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23 February 2015 11:02:31

It's just we'll always remember 2012 exceptional March with several days around 20C being followed by an appalling summer and a foul April - in the first few days this:


Edicius81
23 February 2015 11:39:49


 


Using my observations over the past 11 years, a correlation of spring mean temperature with summer mean temperature produces an R-square value of just 0.0529 at best, which means there's about as little correlation as you can have.


Similar results were obtained correlating spring rainfall with summer temperature.


But get this... a correlation of spring sunshine with summer temperature gives an R-square of 0.572, which while far from strong, is a surprisingly high value (out of a possible 1.0 for a perfect correlation)... but with the low data count, hardly significant on its own.


 


I'll see if I can locate historic data for total sunshine and mean temperature by month.


Originally Posted by: Stormchaser 


SC, is that a positive or negative correlation? Given 2007 and 2012 I'm tempted to think negative, but I'm reasonably sure that 2013 and 2014 had bright springs and decent summers to boot.

Stormchaser
23 February 2015 11:46:51

Just did correlations using data for Heathrow going back to 1957, from which the spring sunshine/summer temperature results are very different to my local figures, only giving an R-square of 0.12 at best. This implies that the apparent quite strong negative trend (there's your answer Waine) was an artifact of low data counts for my local observations, with the extremes of 2007 and 2012 strongly skewing the results.


Using spring temperature gives an R-square of 0.16, which is actually slightly better than for spring sunshine, but still very weak.


 


I suspect that there may be stronger relationships between seasons when considering the broad scale pattern, but these are not reflected in surface conditions due to the large number of other variables at play - such as sea surface temperatures, soil temperatures, how much dust there is in the atmosphere... these and many more make the difference between a hot, dry southerly and a damp, cloudy one, for example.


Long story short, the summers of 2007 and 2012 were not as such a consequence of the exceptional warmth and large sunshine amounts in the preceding springs.


Having said that, it's not out of the question that the background drivers leading to those two dire summers also played a part in bringing about April 2007 and March 2012. Low solar activity was at play during those years and I reckon that had a role in producing those 'locked-in' patterns, which haven't been so common these past two years during which solar activity has been higher.


 


I realise I've drawn this thread some way off topic, not setting the best example as a mod, but it was worth a gander I thought 


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idj20
23 February 2015 13:30:25


 


SC, is that a positive or negative correlation? Given 2007 and 2012 I'm tempted to think negative, but I'm reasonably sure that 2013 and 2014 had bright springs and decent summers to boot.


Originally Posted by: Edicius81 



The trouble with the last two summers is that it involved a northern blocking pattern of one type or another, thus the Midlands and towards northern and western parts of the UK did well for summer-like weather as a result, while here at the South East it took ages to get going as winds kept coming in from the north east quarter (in from the North Sea).
  In fact, Spring 2013 has been perishing cold at this end for most of the time, and by the time the weather finally got properly warm over Kent, a fair chunk of summer has already been done and dusted.
  What's the betting that this persistent Azores ridging that we have had for most of this winter thus kept the real snow at bay over Southern England then bugger off come the summer months when we need it the most.


Folkestone Harbour. 
Scandy 1050 MB
23 February 2015 14:57:37




The trouble with the last two summers is that it involved a northern blocking pattern of one type or another, thus the Midlands and towards northern and western parts of the UK did well for summer-like weather as a result, while here at the South East it took ages to get going as winds kept coming in from the north east quarter (in from the North Sea).
  In fact, Spring 2013 has been perishing cold at this end for most of the time, and by the time the weather finally got properly warm over Kent, a fair chunk of summer has already been done and dusted.
  What's the betting that this persistent Azores ridging that we have had for most of this winter thus kept the real snow at bay over Southern England then bugger off come the summer months when we need it the most.


Originally Posted by: idj20 


Not sure if you have seen Gavin P's Flash late yesterday, but of the 3 models he looked at for an early Summer peak only the Jamstec IOD is going for a warmer than average Summer and this model isn't great in terms of verification - worst of the lot was the Bejing model showing lots of northern blocking with the trough over the UK.  LRF's as always are JFF but interesting none the less and as you say would be typical for northern blocking to appear in the Summer as it's been so absent for this Winter.  


Current MO and latest GFS run struggles to build HP over the UK but gets there in the end, but again slight hints of an easterly component. March might not be the nice month it looked to be a week ago at least the first half anyway - all FI so lots to change yet.

