Summer 2015

[Captain Shortwave]

skewed?

So the Beijing climate model, along with the new Canadian long range model, must also be skewed.... as both showing a similar trend towards a cooler than ave. summer. 

 

Always consider reasons when the models don't give us what we are chasing. As for the CFS ensembles you posted, that is now showing all four weeks with a below ave temp anom today...

The longer rangers do have history of once a pattern has established that it will simply keep running with it. For example last year all the longer rangers kept running with Scandi heights throughout the summer with near to above normal temperatures, of course that wasn't the reality as heights to our east were balanced out by periods where heights were to our west (Late June/Early July where is was close enough to give fine conditions and of course the rather poor August)

Interestingly the CFS anomalies which I posted for the first half of June are now being replicated in the GFS extended ensembles. Looking at the 500mb anomalies, there is solid consistency to build heights between the north and east of the UK giving some sort of easterly flow. The CFS temperature anomalies have performed very poorly this spring, that is pretty much fact with few if any near or above average predictions which conflicts with the reality that is that March was near normal, April was comfortably above normal and May which is going to come out near normal.

It will be interesting to see if the GFS is onto something here.

Edited May 21, 2015 by Captain shortwave

[BornFromTheVoid]

Over the last few months, there have been persistent record cold temperatures in the sub polar gyre region of the north Atlantic, associated with much below average SSTs.

 

 

 

Some scientists have linked this with a weakening of the Atlantic Meridional Overturning Circulation (AMOC), the surface section that flows northward near us is often called the Gulf Stream.

Whatever the cause, the cold SSTs have been gradually moving toward us over the last 2 months, and are now beginning to envelop the British Isles. The animation below shows the 1 week average SST anomalies over the last 7 weeks, with the final image showing the last available individual day.

 

 

The unisys SST map now shows some very cool SSTs surrounding us too.

 

 

I think this could well be worth keeping an eye on during the summer months, given the record cold temps associated with them occurring just to our west. These very cool SSTs are likely to have an influence and at least a slight cooling effect. Whether or not they usher in a spell of below average months remains to be seen though.

[IanR]

hasnt the unusually cold winter in the north east of north america had an effect though, ejecting the cold airmasses over the north atlantic during the winters months having a cooling effect, which is still having repercusions ?

[BornFromTheVoid]

hasnt the unusually cold winter in the north east of north america had an effect though, ejecting the cold airmasses over the north atlantic during the winters months having a cooling effect, which is still having repercusions ?

 

I'm sure the set up with cold moving down over the NE US into the Atlantic is playing a part, but even when the NE US has been mild (see the first animation) the Atlantic sector discussed has been record cold anyway.

 

 

Quite interesting that. I think it will all depend on where the predominant wind direction is this summer. If we get winds mainly coming from the continent, then I see no reason why we can't have a hot summer. On the other hand, if the winds are very Atlantic based this year then I think it could actually be a very cool one indeed.

 

We could certainly still see a very warm summer, I guess these cold SSTs simply increase the risk of colder conditions at times, and the alter the likelihood of coastal fog, low cloud and things like that.

[sundog]

The patterrn of the sst,s in the Atlantic in May has often been said to help predict the NAO for the following winter although of course it doesnt always work out like that. This month would i be right in saying using that method that a + NAO is the signature for next winter. I think it was right last year but wrong the year before.

[sundog]

Looking at the map that Bftv posted one would surely think that the vast area of cold water is in the 'wrong place' if the gulf stream was doing its job properly?

[Gael_Force]

The patterrn of the sst,s in the Atlantic in May has often been said to help predict the NAO for the following winter although of course it doesnt always work out like that. This month would i be right in saying using that method that a + NAO is the signature for next winter. I think it was right last year but wrong the year before.

This diagram from the UKMO winter outlook for 2014/15, indicates it is still used and considered influential. Looks to be even cooler than last year at this stage.

 

 

The ocean profile is interesting in that it shows such a difference between the Pacific and Atlantic. I'm sure I read somewhere that is a low solar signature, where ridging on Pacific side pushes everything over to our side and is what causes the cooling seen in Europe over past low cycles.

[Weather-history]

I have never understood why the SSTs in the North Atlantic in May could have some impact on the pressure patterns in 6 months time?

Why May and why not other seasons?

[cheeky_monkey]

Just looking at the El Nino records for summers in the last 30 years..im going to stick my neck out and say there will be one hot summer month..based on the fact that 1991 had a hot August...1994 had a hot July...1997 had a hot August.. and 2006 had a hot July..so maybe a hot August for 2015?

[MP-R]

Just looking at the El Nino records for summers in the last 30 years..im going to stick my neck out and say there will be one hot summer month..based on the fact that 1991 had a hot August...1994 had a hot July...1997 had a hot August.. and 2006 had a hot July..so maybe a hot August for 2015?

 

We're certainly overdue a hot August so that would be nice.

 

Shame about all the following winters though...

[summer blizzard]

Just looking at the El Nino records for summers in the last 30 years..im going to stick my neck out and say there will be one hot summer month..based on the fact that 1991 had a hot August...1994 had a hot July...1997 had a hot August.. and 2006 had a hot July..so maybe a hot August for 2015?

 

Something like 80% of 18C+ summer months have occurred with +MEI values however there's no real bias towards EL/La producing warm or cool summers. This suggests that EL Nino summers are more probably more polarised being further from average in both directions.

[Captain Shortwave]

It could be June then that comes off trumps if we can get high pressure in across the UK and Europe. It would be nice to see another month take the heat as recently it has only been July that has done the business.

[sundog]

If we do get a warm/very warm june is there a greater chance of a colder then average December. I think someone on the forum mentioned that a few yrs ago. The last time we had a colder then average Dec was Dec 2010 and i suppose overall the Junes since then have not been great overall.

