Willis on why Piers Corbyn claims such a high success rate

(elevated from a comment on the Putting Piers Corbyn to the test thread ) Willis Eschenbach says:

Martin Gordon says:

July 15, 2012 at 5:31 am

I note that Piers is declaring this period (13/14) a success on the Weather Action website.


Thanks for the link, Martin. I hope folks are starting to see why Piers claims such a high success rate. Here’s his map for the period:

OK, so what are the important parts of his forecast? Obviously, it’s the shaded areas where he predicts “thunder, tornados, and giant hail” in the north central region, and “thunder, tornados, and large hail”, in red meaning extreme warning, for the Great Lakes and eastward.

Here are his claims that he says “verify” his forecast.

R4 period 13-14 July extreme events verification:

=> USA

– Sev Thunder events Seattle ~13-14th http:fb.me/23Zp3jkkI CONFIRMS WeatherAction long range specific warning for 13-15th on USA Maps forecast 13-15 July + Piers discusses on fb

Let me echo Martin’s amazement that a single comment on Facebook is taken as a verification of his forecast. Anyhow, here’s the Facebook comment (emphasis mine)

Severe Thunderstorms Possible In Seattle (1:10PM PDT 7/13/12 -Charchenko) Hello everyone, after those exciting thunderstorms arriving earlier than usual through the seattle metro area. Were in a break in the weather right now up and down the I5 corridor but storms are still rumbling around port townsend and sequim areas. We are under a slight risk for severe thunderstorms west of puget sound which is extremely rare and usually only happens once every 5 years. We could see some large hail around 1″ and damaging winds possible, we could even see a few supercells! We will continue to update throughout the day monitoring these storms!

To which Piers replies:

Thanks for informative posting. VERY INTERESTING. Our WeatherAction long range forecast issued June29th [Free this month, email piers@weatheraction.com with ‘USA PLEASE’ in title bar] predicts thunder in Pacific NW ~ WA, OR, ID, MT for 13-15th July (and did not predict any for July prior to that). Thanks, Piers

I suppose you could claim that someone on Facebook saying “severe thunderstorms possible” is a verification of the forecast, but take a look at the actual weather service storm, hail, and tornado reports for those two days …

Very little happening there at all, certainly no concentrations of thunderstorms, either in his forecast areas or anywhere.

– 13 July BIGGEST hail in 30yrs http://www.king5.com/your-news/162444096.html WA NW USA

– Sev Thunder Warning Union+Wallowa Co OR 14th till 3:00pm PDT. #orwx CONFIRMS WeatherAction long range thunder specific forecast for OR 13-15th

I’m sorry, but a single report of hail in Oregon absolutely does not confirm a forecast of hail in the upper midwest, or Great Lakes/New England. Piers forecast said NOTHING about hail in the Pacific Northwest, this is totally bogus.

– Severe Thunderstorm Watch for portions of the area in ID until 11:00pmMDT/10:00pmPDT. ‪#idwx CONFIRMS WeatherAction long range thunder specific forecast for ID13-15th

Again, there may have been a “severe thunderstorm watch” for Idaho … so what? Take another look at the actual storms shown above. I gotta give him credit, though … he has used other people’s warnings and claims that thunderstorms are “possible”, and also thunderstorm watches, in other words other people’s forecasts, as confirmation of his own forecasts. This is sheer forecasting genius, right up there with claiming that a forecast of a 50% chance of a typhoon was verified by no typhoons.

Finally, take another look at the map of his forecasts, and compare it to the storm reports. The few places that there actually was hail in the US were places that he did not forecast hail. The places he gave the strongest forecast for extreme thunderstorms, hail, and tornados saw only a couple scattered thunderstorms, not a single report of hail, and no tornadoes.

And yet he is trumpeting these results as a verification of his forecast? I gotta say, “verification” must mean something very different on his planet.