LA2B MeridFlowEuro09
23 February 2015 17:29:23

 


The North Atlantic Polar Vortex / Siberian Express High sitting in a WSW to NNE location when based on the Mean PFJ Mean 500hPa Situation for the USA Canada they see Increasing NW flow from Arctic via Alaska and NE Canada, this brings the Polar Vortex at 120-144 in Two parts one N USA SE Canada and the Other from NW to North Atlantic across Iceland with areas of West NW winds but it has shortwave Low's to the South & SE in Mid To NE Atlantic and the UK, for period Wednesday 25th to Sunday and Monday at T144 and T168 heavy speeds of rain with snow in Mid and Upper Level Scotland, this also likely on the Thursday Friday charts both GFS and the UKMO show plenty of This, the South if UKMO T144 Bears Fruit for Sunday 12z UK could get Cold air and with the Northwest and North UK most likely cold enough there Sun/ GFS does it Monday unlike UKMO, NW flow has all widespread Cold Low Pressure WNW winds, GFS brings three Shortwave Lows for Central and South UK Friday Night Sat- Sunday right to Sunday Night GFS has it, while the UKMO differs for Sunday at 144h.😊😄


Climate is warming up, Scotland and N Ireland and North England still often gets some Winter frost, ice and snow, November to March, but the SE and South UK including S Central England and Wales, together with the West and North through the year, they sometimes get more rain than London and S SE England, where some longer dry fine spells without much heavy rain is seen every year.

The North Atlantic Sea often gets some much Colder Wintry conditions from November to March Months, and Mild SW and South winds tend to be more frequent over the East and SE of North Atlantic Sea, as the Azores High tends to stay in charge. 

With this warmth and heat, the Central and South UK has become mostly free of snow and frost.
Phil G
23 February 2015 23:19:40
Gooner
23 February 2015 23:31:36


Again hints at a cool Easterly from GFS


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


nsrobins
24 February 2015 07:41:54

More hints in the 15 day guess range of a switch to heights buidling to the N or NE.
I wouldn't give it the time of day normally but the mighty CFS is trending the same way


 


The issue I have in mid-March is all a bit 'too late to be bothered' so it has to be a special combination of synoptics and a lot of luck to get a decent NE flow with snow. Never say never though LOL.


Neil
Fareham, Hampshire 28m ASL (near estuary)
Stormchaser, Member TORRO
Gooner
24 February 2015 08:22:40


Miles away but the hint remains


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


moomin75
24 February 2015 09:15:14

Oh the sweet, sweet irony of several successive GFS runs now showing an Easterly in FI.


As it's going to be March and a fat lot of good to anybody, other than to produce slate grey skies and drizzle, there's no doubt this will verify perfectly at T+0.


Irony of irony.


Witney, Oxfordshire
100m ASL
GIBBY
24 February 2015 09:18:48

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS.

THE CURRENT GENERAL SITUATION A chilly Westerly flow across the UK will slowly become less cold as a series of frontal troughs cross over from the West through tonight and tomorrow.

http://www.wetterzen...cs/Rtavn001.gif

MODELS-2 WEEK HEADLINE Changeable and windy with rain at times and hill snow across the North especially at first. Possibly brighter and drier from the South later.

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream Ensemble Forecast shows a strong West to East flow across the Atlantic through this week before it weakens somewhat as it moves back more to the North of the UK later in the period.

http://www.theweatheroutlook.com/twodata/datukgfshires.aspx?display=jetstream&model=gfs

GFS OPERATIONAL The GFS operational today shows a very changeable week ahead with the emphasis slowly shifting away from rather cold conditions later this week to milder westerly winds, still quite strong at times with rain at times too for many. through the second week a shift to High pressure from the South dries things up generally but as this shifts to the NE and pressure builds to the nW a cold and unsettled pattern is shown to develop later.

http://www.wetterzen...s/Rtavn1441.gif

http://www.wetterzen...s/Rtavn3841.gif
 
THE GFS CONTROL The GFS control run is quite similar in the shorter term with rain at times in fluctuating temperatures but less keen on developing a colder theme later with High pressure then shown over Europe with a ridge to Southern England making the South drier and rather cold for a time and without the rise of pressure to the NW that the operational shows unsettled, windy and milder conditions look likely for the NW.

