summer blizzard

I suppose the bigger question then is what percentage of April's have a second half cooler than the first. Much like March there's certainly nothing forecast in terms of anticyclonic weather that would make it worthy.

Excited though we are getting, years like 2007 and 2020 did go off the boil so I think we should avoid being too bullish.

damianslaw It may be a local bias however while growth was advanced, most trees appear to have stalled. It is the grass and flowers that are proceeding at pace.

One interesting observation this spring is that as a result of the depressed sunshine and to a lesser degree maxima, while they got a very early start in late Feb, the majority of trees are still barely budding. It's the grass and flowers that seem quite happy. I was looking through my photos and contrasted to this day in 2020 when i had a full park of blossom, it was quite stark.

20MAR2024: Nino3: 1.0, Nino3.4: 1.3, Nino4: 0.9 27MAR2024: Nino3: 0.9, Nino3.4: 1.0, Nino4: 0.8 March ONI fell to +1.2.

Rolling CET for April-March rose to 11.23C.

BruenSryan Interesting, the rain never jumped out. March in particular seemed cold and dry with occasional snow but perhaps I missed a few fronts across the south. April is clearly wet for April but below 100mm which is why I will have deemed it forgettable.

Addicks Fan 1981 Best matches are 1954, 2007, 2010 however there are no good recent PDO matches given that we in an exceptional -PDO cycle currently.

raz.org.rain That was 1988.

32.9C on July 5th.

2006 only had a wet March and May and even then, only the second half of March. Summer 2006 was really just the culmination of a dry period starting in November 2004. I don't remember much of late 2017 but I'm not really sure that March and April were even regarded as wet. 2013 was not really a wet period. Jan may have been regarded as wet but here in West Yorkshire I went 20 days without precipitation in February. March was not that wet and neither was the spring or June. It's interesting that both September 2013 and 2006 both ushered in wet periods for the next year. I tend to believe there's no real link between the spring weather and summer. The most convincing theory I read was plumes in spring are more indicative.

I suspect that mid-April to mid-May will be our most settled period (followed by the second half of June before summer is done). 20C - 25th April 25C - 5th May 30C and 90F - 25th June.

July 23 was a humid month while July 20 felt cool. I prefer 20.

Down to -5 at the sub-surface.

damianslaw I don't think one can ever really tell what the summer will be like from the spring. Spring 2012 saw the brilliant March and a glorious final third of May but still went for the jugular. Spring 2006 I believe had the latest 20C since 1996 at the time but a few days later bumped to the high twenties.

Was wondering if there’s a record of average strength at 10hpa over winters as this would have to be on the weaker side.

My general rule with the CFS and most ENSO models is to ignore actual values since they tend to amplify the sub-surface too much when it's rising and falling. If we look at first year peak values though we get.. 54: -0.9 64: -0.8 70: -1.4 (peak in Feb 71) 73: -2.0 83: -1.0 88: -1.8 95: -1.0 98: -1.6 05: -0.9 (peak in Jan 06) 07: -1.6 10: -1.6 16: -0.7 20: -1.3 So the range is -0.7 to -2.0 with a middle ground of say -1.4. Worth saying for winter that a weak La Nina is probably preferable to a strong one.

9.2C, 53mm. Relatively settled compared to recent months with a -AO and the UK seeing somewhat transient ridges between slow moving Atlantic and Scandinavian Lows.

Going, going, gone.

13MAR2024: Nino3: 0.9, Nino3.4: 1.1, Nino4: 0.8 Sub-Surface down to -4.

Just looking at transition speed from those who developed a La Nina as forecast and we're at least moderate at peak. 63/64: +1.4 to -0.6 was 6 months. 73/74: +2.1 to -0.5 was 5 months. 83: +2.2 to -0.5 was 8 months. 87/88: +1.7 to -0.9 was was 9 months. 94/95: +1.1 to -0.5 was 8 months. 97/98: +2.4 to -0.8 was 7 months. 09/10: +1.6 to -0.7 was 6 months. 15/16: +2.6 to -0.5 was 8 months. Closest decline thus far is 1998 and 2016. We are tracking about a month ahead of 98 and 2 months quicker than 16 given the same pace but lower peak. So current tracking suggests 6 months which is at least -0.5 in MJJ. First year Nina's declared by MJJ are 54, 64, 73, 88, 07, 10.

Addicks Fan 1981 Current modelling suggests we flip much quicker and harder. Think 1998 or 2010.

raz.org.rain Probability is not guarantee. I personally do believe that transitions do impact our climate however we must remember that in any given year there is a 33% chance of a cool, warm and near average outcome. That transitions may tip the scales does not mean that the likelyhood falls below say 1 in 5. You would not bet your car on it, but neither would you be shocked.

SqueakheartLW Yes, indeed. While i'd ignore model strength for now as they are poor, the inability of this Nino to form a sustained standing wave means that it appears likely to collapse pretty quickly even if sub-surface SST's are only -2 or so. I think it's more the case that since ~2002 we have arguably been in a multi decadal Nina/-PDO pattern, hence why we are seeing this Nino get sandwitched like 1972 and 2009.

06MAR2024: Nino3: 1.0, Nino3.4: 1.4, Nino4: 1.1