Model Output Discussion - Heading Away From Easter

[Cheshire Freeze]

Lol! Damn at 192 and 216 hrs it looked promising I hadn't seen the 240hrs then the block reinforced!

Like John Holmes pointed out, it looks to be a rinse and repeat, locked in pattern. Even I wouldn't mind some warmth and convection now BUT seeing as we've come so far, I wouldn't mind a history defining March and April period!

If anything, looking at the output, any slightly less cold period in the interim merely serves to allow cold to regroup to our NE before the threat of it spreading SW yet again.

Edited March 29, 2013 by CreweCold

[nick sussex]

Back to square one at 240 hrs ECM. Azores high being forced back south and a potential undercut lining up out west which would draw some bitter cold air back across us from the E/NE

CC haven't you had enough yet? I haven't gone over to the dark side but really these synoptics are really beginning to grate on me, snow in April is just one long if only!

And whilst this continues for the UK then its a washout down here.

[Richie V]

Back in 1991 I orded a massive dose of global warming, all looked good for a while. I just want my money back now.

Gavin....

May our blowtorch dreams come true

[SE Blizzards]

I know i've been banging on about a possible cold N'ly/NE'ly outbreak for a couple of days now, but there really is quite a signal now from various models for this to happen, albeit at slightly different times.

It really is looking bleak for those that are wanting any warmth. The first part of April seemingly wants to go down the same route as March. Quite unbelievable.

Edited March 29, 2013 by SE Blizzards

[MR EXTREMES]

Wow... Even I'm looking for spring now! These Synoptics are making me wonder what could happen next winter! Something has certainly changed with jet stream and NH blocking patterns. I believe this pattern is similar to march 1962 let's hope we get the winter to follow !

id be inclined to say this is absolutely a direct result of the sw in the later winter months.

this will in no way be like this next winter if it is then id be very worried but its unlikely i think nicks sussexs idear is a likely outcome but once again very 1975 and id punt for a dry hot summer this year and good thundery activity.

but until then winter continues from each model.

id also get down the bookies 100f this year could come close.

[Cheshire Freeze]

CC haven't you had enough yet? I haven't gone over to the dark side but really these synoptics are really beginning to grate on me, snow in April is just one long if only!

And whilst this continues for the UK then its a washout down here.

Haha see my second post.

id also get down the bookies 100f this year could come close.

Reasoning for this? Pattern matching from previous years seems futile to me, hot or cold.

FWIW CFS anomaly maps going for a consistently mixed summer.

Edited March 29, 2013 by CreweCold

[Purga]

A pretty wintry run (more so than 00z) from ECM 12z right through to 240hrs

An upper air cold pool crossing the south may assist some snow showers at 96-120 hrs

The ECM precipitation charts at the same time frame show it skirting the far south and then into the south west.

A bit of a shift north could do the trick.

At 240hrs the Scandi trough aids a strong SW push of very cold uppers and the ridge from the azores looks like becoming a cut off HP over Iceland helping to push energy SE under the block (trough starting to disrupt under in mid Atlantic) and thus perpetuating the cold pattern

A step back for the mildies this time and a shift towards longer cold regime.

Let's see what the ENS bring and compare the ECM mean chart at the same time later on.

Edited March 29, 2013 by Purga

[Captain Shortwave]

CC haven't you had enough yet? I haven't gone over to the dark side but really these synoptics are really beginning to grate on me, snow in April is just one long if only!

And whilst this continues for the UK then its a washout down here.

I think it's the fascination of how the weather over Europe as a whole has gone completely off on one and just refuses to stop. Whilst we are used to locked in westerly patterns for months on end, it's just amazing to see a completely opposite weather scenario doing the exact same thing, just locking in with next to no end in sight.

Sorry about the rain, you now know what our summer last year was like

[Purga]

Crikey we are in winter Purga-tory here (see what I did there )

The cold really does not want to relent.

JMA cold throughout

Nice one !

[nick sussex]

id be inclined to say this is absolutely a direct result of the sw in the later winter months.

this will in no way be like this next winter if it is then id be very worried but its unlikely i think nicks sussexs idear is a likely outcome but once again very 1975 and id punt for a dry hot summer this year and good thundery activity.

but until then winter continues from each model.

id also get down the bookies 100f this year could come close.

