Model Output Discussion - Spring 5th March Onwards 6z--->

[Summer Sun]

00z ensembles again suggest around 7 days minimum of settled weather for the UK

 

Aberdeenshire

 

 

London

 

 

After good Friday's rain it turns much drier

 

 

The ECM ens remains unchanged with the high last through-out next week

 

 

Temperature in general around or slightly above average so it will start and feel warmer with temperatures in the south getting towards the mid teens

[coldcomfort]

Morning all

 

I'm far from convinced we've even got the detail for the coming weekend sorted. The earlier meme of a fine, warm Easter seems to have been consistently downgraded over the past few days.

 

This morning's GFS 00Z OP, which seems to be canned by the usual suspects on an almost daily basis, is strongly anticyclonic though for those looking for warmth, profoundly frustrating.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015040100/gfs-0-120.png?0?0

 

Not terribly warm

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015040100/ECM1-120.GIF

 

Better though not really a heatwave but would be pleasant enough for all.

 

http://modeles.meteociel.fr/modeles/gem/runs/2015040100/gem-0-120.png?00

 

GEM different again - so a long way to go yet before we can be confident beyond Friday which doesn't look too promising it has to be said.

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.obs.gif

 

As of yesterday, the AO coming off its current high number

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

 

Looking ahead, a sharp fall back to neutrality as perhaps once again we try to get the set up of heights over the Pole and LP further south but huge scatter into the medium and longer term periods so lots of options on the table. EC32 apparently suggests the return of the Atlantic but that's default so I remain to be convinced. The emphasis for HLB seems to have shifted back to Scandinavia from Greenland in the last few days but that might just be indicative of no strong signal into mid-month. GFS has toyed with any number of HLB and MLB scenarios into FI so we'll see...

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

 

The NAO is starting to catch my eye - it's been as positive now as it's been all winter but the signs are for at the least a return to neutrality and quite a cluster of members going negative and, apart from a brief period at Christmas, the NAO has been positive for ages.

 

http://modeles.meteociel.fr/modeles/gfs/archives/gfsnh-2014122500-0-6.png?0

 

This is the last time the NAO went negative - Christmas Day in fact. The key, I think, is the large LP in mid-Atlantic which would depress the pressure anomaly for that region. Going forward, a negative NAO in April might suggest a deep LP in mid-Atlantic throwing HP north or east ahead of it and I wonder if that's where we might be in mid-April with the Atlantic dominated by a static deep LP and strong HP over NW and NE Europe ahead of it.

Agreed....I said as much in the moans thread yesterday, there's still plenty of potential for a disappointing Easter overall, especially in the east. Unlike recent days all the main models now keep HP rather more west based too as we move towards midweek, so I will remain sceptical about any proper 'warmth', but given light winds and any cloud breaks it should at least feel quite pleasant.

Edited April 1, 2015 by coldcomfort

[IDO]

Agreed....I said as much in the moans thread yesterday, there's still plenty of potential for a disappointing Easter overall, especially in the east. Unlike recent days all the main models now keep HP rather more west based too as we move towards midweek, so I will remain sceptical about any proper 'warmth', but given light winds and any cloud breaks it should at least feel quite pleasant.

It's early April in the UK and the most I ever expect for an early Eater is dry weather. Sporting events, walks, shopping, getting out and about are all possible. A washout looks like being off the register and that is the main theme. We would need to strike lucky to get any very mild weather and with the CET so far this year having been just above average the expectation has always been aligned with that. In the sun it could feel pleasant, not unlike today, with NW'ly winds and uppers of -4c temps still about 10c in the south. It was 13c in the Surrey area yesterday when the sun came out. During Easter there should be light winds so certainly feeling warmer than currently. The met update showing high confidence for HP till mid April with average temps for most, maybe above in the south. It could be a lot worse as Gibby says.

[Frosty.]

No downgrades to the fine outlook in my opinion, high pressure looks dominant next week and even further ahead, some will moan that it's not going to be as warm as they would like but to see high pressure sat on top of the UK with dry conditions and light winds, sunny periods and pleasant daytime temperatures is good enough for me, the latest mean charts from gefs and ecm are as good as yesterday.

