Summer 2018 - General Discussion

Artane2002 · 24-03-2018 9:12pm

sryanbruen wrote: »

2006 and 2013 did not have the curse of the number "8". :P

But 8 is a lucky number in Asia so it may come to our rescue this time

On the flip side, I've heard that you pronounce "8" as "ba" in China... ba... bad

sryanbruen · 25-03-2018 6:48pm

sryanbruen · 25-03-2018 11:34pm

amadangomor wrote: »

What are the chances we get a prolonged period with the jetstream south of us? I'm talking 4/5 months plus. If so would it mean continuing easterlies in general and the chance of a scorching summer? 1995 springs to mind

If only it was as simple as that. The jet stream needs to be the north of us but then go in a southerly trajectory once it's north over us. High pressure needs to be somewhat up to the mid to northern side of the British Isles for easterlies. To show what I mean, here's the reanalysis for Summer 1995 as an example (a perfect example at that for what I'm trying to say):

Summer 1976 is also another very good example:

Artane2002 · 26-03-2018 10:10pm

Sorry, I have no clue why I said the summer may be slightly warmer than average. I feel like it may be average in the west but a little cooler than average in the east. Problem is, with the low SSTs at the moment on the east coast, an easterly will cool down the east coast a bit. They will take a bit of time to recover with the way the weather is behaving. The warm easterlies may lead to heavy showers if the SSTs remain cold. This would be more of a problem for eastern England, with SSTs of 3c there. This will probably modify warmer air a bit which means it won't be as warm as it could have been when it reaches us. Land heats warmer than the sea during the summer so the west might escape this issue if there is an easterly.

The sea is of course going to warm up but unless we see exceptionally warm weather that warms the sea up, easterlies will possibly be a let down for those on the east coast.

LoMismo · 27-03-2018 12:50pm

I still need gloves and a hat cycling to work, and it's pretty much April now. Whenever you're ready, Spring, feel free to show up. Looks like it's going to be Baltic and miserable for the next while too, sigh.

sryanbruen · 27-03-2018 9:13pm

To add emphasis to the terrible outlooks for Summer that you can see in this thread, here's the reanalysis for Summer 2012, a Summer that we're all aware of for being very very bad!

thomasj · 28-03-2018 2:03pm

Just seen this on netweather, for next tuesday this can't be right can it?

Obviously likely to change, but there hasnt been any talk for snow Tuesday has there?

Graces7 · 28-03-2018 4:20pm

thomasj wrote: »

Just seen this on netweather, for next tuesday this can't be right can it?

Obviously likely to change, but there hasnt been any talk for snow Tuesday has there?

Here today we have hail and gales.. nothing would surprise me any more,

sryanbruen · 30-03-2018 6:21pm

Another two very poor analogues to add to the collection for Summer 2018.

Summers that followed the top 20 wettest Marches on record:

Summers that followed the top 20 wettest Aprils on record (as the outlook into the first week looks very wet):

Artane2002 · 30-03-2018 6:29pm

That first chart looks disgusting. Surely it can't be worse than that?

sryanbruen · 31-03-2018 4:26pm

Artane2002 wrote: »

That first chart looks disgusting. Surely it can't be worse than that?

The outlooks for Summer 2018 are certainly not good and sometimes alarming.

Artane2002 · 31-03-2018 4:49pm

If you go with the opposite of what the CFS shows, then you shouldn't be too far off

. It was showing a (very) mild winter but that didn't verify. It was showing a cooler than normal summer last year but again, that didn't verify. :P

Obviously this is very far off so it probably won't happen but the CFS is showing a northerly for the end of April/start of May with -8 uppers clipping the north coast with widespread -6c uppers!

Edit: My statement about what the CFS showed turned out to be incorrect. Sorry about that.

JCX BXC · 31-03-2018 6:30pm

thomasj wrote: »

Just seen this on netweather, for next tuesday this can't be right can it?

Obviously likely to change, but there hasnt been any talk for snow Tuesday has there?