Yes I think this cold needs to be put in the context of the time of year, blocking is always more likely in spring because of the weaker jet. This year this has come in conjunction with unseasonable cold available to tap into and the synoptics have played ball by directing that into northern Europe.

To get these types of synoptics in mid winter especially in terms of longevity would be incredibly rare, if you look at the upper air values and then adjust them to mid winter you'd probably be looking at a spell of such intense cold that would beat December 2010.

Hopefully this blocking signal will wane with time, lets hope it disappears by late spring and summer to deliver some decent temps and sunshine and not last summers dismal weather for the UK.

[MR EXTREMES]

I think it's the fascination of how the weather over Europe as a whole has gone completely off on one and just refuses to stop. Whilst we are used to locked in westerly patterns for months on end, it's just amazing to see a completely opposite weather scenario doing the exact same thing, just locking in with next to no end in sight.

Sorry about the rain, you now know what our summer last year was like

be good for the experienced forecasters to learn from this though could well be the best learning curve for a very longtime now will this give the strat crew and the longrange forecasters an idear on how this march as really thrown up some suprises not so much cold snow just the overall pattern and its amazing how all models are very much running in sync with each other now.

do the weather models struggle with to much complexity.

[MR EXTREMES]

Yes I think this cold needs to be put in the context of the time of year, blocking is always more likely in spring because of the weaker jet. This year this has come in conjunction with unseasonable cold available to tap into and the synoptics have played ball by directing that into northern Europe.

To get these types of synoptics in mid winter especially in terms of longevity would be incredibly rare, if you look at the upper air values and then adjust them to mid winter you'd probably be looking at a spell of such intense cold that would beat December 2010.

Hopefully this blocking signal will wane with time, lets hope it disappears by late spring and summer to deliver some decent temps and sunshine and not last summers dismal weather for the UK.

i dont know why i said 1975 but heatwaves stand out this year but i think second week of april is going to be a turning point but the blocking weaker jet makes absolute sense to me nick.

anyway i had some some white stuff absolutely stunning seeing the drifts recently this is why uk is really such an unpridictible place i bet the weather models hate us although running very smoothly now.

and yes nick time to get them shades ready mate wont be long then its heat and thunder yeah i love the extremes.

[Summer Sun]

A look a GFS, ECM and BOM Access at t240

GFS has the cold hitting the east of the UK before getting pushed into eastern Europe

The GFS ensemble average has the uppers at 0c to -4

The ensemble average for the latter part of its run is to lower heights over Greenland and build pressure over the UK

BOM keeps the uppers at around -4 to -6 with the high staying over the UK

ECM is the coldest of the 3 with the low sinking south pushing the Azores high back bringing a renewed cold blast

Until the ECM ensemble run is out in an hour or so we don't know what support this will have

[J10]

Wow... Even I'm looking for spring now! These Synoptics are making me wonder what could happen next winter! Something has certainly changed with jet stream and NH blocking patterns. I believe this pattern is similar to march 1962 let's hope we get the winter to follow !

But not summer 1962. Please

http://www.london-we...rticle.102.html

The strange thing about current synoptics is that it is like one of the crazy GFS runs, but it is actually coming off.

Edited March 29, 2013 by Jackone

[Frosty.]

Cold fans cup runeth over again with more icy charts from the ecm 12z to follow up the wintry ecm 00z op and ens mean, the T+240 chart is EPIC for yet another arctic/scandinavian blast of bitter winds and snow although even before then it's Cold with a capital C, actually very cold for this time of year and still no realistic end within sight of this extraordinary cold spell which has now lasted weeks and still has much power to add. The only thing missing is an atlantic attack from the southwest which we had last week resulting in the blizzards/drifting but there is no sign of spring, winter set to continue for many days to come, at least the sun is getting stronger but the air will be getting colder again next week from the east and then potentially reloading from the northeast/north. So, lots more frosts to come and an increase in wintry showers, especially next week although a scattering of snow showers tomorrow in central and eastern areas after a sunny start, sunday looks drier and sunnier, as does monday but then more showery from tuesday onwards but still with sharp frosts. BRRRRRR

[MR EXTREMES]

But not summer 1962. Please

http://www.london-we...rticle.102.html

The strange thing about current synoptics is that it is like one of the crazy GFS runs, but it is actually coming off.

very intresting jackone not this year i think 75 is my year closest to this but if this is to follow 62 then im dreading winter 2013/14.

i think northern blocking could aid us like it does in winter when we get it hot easterly winds or southeasterlies.

but who knows at the moment blooming cold i must say i myself never been this cold in my lifetime although april 2008 threw up suprise snowfall.

and if im correct not a good summer really not had good summer since 2007 but im still going against the grain 1975 summer.

