A poor start to the summer to say the least. We have not had a decent summer since 2006. 2009 and 2010 were slightly above the 1971-2000 average but no year has been above the 1981-2010 average since 2006. This year is looking no better. Indeed this summer is looking very similar to last year which was 1C below the 1981-2010 mean.

The deadline for CET entries is 23:59 on 30 June. Entries will be accepted up to 48 hours late but with the usual penalty regime applied for those who are participating in the annual competition.

Please place your July CET predictions in this thread

Historic data summary

Here is the usual rundown of historic data.

The July CET was only 15.2C last year which was similar to 2007 and 1993. The last time we had a July colder than last year was 1988 with 14.7C. We have not had that many very warm July's recently with 2006 at 19.7C being a notable exception. 1999 and 2003 were not too bad in the upper 17's but you have to go back to 1995 for the last time we exceeded 18C apart from in 2006. In 2010 we managed 17.1C. 

Long run averages:
1971-2000: 16.5C
1981-2010: 16.7C

Here is a chart of the July CET since 1961 with a 10 year moving average

Here are some details of what the models and forecasters generally are saying at the moment

GEFS
http://www.wetterzentrale.de/pics/MT8_London_ens.png

Fairly average start to July

ECM ensembles (De Bilt)
http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

The ensemble mean looks to be below average in early July

Weatheronline
http://www.weatheronline.co.uk/cgi-app/reports?MENU=Month-ahead
Looks distinctly average at best with unsettled cool conditions at times but some warmer spells.

Netweather
http://www.netweather.tv/index.cgi?action=summer-forecast-2012;sess=

Hints at something better than June with the best weather towards the end of July.

Met office (issued 20th June)
http://www.metoffice.gov.uk/media/pdf/7/6/A3-plots-temp-JAS.pdf

A great deal of uncertainty even near the beginning of July but generally there is a signal for a cooler than average July which ties in quite well with the pattern matching below. 

Pattern matching (just for fun)

The best pattern matching analysis I can find this month revolves around looking at the May / June temperature combination. Years similar to 2012 since 1950 are as follows:

1954 May 11.2C, June 13.4C, July 14.2C
1956 May 11.7C, June 13.1C, July 15.8C
1969 May 11.2C, June 13.9C, July 16.8C
1974 May 11.0C, June 13.9C, July 15.2C
1978 May 11.7C, June 13.7C, July 14.8C
1980 May 11.2C, June 13.8C, July 14.7C
1981 May 11.2C, June 13.2C, July 15.5C
1997 May 11.5C, June 14.1C, July 16.7C
2011 May 12.2C, June 13.8C, July 15.2C
2012 May 11.7C, June 13.4C?, July ????

What this shows is that in 7 years out of 9 (80%) the July CET was less than 16C - i.e. more than 0.5C above average. In the other two years (20%) the July CET was average. In 2/3rds of years the July CET was 1C or more below average.

I had a quick look at the rainfall stats as well given the very wet June. The 1971-2000 CEP mean is 48mm. The mean for the 9 years above is 62mm - i.e. 30% above average. In two years (1981 and 2011) rainfall was exactly average but in all other years it was above average.

So unfortunately I have to report that in summary the pattern matching strongly points to a cool, wet July with perhaps a 20%-25% chance it will be average and virtually no chance of a better than average month.

Edited by user 26 June 2012 20:47:44(UTC)  | Reason: Not specified

I've got to go away tomorrow so in case I forget/can't get access i'll go for 15.6C

Edited by user 26 June 2012 21:17:38(UTC)  | Reason: Not specified

I am not suprised in the very least the outlook is bad and I'll do some calculations before I go for my forecast guess.

But I am looking at a poor one.

I've just got a feeling that northern blocking is starting to diminish and the signs are there that the jet might return north, allowing the Azores and Euro highs to take more of a front seat.

Therefore, I am anticipating a MUCH better July nationwide, but particularly in England and Wales.

CET prediction is therefore a very warm 18.0 with rainfall below average.

Call it hopecasting, but I genuiinely believe that a change is on the way!

Originally Posted by: moomin75

I've just got a feeling that northern blocking is starting to diminish and the signs are there that the jet might return north, allowing the Azores and Euro highs to take more of a front seat.

Therefore, I am anticipating a MUCH better July nationwide, but particularly in England and Wales.

CET prediction is therefore a very warm 18.0 with rainfall below average.

Call it hopecasting, but I genuiinely believe that a change is on the way!

 

Well, the NOAA analogue years contain the two warmest Julys on record and the forecasted MJO phasing reanalysis also features '83 for 2and 3 (July) - just a pity there are a couple of 14 something duffers lurking there too.

16.3c for me please. Cool/ ave first half heatwave towards the end 30c reached.

14.9 for me

16.5c for me please GW!

16.9C please.

13.8°C for me. Looks like another month dominated by the same pattern that brought us the coldest and dullest June for decades. Forecast is already showing some 12°C maxes here (average is 19) so well below average seems like a safe bet.