Netweathers own automated forecasts are horrifically inaccurate and extremely skewed towards a snowy outcome, take no notice.

sryanbruen · 01-04-2018 12:08pm

As a result of the new cool SST anomalies to the east of the equatorial Pacific recently, I took the liberty into making this reanalysis of Summers that were preceded by two La Nina years and then followed by a La Nina for a third consecutive year. So like 2016-17 was a La Nina (a very weak one though) and 2017-18 was a La Nina (a weak one) and just hypothetically speaking if 2018-19 were to be another La Nina year. This is all hypothesis for now though because we are in the Spring unpredictability barrier for ENSO.

The reanalysis does show blocking and a trough down to the Bay of Biscay but it's a more decent scenario with easterly influences. Perhaps quite thundery at times if this reanalysis were a thing. The Summer of 2000 is in there which was very decent for Ireland and Summer 1975 is in there too which was a spectacular Summer, very sunny and warm.

Carol25 · 01-04-2018 1:48pm

Sryan, I hope thats not an April fool?

sryanbruen · 01-04-2018 2:08pm

No, I take weather seriously

. I'm bad at jokes anyway.

Here's the reanalysis charts for both of those Summers I've highlighted.

Summer 1975, cold first few days of June with some snow falling as far south as London but then becoming quickly warm, dry and sunny with a persistent area of high pressure that would stay with us for much of the Summer, helping 1975 to become one of the sunniest years on record. This was at a time when we were in the middle of the worst drought of the 20th century that begun in October 1974. Many places had to wait 'til September 1976 to see some significantly wetter than average weather.

Summer 2000. This chart does look bad. It looks cool and unsettled but it was a rather changeable warm Summer in Ireland. June was very similar to that of 2017 but drier. Casement Aerodrome had 28c on June 18th. July was a close to average month in terms of temperature, rainfall and sunshine though the east of the UK had a very poor, cold and wet month. August was mostly dry, sunny and rather warm.

sryanbruen · 01-04-2018 6:55pm

Years where January was the warmest month for the first three months using the CET.

Interesting how 1975 appears here too.

Year|Jan|Feb|Mar
2013|3.5|3.2|2.7
2008|6.6|5.4|6.1
1976|5.9|4.5|4.8
1975|6.8|4.4|4.8
1974|5.9|5.4|5.8
1969|5.5|1.0|3.3
1944|5.8|3.6|5.2
1932|6.3|2.9|4.7
1930|5.6|2.5|5.3
1924|4.7|3.3|4.1
1916|7.5|3.8|3.3
1906|5.3|3.1|5.1
1900|4.4|2.6|3.7
1898|6.6|4.8|4.3
1888|3.2|1.8|3.1
1875|6.4|2.3|5.1
1866|5.8|4.4|4.8
1853|5.1|0.6|3.4

Data from the UK Met Office.

sryanbruen · 01-04-2018 7:02pm

Here's the reanalysis of the years named above, another poor analogue for Summer 2018.

Clonmel1000 · 01-04-2018 9:52pm

Sryan any prospect of an improvement on the cards?

sryanbruen · 03-04-2018 5:45pm

Summers following cold Easters using the CET.

The 1981-2010 CET average for Easter is 8.07c so any Easter period (Good Friday to Easter Monday) that has a CET below this is considered in the reanalysis and surprisingly, there is quite a lot!

Yet again, another very poor reanalysis with a southerly tracking jet stream and an area of low pressure parked right over top of us. Dreadful chart!

sryanbruen · 05-04-2018 8:39am

1995/96 was one of the Winter analogues we looked at because it had many similarities to the outlooks for 2017/18 including ENSO, QBO, solar activity etc. The latest ENSO figure from NOAA had just released for Jan-Feb-Mar and 2017/18 was an official weak La Nina season, just like 1995/96. What I found intriguing is the similar ENSO anomalies for the tri-monthly periods of both years and the fact that both years had a mild January (not counting the northern part of the country in 2018 where it was cold), cold February, a delayed Spring including a cold March and the coldest May on record. The Dec-Jan-Feb anomalies for both seasons was -0.9 below the average and the Jan-Feb-Mar anomalies for both seasons was -0.8 below the average.