THE GFS CLUSTERS The GFS Clusters this morning look very undefinitive as a mix of options are shown between High pressure to the SW or West to a more unsettled West or SW flow for all with rain at times and High pressure further away to the South or SW.

http://www.weatheron...=0&WMO=&PERIOD=

UKMO UKMO this morning again shows an unsettled and changeable period throughout its run this morning with rain at times on brisk Westerly winds for all and brief colder phases with showers, wintry on hills over the North.

http://www.wetterzen...cs/Rukm1441.gif

THE FAX CHARTS The Fax Charts this morning show a series of troughs crossing the UK over the next 24-48hrs with spells of showers then rain and milder air briefly. Then a cold front crosses the UK from the NW on Thursday with further rain the colder air again before further milder and unstable air returns from the West on troughs over the weekend.

http://www.weatherch...momslp.htm#t120.

GEM GEM this morning shows a period of storminess developing early next week following this weeks changeable mix as fast moving vigorous Lows move East over or to the North of the UK. Then towards the end of the run High pressure builds quite quickly from the SW with more settled conditions developing for many by 10 days time.

http://www.wetterzen...cs/Rgem2401.gif

NAVGEM NAVGEM maintains it's theme from yesterday showing a strong Westerly flow across the UK through the next week with some milder weather at times but with colder interludes too with showers turning wintry over the hills at times.

http://www.wetterzen...cs/Rnvg1681.gif.

ECM ECM this morning shows the same basic theme though with some differentials these mostly focusing on the end of the period when the build of pressure from the South and SW is coupled with rising pressure over NE Europe which could lead to a chilly if dry period as we move forward from the end of the run towards next weekend.

http://www.wetterzen...cs/Recm2401.gif

ECM 10 DAY MEAN The 10 Day Mean Chart shows a strong build of pressure towards Southern Britain coupled with High pressure over Eastern Europe too. How these two features interact later is up to debate but for now it provides dry and brighter conditions than for some while for many with any rain confined to the far NW

http://www.wetterzen...cs/Reem2401.gif

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend towards drier and more anticyclonic weather later in the period is maintained with small nuances between output on how this transpires.

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKM & ECM The current verification statistics for the past 31 days shows ECM leading the way at 3 days with 97.5 pts followed by UKM at 97.1 pts and GFS at 96.4. At 5 days ECM  continues to lead the field at 90.0 pts over UKMO at 88.1 pts and GFS at 86.2. At 8 days ECM remains the leader with 63.6 pts over GFS's 58.7 pts. Then at Day 10 ECM retains superiority at 46.3 pts over GFS at 41.9.

http://www.emc.ncep....L_MSL_G2NHX.png

http://www.emc.ncep....L_MSL_G2NHX.png

http://www.emc.ncep....L_MSL_G2NHX.png

http://www.emc.ncep...._MSL_G2NHX.prig
 

MY THOUGHTS The theme of drier weather shown between the output remains for later in the period with the current unsettled and changeable conditions contiuing for around another week with the same day to day fluctuations in temperature remaining a feature amongst the rain and showers at times plus some wintriness at times over Northern hills. Then more interestingly there are strong signals emeging of drier weather moving first into the South of the UK and probably extending further North later. How this transpires synoptically is yet to be pinned down but it looks like a High lying close to the South will bring benign and dry conditions in temperatures largely close to average by day wuth the risk of patchy frost at night as winds look like maintaining something of a Westerly element at this time. All this while pressure is also becoming High over Eastern Europe and some output acknowledges this in hinting that the Southern UK High could become absorbed by this in some way which could give rise to something of a continental feed into the UK later and if this transpired would lead to colder conditions across the UK in SE or East winds. All a long way off to take very seriously at the moment but it is something that is been shown in a minority of output in recent days and should be watched with interest. However, I'm sure there will be much waxing and waning on this scenario over future model output and in any event it all seems a million miles away yet given that we have definately got at least another week of Atlantic volatility looking likely before any of that happens. So summarising unsettled and changeable over the next week or so with rain and showers and temperatures near to or occasionally a bit below and above average before more settled conditions arrive from late next week with a cessation in the amount of wind and rain for most and more in the way of sunshine by day and possible frosty nights.  

Issued at 09:00 Tuesday February 24th 2015


Martin G
Kilmersdon Radstock Bath Somerset



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David M Porter
24 February 2015 09:27:57

If we do end up with a fairly strong HP to the north or north-east of the UK as the GFS op runs have been indicating at times in FI in recent days, it would be the classic example of what I call "sods law". We've had no northern blocking all winter and so it really would be the ultimate irony if it were to develop in March. It wouldn't surprise me though if that were to happen; I've seen this sort of thing happen in the past, more than once.


Lenzie, Glasgow

"Let us not take ourselves too seriously. None of us has a monopoly on wisdom, and we must always be ready to listen and respect other points of view."- Queen Elizabeth II 1926-2022
KevBrads1
24 February 2015 09:57:04
Some of the charts next week do remind me somewhat how March 1995 started off. UKMO 0z even has a potential runner on it, like what happened in early March 1995.

