[Geysers] Old Faithful Dec 21-22 2016 - Consecutive Shorts

[Lynn Stephens]

I'm at Cape Disappointment without my library so can't give exact information.

Regression formula was periodically reevaluated when percentage of predictions outside the limits got too high.   At one time the prediction formula was plus/minus 5 minutes.  I've been trying to track down when it went to plus/minus 10 minutes.

I don't remember whether Rick's annual/biannual update if geyser activity had the full chart in it.  Those may be a source of information on the formula.  John Railey did some of the statistical analysis for Rick.  You might check Landis 1987 and 1988 reports.  Another source-the  junior ranger booklet had a modified version of the regression formula at least it did until 2-3 years ago.

Lynn
Sent from my iPhone

> On Dec 29, 2016, at 06:15, JEFFREY CROSS <jeff.cross at utah.edu> wrote:
> 
> Years ago, someone reported a formula of the form y = mx + b for predicting Old Faithful.
> 
> Y is the interval
> X is the duration
> 
> How has this formula changed from one year to the next?
> 
> Specifically, are the current values of m and b what they always were?  Larger?  Smaller?
> 
> Jeff Cross
> jeff.cross at utah.edu
> 
> 
> ________________________________________
> From: geysers-bounces at lists.wallawalla.edu [geysers-bounces at lists.wallawalla.edu] on behalf of M.A. Bellingham [mabellingham at gmail.com]
> Sent: Monday, December 26, 2016 10:33 AM
> To: Geyser Observation Reports
> Subject: [Geysers] Old Faithful Dec 21-22 2016 - Consecutive Shorts
> 
> From a Facebook report on Dec 22, 2016
> 
> Dave Monteith: "Old Faithful had a 2h14m closed interval last night."
> 
> Dave responded to a question : "The question was asked -- "how
> confident was I that an eruption wasn't missed?" I am very confident.
> The webcam recording clearly shows a non erupting Old Faithful during
> the interval."
> 
> Gordon Bower replied " I am now curious -- when is the last time we
> had a pair of consecutive shorts? Even in the early 90s, when ~40% of
> intervals were short, those were "newsworthy" and happened only a few
> times a season. I can't remember hearing about a pair of them in long,
> long time"
> 
> Gordon then followed up with " A search of the GeyserTimes archive
> suggests it hasn't been witnessed in this century (the data are fairly
> complete since 2000). (There was one apparent instance of consecutive
> mediums, 28 July 2010, 1319E 1433E 1546E - but for some reason no
> human observations are showing up on that date.)"
> 
> I miss the days of substantive discussions on the Listserve, so I
> appreciate Gordon's knowledge-based curiosity, and wanted the
> non-Facebookers to know of these consecutive shorts.  I hope it
> reaches those of you with interest.  The other 15 comments on Facebook
> were mostly just that, comments.
> 
> MA
> 
> M.A. Bellingham
> mabellingham at gmail.com
> _______________________________________________
> Geysers mailing list
> Geysers at lists.wallawalla.edu
> 
> _______________________________________________
> Geysers mailing list
> Geysers at lists.wallawalla.edu
>