not happen. I was an amateur compared to the faculty at CSU, and I was sure all that time before the October Banff conference after seeing the program in May, that my work would be cut to pieces and I would get up red-faced with nothing to say. I had palpitations that whole summer of this nightmare scene, and even redid my paper. Perhaps I had made egregious errors; I was the one that was biased and couldn’t see it.

The evening before my talk in October, I ran into Professor Grant, and he informed me at that time that they were not going to address my work after all. Whew. I had even considered not going; the fear of humiliation was that bad!

Paul Mielke, Jr., also came by, and he simply said, “We screwed up.” I admired him for that and his courageous 1979 article in the J. Amer. Stat. Assoc. In essence, in that article, he had stated that there was no real basis for the 10 million dollar CRBPP the BuRec had signed up for. Can you imagine? The BuRec REALLY did need a “Resident Skeptic!”

The 1979 Banff talk went fine, even got an accolade and a laugh, and I ended by saying, “Who wouldn’t have believed all this evidence was NOT due to cloud seeding?”, trying to put the best face on the CSU seeding collapse that evening. It was an amazing trifecta of indications that seeding had increased snow that CSU scientists had encountered and embraced, but were now gone.

But that was not to last.

CSU scientists began looking again at their Climax experiments and began publishing claims that they had resuscitated valid increases in snow in those experiments in 1981, though they were smaller ones, stratifying the data again by 500 mb temperatures asserting or implying that they had something to do with cloud tops and cloud seeding potential. It was quite a discouraging blow if you care about science.

Neither I, nor Owen Rhea of CSU, could let such claims go unchallenged and we each reanalyzed the new Climax experiment reports, both of us finding a second time in the following years that those claims of increased snow due to seeding by the experimenters were ersatz. There’s much more on this, but will end this discussion here for some hint of brevity.

And, so, while the story today is centered on my work in Israel, the full ppt “book” has a lot of backfill to my experiences in Durango like the ones above, experiences that caused me to distrust any publication regarding a cloud seeding success without extreme scrutiny, the kind that reviewers of journal manuscripts mostly don’t have the time or inclination for.

14.  1983, a real no-no: a request for an independent panel to investigate the reporting of the Climax I randomized experiment

This was a painful chapter, but in trying to be totally candid, it has to come out. There are likely still those out there that know about it, though, as I wrote in my request for this to the Amer. Meteor. Soc., I hoped it would remain completely behind the scenes. It did not. Prof. Grant himself later told an audience that he was under investigation.

Here’s why: CSU statistician, Prof. Paul Mielke in 1979 J. Amer. Stat. Assoc., while withdrawing the claims that the Climax experiments had increased snowfall, observed that both experiments, Climax I and II, had experienced favorable draws that created the impression that snow had been increased on seeded days. It was a courageous post. Here’s what he wrote:

Very recently, in connection with design studies for a possible experiment of this type in central and northern Colorado mountains, station-by-station precipitation analyses of the Climax I and II experimental units were made for all available hourly stations in Colorado. The resulting maps of seeded to non-seeded mean precipitation amount ratios and non-parametric teststatistic values plotted over the western half of Colorado indicated (for meteorological partitions such as warm 500 mb temperatures) that the Climax experimental results were part of a region-wide pattern rather than an isolated anomaly produced by seeding. In particular, these recent results cast serious doubts on consistency of apparent effects associated with replicated five-year winter periods of the Climax I and Cllimax II experiments.

Later, however, while looking for something else, I ran into this statement at the very end of the article by Mielke et al. (1970, J. Appl. Meteor.), an article accepted for publication on June 30, 1969:

“In an attempt to better define the area extent of the differences between the seeded days and non-seeded days beyond the boundary of the experimental network, available data from all Weather Bureau stations in Western Colorado are currently being investigated.”

Mid-1969 was time that large contracts were being formulated by the BuRec and signed by contractors involved with the CRBPP. One, at least, had already been signed in 1968, the one with CSU scientists for a CRBPP design document, whose interim document was released in October 1969.

What to do after I ran into what seemed to be a “smoking gun”?

