Friday, July 04, 2008

Corbyn on July

For some reason I never saw a copy of Piers Corbyn's June forecast, so I can't evaluate that. He did breathlessly announce on the 26th (Thursday): Our long range forecast for deluges and floods between 29th June and 2nd July still stands - so Glastonbury and Wimbledon watch out! However the only report I saw about Glastonbury at that time said it was pretty dry, even sunny by Sunday, and the drizzle at Wimbledon on the 2nd certainly wasn't enough to save Andy Murray. With typical chutzpah, he is still claiming he got this right - can anyone point to any "exceptional torrential downpours" in this interval? (I'm aware of some fairly heavy rain on the 27th, I even got to enjoy it as I was in Sheffield at the time.)

Anyway, on with July. It's going to be extremely wet ("probably one of the three wettest Julys on record") with a rainfall of 160-250% of the average over England and Wales. Just to be difficult, his temperature prediction is for the daily max rather than mean as previously. This is predicted to be 0.2-1C below mean, and he also says that the mins will probably not be below normal. I reckon I can therefore reasonably assign a range of about -0.5C to +0.2C for the means (for comparison with data). If the mean is outside this range, then it is hard to see the max being in Corbyn's prediction. I think this is probably generous to him, but will be happy to hear alternative suggestions.

As well as the UK weather, he has thrown in some typhoon predictions for free. Apparently there's a 60% chance of Japan taking a hit in the first half of the month or so. No sign of them so far and it has been particularly cold here this year, although I don't know what the sea surface temperature is looking like in the formation zone.

I've been away, BTW, for those who were wondering if I'd given up entirely.


skanky said...

Rainfall totals, in Weston Park, in Sheffield for 25th, 26th & 27th was
0.8mm, 16.4mm and 0.8mm respectively.

Most of the notable rainfall amounts seem to be before 29th June and the last few were a bit drier, it seems.


Hank Roberts said...

Want to follow another predictor?

BF said...

So where are your own predictions based on the CO2 driver theory? LOL!

Let's have a look at how old Jeremiah Hansen's predictions panned out, shall we?

At least Corbyn gets it right some of the time, whereas Hansen and you guys get it right none of the time.

BF said...

By the way, Corbyn has written to the Inquisitorial Project on Climate Change and to George Monbiot of the Gonadian asking them if they really do believe there is evidence of the CO2 driver theory in the available data to please present a graph of it, however neither party has replied to date.

Can anyone hear help?

James Annan said...


Thanks for the data. I certainly got wet on the 26th and I'm fairly sure that news the next morning reported on "overnight" rain so I guessed it had probably spread over to early on the 27th.


I've been keeping out of the sea ice debate, as I can see there are arguments either way and have no direct experience to judge. At a first glance, this seems to give a strong advantage to last year, but on a closer look much of this year's ice is down to 60% coverage which could probably vanish fast. I also have no idea whether eg the recent comments of Mark Serrezze are really informed expert judgement or more motivated by public attention. Has he a track record in making seasonal predictions, or even a validated method of hindcasting recent interannual variability? He stands to look a bit foolish if this year ends up a long way short, so I hope he knows what he is doing!

skanky said...

Yes, I *think* the RF totals are reported at 09:00, but am not sure if they are for the previous 24hrs, or whether they are retrospectively entered into "yesterday's" day. I should ask WP or work it out as I live in Sheffield but get the data monthly.

Incidentally, on Corbyn's June forecast seems to have been generally scarce:

Tilo Reber said...

"I've been away, BTW, for those who were wondering if I'd given up entirely."

Now that you are back, could you answer these questions?

1. Why has there been no temperature rise in the past 11 years? Do you have any explanation other than "noise"? How much longer will this have to continue before it becomes, "statistically significant"?
2. Same questions with respect to there being no sea level rise for the past 3 years.
3. When do you plan to have your own estimates of the future decadal, CO2 induced, warming trend ready?

James Annan said...


I've already discussed this stuff ad nauseam. Have a look at this pic and then try to tell me that global warming has stopped.

EliRabett said...

Eli is generally with you on it can go either way, but still it was good to take a small bet on the basis of general aggro and something for idle paws.

Point is that it is going to be close, and last year was very down.

BF said...

I see the Met Office has been forced issued severe weather alerts across parts of northern and south eastern England warning that up to 40mm of rain could fall in some areas. Both the Wimbledon mens final and the British Grand Prix at Silverstone were punctuated by large down pours.

So far, Corbyn's forecast for this month seems pretty much on the money.

So how are your own CO2 driver forecasts standing up by comparison - anyone?

Magnus said...

Well well, if you have extra time take a look at this ;) and after...

Tilo Reber said...

"Have a look at this pic and then try to tell me that global warming has stopped."

Maybe you didn't notice, but I was talking about the last 11 years, not the last 60 years. Do you think that my chart for the last 11 years is incorrect? If so, then where is it incorrect? Or maybe you could show me your chart for HadCrut3 RSS and UAH data for the last 11 years. In any case the main question was this:

1. Do you have a better explanation than "noise" for an 11 year flat trend?

2. How long does it have to stay flat before it becomes statistically significant?

There is also your promised estimate of the decadal trend. How close are you to getting that out?

cce said...


Here's a more . . . competent graph.

