May CET

[Nick H]

In an established warming trend (I take it we all accept that the world is warming?) where the Uk has demonstrably warmed by somewhere in the region of three quarters of a degree to a degree then I hardly see anything significant or unusual about two months which come in approximately three quarters of a degree to a degree above the 'historic' average.

Fine though, so as not to detract from the already established facts of Global Warming I retract my lack of surprise at two months coming in at almost precisely the level of warming observed and am now astounded that March and May have come in slightly less than a degree above the 1971-200 mean. I have in fact spluttered coffee all over my keyboard in shock

How long before 71-00 is ditched as totally useless in our changed reality?

Hi snowmaiden,

I've lost you here (rarely happens I know!).

I think your original point was that the truly exceptional April would somehow detract from the fact that recording the 2nd/3rd warmest spring was little short of remarkable.

The fact is, the assertion of the warmest spring on record is made by reference to all 349 years of CET data. The fact that the 1971-00 may be of little utility or not realistic of our current warming trend is by-the-by.

Recording the 2nd/3rd warmest spring, the warmest autumn, summer in the top 10, the warmest April, the warmest September etc in the past year is astonishing and, needless to say, worrying.

[Optimus Prime]

March at 7.2c was 0.9c above the 71-000 average and would be in the above average category. While 7.2c is 1.5c above the 61-90 average and will be in the well above average category not exceptionally above.

The BBC are still using these definitions on their website but some of the data on the BBC weather archives are incorrect. December 2001 was 0.9c below average. BBC gave it close to average while Metoffice put it into the below average category.

The BBC managed to really confuse us with their November description;

" 0.1 °C above the 1961-1990 average, , which is in the close to average category. Coldest since 1998, when 5.7 °C was recorded. Joint 2nd warmest in the series with 1921 and 1995, warmest in series 2001 which recorded 13.0"

http://www.bbc.co.uk/weather/ukweather/yea...05_review.shtml

November was actually 0.1c below average and for some strange reason have confused October 2001 within the statement and I think January 1995 and 1921 is intermingled in there somewhere. Either way it's confusing and they haven't corrected it for nearly 2 years.

Some month vary but this is how the definitions went;

0-0.5c close to average

0.6c-1.2c above/below average

1.3c-1.9c well above/below average

2.0c+ exceptionally above/below

Edited May 27, 2007 by Optimus Prime

[Nick H]

March at 7.2c was 0.9c above the 71-000 average and would be in the above average category.

Let's get this straight, a month in the top 10.5% of all such months is only classed as "above average". Come off it. Exceptionally above average surely.

0-0.5c close to average

0.6c-1.2c above/below average

1.3c-1.9c well above/below average

2.0c+ exceptionally above/below

And I think these defintions are very silly. Who made them up, Met Office?

You can't lay down universal categories like this. I believe Mr Data made a similar point: there is likely to be far greater divergence from the mean in winter than there is in summer.

Edited May 27, 2007 by Nick H

[Weather-history]

Let's get this straight, a month in the top 10.5% of all such months is only classed as "above average". Come off it. Exceptionally above average surely.

Nick

I think the problem is you were basing those terms against the whole series, when infact the Met Office were basing them against a 30 year average.

See if you call March 2007 exceptionally above average, how do you describe March 1997 which was 1.2 above the March 2007 value?

Edited May 27, 2007 by Mr_Data

[Optimus Prime]

You can class it as you like but the Metoffice official definition sais it was either above-to-well above. It was a mild month overall but not exceptionally so. And I don't think 1.3c above the rolling 100 year average is particularly remarkable.

But does fall in line with how mild the year as a whole is these days.

[Nick H]

Nick

I think the problem is you were basing those terms against the whole series, when infact the Met Office were basing them against a 30 year average.

See if you call March 2007 exceptionally above average, how do you describe March 1997 which was 1.2 above the March 2007 value?

Hi Kevin,

But the point is that some people are claiming that the fact we are heading for one of the warmest springs is somehow made less remarkable by the fact that March and May are "only" 1C above the 1971-00 mean. We base our assertions on the warmth of springs by reference to all the data, not the most recent mean.

It's like saying that if July 2006 had been an average month, then 2006 would not have been the UK's warmest year on record. The fact is July 2006 was not average and the year 2006 was the warmest on record. It's also like saying "if the last week of Feb 19xx had been colder, we would have had the coldest Feb on record." There's no difference.

