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Retron
17 January 2015 07:29:19

Answer is the models. Many GEFS have shown an easterly, and there is an easterly influenced and much improved 0z ECM at day 8. A time of gentle upgrades may await.

Originally Posted by: Whether Idle 


Indeed, there remains a great deal of scatter amongst the ensembles that we can see. Perhaps MOGREPS is giving a stronger easterly signal, or maybe they're just referring to the gentle easterly waft that could occur midweek as the disrupting low moves southwards?


That said, Fergie over on NW has been saying the past couple of days that a clean transition to westerlies is by no means nailed on and as long as the ensembles retain their scatter towards the end of the week that remains the case.


That graphic a few days ago on the BBC forecast, showing a generic sequence of warm sectors approaching from the west and being swept away SE'wards, seems just as relevant today. The message was "we think it'll turn milder in due course but it may take several attempts before the Atlantic westerlies finally return". The midweek trough disruption (some call it a "slider") is one such attempt but that'll probably fail. The operational ECM and last night's control show a second attempt at the end of the working week also failing, with only the third such attempt, the beginning of the week after next, going far enough east to allow milder weather in for us.


The operational GFS meanwhile shows the second trough disruption (the one at the end of next week) failing to keep us in cold air. The GEFS tend to back up the operational, but bear in mind we're seeing the new GFS and the old ensembles, so effectively two different models. The ECM ensembles seem to be 50/50 regarding whether the second trough disruption brings an end to the cold spell, as were MOGREPS yesterday from what I can make out. It remains to be seen whether the ECM ensembles this morning maintain that trend, it's around an hour until we find out!


So, to sum up:


It's cold.


There's a risk of snow in places today and tomorrow.


A trough disrupts over or close to the UK midweek, with a chance of snow almost anywhere (exact track to be confirmed)


A second trough disruption event occurs at the end of the week. There's around a 50/50 chance of it coming over the UK (with a further snow risk) or passing to the east, in which case the cold spell ends.


In the event the second trough disrupts over the UK, a third attempt looks likely a couple of days later. Such an attempt is likely to end the cold spell but by then it's so far out as to be only for interest's sake. Even then, some ECM ensemble members maintain a cold outlook.


If you're a weather fan this is shaping up to be a fascinating week ahead. If snow is all you care about then it could well be a frustrating week!


Leysdown, north Kent
nsrobins
17 January 2015 07:29:41

Answer is the models. Many GEFS have shown an easterly, and there is an easterly influenced and much improved 0z ECM at day 8. A time of gentle upgrades may await.

Originally Posted by: Whether Idle 


You do me a disservice, Sir!


ECM has returned the SW flow from Day 9. I've not trawled through the whole GFS suite but the 20 member plot looks uninspiring. If someone can post a decent Easterly at Day 8 and beyond please do.


Neil
Fareham, Hampshire 28m ASL (near estuary)
Stormchaser, Member TORRO
Whether Idle
17 January 2015 07:48:59


 


You do me a disservice, Sir!


ECM has returned the SW flow from Day 9. I've not trawled through the whole GFS suite but the 20 member plot looks uninspiring. If someone can post a decent Easterly at Day 8 and beyond please do.


Originally Posted by: nsrobins 


Neil, I can't be bothered to trawl this morning.  Still a slight beer head from a beer related weather summit with Sir Gusty of Folkestone yesterday evening. I believe that the ECM is easterly influenced out to day 7 poss 8 and that it will not take much for the models to shunt the high 200 miles west over Norway and for a better disruption and sliding underneath triggering an easterly.  Just because the models aren't showing it doesn't mean it can't happen.  I will have a trawl later maybe.


Dover, 5m asl. Half a mile from the south coast.
White Meadows
17 January 2015 07:51:55
Signs of prolonged cold still look bleak this morning. Nao going positive to end January so enjoy the next few days while a wintry feel lasts, if it's cold you long for.
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/new.nao_index_ensm.html 

It won't be for a week or so before tentative signals for blocking in February are shown, if any as it seems we're in for a westerly 'spell' at least. All I can do is hope it doesn't lock in although sea surface temps usually suggest otherwise into February.
doctormog
17 January 2015 08:01:35
Just out of curiosity, when it is cold why do the pessimists ignore then short term and only comment on "FI" output (as currently) yet when we are stuck in a mild spell many discount FI as unreliable if it shows a change to cold (as recently)?