[Richard2901]

June is a very poor month these days. My least favourite month of the year. There hasn't been an outstandingly good one here since 1970 and the last really good one was in 1996. Since then only 2003 and 2013 have been passable. We've had to endure some of the wettest and/or dullest on record (1997, 2002, 2004, 2007, 2011, 2012 and 2014) with June 2012 close to being the coldest as well.

 

It's just shocking that only one June in the last 18 years has managed to achieve the 1921-50 sunshine average. It used to be sunniest month of the year but hasn't been since 1996 and hasn't been sunnier than May since 2003. Even last year with May's appalling sunshine total June still managed to be duller, and by a significant margin.

 

Looks like June 2015 is going to get off to a terrible start with rain and maxes of 11C forecast further adding to the 500-hour plus summer sunshine deficit since 2007 as well as continuing a horrendous 5-weeks of relentlessly unsettled weather.  I truly despair at how awful our weather has become this century and it's a toss-up between June and August as to which month has deteriorated the most

[weatherguru14]

The warm up keeps getting pushed back and pushed back.. To the point of Thursdays being the only day that looks like any warmth next  week..Wishful thinking..I doubt even Thursday will get any warmth either. It will take forever to  get a decent warm spell. Even though a lot as predicted it..

The GFS charts are nonsense.. anything beyond  3 days is pushing by the looks of it.

I will stop chart watching and just look out the window.. best way to get an accurate forecast..

[Barry12]

June will be a good un

[Gael_Force]

Wonder what the perception is from Alex? As he's been near enough spot on about both our last two summers 

Who is Alex?

[Evening thunder]

I was wondering what effect the SST anomalies may have on pressure patterns, and if they could encourage low pressure in the Atlantic and a downstream high over Europe,  and with regards to that this quote from the Met Office contingency planners forecast is interesting..

 

 

 

In the North Atlantic, sea surface temperatures to the south of Greenland are cooler than in recent years; this pattern of sea-surface temperatures is thought to increase the probability of above-average pressure over northern Europe in summer. At this time of year such a pressure pattern is often associated with above-average temperatures. Computer model signals are weak regarding the most probable atmospheric circulation types over Europe this summer, although there is a slight preference for higher-than-average pressure across northern Europe. This lends support to the increased likelihood of above-average temperatures during June and June-July-August as a whole, which can be seen in the graphs in figure T2; however, uncertainty is large and there is still a broad range of possible outcomes.

 

http://www.metoffice.gov.uk/media/pdf/8/6/A3_plots-temp-JJA.pdf

 

and interestingly enough models are trending for high pressure over Northern Europe this june.. so perhaps these SST anomalies may benefit us to some extent?

 

Although I'd imagine when west/NW winds do occur they may be a bit cooler than normal and the anomalies may have contributed to the quite cold/wintry westerlies we sometimes got last winter.

[weatherguru14]

It just shows you cant relie on  long range  weather charts. flamining june?? We are in for a  cold summer.. so far this weather reminds me of stat of summers from  2007/2012

Edited May 31, 2015 by weatherguru14

[I Cumbria Marra I]

[Mokidugway]

Think I'm coming of NW for a while it's becoming depressing :0.......

[weatherguru14]

Honestly don't know why I look at charts and read comments on long range weather forecasts.. in the space of  2/3 days we have gone from a heatwave june to  a june that's  way below average..

You don't need to be a  genius to know when the jet stream is angled  from Iceland  towards the uk.. You are on the cold side of it. Apart from  1 maybe 2 days   it will feel warm next week. and that's got to be nailed down. it will be also downgraded.

People I talk to in the street even though not interested in weather. comment on the posibilty of  a warm weather on the horizon..even in 2015  predicting weather charts  4/5 days ahead is pointless. They are never accurate.

[Weather26]

That's that heatwave over before it's began then!

[Cheshire Freeze]

It just shows you cant relie on  long range  weather charts. flamining june?? We are in for a  cold summer.. so far this weather reminds me of stat of summers from  2007/2012

 

I said that over a week ago- I can remember the false dawns/promises back then and I can remember the unsettled weather being preceded by a small window of warmer/settled weather before the wet pattern took hold.

[Summer Sun]

Summer begins with a weather warning for strong winds

 

Issued at: 1137 on Sun 31 May 2015

Valid from: 1600 on Mon 1 Jun 2015

Valid to: 1800 on Tue 2 Jun 2015

 

An unseasonably windy spell is likely across many parts of the UK later on Monday, overnight and well into Tuesday, as active frontal systems sweep across the UK. An initial swathe of southerly gales will move east across many parts later on Monday, giving gusts to 50 mph widely but 60-65 mph across exposed Irish Sea and perhaps some English Channel coasts. Winds will become west or southwesterly on Tuesday, with further gales in places, before gradually easing later. Heavy rain will accompany the strong winds at times and large waves may affect some coasts in the west and south. Given the unseasonable nature of the winds, the public should be aware of the potential for disruption to transport and outdoor activities. Damage to some trees seems likely, given that they are in full leaf. There remains uncertainty in the areas likely to be worst affected and this warning will be updated on Monday in the light of new information.

 

Chief Forecaster's assessment

 

A powerful jet stream stretching across the Atlantic into the UK will steer a number of active weather systems across the UK during Monday and Tuesday. One such system will sweep eastwards later on Monday into Monday night, with the windy weather maintained well into Tuesday by a vigorous depression passing northern Scotland. Developments are complex so there is still considerable uncertainty in details of these developments, especially by Tuesday, when it may be less windy across parts of the south.

 

http://www.metoffice.gov.uk/public/weather/warnings/#?tab=warnings&map=Warnings&zoom=5&lon=-3.50&lat=55.50&fcTime=1433113200&regionName=uk