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The day that a weather forecaster gets it right more then chance is when weather stops being weather. Luckily we can predict climate decades away. /sarc

Susan Corwin

The Seattle to Portland Bike event is this weekend, so I have special interest in this weekend’s weather.
The official forecast, up until Friday was “sunny, highs of 76-80.”
As of Friday, the forecast changed to “cloudy, cool, showers” and a thunderstorm came
through areas last night. Lots of drizzle areas, etc.
So, right now, for the Seattle/Portland area, “cool, showery, some thunder” predicted 2 weeks out stomps on the weather service and is about as close to describing what is happening as you can get with the English language. Go check the traffic cams.

The FAA has a web site set up with web cams placed at airports so pilots can see real time weather plus include a briefing forecast. However, the weather changes and varies from the forecast and the pilot ends up diverting or returning. Point is that weather forecasting is predicting a chaos picture that has probabilities beyond our capacity.
From weather forecasting is easier when it is happening just down the road and you are the next target moments away. However, the long range forecasts even in general are “chance” driven. I think people are often too enamored with the sensationalism and drama in weather forecasting and presentation.


Thanks for posting this. I am glad to see that even AGW skeptics like Piers Corbyn get the critical analysis they deserve.
Piers claims to have a secret exclusive technique to be able to forecast the weather well ahead of anyone else and furthermore regularly trumpets the accuracy of their predictions; he deserves Willis’ scorn.
Like those who claim exclusive insight into the affects of CO2 and man-made global warming catastrophes or those who scream about the “sun” and the coming maunder minimum, both extremes largely make unsubstantiated claims based on far too many assumptions!
It is so sad that the lamestream media reports such unsubstantiated nonsense regularly when it comes to the environment.
Modern society is clearly no better than the Iron or Medieval ages (characterized as periods when nonsensical superstitions abounded)!!!

Man Bearpig

For clarity here is the summary forecast from Piers’ forecst.
”JULY 13-15 A change in circulation. Low pressure in North part of West USA, so showery Vancouver & NWP coast. Major thunderstorms, with large hail, tornados and local flooding in lower mid-West, south of Lakes and in north central parts of USA. Forest fires in S/W re-ignite Standard meteorology in this period will substantially underestimate levels of precipitation and strengths of thunderstorms, tornado risk, hail and winds.”

I remember being taken to the circus in Chicago when I was about 4 or 5 (1947 or 48) and being greatly impressed by the clowns who my father knew personally. After the performance I was sitting on the dressing table when his friend pulled off his big red nose. I began to cry but I also learned something about entertainment and role of clowns in it.


My wife is a great fan of Piers, which might be a source of some friction, as I consider him a snake oil salesman, but, luckily, I am a great fan of my wife

Ross Lea

If you want a reply from Piers just check out this presentation to a S.A. Green group.
Piers at his eccentric best.

John F. Hultquist

The map is sufficiently general as to be useless in most places. Take the OR-WA region. It is often cool and showery with some thunder somewhere within this diverse area in mid-July. There are sea level communities, coastal mountains, the Olympics, the Cascade Range, high volcanoes, and a lower elevation interior. Then to predict “hot” in the USA’s southwest in mid-July is an easy call. Likewise winds off the Gulf of Mexico into the middle south.
Then again, “giant” hail in the upper-Midwest versus only “large” hail in the OH-PA-NY region might be worthy of confirmation.
My idea of large hail would be, say, larger than ¾ of an inch (~2 cm).
Giant hail would be, say, larger than 2.5 inches (~6.5 cm).
Again, these are big regions and typical weather (“climo”) will include storms with hail. So, where was the “giant” hail? Where was the “large” hail?

Paul Vaughan

Piers’ long range forecasts should be compared to other long range forecasts, not Willis’ hindcasts. Where are Willis’ long range forecasts for comparison? Willis: Go head-to-head with Piers for one year of long-range forecasting and see how you do. See if you can even beat random forecasts. Piers has nailed everything for Vancouver, British Columbia, Canada from 15 days out (first 2 weeks of July 2012) while the long range forecasts people commonly use on their cell phones here have been completely wrong. He predicted exactly when there would be changes in circulatory patterns and we experienced concordant weather pattern shifts. Willis, all you seem to have to offer is negativity & criticism; how about offering something constructive http://i49.tinypic.com/2jg5tvr.png instead of destructive?