It seemed inappropriate to me to have the CSU scientists answer such a profound question on which millions of dollars might depend on the answer: “What happened to the 1969 study that was “underway”? So, I stewed for quite awhile on this seeming “smoking gun.”

Millions of dollars would have been saved, of course, if the CSU scientists had discovered/reported in 1969 the evidence that Climax I had been compromised by a “lucky draw.” It can be assumed that the BuRec would have backed off their plans for the randomization of the CRBPP; perhaps had gone into a research mode with ground and air measurements, or canceled the project altogether to ruminate on what really happened in Climax I. Note: it was well known at E. G. & G., Inc, that CSU scientists opposed randomization of the CRBPP on the basis that, “it’s already been done” (in their own experiments).

Ultimately, in 1983, following a reaction to the CSU scientists’ responses to my friend, Owen Rhea’s reanalysis of the Climax II experiment, I wrote up my request and sent it in to several organizations including CSU, the AMS and NAS. The AMS didn’t know how to go about this (D. Landrigan, personal communication) and I got no response from the NAS.

There was, however, an internal investigation by CSU faculty panel that found no problems in the reporting of the Climax I experiment. I also received a threat of legal action by then Acting Colorado State University President, Robert Phemister if I persisted in my calls for an investigation of the CSU reporting. I didn’t. I still wish that there had been a wider look besides that by CSU faculty, one of whom was a co-author of a seeding paper.

I really hated to do it, knowing the fallout. But, what would you have done if you found the 1969 Mielke et al. “smoking gun?” I just didn’t think they should answer a question with millions of dollars riding on the answer.

I let this issue go downstream, but you can only imagine how CSU and their sympathizers that found out about my unprecedented action might have felt about me. I had asked for an investigation of the most beloved persons in all of weather modification, Lewis O. Grant and Paul Mielke, Jr., both of whom I actually liked as people!

Peter Hobbs, when he found out, was livid; he was not involved because he was on sabbatical in Germany. No one was involved but me. But, I got a raise the next year, 1984. ??

I presented a paper at the Park City, UT, weather mod conference in 1984 with all those present from CSU who knew what I had done. Gads, how did I make it through that one! The tension was so thick. My paper, one that later became part of an AMS Monograph with the other presentations, was titled (I had been assigned this title), “How good are our conceptual models of orographic cloud seeding?”


15.  Tension highlight at Park City

It was during this conference that Prof. A.G. from Israel took me aside to sternly lecture me about how wrong I was about the clouds of Israel (from my 1983 rejected article by the J. Appl. Meteor. that asserted they weren’t being described correctly. It was also at that time that he informed me that he had been a reviewer, one of course, that helped reject that paper. His lecture had no effect whatsoever on what I thought about those clouds, why I hopped a plane to Israel two years later.


If you have read our papers on the Climax experiments, you will know that there was suggestions of tampering with the key NOAA target gauge precipitation data in Climax II (Rangno and Hobbs, 1987, 1995, J. Appl. Meteor.) The values used by the CSU scientists in their analyses were not the ones that were published by NOAA for that gauge; the values that the experimenters used increased the supposed seeding effect, but modestly (4%). And there were many other discrepancies in the 500 mb temperature assignments of storms from those published by NOAA that also “helped” the Climax II experiment “replicate” Climax I.

In contrast, errors were negligible in Climax I; all the precipitation data were the same as in the NOAA publications, for example. Climax I was gifted by a lucky draw of storms with NW flow on seeded days, the direction from which Climax receives it greatest daily precipitation and the set of control stations chosen by the experimenters halfway through the experiment, the least. Climax II had no such luck. Check it out below:

Percentage of the total experimental seeding season precipitation at Climax I (a)and II (b ) for three wind direction categories using the winds at mountain top level 4 km ASL or 600 mb level, whichever was available in the NOAA publication, “Daily Series, Northern Hemisphere Data Tabulations, Radiosonde and Rawinsonde Checked Data.” The solid bar is for seeded days, and the cross hatched ones for control days. Climax receives its greatest average daily amounts in NW flow. (From an unpublished manuscript rejected by J. Appl. Meteor. in 1983.

To my knowledge, the results of the 1969 begun Mielke et al. investigation were not made known to the BuRec until Mielke’s 1979 J. Amer. Stat. Assoc.) comment.