And March 1997 would also be classified as exceptionally above average.

Edited May 27, 2007 by Nick H

[Optimus Prime]

July and September 2006 were remarkable by the fact they added a whole 0.6c to the CET and that they came in hand in hand in one year (October being a whisker away from also being an all time record breaker)

But the CET 19.7c and 16.8c wasn't that substantial because they were both only 0.2c above the previous record set. This perhaps shows how far the climate gets stretched eveytime months like this occur and when will the breaking point happen.

[Snowly does it]

Hi snowmaiden,

I've lost you here (rarely happens I know!).

I think your original point was that the truly exceptional April would somehow detract from the fact that recording the 2nd/3rd warmest spring was little short of remarkable.

The fact is, the assertion of the warmest spring on record is made by reference to all 349 years of CET data. The fact that the 1971-00 may be of little utility or not realistic of our current warming trend is by-the-by.

Recording the 2nd/3rd warmest spring, the warmest autumn, summer in the top 10, the warmest April, the warmest September etc in the past year is astonishing and, needless to say, worrying.

I am certainly not arguing that the recent returns are anything but astonishing Nick, they are and they are worrying. I am more interested in what we should 'expect' in our new and changed climate - only form here can we determne the ongoing nature of, and rate of, change. Thats what I belive anyway. As such, both March and May are 'in pattern', it is April that is exceptional - both against the long and short-term measures and averages.

[Weather-history]

This spring we've had.....

An above average March

An April passing off as a (1971-2000) average May

And an above average May.

Basically we've had a spring with two Mays, if you think about it.

Edited May 27, 2007 by Mr_Data

[West is Best]

one month (April) has been exceptionally warm and the other two are (will be in a few days) just slightly above average

March and May will be around or above 1C above the mean i.e. 'well above average' by the Met Office definition.

The truth on this is that April was substantially above average, but this shouldn't dent the fact that the two months either side are also well above average. This is most unusual in that one might have expected a more stark correction. Outliers do occur. They don't always take the seasonal record with them.

An analogy here that comes to mind is with red Bordeaux. The 1990 year was a glorious one - exceptional. So much so that it nearly meant we lost sight of just how good 1989 and even 1988 were. April was exceptional, but this doesn't mean March and May were entirely without note.

[summer blizzard]

I am not saying March and May did'nt help, but if u add the anomolies together...

3.1C+0.9C+0.8C?=4.8C

4.8C/10=0.48C

0.48C=10%

3.1C is between 60% and 70%, therefore April is over 60% responsible for this anonomously warm Spring, personally, i find the winter figures much more interesting.

[Scorcher]

March and May will be around or above 1C above the mean i.e. 'well above average' by the Met Office definition.

The truth on this is that April was substantially above average, but this shouldn't dent the fact that the two months either side are also well above average. This is most unusual in that one might have expected a more stark correction. Outliers do occur. They don't always take the seasonal record with them.

An analogy here that comes to mind is with red Bordeaux. The 1990 year was a glorious one - exceptional. So much so that it nearly meant we lost sight of just how good 1989 and even 1988 were. April was exceptional, but this doesn't mean March and May were entirely without note.

I agree completely, there is also no way you can consider April to be the anomaly when it came so soon after several exceptionally above average months. Let's not forget that March and May have both been above average which in years gone by would have been notable.

[Iceberg]

Getting back to May.

Temps held up pretty well over night considering the conditions and the forecasts.

6's or 7's for most of England with a small pocket of 5's in central southern england (GFS was predicting 4's and 5's even down to 2.)

Overnight temps keeping up to this degree with massively help the final CET figure. With temps during the day maxing out just in double figures for most of the CET zone an average of 8.5C won't drag the overall figure down as much as possibly thought.

[Snowly does it]

Getting back to May.

Temps held up pretty well over night considering the conditions and the forecasts.

6's or 7's for most of England with a small pocket of 5's in central southern england (GFS was predicting 4's and 5's even down to 2.)

Overnight temps keeping up to this degree with massively help the final CET figure. With temps during the day maxing out just in double figures for most of the CET zone an average of 8.5C won't drag the overall figure down as much as possibly thought.