The sole basis upon which the legitamacy of AGW theory hangs is the premise that long term weather is even easier to predict than short term weather. That is why skeptics see Climatology as being baseless.
The climatism of the weather fearmongers has evolved to the point now where it has the credibility of earthquake prediction science. The official `science’ of the global warming alarmist community is simply to pray for catastrophe and then point. The only real `consensus’ that exists, now that Bush is gone, is to simply blame capitalism whatever Nature brings our way.


Well Willis, ain’t that a howdy doo. While we are chanting one day/week/month is not gorebull warming you come along and highlight ONE specific forecast of Piers’ and Weather Action and proclaim him close to fraudulent.
Ahem, he CLAIMS about an 80% I believe. Wouldn’t about 10 forecasts be needed to even BEGIN deciding whether he is full of it or not???

Nice, Willis!
Whatever side one takes, there are always idiots and charlatans on the along for the ride or for their own benefit. In this argument, it is good to see that the skeptical side deals equally with allies and foes. The warmist side, from the IPCC to Gore to the EPA, uncritically parrots anything that furthers its cause.


How about a comparitive summary against other forecasters, here in the UK he beats the Met Office hands down whose accuracy increases markedly if you invert their long range forcasts.

Seems to be valid from looking here http://www.spc.noaa.gov/climo/reports/120713_rpts.html
Hail Reports (CSV) (Raw Hail CSV)(?)
Time Size Location County State Lat Lon Comments
2233 150 3 WNW MENDOTA HENNEPIN MN 4490 9322 (MPX)
2249 100 4 WNW FARIBAULT RICE MN 4433 9335 (MPX)
0032 100 2 SW FROST FARIBAULT MN 4356 9396 (MPX)
0044 100 4 S BANCROFT KOSSUTH IA 4324 9423 (DMX)
0045 100 2 NNE BRICELYN FARIBAULT MN 4359 9379 (MPX)
0123 100 1 E MANCHESTER FREEBORN MN 4372 9343 (MPX)
0130 100 1 S WHITTEMORE KOSSUTH IA 4305 9442 (DMX)
0210 100 3 SE WEST BEND KOSSUTH IA 4293 9442 (DMX)

Papy Boomer, Chelsea, Québec, Canada

Right now (14:45), in Chelsea QC, just north of Ottawa, I can hear the sound of thunder happening. The date is Sunday, July 15, 2012. There is at least a thunderstorm going on in the area called “south of Lakes” on the map for July. I don’t know if it is just south of the Ottawa area, that there is something going on that look like ““thunder, tornados, and large hail”, in red meaning extreme warning, for the Great Lakes and eastward”. Since the north fringe of the area covered by Piers, the circle include the Ottawa area.
By the way, we didn’t had any rain for several weeks now. And not much is planned for the comming days. Maybe it’s just a “chance” that some of its prediction comes through.
Papy Boomer

Jim R

Why are we not allowed to check Corbyns past predictions of weather without having to pay and if we do pay there’s restricted access? Using astrology to predict weather and you folk give him the oxygen of publicity? You’re so funny. A science web site?


Does he also make stock market predictions?
(Maybe there’s a solar Elliott Wave)

Anyone who could give a forecast more than 50% of the time close (not accurate) to what follows is doing reasonable job. In my experience both Dr. Corbyn and the British Met Office are above the line.
Dr Corbyn emphasizes his successes because he has to earn living, Met Office ignores their failures since they have to earn their living too.


See below:
Jim R says:
July 15, 2012 at 12:06 pm
Why are we not allowed to check Corbyns past predictions of weather without having to pay and if we do pay there’s restricted access? Using astrology to predict weather and you folk give him the oxygen of publicity? You’re so funny. A science web site?
Why do you bother to post this? There is no such thing as a free lunch. Astrology? ASTROLOGY? Waterstones, or even Tesco sell dictionarys, please buy one.

Leon Brozyna

He might have a future with the Farmer’s Almanac …


Whatever else one might throw at (C)AGW skeptics in the way of criticism, one should acknowledge that their attempts to undo “over-baked science” is indiscriminate – friend or foe beware.