Why would anyone do call for a behind the scenes investigation that would only have negative fall out for everyone involved? I felt I was representing those people outside the cloud seeding community who really paid for the CRBPP. That, too, was the way I felt about my trip to Israel. OK, I know you’re rolling your eyes now, but it was true, I really did think, “Someone has to do something about this!” If I was arrogant (“confidant” is a better word) it was because I thought I could do something given my particular cloud-centric background. I think a lot of “activists” think this way; that they can do something.

16.  Intermission and time for a “Get a life!” note

Following the above comments, it seems like an appropriate point for a reader to erupt with, “Get a life!” See the note at the very end of the science portions of thes piece if that’s what you might be thinking at this point, which is not an unreasonable thought at all. 🙂

I did have an outside life somehow. I was single during most of this time, too. There’s no way you could be married/have a partner, and be doing what I was driven to do. Playing baseball, doing some extracurricular forecasting on the radio and for the Washington Huskies comprised most of that outside life.

OK, enough intermission….

17.  A “fruitful perception”

Not trusting cloud seeding peer-reviewed literature, no matter how highly regarded it was, was a fruitful perception. I think you can see why by now!

Over the following twenty years after Durango I reanalyzed, with Prof. Peter Hobbs as my co-author on all but one article, no less than six peer-reviewed, journal published cloud seeding experiments. Not one was the success the original experimenters claimed it to be! PDFs of these reanalyses, and other commentaries on cloud seeding in the literature can be found here:

Important Footnote: To fill out my CV even further on the above page, I have even included my rejected papers and non-submitted reviews as well to make it look bigger than it really is. Of course, those latter items REALLY don’t count in official CVs except to ME. I am hoping to one day to have, as other scientists do, a subset of my papers published: “The Collected Rejected Papers of Arthur L. Rangno.” The volume would be quite thick.

All those published reanalyses and commentaries, and articles/reviews that weren’t accepted or not even submitted, was a vast amount of material I had created, and they were accomplished on my own initiative, my own time (except one, the Skagit reanalysis, was on Peter Hobbs’ time, but my initiative). That is, I worked on these kinds of things on my weekends, evenings, before work, after work at the office, etc. , on and on over years, probably amounting to thousands of volunteer hours to evaluate and “out” faulty cloud seeding claims and to get my views of the cloud seeding arena into print. I even drafted most of my own figures.

I had no funding, of course, for these, well…”altruistic” efforts, as I thought of them. I just felt I had the skills to expose faulty cloud seeding literature being a forecaster and a “cloud man.” I also felt I had a duty to do it since it was likely that no one else would.

To readers: anybody down here?

18. Peter V. Hobbs and his group’s work in cloud seeding

19. Life beyond science volunteering: some anecdotes, some humor…maybe

The almost fanatical activity described above can be also be seen as a “crackpot alert.” But, maybe a good one? Yes, and you might well be thinking, as noted, “get a life!”

Well, I did have some outside activities, like playing baseball in a hot semi-pro league called the Western International League, so there. Eight guys were signed off my team over the several years I played on it; one, Mike Kinunen, was pitching for the Twins the next (1980) summer and the guy that batted 3rd in front of me, made the last out of the 1980 college World Series in Omaha playing for the #5 Hawaii Rainbows (defeated by the Arizona Wildcats!) I was the oldest starting player in that league in those halcyon days of my late 30s. In case you don’t believe me:

In my last playing year, I was the recipient of the Jim Broulette “Mr. Hustle” Award in 1980. No, it wasn’t for being a great player, but rather for being an “inspirational” one, which is not as good as being given an award for being great (I had an off year..). FYI, this what I looked like during the era of ruining cloud seeding papers except I wasn’t wearing a baseball uniform when I was doing that.

In a further nostalgic sports report and waste of your time, after the WIL, I pitched batting practice for the Seattle Mariners, 1981-1983. An anecdote about that:

I showed up for a tryout at a workout they were having on the U of WA Husky baseball field in 1981 after the MLB strike had ended and, after pitching BP there, I got to be one of the regular Mariner BP pitchers in the Kingdome, an unpaid job, btw. You get tickets behind home plate. It was so much fun, but stressful. There was an uneasy quiet if you threw as many as three balls that weren’t smacked.