It all sounds more like mind games than analysis.

The week looks cold with uncertainty beyond then but the chance of a breakdown to something more mobile. As years (decades?!) of watching such scenarios I would be very reluctant to pin a time or details on the breakdown, it could be earlier than shown but it could end up much later.
Whether Idle
17 January 2015 08:04:58

Before people slag off the CMA, last Saturday, it and the Brazilian model 😉 were the only 2 models showing the current cold spell.  I chose not to post the charts then, but referenced them.


 


Neil, here is a possible easterly:



 


Dover, 5m asl. Half a mile from the south coast.
Nordic Snowman
17 January 2015 08:11:56

My take on things is that the Scandi High will slowly migrate E and the Atlantic will eventually win through with lowering heights over Scandi from next weekend or shortly after.


Bergen ensembles do show a return to somewhat unsettled conditions after the quiet and benign spell:-



Bjorli, Norway

Website 
Retron
17 January 2015 08:29:03

After a little bit of uncertainty yesterday, the ECM ensembles have gone back to a cold end of the week:



Leysdown, north Kent
The Beast from the East
17 January 2015 08:30:56


 


 


 I've not trawled through the whole GFS suite but the 20 member plot looks uninspiring. If someone can post a decent Easterly at Day 8 and beyond please do.


Originally Posted by: nsrobins 


There are a few but most back up the op and control


As Doc says, try and enjoy the short term cold but we are looking at a fairly quick breakdown and now looking ahead to the next cold spell. Hopefully we will get another shot by mid Feb


"We have some alternative facts for you"
Kelly-Ann Conway - special adviser to the President
The Beast from the East
17 January 2015 08:32:09


After a little bit of uncertainty yesterday, the ECM ensembles have gone back to a cold end of the week:



Originally Posted by: Retron 


Strong agreement for a warm up post day 7


 


 


"We have some alternative facts for you"
Kelly-Ann Conway - special adviser to the President
marting
17 January 2015 08:37:48
I have had a look through the GEFS runs and quite a mix throughout. More in favour of atlantic, but still plenty at day 7 and day 12 that provide cold outcomes. Still scanid highs and high blocking out in the distance. So plenty of interest.
The Reading mean above remains quite low and way below 10c - so returning to average
Martin
Martin
Greasby, Wirral.
Retron
17 January 2015 08:38:04

Just out of curiosity, when it is cold why do the pessimists ignore then short term and only comment on "FI" output (as currently) yet when we are stuck in a mild spell many discount FI as unreliable if it shows a change to cold (as recently)?

Originally Posted by: doctormog 


I'm not really sure, but it's been a part of forums like this for over a decade. Maybe it's just human nature to look for the end of something people have been looking forward to?


Still, it's -2C outside, the sun is shining and there's snow crossing the Reading area as I speak, heading this way. Even if that snow doesn't make it, or turns to rain, it feels far, far more like winter than the weather we endured this time last year. And that's just here: I'm sure it's similar elsewhere too.


The outlook is cold, we've a chance of more snow (and an almost certainty of more frosts) and any breakdown remains out in fantasy land.


I can't really see any cause for pessimism, as even if it does turn milder next weekend we'll have had a seasonal week's weather.


 


 


Leysdown, north Kent
Retron
17 January 2015 08:39:35


Strong agreement for a warm up post day 7


Originally Posted by: The Beast from the East 


Er, not really. There wasn't yesterday either to be fair, rather there was just a hell of a lot of scatter regarding Friday's trough disruption.


 


Leysdown, north Kent
GIBBY
17 January 2015 09:03:50

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY SATURDAY JANUARY 17TH 2015.

NEXT UPDATE SUNDAY JANUARY 18TH 2015 08:00

THE CURRENT GENERAL SITUATION
A slackand cold airflow across the UK today. A frontal trough will move up over the English channel tomorrow.

MODELS-2 WEEK HEADLINE Rather cold and unsettled with rain or snow in places. Frost at times.