[coldcomfort]

It's early April in the UK and the most I ever expect for an early Eater is dry weather. Sporting events, walks, shopping, getting out and about are all possible. A washout looks like being off the register and that is the main theme. We would need to strike lucky to get any very mild weather and with the CET so far this year having been just above average the expectation has always been aligned with that. In the sun it could feel pleasant, not unlike today, with NW'ly winds and uppers of -4c temps still about 10c in the south. It was 13c in the Surrey area yesterday when the sun came out. During Easter there should be light winds so certainly feeling warmer than currently. The met update showing high confidence for HP till mid April with average temps for most, maybe above in the south. It could be a lot worse as Gibby says.

Indeed IDO, don't get me wrong it looks a very useable Easter, if not the Excess's hottest on record That said I think it is continuing to look rather more disappointing the closer we get to it, especially in the east with mid single digit maxima and as I mentioned previously given the more west centric HP the first half of next week doesn't look as good as it has done recently. However, if you had offered me this as Easter weather a few weeks ago i'd have grabbed it with both hands, so as is often the case it's all relative I guess.

Edited April 1, 2015 by coldcomfort

[stodge]

It's early April in the UK and the most I ever expect for an early Eater is dry weather. Sporting events, walks, shopping, getting out and about are all possible. A washout looks like being off the register and that is the main theme. We would need to strike lucky to get any very mild weather and with the CET so far this year having been just above average the expectation has always been aligned with that. In the sun it could feel pleasant, not unlike today, with NW'ly winds and uppers of -4c temps still about 10c in the south. It was 13c in the Surrey area yesterday when the sun came out. During Easter there should be light winds so certainly feeling warmer than currently. The met update showing high confidence for HP till mid April with average temps for most, maybe above in the south. It could be a lot worse as Gibby says.

 

Fair enough but one or two people on here were talking about dry, settled and warm conditions for Easter not so long ago quoting high teens and even up to 20c so I do feel one or two have over-egged the Easter pudding (pardon the pun). 10-13c in early April is frankly unexceptional and yes, dry weather is to be welcomed but as we've had both heatwaves and snow at Easter in recent years (though not at the same time) the thrust is unremarkable.

 

We've also seen Friday downgraded considerably to this:

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015040106/gfs-0-54.png?6

 

Nothing very dry, settled and warm on that.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015040106/gfs-0-78.png?6

 

Dry most and fine for many. Perhaps more cloud to the SE on that light NE'y but nothing too warm.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015040106/gfs-0-102.png?6

 

Sunday looking similar - again a cool breeze and perhaps more cloud to the SE.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015040106/gfs-0-126.png?6

 

Monday perhaps the best of the lot with more sunshine especially for central parts.

 

The active Scandi trough prevents the HP heading NE and there's too much energy in the jet to send it NW so the HP is stuck around the Brirish Isles for some time and this is a position we've seen many times before which can mean more and more cloud gets trapped within the circulation with time.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015040106/gfs-0-168.png?6

 

A half-hearted attempt at retrogression

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015040106/gfs-0-252.png?6

 

This was the kind of chart I was alluding to in my previous. The trough moves out of Scandinavia and a new slow-moving Atlantic LP encourages HP development downstream so the HP sits near the British Isles so as the original HP recedes SE into Europe, a new centre can form near or just to the east drawing in a southerly feed so the possibility of a negative NAO and warmth - this is where your first 20c originates. Let's see if the OP into low-res offers more in this fashion.

[coldcomfort]

Fair enough but one or two people on here were talking about dry, settled and warm conditions for Easter not so long ago quoting high teens and even up to 20c so I do feel one or two have over-egged the Easter pudding (pardon the pun). 10-13c in early April is frankly unexceptional and yes, dry weather is to be welcomed but as we've had both heatwaves and snow at Easter in recent years (though not at the same time) the thrust is unremarkable.