They released me at the end of 1983 because the “guys” were complaining that my ball had too much movement in BP; I was “cutting the ball”, giving it extra spin (private communication, Steve Gordon, backup catcher, 1983). (Unbelievable).

The Mariners of note in those days were Tom Paciorek, Dave Henderson, Bruce Bochte, Richie Zisk and Gaylord Perry, the latter who said my BP was “horrible” in 1983 after he joined the Mariners– he didn’t hit it so well. Of course, he was a washed up pitching buffoon in those days–what would he know about hitting? (Just kidding, Gaylord.) I did throw harder than normal BP pitchers and off or near the pitching rubber, just like I did for my WIL teammates who loved my BP. They wanted zip on the ball like real pitching and I thought the MLB players would, too. And they did, too, that’s why I got “hired” in the first place.


Forecasting for the Washington Husky baseball and softball teams.

I was also the de facto weather forecaster for Washington Husky baseball and softball teams calling rain delays, tarp placements and removals and such beginning in the mid-90s. I had met the Husky baseball coach during my WIL experiences and began forecasting for softball during the 1996 NCAA regional tournament in Seattle which was impacted by numerous showers and even a thunderstorm.

The weather during these spring sports seasons is occasionally showery in Seattle, lots of Cumulonimbus clouds form on those kinds of days, rather than the easy to predict day-long rains from fronts. Radar was pretty useless in showery situations. Why? Because the lifetime of showers is short, and the Huskies could play in SOME rain, just not too hard. So, an incoming shower had to be evaluated by eyeball to assess whether it was dissipating or not; was it all ice or what, and would it rain hard enough to require a tarp and a rain delay? So that’s how I did it, almost completely by eyeballing showers, their movement and growth pattern and assessing their stages.

When the tarp was on the softball diamond during showery days, it was almost harder to call when it should be removed since it took about 45 min to get the game going again; the players had to warm up, besides taking the tarp off themselves. This meant predicting whether a shower would even form in that 45 min time frame, and if so, would it affect the game? The worst possible scenario was that you said to remove the tarp, everyone warmed up again, the crowd came back into the softball stadium, and then it rained hard right after that. It was a stressful volunteer job. Fortunately, that did not happen. I was lucky.

It sounds disconnected, but this was exactly the kind of skill I took to Israel in 1986.


Before the Husky forecasting era, I had been a forecaster on two different radio stations in Seattle, KUOW-FM (1987-1992), an NPR affiliate in which I came on during “Weekend Edition”, and on a local rock station, KZAM-FM, M-F, for about six months in 1982. For both stations I was doing very short-term forecasts for Seattle using the time of day, such as “no rain through 11 AM, then rain beginning between 11 AM and 2 PM”, etc. When I started these efforts, Seattle had no dedicated weather radar! Doppler weather radar became available only in 1992. In place of radar, you had to use upwind station reports, satellite imagery, know the “territory”, and eyeball the cloud situation along with knowing what the computer model predictions were, and then evaluate how the cloudscape, obs, and how the model predictions were meshing with what the sky was doing.

Perhaps, for sophomoric entertainment, you would like to hear one for KZAM-FM in 1982. In listening to this (sorry, its not real clear), we have to remember that, as the LA Times wrote in 1981, weather forecasting at that time was an era of “clowns and computers” as they headlined. You were expected to come up with some “schtick” if you were a media weather forecaster. And I was encouraged to do so by KZAM-FM. It got a little wild, as you will hear. To stay with the theme of “sports and weather”, I reprise my “sports-like” 1982 weather forecast on KZAM-FM, one that mentioned Gaylord Perry in context with a low pressure in the Gulf of Alaska with “moisture and rotation on it”, known for cheating by throwing spitballs. And damn him for criticizing my BP! It’s a little muffled, but you’ll get the idea. Remember I was forced to do this by the forecasting motif of the day….

OK, I am having more fun now as I remember those crazy days….I still worked at the U of WA cloud group full time during these efforts, too. Good grief, how did I manage all this?

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.