Temps tonight look rather lower possibly as the skies clear, I would think it was be a rounded up 12.3 as of yesterday, today will take it to 12.1, Tuesday down to 12 (mainly due to minima), Wednesday hold steady and Thursday may see it back to 12.1. Cannot see the record going, but possibly equalled from here.

Neither March nor May imo will be more than or equal to a degree above the 30 year mean and hence in a warming trend are both entirely unremarkable. April is stunning.

[Iceberg]

You could be right Today will probably be a critical day, I am not at all convinced by the 00Z run temp figures though (It still has a max of 4C for me today up until midday when the temp is already at 7C !.)

Tuesday night looks a bit bizarre as well with 850's of +5 and a dp of 1C it has 2m temps of -2 or -3. Hopefully the next run will be a bit more accurate.

[The PIT]

Dunno cold here at 5.4C and falling. Brrr.

[kold weather]

Ah well, I'm happy enough at the moment with how its all going, should come in between 12-12.2C and I'd guess 12.1C the most likely figure...which is what my May CET actually is, good job given how bad my April forecast was!

[Optimus Prime]

Philips current CET is 12.2c (+1.1c) and Metcheck is at 12.1c.

There will be a drop today. By the 31st expect it to be around 11.9c. Only 0.6c above average so quite a close to average month overall but an amazing contrast to April. But like August and July/August and September.

[Weather-history]

Using Philip's rainfall value as a base, here's the wettest Mays on record since 1776

151.8 1773

142.4 1782

140.7 1967

129.6 1932

129.1 1843

123.1 1886

122.4 1924

121.9 1811

121.5 1869

119.1 1979

117.6 1878

115.8 1969

115.2 1983

114.9 2006

113.9 1807

110.4 1796

110.1 1813

109.5 1797

108.1 1766

105.7 1942

104.1 1847

104.1 1955

101.4 1817

100.1 1830

98.4 1820

98.0 2000

97.9 2007

Edited May 28, 2007 by Mr_Data

[reef]

Interesting. Only 28mm up here in Ferryhill, Durham, so May has only been wet in the South. Philip is quoting 140% on his site for NE England, so either my rain gauge is vastly innaccurate or summat else. Ken Cook at Copely (down to the south west of me) only has 45mm, which is 76% of the norm.

We've only had 50.1mm here aswell, which is only marginally above average for May. Last May on the other hand saw 92.1mm.

[Lettucing Gutted]

Using Philip's rainfall value as a base, here's the wettest Mays on record since 1776

151.8 1773

142.4 1782

140.7 1967

129.6 1932

129.1 1843

123.1 1886

122.4 1924

121.9 1811

121.5 1869

119.1 1979

117.6 1878

115.8 1969

115.2 1983

114.9 2006

113.9 1807

110.4 1796

110.1 1813

109.5 1797

108.1 1766

105.7 1942

104.1 1847

104.1 1955

101.4 1817

100.1 1830

98.4 1820

98.0 2000

97.9 2007

How wet were the cold Mays of 1902, 1996 and 1816?

[Weather-history]

How wet were the cold Mays of 1902, 1996 and 1816?

Not especially wet. 1996 was on the drier side of average, the other two on the wetter side of average.

151.8 1773

142.4 1782

140.7 1967

129.6 1932

129.1 1843

123.1 1886

122.4 1924

121.9 1811

121.5 1869

119.1 1979

117.6 1878

115.8 1969

115.2 1983

114.9 2006

113.9 1807

111.7 2007

Edited May 29, 2007 by Mr_Data

[Kentish Man]

According to Philip Eden's site the CET remains at 12.2C (May 1 -28). In fact there was a 0.1c drop from 12.25C to 12.15C but rounding down yesterday and rounding up today kept the "headline figure" the same.

Edited May 29, 2007 by Kentish Man

[Polar Continental]

My mean here in Burton is down to 12.1c after a high of 12.6c five days ago, so a drop of 0.5c, with lows of 2c forecast here tonight and not especially warm days for the outlook, i think this will drop another 0.1c or possibly 0.2c making the overall mean not far off from the May CET average here.

Paul

Edited May 29, 2007 by Paul Carfoot

[DR Hosking]

Here in Northamptonshire the MAY CET is currently -0.1 bellow 30 year average, but the rainfall is 111mm and counting! Thats 220% of average, it was running at 140% even before the weekends delluge. So a very wet, average temperatured May for us here.