 

We've also seen Friday downgraded considerably to this:

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015040106/gfs-0-54.png?6

 

Nothing very dry, settled and warm on that.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015040106/gfs-0-78.png?6

 

Dry most and fine for many. Perhaps more cloud to the SE on that light NE'y but nothing too warm.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015040106/gfs-0-102.png?6

 

Sunday looking similar - again a cool breeze and perhaps more cloud to the SE.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015040106/gfs-0-126.png?6

 

Monday perhaps the best of the lot with more sunshine especially for central parts.

 

The active Scandi trough prevents the HP heading NE and there's too much energy in the jet to send it NW so the HP is stuck around the Brirish Isles for some time and this is a position we've seen many times before which can mean more and more cloud gets trapped within the circulation with time.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015040106/gfs-0-168.png?6

 

A half-hearted attempt at retrogression

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015040106/gfs-0-252.png?6

 

This was the kind of chart I was alluding to in my previous. The trough moves out of Scandinavia and a new slow-moving Atlantic LP encourages HP development downstream so the HP sits near the British Isles so as the original HP recedes SE into Europe, a new centre can form near or just to the east drawing in a southerly feed so the possibility of a negative NAO and warmth - this is where your first 20c originates. Let's see if the OP into low-res offers more in this fashion.

Unless I'm missing something Sun-Mon look downright cold across much of central and eastern England. 850's of <-5c, a stiff breeze and lots of cloud will make for a bracing walk and an even more bracing dip in the southern North Sea..

[IDO]

Fair enough but one or two people on here were talking about dry, settled and warm conditions for Easter not so long ago 

 

Yes can't argue with that. 3-5 days ago there was a window where it looked like a warmer Easter was possible, but being a weather watcher downgrades are part of the deal and now it is west is best.

 

Not sure about the GFS outlook rain wise for Friday. It looks quite complicated if the FAX is a guide with trailing fronts behind the main warm front:

 

 

 

The GFS forecasting a wet day but the hi-res WRF still maintaining a better outlook for the south:

 

 

 

The WRF still has the trailing fronts but they are weak and a mix of drizzle and cloud...

[stodge]

Indeed - Friday looks far from cut and damp (not dry) just yet. Timing may be everything (as it is with so much else).

 

The GFS 06Z OP in low-res completely different from the 00Z in firing up the Atlantic going in to the middle of next month. Any warm southerly transient at best but clearly lots of options still on the table.

[Frosty.]

The Gfs 6z shows increasingly settled weather from the Easter weekend onwards with high pressure taking control, during the transition period as the orientation of the high changes, temperatures ebb and flow with alternating mild and chilly days and night frosts but gradually the anticyclone migrates further east which enables a progressively warmer and more humid unstable airmass to push north across the UK with sunshine but also a higher risk of thundery showers breaking out, the run ends cooler and unsettled with westerly winds by mid month.

[Frosty.]

The GEFS 6z mean shows high pressure centred to the west of the UK early next week but there is strong support for it slowly migrating eastwards, eventually this enables warmer air from southern europe to waft north into the UK. Looking at next week, it's dry with sunny spells and light winds, daytime temps gradually creeping to just above average, especially in prolonged sunshine but nights will be chilly with a risk of frosts where skies clear. It's a very pleasant outlook with high pressure domination until at least mid month.

Edited April 1, 2015 by Frosty.

[Summer Sun]

WSI euro weather are suggesting an omega block set up across Europe from this weekend and into next week

 

 

A spell of settled weather looks a good bet now for the UK which will begins during the weekend just the positioning of it and cloud amounts left now to sort out

Edited April 1, 2015 by Summer Sun

[Summer Sun]

After an unsettled start to the BH weekend its a gradual improvement with high pressure settling things down nicely from this afternoons UKMO

 

 

Even without any sunshine it will be feeling milder for just about all with temperatures getting into double figures widely (10c to 13c) and where the cloud does break it will be feeling very pleasant.

Edited April 1, 2015 by Summer Sun

[Frosty.]

The Gfs 12z really blossoms into a pleasantly warm run by the second half of next week onwards with high pressure eventually migrating far enough east to allow a warmer southerly flow to bathe most of the UK by then. This is much better than yesterday's 12z. High pressure domination is on the way, starting cool but gradually becoming warmer with increasing amounts of sunshine as HP works it's way into a more favourable position.

[Frosty.]