[Gibby]

Hi everyone. Here is tonight's Good Friday look at the 12z output from GFS, UKMO, GEM and ECM for tonight the 29th March 2013.

All models show the current cold weather is likely to stay for the next week or so as High pressure to the North and Low pressure to the South continue to refuse to change their positions anytime soon. As the week passes the current less windy weather will be replaced by a stronger Easterly flow as High pressure strengthens to the North. With origins over a very cold Northern Europe the wind will bring very cold air across the UK, especially in the South. In addition a few more in the way of wintry showers could occur from midweek on following a largely dry if cold and bright remainder of the Easter weekend. Sharp Frosts at night will continue to be a feature of the weather in the coming week, harshest in the clearer NW.

GFS then moves into FI with the cold NE flow backing towards the North as High pressure drifts slowly South to the West of the UK with some wintry showers near Northern and Eastern coasts and more frost at night. Later in FI a pattern change is accomplished as the Jet Stream rises over the top of the collapsing High over the UK and milder SW winds develop with troughs of Low pressure crossing East over the UK with rain at times to end the run.

The GFS Ensembles show the slow climb out of the very cold conditions towards more normal April conditions after 10 days time. However, the operational run may be over ambitious with it's transformation to rather mild conditions at the end of the run. Rainfall is pretty rare throughout the run.

The Jet Stream shows a change afoot in a week or so time. The current flow running East at low latitudes well South of the UK maintains it's position until midweek next week when a strong ridging of the flow in the Atlantic breaks the pattern down as it rides over the High pressure sinking South over the UK.

UKMO shows a cold NE flow with scattered wintry showers chiefly in the South and East with a cold and raw NE wind. In the Atlantic though there are signs of change as it too shows the Jet flow riding High up towards Iceland in the closing frame.

GEM shows a cold ENE flow at day 6 with High pressure still up to the North and Low pressure to the South. Some wintry showers will occur over Southern and Eastern Britain with the brightest weather in the NW.

ECM finally shows things a little differently than this morning with the cold NE winds maintained towards the end of next week before a trend towards a Northerly at the end of it's run looks stronger than this morning which of course would mean maintaining the cold feed a while longer with wintry showers moving down from the North on day 10.

In summary there is no short term changes tonight with another week of cold and at times windy weather with the occasional snow flurry in the East and South. It's all eyes on the longer term possibilities as the Jet flow rides North over the Atlantic and promotes a collapsing High cell in the vicinity of the UK. This could of course lead to milder conditions with time as GFS suggests with Low pressure back in it's more regular home to the NW. Alternatively High pressure could end up over the Atlantic with a Northerly flow the end product as per ECM tonight. It's a case of watching and seeing how things develop over the coming few days but a chance of a pattern change is a growing possibility for the 2nd week of April as things stand tonight.

[snowking]

But not summer 1962. Please

http://www.london-we...rticle.102.html

Funny you should mention that

I posted briefly over in the seasonal thread earlier, and at the moment to two best matches in terms of QBO and ENSO expectations are 1978 and 1962

What I would say at this stage is that despite both of these years being followed by cold winters, this is being used as an analogue for SUMMER. We are far from seeing how the QBO in particular will actually develop through the year, so this doesn't in any way mean at this stage we should be preparing for another 1963 (the potential winter analogues won't be clearer until autumn)

I suspect a rather low pressure dominated summer though - the signal from those two years is a mean Sceuro trough

SK

Edited March 29, 2013 by snowking

[stodge]

Evening all

Well, I'm no Martin and I don't have his eye for detail for trend-spotting but my limited observations from this evening's 12Z Operational output:

http://modeles.meteociel.fr/modeles/gfs/runs/2013032912/gfs-0-144.png?12

Solidly cold and settled. The HP is well off to the NE which was the trend highlighted by this model in the 00Z but is more accentuated here.

