Lettucing Gutted

I haven't started one of these for a very long time so here goes. Make your CET guesses without penalties before the 1st October. After that guesses can only be made with penalties until the end of the 3rd October. My guess is 14C. Last sub 6C October in 1740. Last sub 7C October in 1896. Last sub 8C October in 1992. Last sub 9C October in 1993.

Compared to what was originally expected by most people methinks this "cold spell" has turned out to be a damp squib with the first 6 days CET failing to average below 13C. So 1992 remains the last time this happened. It also seems there is yet another September Indian Summer on the way. Certainly not what I want in the autumn.

Yeah great point there. I hate to admit it but this looks like a strong signal for a +NAO and +AO to me sadly. Those are some very surprising anomalies there. The Arctic looks very cold here and yet I always remember reading that the Arctic becomes ridiculously warm during El Nino years. Similarly I remember reading that South East Asia/Australasia usually get heatwaves and fires during El Nino years and yet the SSTs are unusually cool there too in these charts. On another note I wonder how the extreme ranges of the CET this century will respond to the Atlantic cooling if it continues and intensifies. Will we be seeing more warm/hot CETs like these or even warmer?:- -January 2007 7C -February 2002 7C -March 2012 8.3C -April 2011 11.8C -May 2008 13.4C -June 2003 16.1C -July 2003 19.7C -August 2003 18.3C -September 2006 16.8C -October 2001 13.3C -November 2011 9.6C -December 2006 6.5C Or will we be finally seeing more cool/cold CETs like these or even cooler?:- -January 2010 1.4C -February 2010 2.8C -March 2013 2.7C -April 2012 7.2C -May 2013 10.4C -June 2012 13.5C -Julys 2007 and 2011 15.2C -August 2014 14.9C -September 2012 13C -October 2003 9.2C -November 2010 5.2C -December 2010 -0.7C

Have no fear. Your wish shall come true.

17C Last sub 11C September in 1952. Last sub 12C September in 1986. Last sub 13C September in 1994.

Indeed, we might even finish in the 17s for the first time since 2004 ending a 10 year run of sub 17C Augusts, the longest run since 1960 through 1974.

It looks like were on track for a consistently mild month with minor variability compared to the cooler but very variable June and July we have just had.

That'll be the coldest since 1986! Although only just beating 1993. It will be very remarkable if we get another sub 15C August this year. The last time we had 2 consecutive sub 15C Augusts was 1985-1986.

I would have thought November 2010 would have had the biggest fall from start to finish. Recently March 2013 also had a big fall from start to finish. Since late winter through midsummer months are usually "warming months" its very unusual to get any significant drop let alone a big drop in these months.

I think for the country as a whole but I believe that some parts of the country recorded their highest yearly maximum in March in 1965. or the JPI. July Pattern Index!

Rest in pieces summer 2015! 20C Last sub 13C August in 1912. Last sub 14C August in 1986. Last sub 15C and last sub 15.5C August in 2014.

Looking at the CET data the last time there was 3 years without a sub 17C July was back in 1899-1901. Along with 1868-1870 that is the longest run on record. 2013-2015 could well equal this.

Judging by the article it seems the "cool spell" was probably caused by evaporative cooling due to heavy rain falling and evaporating into a shallow surface layer of cool Maritime Polar air from the Sea Of Japan/North Pacific. If the cool air had come from Russia (Continental Polar air) conditions would have been dry instead of wet.

It's funny you mention 1923. After looking at the CET data 1923 is the only cool summer (near sub 15C) to have a very warm July in the 17Cs. If 16.3 is 6 degrees below average that means that Leeds get very warm Julys on average at a subtropical 22.3C! If anything I'd say it's more of a case of the cool Atlantic and the return of Northern Blocking offsetting the warming effects of El Nino and weakening the Azores High and Icelandic Low. Usually El Nino gives us warm or hot summers.

The instability would be driven by the sharp vertical temperature contrast between the deep very cold airmass and the warmer ice-free water or snow free land. The instability would be further enhanced by the steep lapse rate created by the very cold upper level air.

I know supercells can form along frontal zones but I am specifically talking about a supercell forming solely in Arctic or very cold polar air that becomes very unstable without any warm and humid tropical/subtropical/mid latitude air being involved.

I know we can easily get thunderstorms during polar and arctic outbreaks including the best, Thundersnow! I have also read in my old weather books that severe thunderstorms occurred during the east US Blizzard Of January 1996 as well as the east US Blizzard Of March 1993. I have also read the reports on Mr Data's threads about the cold spells of October 1922 and October 1926 which both mentioned severe thunderstorms occurring over parts of the UK during those cold spells. But would such severe thunderstorms in Arctic air be actual supercells or just severe non-supercell thunderstorms such as squall lines or Mesoscale Convective Complexes or even just severe isolated non-supercell storms?

I predict the Minimum Of Arctic Ice this year will be less then 2.km. The bad news from the Arctic never ends these days. So much for the cooling North Atlantic.

I hope even my guess doesn't prove to be too low... Were going to be well above 20C for a while.

UK warming is back with a vengeance. The warmest year on record (2014) followed by more summer heat records.

I chose the "Quite cool. Temps ranging between 15 to 20*C. Nothing warmer" option for my ideal "Summer Of Heaven". So far I appear to be the only 1 who chose this option. Additionally as well as cool, I would like summer to be dry and only slightly wet at worst with any wetness due to light rain, light showers and drizzle. I would also like any storms and showers to be of the "Low Precipitation" form (as the Americans say ). I hate heavy rain, floods and monsoons as well as heat. As long as its cool/cold I don't mind whether its sunny or cloudy. I also prefer calm or light breezes. No blowtorch Azores/Bartlett High and Atlantic Low driven hairdryers or muggy Atlantic mush please.

If I'm not mistaken the June 1971-2000 CET along with October are the only ones to be below the 1961-1990 mean though only slightly.

I hate these months that tease us with being the coldest for a long time only to finish average or even above in the end!

20C Last sub 14C July in 1922. Last sub 15C July in 1988. Last sub 15.5C July in 2011.

My ideal year would be a very cold year with a cold winter, cold spring, cold summer and cold autumn all included and would be made out of these months:- January 1963 (-2.1C) February 1986 (-1.1C) March 2013 (2.7C) April 1917 (5.4C) May 1902 (8.9C) June 1916 (11.8C) July 1965 (14C) August 1956 (13.5C) September 1952 (10.7C) October 1817 (6.4C) November 1919 (3.3C) December 2010 (-0.7C) Year CET 6.07C! I would have chosen the all of the coldest months on record but 22nov10blast beat me to it! I must admit, I find Summer Blizzard's choice unusual. A cool/very cold late summer through late winter period yet with a very warm early spring through mid summer period. Hyper continental! Not even countries like Alaska, Canada and Russia and Scandinavia can pull that off!