THE JET STREAM ENSEMBLE FORECAST The Jet Stream Forecast shows the flow rather weaker than o flate though sufficiently strong to maintain a generally Atlantic driven pattern of cold zonality with the positioning of the flow remaining South of he UK and troughed down over Europe towards the Meditteranean.

GFS NEW OPERATIONAL The GFS operational continues to project rather cold and unsettled conditions across the UK with the weather determined by disturbances coming SE down over the UK from the NW. There will be extended periods of rather cold and unsettled weather with showers or longer spells of rain, sleet and snow interspersed with clearer weather with wintry showers and frosts at night. with little sign of any pattern change right out to the end of the run and beyond.

THE GFS CONTROL The GFS control run also shows rather cold and unsettled weather in the first week with Low pressure feeding SE across the UK with rain, sleet or snow and wintry showers for all. Next weekend shows a marked ridge deliver a cold and frosty period before a more Atlantic driven Westerly with rain at times takes hold with less cold conditions overall though still chilly enough for wintry showers on Northern hills at times.

THE GFS CLUSTERS The GFS Clusters show strong support for cold zonality conditions to be the more likely weather pattern we find ourselves in two weeks from now. Low pressure to the North and East of the UK is shown by 65% of  the pack while the other 35% a more traditional less cold zonal pattern under westerly winds with a 15% support for High pressure to lie close to Southern Britain in 14 days time.

UKMO UKMO this morning shows a period of trough disruption over or to the East of the UK. A band of rain, sleet and snow will spread East towards midweek followed by a chilly NW flow with showers with hints of a recurring pattern later on in the week as new Low pressure to the North sends troughs SE.

THE FAX CHARTS The Fax Charts illustrate a complex pattern synoptically over the UK for the next 5 days or so. Various weak troughs at first will give rise to some rain or sleet in the South while the West receives the risk of this on Tuesday spreading East under an occlusion and giving some snow in places. then a cold NW flow with wintry showers follows this trough midweek.

GEM GEM today shows a cold and unsettled week to come as Low pressure slides SE down across the UK from the NW. Under the extensive cold air lying across the UK such Low pressure and troughs will deliver spells of rain, sleet and snow with some disruption possible towards the North and East in particular. A strong ridge next weekend bringing sharp frosts and sunny days then sinks away South to allow milder Westerly winds with rain at times to end the period.

NAVGEM NAVGEM keeps the rather cold and unsettled weather going throughout this morning's run as Low pressure areas slide SE over Eastern Britain or the North Sea. Spells of rain and sleet would be succeeded by sunshine and wintry showers in a blustery NW wind at times.

ECM ECM this morning too maintains a rather cold outlook with the weather powered by successive pushes of Low pressure down over or just to the East of the UK, each bringing their own version of unsettled conditions with showers or longer spells of rain, sleet and snow in strong and blustery winds from the NW at times. At the end of the run it looks like a rinse and repeat pattern is setting up to continue the theme beyond the time parameter of the run.

ECM 10 DAY MEAN The ECM 10 Day Mean Chart continues to show a similar evolution on each output with the chart made up of plenty of cold zonality options made up of Low pressure to the North and down across NW Europe to the Med. It therefore looks like continuing rather chilly weather with rain or showers falling as sleet or snow at times is the most likely outcome 10 days from now.

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The differnces in trend today focus on moving the axis of the disrupting troughs further East than yesterday morning towards Eastern Britain and the North Sea with the UK under a chilly NW flow for much of the time.