Ummm … the eastern half of Texas from Houston to the Red River has not been very hot, rather, we have had seasonable weather. Here in North Central Texas temps have been in the low to mid 90s with 70 deg dew point which is par for the course here … also we have had and are having afternoon T-showers in the area … Take a look at the present WV satellite imagery for this period, note the low that moved from LA to TX in the last 24 hrs; this has contributed to our conditions the last couple days …

ice doesnt look too well
I wonder if we will get significant ( visible by sensor from space ) open water inside the
85n line. extent is dropping by big rates…2007 record could get crushed.
the right weather… and we could hit ‘ice free’ ( 1 million sqkm in area) this year.
or not.


As far as the Vancouver forecast mentioned by Paul Vaughan, Environment Canada was 48 hours ago calling for sun and clouds on Sunday and sunny with a few clouds for the next five days. This morning they offered thunderstorms and rainy until Thursday. Thunderstorm indeed occurred over the lower Mainland… So Piers was spot on for this week end in southwest BC i.e. a 100km north of Seattle.
Instead of this highly questionable post and the previous one, why not invite Piers to write a detailed post on his forecast?

If northern hemisphere’s temperature oscillations both land and SST are direct result of the solar activity,
do not see reason why the same solar output can’t be associated with the weather.
Dr. Corbyn’s skill appear to be in forecasting local conditions, which obviously has to do with the trajectory of the polar jet-stream.
The Arctic polar jet stream is a strange beast, result of interacting of solar wind with ionosphere, stratosphere and troposphere, even NASA acknowledges the fact:
and more here.

u.k. (us)

When someone can predict how all the variables in a 9 horse race play out, I will take notice.
Until then, can’t we just fix the timing of traffic lights ?………


He COMPLETELY missed the Southeast/mid-atlantic in the July8-12 timeframe. He calls for hot and sunny and reality was cloudy, unsettled, cooler than normal, and rain. We’ve only gotten back to normal temps in the last two days or so here in NC.


Mosh, I was thinking same thing. If we get the wind we got in ’07, we could shatter the 2007 record low. And you think the howling from the left was bad then???


Paul Vaughan says:
July 15, 2012 at 11:25 am
Piers’ long range forecasts should be compared to other long range forecasts, not Willis’ hindcasts.

The point of the article is not the accuracy of Piers’ forecasts. The point is that he claims that some of his forecasts were accurate when that does not seem to be the case.

Gary Pearse

Steven Mosher says:
July 15, 2012 at 12:45 pm
ice doesnt look too well
Don’t forget that the 2007 low was aided by strong winds that flushed a good proportion of the ice including some multiyear ice, out through the Fram Strait. Without similar wind conditions, it is less likely to “crush” the 2007 record low. Also, ice loss slows significantly after the easy “southern ice” of Hudson’s Bay, Bering Sea, etc is gone. Regarding the 85N circle, the 65/70 days of above zero is half over:
Anyway, we won’t have long to wait.

Farmer Charlie

Over here in the UK, thirty years of farming has taught me that ‘tomorrow will be the same as today’ is accurate 66% of the time.

Until then, can’t we just fix the timing of traffic lights ?………
Good question. But why have traffic lights timed to meet traffic flow and miss out on all those tax dollars generated by stop and go traffic?
Smart (smart for the tax man) lights will stop 100 vehicles to allow for one vehicle to enter the congestion.

Almost a Laplander

I don’t know… He made a forecast in early april that central europe and especially northeastern areas would be having the coldest may for 100 years. May wasn’t especially cold, but it has been the coldest june for 84 years in Sweden and not much warmer in Finland. Nobody else I know came even close of predicting the weather like he did. BBQ summer, they said…
So I would not discredit him so easily. He does have some skill (or incredible luck) in predicting long term weather.

Green Sand

Steven Mosher says:
July 15, 2012 at 12:45 pm
“the right weather… and we could hit ‘ice free’ ( 1 million sqkm in area) this year.
or not.”

Genuine question, are you suggesting that http://www.arcus.org/search/seaiceoutlook/2012/july is that far out or am I getting lost between area and extent or are we into a new metric “ice free in the circle”?
If we are into a new metric do we have access to comparable historic data?