I wonder if the similarities will continue into the Summer.

Summer 1996 was a decent Summer. June was excellent with a lot of sunshine, warm days, very dry and some rather cool nights. July was rather warm with dry conditions but not very sunny. August was fairly warm but wet and dull. To be honest, I've seen far far worse Augusts than 1996. Not the worst Summer you can find, I definitely wouldn't mind it though a very strange Summer at that with some thunderstorms I might add. ('Cause I know how much some of you love thunderstorms) Would love a month like June 1996.

These are the IMTs and anomalies from the 1981-2010 averages for each of the months in 1995/96:

December: 4.1 (-1.5)
January: 6.7 (+1.2)
February: 4.5 (-0.8)
March: 6.6 (-0.5)
April: 8.8 (+0.3)
May: 8.9 (-2.4)
June: 13.9 (+0.2) - cool nights suppressed the mean temperature
July: 15.7 (+0.3)
August: 15.6 (+0.2)
September: 13.7 (+0.7)
October: 11.1 (+1.0)
November: 6.5 (-0.7)
December: 4.4 (-1.2)

IMTs as always are calculated from Met Éireann and UKMO's historical data.

Don't forget, 1996 was the year of solar minimum.

Here's the reanalysis' for Summer 1996.

June

July

August

Summer

One of the best Summers (in terms of the actual conditions) we can find for an analogue for Summer 2018 up to now.

sryanbruen · 08-04-2018 2:42pm

Summers following sunny Februaries, not a good one again.

Summers following dull Marches. Not brilliant but better than many of the analogues. Anticyclonic if rather cool solution on this reanalysis.

I'd like to note, 1996 had a very sunny February and a very dull March too - another reason why 1996 is a good analogue for this Summer.

sryanbruen · 12-04-2018 6:21pm

How does the Summer look historically with a wet March and wet April in the same year? Again, not a pretty one though there is a large variety of Summers in this one in particular that I don't think the overall average of the reanalysis is much to speak of. For instance, there is a deep low over Greenland which would usually mean a positive NAO which is good for Summer normally, and there's a deep trough over the Mediterranean too with weak low heights over us and a ridge out in the Atlantic. This is not far off a good setup for warm and settled conditions.

Artane2002 · 12-04-2018 8:20pm

To lighten the mood here and for once deliver good news, 2018, 2013, 2006 and 1995 all had colder March minima than the January/February minima. Most of you should know what came during summers 1995, 2006 and 2013. Only 3 years but this thread does need good news!

sryanbruen · 13-04-2018 9:42am

Just a round up of every analogue/reanalysis I have done so far and what each showed:

Summers following cold Marches - High pressure just to the northwest ridging over us allowing the jet stream on a northerly track and creating warm easterlies with a trough to the southeast of Europe. A nice reanalysis to start us off with here.

Summers ending in "8" - I think this is one that the majority are aware of by this stage but if you don't know already, there has not been a "good" Summer ending in the number "8" since 1868. Of course, you could make exceptions such as 1968 which was arguably good in the north and west though rather cool. Just even look at the recent examples of these Summers: 2008 - very wet especially August which was one of the dullest on record too. A fairly warm July and close to average June but both months were very wet too. 1998 - very wet and dull June. Very dull July. Decent August mind you with fairly mild and sunny conditions. 1988 - mainly settled and dry in June but very cold, wet and even stormy July with a rather indifferent poor August. The reanalysis perfectly captures the poor nature of these Summers as it shows very stubborn blocking over Greenland and the Arctic with a deep trough over us and the jet stream on a southerly track.

Summers following sunny Winters - Very similar to Summers ending in "8" with a trough over us and stubborn blocking up to the north. Perhaps the jet stream not on as much a southerly track though.

Summers with low solar activity following sunny Winters - Deep trough over us and blocking over Greenland/Arctic. I think you get the picture.......

Summers following wet Marches - low pressure everywhere, even Greenland and the Arctic!

Summers following wet Aprils - Blocking up to the north with a trough over us and a southerly tracking jet stream. Are you seeing a theme here?