MANCHESTER SUMMER INDEX for 2021: 238
Timelapses, old weather forecasts and natural phenomena videos can be seen on this site
http://www.youtube.com/channel/UCgrSD1BwFz2feWDTydhpEhQ/playlists
briggsy6
24 February 2015 11:38:52

For those of us with poor long term memories, what did happen in March 1995?


Location: Uxbridge
Gavin P
24 February 2015 12:45:06

Hi all,


Here's today's video update -


Easterly Winds For March? 



Signs of pressure trying to build towards Scandinavia...


Rural West Northants 120m asl
Short, medium and long range weather forecast videos @ https://www.youtube.com/user/GavsWeatherVids
moomin75
24 February 2015 13:48:49


Hi all,


Here's today's video update -


Easterly Winds For March? 



Signs of pressure trying to build towards Scandinavia...


Originally Posted by: Gavin P 

Thanks Gav, but let's hope not! Not in mid-March please.


Witney, Oxfordshire
100m ASL
Saint Snow
24 February 2015 14:19:44


Thanks Gav, but let's hope not! Not in mid-March please.


Originally Posted by: moomin75 


 


I'd more than welcome a repeat of March 13, but that set-up was very specific - IIRC, the block was well to the north, meaning most of the UK was under E'lies - not just the southern portion



Martin
Home: St Helens (26m asl) Work: Manchester (75m asl)
A TWO addict since 14/12/01
"How can wealth persuade poverty to use its political freedom to keep wealth in power? Here lies the whole art of Conservative politics."
Aneurin Bevan
Stormchaser
24 February 2015 17:37:28

GFS and GEM are really powering the energy NE on their respective 12z runs.


A good way to avoid the easterly but we can't rule out the pattern turning out to be more amplified after all.


In light of the way the GFS 12z unfolds days 9-14, I'm hoping it's on to something 


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Keep Calm and Forecast On
idj20
24 February 2015 17:49:48


GFS and GEM are really powering the energy NE on their respective 12z runs.


A good way to avoid the easterly but we can't rule out the pattern turning out to be more amplified after all.


In light of the way the GFS 12z unfolds days 9-14, I'm hoping it's on to something 


Originally Posted by: Stormchaser 



Until we get to that, it does look like we may have to put up with one more bit of storminess on Sunday night and into Monday, especially over the northern half of the UK as this part of the GFS output move closer to the reliable timeframe . . .



Of course, it is still subject to further fine tunings but I think this is pretty much firmed up now, unfortunately. If we do get to have snow as often as we get to have gale force winds, every single winter would end up being bumper snowfests!


Folkestone Harbour. 
KevBrads1
24 February 2015 18:21:33


For those of us with poor long term memories, what did happen in March 1995?


Originally Posted by: briggsy6 


Cold zonality, snow fell widely and there was a significant snowfall across Wales and Midlands on the night of 2nd/3rd March 1995


MANCHESTER SUMMER INDEX for 2021: 238
Timelapses, old weather forecasts and natural phenomena videos can be seen on this site
http://www.youtube.com/channel/UCgrSD1BwFz2feWDTydhpEhQ/playlists
Gooner
24 February 2015 18:22:51


Thanks Gav, but let's hope not! Not in mid-March please.


Originally Posted by: moomin75 


Would be excellent K


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


Andy Woodcock
24 February 2015 19:16:59

Tonight's ECM looks very wintry to me for next week, 3 days of the whole country under -5c to -7c uppers before a cold high arrives the following weekend.


could be loads of snow up north and some severe frosts later on.


no sign of Spring on tonight's ECM that's for sure!


andy


Andy Woodcock
Penrith
Cumbria

Altitude 535 feet

"Why are the British so worried about climate change? Any change to their climate can only be an improvement" John Daley 2001
Gooner
24 February 2015 19:28:23


Chilly from ECM


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


Charmhills
24 February 2015 20:05:35


Tonight's ECM looks very wintry to me for next week, 3 days of the whole country under -5c to -7c uppers before a cold high arrives the following weekend.


could be loads of snow up north and some severe frosts later on.


no sign of Spring on tonight's ECM that's for sure!


andy


Originally Posted by: Andy Woodcock 


Cold with wintry showers for many if the ECM 12z should verify.


In-between the general bands of rain of course.


Loughborough, EM.

Knowledge is power, ignorance is weakness.

Duane.

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