The reality is simply Piers Corbyn works on commercial basis if he keep getting it wrong then people will not pay him and he goes out of business, in other words if his ‘bad ‘ its self correcting.
On the other hand government and national weather forecasts get incomes no matter what , they in fact can’t lose and even better if they fail really badly they can call for further funding while telling us they need yet another multimillion dollar supercomputer so they can improve their forecasting . In other words if their ‘bad’ outside of public mocking its not self or otherwise correcting .

Brian D

His placement of low pressure over the Upper Midwest was and is still accurate. As far as the weather goes, there was one confirmed EF1 tornado in the Grand Forks, ND area on July 12. No giant hail, but lots of quarter sized hail or smaller reports, along with storm winds and heavy rains. This was from the front that moved through 12th-14th. Another low affecting the region today, but nothing bad happening yet. This one will move through the next couple days, 15th -17th. So we’ll see if the giant hail forecast comes true. I’m assuming we’re talking in a range greater than golfball size (greater than 2″). It’s rather normal for hail to be up to 2″, which is bad enough. Golfball hail is very dangerous.
Storm report links.
Aberdeen, SD
Grand Forks, ND
Sioux Falls, SD
Twin Cities, MN
Duluth, MN

I forecast a “possibility of hail” and the weather service forecasts the “possibility of hail” then I was accurate in my prediction of a “possibility”. I would be willing to bet that I can make forecasts that are nearly 100% accurate using that method. We know where various weather tends to happen. In fact, I will go out on a limb and say that there is a “possibility” of a tropical storm in the Caribbean sometime this year.

Harriet Harridan

Of course Piers does not get it right every time: nobody does. Of course his presentation skills (in my, and it seems others’ opinions) needs some work, but isn’t the important question; is he “more correct” than the standard long range forecasters? The answer seems to be yes, most of the time.
IMHO Willis has a bias against any extra-terrestrial influence on the weather (e.g. against Scafetta, N&Z, Corbyn) and determines to close the minds of others in the process.

u.k. (us)

Confirmation bias aside, screwing with a man’s livelihood is dangerous.
Ask anyone in politics.


A bit unfair to highlight Peirs like that, why mot UKMO who are paid by the taxpayer, rant all day long about global warming and yet make a three month forecast on the 23rd March this year and getting on the bandwagon of drought (nasty AGW you know) they forecast the precipitation for April May and June all being drier than average with May being the driest http://www.metoffice.gov.uk/media/pdf/p/i/A3-layout-precip-AMJ.pdf
Well we all know what happened to that forecasts with April and May being drenced in the UK and June breaking the 100 years record. So why Willis and Anthony start looking down your noses at Peirs what about the bigger target UKMO . At least Piers has to earn his money.
Bad form I’m afraid and ratehr petty and nasty.

What’s up with you and your red herring UKMO? Willis’ post was about Piers Corbyn, not the UK Met Office – and his criticism of Corbyn is correct.
It would have been far more polite to simply ask Willis for his opinion of the UKMO, rather than to cast aspersions at his reasoned analysis of Corbyn’s performance and accuse him of pettiness. The bad form is not Eschenbach’s, but your own.


Harriet. He put “very hot” over Texas in mid-July. I mean, really? No one else saw that coming?

Clay Marley

You’d think predicting “Hot” for the Phoenix AZ area for mid July would be a safe bet. But actually, July 13-15 has been cooler than usual and rainy across much of Arizona. Our “Monsoon” season has kicked off. Today the high is about 15F lower than a typical July day.


I gave the reasons, can you read?


I live 10 miles east of Seattle in Bellevue and a couple days ago we had one of the strongest lighting storms I’ve seen here since arriving in 1978. A house about 25 miles south was hit by lightning and caught fire. The resident inside the house was struck and both he and his dog were tossed across a room.
That doesn’t mean Corbyn isn’t a charlatan, though.