Summers following two years of La Nina which is then followed again by another La Nina event - Blocking up to the north with a trough down to the Bay of Biscay. However, the block is close enough to the British Isles for the jet stream to be on a northerly track and give us hot easterlies. The trough would allow for some thundery incursions. You can see that I was very desperate to finding a good reanalysis for Summer 2018 that I'd resort myself to a ridiculous far out there one like this.

Summers following years where January was the warmest month out of the first three of the year (using the CET) - Low pressure to the southwest and over the UK and Ireland with blocking up to the north........ mmmmmmmmmm

Summers following cold Easters (using the CET). The 1981-2010 CET average for Easter (Good Friday to Easter Monday) is 8.07c so any Easter period below this average was considered for this reanalysis - Low pressure over the Arctic. Low pressure over the majority of Europe including us with a mid-Atlantic block. Awful chart!

Summers following sunny Februaries - Very southerly tracking jet stream with blocking up to the north and a trough over us.

Summers following dull Marches - High pressure just out to the west ridging in across Ireland with low pressure over Greenland and Europe. The flow is from a northerly source. Cold reanalysis but not all that wet.

Summers following years with both a wet March and wet April in the same year - Deep low over Greenland which would usually indicate a positive NAO and in turn good for warmth. Trough in the Mediterranean which again usually good for warmth for us. But there are low heights over us with a mid-Atlantic block. These low heights are very weak allowing the jet on a bit of a northerly track. This is not far off a very good setup!

sryanbruen · 17-04-2018 5:19pm

Artane2002 wrote: »

To lighten the mood here and for once deliver good news, 2018, 2013, 2006 and 1995 all had colder March minima than the January/February minima. Most of you should know what came during summers 1995, 2006 and 2013. Only 3 years but this thread does need good news!

Not to mention, last year Summer 2017 was seemingly going to be a back loaded Summer with an awesome August but look how that ended up. ENSO turned to La Nina. The Summer was front loaded then with June providing the warm conditions. Totally the opposite of what the outlooks showed - before ENSO changed.

It would be great if Summer 2018 could head the other way of Summer 2017.

sryanbruen · 22-04-2018 9:53am

As we're in the Spring predictability barrier, it's always difficult to pin down where ENSO will go next. Thus why I have produced multiple analogues on it here.

This first one is on ENSO neutral Summers following weak La Nina Winters. It has a very deep trough over us with northern blocking over Greenland and a powerful jet stream across the Atlantic throwing depression after depression as us. Doesn't sound like Summer now does it? Keep in mind, we have some disastrous Summers in there such as 1946 (the year of the great harvest failure of course) or 2012 but we also have two great ones in 1934 and 1996 (there's 1996 popping up again). 2001 is not too bad either though like 1996, a somewhat strange Summer.

There are no examples of ENSO neutral Summers following two consecutive weak La Nina Winters historically.

This second one is on weak El Nino Summers following weak La Nina Winters. It is quite a mixed picture with the excellent Summers of 1876 and 1911 in there and 1968 whilst cool was very sunny and dry in Ireland. The rest of the Summers aren't overly terrible but mediocre nonetheless. This kind of reminds me of Summer 1968's setup on the reanalysis with blocking up to the north but close enough to provide dry conditions for Ireland and Scotland whilst England gets wet.

sryanbruen · 22-04-2018 3:35pm

I've made a huge table of nearly every analogue I've done with every year included in them here. The yes under the elements means that year - which is on the left in the years column - had that element to it. We'll be focusing on years that have the majority of the elements such as 1996. The table is created to find out what are those years we should focus on. The years that don't contain much of the elements we look at aren't that important for forecasting this Summer.

For some elements such as QBO and ENSO however I cannot do all years as there isn't data available on these elements for all the years within the table.

The ENSO neutral column is where ENSO for the Summer was neutral following on from a weak La Nina Winter before hand. The El Niño column is where ENSO for the Summer was El Niño following on from a weak La Nina Winter before hand. The mild January column is where January was the mildest out of the first three months of the year (January to March).