MY THOUGHTS I can see where some of the disappointment lies within the cold fraternity this morning in that it wouldn't take too much to lock the UK into a cold and snowy picture for a week or so if we fell on the right side of the disrupting Low pressure zones as they move SE from the NW. As it is the models have firmed up somewhat in putting the axis at a point over or just to the East of the UK meaning the UK will rely on the cold and chilly NW flows on the West side of the disrupting troughs to deliver cold weather with wintry showers through the week outside of the periods of trough disruption. It is a fact though that with cold entrenched across the UK by midweek that trough disruption is very difficult for computer models to predict accurately in advance and sometimes they can be too progressive in displacing the cold away to the East. However, at the moment we have to go on what we see and that is a spell of rain, sleet and snow for all as the first trough disrupts within the vicinity of the UK clearing to wintry showers as the NW flow behind the front is also very chilly. It then looks very probable that further troughs will also slide SE towards NW Europe repeating the pattern late in the week before there seems reasonable support for High pressure to ridge across the UK next weekend settling things down for a time with frost and freezing fog patches by night but bright and sunny days. Looking further ahead still is fairly futile to be honest being with such fluid dynamics of this coming week making any longer term predictions suspect to say the least but going on what's on offer this morning apart from a brief milder interlude in 10 days or so further cold zonality with rain or snow at times in Atlantic winds blowing North of West for much of the time seems the favoured plan longer term for now. As the cold spell goes it is going much the way as I expected to be honest as I have never bought in to widespread disruptive snowfalls across the UK that some on the forums have amplified. There are a few missing vital pieces to the jigsaw required to bring such events with the lack of High pressure to the NE to enhance the cold block of air currently in place over the UK and NW Europe plus of course our old friend the Azores High lurking around too encourages a shift East of any cold pattern. Nevertheless and interesting and fascinating period of model watching is maintained and I can guarantee there will be many more twists and turns towards mild and colder options shown within the outputs of the coming week before any longer term resolution can be guaranteed. So sit back enjoy the ride and remember the more time spent looking at every frame from every model run takes away the time you could be spending watching the cold weather you love so much carry on outside of your own windows. It is only the weather and is thankfully totally beyond our control.


Martin G
Kilmersdon Radstock Bath Somerset



Look up my New Facebook Weather Page  for all the latest up to the minute weather stories as they happen
tallyho_83
17 January 2015 09:10:04


Before people slag off the CMA, last Saturday, it and the Brazilian model 😉 were the only 2 models showing the current cold spell.  I chose not to post the charts then, but referenced them.


 


Neil, here is a possible easterly:



 


Originally Posted by: Whether Idle 


A lot of uncertainty - just shows here? - will the low sink south allow the easterly wind to develop as forecasted or will the milder Atlantic air win and push through the whole country?


 


Home Location - Kellands Lane, Okehampton, Devon (200m ASL)
---------------------------------------
Sean Moon
Magical Moon
www.magical-moon.com


Gusty
17 January 2015 09:25:04

If you sit back and treat FI as T+96 then the outlook continues to scream massive potential.


I note with interest that as early as T+48 the northerly is becoming progressively colder with 850Hpa's around -8c to -9c. 925Hpa temps have reduced now to -4c.


With a slight easterly component you really wouldn't rule out some convective stuff pushing in from the North Sea.


 


 



Steve - Folkestone, Kent
Current conditions from my Davis Vantage Vue
https://www.wunderground.com/dashboard/pws/IFOLKE11 
Join Kent Weather on Facebook.
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Solar Cycles
17 January 2015 09:35:30

Some strange posts creeping in again regarding cold snaps and breakdowns. Regardless of some of us not seeing lying/falling snow this doesn't equate it to this being just a cold snap, as we are due 5+ days of colder than average temps with snow/sleet/rain/hail and frosts. Now we may not see -10 uppers with a raging easterly or a  blocking Greenland high, but it will still go down as a cold spell if the models verify that is.

Gooner
17 January 2015 09:38:14

Weather type GFS Tu 20.01.2015 18 GMT


Weather type GFS We 21.01.2015 06 GMT


Weather type GFS We 21.01.2015 12 GMT


Again J F F  distribution of ppn from the 0z, be interesting to see where the 6z lands it


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


Gary L
17 January 2015 09:49:24

It's looking very messy over the next few days with the outlook uncertain. I found this post from Ian F on net weather useful.