http://www.meteociel.com/modeles/ecmwf/runs/2013032912/ECM1-144.GIF?29-0

Something different from ECM tonight and highlighting the other evolution I posited this morning. The HP is in Greenland with a strong ridge to the UK. The European trough is nearer with a greater risk of wintry showers to Eastern and Southeastern regions. The flow is more ENE'ly whereas GFS is more ESE'ly and there's a considerable pressure differential over southern Scandinavia and the Baltic.

http://www.meteociel.com/ukmo/runs/2013032912/UW144-21.GIF?29-18

As seems to be the case quite often, UKMO splits the difference. Similar ro ECM in that the HP centre is over Greenland but the European trough is less pronounced so a dry and settled ENE'ly looms the outcome from this.

http://www.meteociel.com/modeles/jma/runs/2013032912/J144-21.GIF?29-12

A clear and pronounced E'ly with the air sour ce from further south in Eurasia so perhaps not as bitingly cold as other models. The HP over Greenland is less well defined but still dominant.

http://modeles.meteociel.fr/modeles/gem/runs/2013032912/gem-0-144.png?12

GEM plays close to the UKMO with the Greenland ridge ruling the roost. Again, the air flow is from the East but again not sourced from northern Russia but further south so again perhaps not quite as chill.

http://modeles.meteociel.fr/modeles/navgem/runs/2013032912/navgem-0-144.png?29-17

NAVGEM plays a different game with the HP much closer to the UK so very light winds for the North and the worst of the E'ly chill kept to the far south. That said, fine days would be followed by very cold nights in this set-up.

http://modeles.meteociel.fr/modeles/bom/runs/2013032912/bom-0-144.png?12

BOM plays very close to GFS with a solid block of HP to the north of the British Isles and a keen E'ly for the south. Everywhere dry and settled.

http://modeles.meteociel.fr/modeles/cptec/runs/2013032912/cptec-0-144.png

Everyone's new favourite model of choice (CPTEC). Very close to the ECM and UKMO evolutions.

As I said earlier, the key is how the HP is being modelled. GFS is the most bullish about transferring the HP toward Scandinavia while ECM and UKMO (among others) keep the Greenland HP as dominant with a strong ridge SE to the British Isles keeping the block in charge. Interestingly, those models keeping the Greenland HP in charge introduce a SE moving LP into Northern Scandinavia and it may be that this re-invigorates the cold pool down the line

On ething is clear - precipitation at a minimum over the next week wherever you are in the British Isles but little in the way of warmth either. Well below average daytime meaxima and some very low night time minima on some of tonight's offerings.

[Timmytour]

But not summer 1962. Please

If looking for a build up to another 1963, maybe it's not just this year's spring being like March 1962 we should take note of, but also the preceding year's warm spring...very much like the Spring of 1961 was!

Of course then we could look at the cold of this year linking to a warm spring the previous year....as that is what the spring of 1946 was like.

And the spring of 1945 was also a warm one ....with the twist of the south getting snow at the end of April.

So many different correlations to make in weather patterns, whatever someone wanted to see is no doubt something that can be found in history.

Meanwhile, what we've had has been nothing like 1945 so far, but the models are not steering too far away from the prospect of us getting a similar end to April!

Edited March 29, 2013 by Timmytour

[Summer Sun]

The ECM De Bilt ensemble has the Operational and Control around or above the zero line for the bulk of its run

[Mucka]

I think the chances of seeing another cold plunge around the end of the first week/start of the second week of April, this time from a Northeasterly, have increased today while the chances of the Atlantic pushing in around the same time-frame have lessened.

Here is tonight's JMA either way.

[Guest pjl20101]

I would suggest judging by this chart that is 8-14 days ahead courtesy of CPC that it will still be relatively cool for the time of the year, however it looks less windy too:

http://www.cpc.ncep.noaa.gov/products/predictions/814day/814day.03.gif

It's worth noting as well that the weather this March hasn't just been bad for us, it has been bad all over europe and Spain have had it just as bad if not worse than us as the polar jetstream has been shunted too far south.

[Isabellesnanny]

Apologies as I do not read the models very well yet but do they show the cold weather as continuing to be dry or are further snowfalls espected? Surely going into April the snow chances should be reducing by now?

[nicknacknoo]

Apologies as I do not read the models very well yet but do they show the cold weather as continuing to be dry or are further snowfalls espected? Surely going into April the snow chances should be reducing by now?

Certainly dry in the medium term (up to 5 days). Maybe some snow flurries in the East.