Ian W

Herkinderkin and Willis
You are failing to compare the other products on the market with WeatherAction output. If all products are extremely poor and WeatherAction is only moderately poor then it is the best long range forecast and although you can (and have) nitpicked – it may remain the best. So let’s compare some forecasts.
Here is the UK Met Office forecast for the important Olympic period in UK:
UK Outlook for Monday 30 Jul 2012 to Monday 13 Aug 2012:
It is most likely that the weather will remain changeable. The south is most likely to see the best of any dry, bright, and at times warm weather, particularly at first. Some rain is likely at times but overall, conditions are unlikely to be as bad as we’ve seen so far this summer. However, a lengthy spell of hot, sunny weather does look unlikely. This outlook gives a broad description of the type of weather that is likely to affect the UK as a whole, including significant changes in the type of weather [it does??] and an indication of how it may differ from what you may normally expect. As the Olympics draw closer the Met Office will have local forecasts so that everyone can make the most of the Games experience.
Updated: 1303 on Sun 15 Jul 2012

Well there you have it a professional tax payer funded long range forecast – hardly meets the specificity of Piers forecast for Vancouver does it?
But of course we should also look at the professional diagrams for long range forecasts from the Met Office they are bound to be better than Pier’s brash graphics and be more specific…..aren’t they?
Here they are: http://www.metoffice.gov.uk/science/specialist/seasonal/probability/glob_seas_prob.html
Go on – see if you can make out if its Arizona or Colorado that will have fires or if there will be severe storms in Indiana – not that they are mentioned.
To me the fact that Piers and WeatherAction go out there and actually provide specificity in their forecasts albeit in a florid graphic, is far better than other forecasts. But perhaps Herkinderkin and Willis, you can get together and beat Piers – its obviously extremely easy to create these forecasts scattered with mays, coulds, likely toos and changeables. Although, the forecasts from Piers tend not to be so vague. But have a go we can all sit in the peanut gallery and watch the masters show how easy it is. 😉 😉

If the UEA can call the climategate inquiries a “vindication”,…
Should we treat one data point the same as an ensemble? Obviously not, we expect the average from the greater ensemble of data to be more reliable than one data point.
Should we treat a small organisation with the same expectations of a larger?
If we want to have diversity in weather forecasting & climate forecasts (and not just a few monolithic “it can’t be the sun” organisations), then we have to be tolerant of the independent “single data” point not always being as accurate or slick as the “biased ensemble” … but that doesn’t mean we should tolerate bias or not strive to improve accuracy.
As the UEA would have put it “this is an absolute 100% total vindication of Piers Corbyn … the man walks amongst the angels, indeed his is an angel. Never in the field of human endeavour has there been a more perfect person”. (In other words, a slap on the wrists) … but do it again, and again and again, and lie a bit more … and you’ll only get a vindication!

John F. Hultquist

I spoke with a person in northern Ohio a few hours ago. That is, near Lake Erie and smack in the middle of the triple highlighted danger zone on the opening map. She complained of warmth and humidity and a sameness to that over the last few days. So I checked the 3 day history on the Cleveland/Burke Lakefront (KBKL) page of the NWS. The weather notes there are mostly “Partly cloudy” to “Fair” to “A Few Clouds” but including just one “Light Rain”. Yes, this is just one small site in a big area. Still waiting for reports of triple highlighted weather doom from within that big area though.
Jim R says:
July 15, 2012 at 12:06 pm
Why are we not allowed . . .
” and so on
Maybe you did not intend to start with a puzzling question and then end with a criticism of WUWT. Worthy of note, however, is the following, found in the WUWT masthead:
Commentary on puzzling things in life, . . . and so on


Good weather forecasters have very high risk intelligence which they share with horse-race handicappers, bridge players and expert gamblers, according to psychologists Daniel Kahneman and Amos Tversky.
This is their test:
Personally I think forecasting the weather accurately must be one of the most difficult things to do.

Green Sand.
1. open water above above 85 north, is just a proposition bet nothing more or less.
2. Minimum area: satilite record is 3. “ice free” is 1million sqkm. seems weird
but that is what folks mean by “ice free” < 1million sq km in sept.
As for times before 1979? it doesnt really matter one way or the other. world is getting warmer, you can expect expect less arctic ice..
'ice free' before 2050.. maybe as soon as 2016. volume is getting destroyed.