 


"1. Amplified upper pattern remains favourable for (two) trough disruption(s) early-mid next week
2. Scope of how and where these may occur will NOT be correctly resolved in ANY model at this lead time
3. Ergo, any over-analysis is pointless at this lead time given great uncertainty and variance/volatility in model handling
4. Likely erratic and eventually weakening E'ward progress of occlusion into cold air Tues means uncertainty on areal spread of snow: GFSPPN phase charts to be viewed with due caution. 
5. Risk of rain onto frozen surfaces even where no snow. Varied wintry hazards look inevitable but no compelling evidence for a 'nationwide snow event' in strict defined sense. However, threat of disruptive snow for some areas (starting in parts of NI initially under frontal mass ascent; then W Scotland and Wales) is quite obvious, although no regional detail is reliable for now.
6. The potential for some easterly flow later into the week could not be *wholly* discounted yesterday (despite some claiming so); nor again in this morning's output, albeit still considered a lower probability outcome (ca. 40% support for some easterly component in 00z MOGREPS-G)
7. Attempt to resume westerly mobility later in the week (Weds-Thurs, powered by strong jet) may threaten further snow with second trough disruption. Importantly, the transition/timing and evolution of this switch will inevitably be messy and poorly resolved in all models currently.
8. Further swings in output are a given, as models struggle with upstream driving developments in W Atlantic/US. 
9. Thus, can we desist from further forum freak-outs today...! 🙂 "

David M Porter
17 January 2015 09:59:00


It's looking very messy over the next few days with the outlook uncertain. I found this post from Ian F on net weather useful.


 


"1. Amplified upper pattern remains favourable for (two) trough disruption(s) early-mid next week
2. Scope of how and where these may occur will NOT be correctly resolved in ANY model at this lead time
3. Ergo, any over-analysis is pointless at this lead time given great uncertainty and variance/volatility in model handling
4. Likely erratic and eventually weakening E'ward progress of occlusion into cold air Tues means uncertainty on areal spread of snow: GFSPPN phase charts to be viewed with due caution. 
5. Risk of rain onto frozen surfaces even where no snow. Varied wintry hazards look inevitable but no compelling evidence for a 'nationwide snow event' in strict defined sense. However, threat of disruptive snow for some areas (starting in parts of NI initially under frontal mass ascent; then W Scotland and Wales) is quite obvious, although no regional detail is reliable for now.
6. The potential for some easterly flow later into the week could not be *wholly* discounted yesterday (despite some claiming so); nor again in this morning's output, albeit still considered a lower probability outcome (ca. 40% support for some easterly component in 00z MOGREPS-G)
7. Attempt to resume westerly mobility later in the week (Weds-Thurs, powered by strong jet) may threaten further snow with second trough disruption. Importantly, the transition/timing and evolution of this switch will inevitably be messy and poorly resolved in all models currently.
8. Further swings in output are a given, as models struggle with upstream driving developments in W Atlantic/US. 
9. Thus, can we desist from further forum freak-outs today...! 🙂 "


Originally Posted by: Gary L 


Very sound advice IMO.


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
hobensotwo
17 January 2015 10:09:16


who are you? 


Originally Posted by: lezrob 


Name: Ben Holland


Age: 32


Location: Parish of St Martin Jersey 87m asl.


Weather Interests: Extreme events i.e. Cold, Hot, Stormy. Living in Jersey can feel like Autumn all the time.


Occupation: IT Manager

Gooner
17 January 2015 10:13:22


Virtually identical to what H Willets showed last night


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


Gooner
17 January 2015 10:20:21


Looks like a week of cold ( at times very cold weather) with wintry ppn never far away


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


JACKO4EVER
17 January 2015 10:28:08
Some flip flopping around at the moment, hopefully the cold will be further downgraded in today's runs. Today's snow hasn't materialised here thank goodness and tomorrow now looks ok too. Further ahead, quite a mixed picture but perhaps milder by next weekend? All acceptable for the milder camp- after all quite a lot of cross model support only 48 hours ago for a real wintery blast.
nsrobins
17 January 2015 10:30:34

Yes I do concur that the outlook remains uncertain, but when I hear of potential easterlies and only see a few marginal charts depicting it it is very difficult to become enthused.
It doesn't help by the fact that we are now in a cold spell, and we have just had a passing shower of rain and the sun is now out in a light westerly breeze making it feel almost spring-like here. A case where facts and perception clash perhaps?


Neil
Fareham, Hampshire 28m ASL (near estuary)
Stormchaser, Member TORRO

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