Hansen Scenario B vs GISS vs RSS

If anyone has version 5.1 of the UAH satellite data, I'd like to add that data to the graph. Then skeptics can compare Spencer and Christy's version of the past, circa 2005, and Hansen's version of the future, circa 1988.

skanky said...

cce, have you looked at the University of Washington versions of the data?


cce said...


It's my understanding that there's no "lower troposphere" version of the UW analysis.

skanky said...

Makes sense. I had read that article wrong and taken all datasets after the reference to T2LT to versions of the same thing. It explains one or two other things elsewhere, too. Thanks.

BF said...

james annan said... "I've already discussed this stuff ad nauseam. Have a look at this pic and then try to tell me that global warming has stopped."

Dear James
Thank you for providing the graph of various global warming trends. I must say that it struck me as somewhat suspicious. I decided, therefore, to ask someone with demonstrable statistical skills in the field of climate research to examine it for me, and without telling that person where the graph came from. See below for a copy of the findings.

Best wishes, bf

Re: Graph of various warming trends

The graph is flawed. Here are the steps followed by its author:

1. He/she took NOAA's database - the one referring to surface stations only. We know that THIS database is flawed and unreliable.

2. He/she plotted the years from 1940 to 2020; however, he/she left blank the data from 1940 to 1950, and only filled in the spaces with delta T from 1950 to 2008.5, which means that the graph was plotted with blank spaces before 1950 and after 2008.5. This practice is usual with people who want to try and impress readers or an audience. If the fluctuations of temperature were higher before 1950, the trend lines would be closer to the horizontal, and you wouldn't notice the inappropriate data manipulation.

3. He/she plotted an almost perfect square graph, which make the lines appear higher than those in statistically acceptable graphs.

4. He/she has erased the horizontal lines, so one cannot see that the trends were drawn over other plots that are invisible in the graph.

5. He/she has used linear trends, when - correctly - for all plots where values are fluctuating from negative to positive and vice-versa, logarithmic, potential, or polynomial trends MUST be applied.

6. So many trends appearing in one plot is considered bad practice because each linear trend line crosses the y axis at a different point. For example, one trend line crosses the y axis at -0.45 °C, another line crosses at -0.25 °C, another at 0 °C, and yet another at 0.25 °C. This practice is not considered legitimate because it is flawed and misleading. When showing different trends pointing to different values on the y axis, one MUST plot a single graph for each trend and specify at which value the trend line is crossing. If not, the graph is considered flawed, distorted, twisted, misleading, etc.

I’ve attached three files, one showing a flawed graph, similar to the one sent me, another one showing the graph correctly using the flawed database and finally the last one showing the graph correctly using a credible database so that you can appreciate the differences between the wrong way and the correct way of plotting graphs.

Distorted graph-incorrect database:

Correct graph-incorrect database:

Correct graph-correct database:

Tilo Reber said...

We have used Gavin Schmidt’s own ENSO corrected data to show that the current decade long flat temperature trend is not related to ENSO.

Gavin has now been asked four times on Real Climate, in his own ENSO thread, about the ENSO corrected flat trend. Namely, if the trend is not a result of ENSO, which it clearly isn’t, then what elements of natural variation have overriden the +.2 C of man made warming that we should be seeing. It speaks volumes that Gavin is running away from the question.

If we know so little about natural variability that we cannot give an attribution to a period that has already occured, then how can we assume that we know enough about natural variability to create models for the future or to isolate a climate sensitivity signal.

Henk L. said...

Corbyn also promised a hurricane 18-22 June, with 75% chance to hit land somewhere around the Gulf of Mexico.

cce said...

skanky said...

Max & Min compared to averages can be found here:

James Annan said...

Well spotted. In that case I will use that min value, and adjust the anomaly in line with the difference in the means according to CET (cos PC uses 1961-1990, Philip Eden uses 1971-2000 as their normal climate).

skanky said...

Incidentally, PE uses Excel to produce his web pages and that seems to cause compatibility issues with FFX. However, FFX users can install the "Remove This Permanently" add-on to clear out the invisible objects that cover the links and prevent you from clicking on them. It often involves removing several items, but after that the website becomes navigable.

BF said...

Corbyn's solar based forecasts on the money again..

Piers Corbyn ... scored a significant hat-trick in trial extreme forecasts for last weekend in the USA and Pacific; and immediately - on 22 July - announced typhoon prospects in the run-up to and during the Olympics.

The Weather Action trial Extreme Events forecast ... for the period immediately around 18/19 July correctly forecasted the formation of Typhoons in the West North Pacific; the formation of Tropical storms in the Atlantic/Caribbean/ Gulf Of Mexico region; and for 18th-20th a New York area heat wave/hotspell in which temperatures would be 80% likely to top 95F (35C).

James Annan said...

"for the period immediately around 18/19 July correctly forecasted the formation of Typhoons in the West North Pacific"

This is just a blatant lie. He forecast 2 typhoons to hit the Philippines/Taiwan/China at 80% probability, and this failed to occur. He also forecast two typhoons in the region of Japan (with 80% probability), with one hit (60% probability), and this did not occur either. In fact, out of these 4 forecast Typhoons, only one occurred.

No wonder he claims 80% success when such clear-cut failures are asserted to have validated!