I'll be editing this post throughout here as it's a long table so I'm bound to make mistakes in it.

Year|Cold March|Wet March|Wet April|Easterly to westerly QBO|ENSO neutral|El Niño|Near solar minimum|Cold Easter|Mild January
1853|YES||||||YES|YES|YES|
1866|YES||||||YES|YES|YES|
1870|YES||||YES||||||
1874||||||||YES|||
1875|YES||||||||YES|
1876|YES|YES|YES||YES|YES|
1880||||||||YES||
1891|YES||||YES|||YES||
1894||||||||||
1895|YES|YES||YES||YES||
1898|YES||||||||YES|
1900|YES||||||YES||YES|
1906|YES||||||||YES|
1910|||YES|||||YES||
1912||YES|||||YES|||
1913||YES|YES||||YES|YES||
1914||YES||||||||
1916|YES|YES||||||YES|YES|
1919|YES|YES||||||||
1920||YES|YES|||||YES||
1924|YES||YES||||||YES|
1925|YES||YES|||||||
1930|YES||YES|||||YES|YES|
1932|YES||YES||||YES|YES|YES|
1934|YES|YES|YES||YES||YES|YES||
1935|||YES||||||||
1939|YES|||||||||||
1944|YES||||||YES||YES|
1946|YES||||YES|||||
1947|YES|YES|YES|YES||||YES|
1949|YES|||||||||
1950|||YES|||||||
1952||YES||||||YES|||
1955|YES|||||YES|||||
1957||YES||YES||||||
1959||YES|YES|YES||||YES|
1960||||||||YES||
1961|||YES|YES||||YES|
1962|YES||YES|||||||
1963|YES|YES|YES|YES|||YES|YES|
1968|||YES|||||YES|
1969|YES|YES||YES||||YES|YES
1970|YES||YES|||||YES|
1974|YES|||||||YES|YES
1975|YES|YES|YES|YES|||YES|YES|YES
1976|YES||||||YES|||YES
1978||YES||||||YES||
1979|YES|YES|YES||||||
1980|YES|YES||YES||||YES|
1981||YES||||||YES|
1982||YES||YES||||YES|
1983|||YES|||||YES|
1984|YES||||||||
1985|YES||YES|YES|YES||YES||
1986|YES|YES|YES||||YES|YES|
1987|YES|YES||YES|||||
1988||YES||||||YES|
1989||YES|YES|||||YES|
1990||||YES||||YES|
1991||YES|YES|||||YES|
1992||YES|YES|YES|||||
1993|||YES||||||
1994||YES|YES|YES||||YES|
1995|YES|YES|||||YES||
1996|YES|YES|||YES||YES|YES|
1997||||||||YES|
1998||YES|YES|YES||||YES|
2000|||YES||||||
2001|YES|YES|YES|YES|YES|||YES|
2002|||YES||||||
2003||||||||||
2004|||YES|YES|||||
2005|||YES||||||
2006|YES|YES||YES|||||
2007|||||||YES||
2008|YES|YES|YES|YES|||YES|YES|YES
2010|YES|YES||YES||||YES|
2012|||YES||YES|||YES|
2013|YES|YES|YES|YES||||YES|YES|
2014|||||||||
2015|YES|YES|||YES||||

MidMan25 · 22-04-2018 5:08pm

Why use Easter when it can fall between the end of March and end of April?

sryanbruen · 22-04-2018 5:19pm

MidMan25 wrote: »

Why use Easter when it can fall between the end of March and end of April?

Analogues are used to build up a big picture when you combine them all into one, the individual ones don't matter. Cold Easters have occurred in late April (must have a CET below 8.07c) just as much in late March. The date does not matter. Cold Easters is just one analogue. You can do years with similar Easter periods to 2018 or ones that were the exact same as 2018. There's loads of different analogues you can produce just by one element.

What has been good (also bad) with these analogues is their consistency with the large majority showing the same outlook, a poor Summer with the best chance of any good weather earlier in the season. Temperature is a bit variable but mainly warm and damp. That's what I have gathered from them so far.

Summer 2018 - General Discussion

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