Tonight's Ecm 12z also shows a big change to high pressure domination with the high drifting slowly east to enable a draw of warmer air from southern Europe, the south in particular would become warm later next week with temperatures close to 20 celsius, it's looking good for a decent window of fine and pleasant weather practically nationwide.

[ANYWEATHER]

For the semi reliable time frame up to  T+144 high in control, but delivering somewhat cold and cloudy conditions.  A slow springs Beckons...    

[Lincs Observation]

Tonight's Ecm 12z also shows a big change to high pressure domination with the high drifting slowly east to enable a draw of warmer air from southern Europe, the south in particular would become warm later next week with temperatures close to 20 celsius, it's looking good for a decent window of fine and pleasant weather practically nationwide.

 

Good evening all

 

I dont post in here at all i just read but i would like to add a curveball comment to the discussion, i have been watching the trends over the past two seasons and have come up with what to some maybe a half cocked theory.

 

Now what i look for is the jet stream and interaction with the seasons in the Uk, what i have observed over the past few years with the Jet, is it almost sets a signal to how the year will progress. For example the jet has been southerly on the whole for some years now (It does track as we expect, however as a general observation) giving us either very wet or snowy winters and wet or average summers. The Azores have in the main been locked out by the jet. However the Azores has been constantly edging and ebbing in recent months with more or a tracking jet and in my mind seems to be setting out its stall for the coming summer. Now those who are far more educated in this subject than i am may say im talking cobblers but its my guess that this trend for migrating Azores to our shores this year will be more evident with a more mobile jet.

 

In conclusion i expect a normal late spring with the chances of a summer unlike we have seen in a few seasons.

 

LO

Edited April 1, 2015 by Lincs Observation

[bluearmy]

Karl, the ECM 12z run brings mid teen maxes at the most by end next week.

[Nouska]

Good agreement between control and deterministic on the Reading EPSgram - only a couple of days where mid teens are shown. .

[Summer Sun]

Little change from the ECM ens once the high builds in during Saturday it lasts through-out next week its just a case now of pinging down the wind direction

 

 

Temperatures look likely to be around or slightly above average though some north sea facing coasts could remain on the chilly side especially if we pick up a north easterly wind

[Captain Shortwave]

Karl, the ECM 12z run brings mid teen maxes at the most by end next week.

The persistence to drop low heights in the south and east of Europe has been a frequent pest at preventing warmer conditions developing over the UK as we cannot develop an Omega type mid latitude block over Western Europe which could provide such a set up (despite the frequency of achieving a fairly decent upstream pattern).

 

That said the ECM isn't the best at predicting maximum temperatures (It frequently underestimates them).

 

The ECM ens pointing at a reasonably long dry and settled spell starting from this coming weekend.

 

The uper ridge looks weakened though so even a south or south easterly flow won't match the potential it could have (low twenties is possible at this time of year). Mid teens looks reasonable, maybe high teens in favoured spots.

[Milhouse]

It looks as if the cold plunge of air has been watered down a bit for the weekend so on both Friday and Saturday temperatures remain in double figures, as shown on the GFS. Warmest temps likely over northern and western areas with mid teens possible in favoured sheltered spots.

[Frosty.]

Karl, the ECM 12z run brings mid teen maxes at the most by end next week.

I disagree, I think mid to upper teens celsius from this chart or something similar, like the Gfs 12z showed with a draw of milder / warmer uppers spreading up from the continent towards the end of next week and with the addition of decent sunny spells, I stick to what I said before.

Edited April 1, 2015 by Frosty.

[bluearmy]

Karl - you were referencing the ECM op 12z. That doesn't bring temps higher than mid teens, even allowing for the few degrees that the raw data usually undercooks. I would say that beyond nxt weekend, the upper ridge looks to move a bit further east which, in tandem with a mid Atlantic trough, should push temps up to a more springlike figure.

[Frosty.]

Karl - you were referencing the ECM op 12z. That doesn't bring temps higher than mid teens, even allowing for the few degrees that the raw data usually undercooks. I would say that beyond nxt weekend, the upper ridge looks to move a bit further east which, in tandem with a mid Atlantic trough, should push temps up to a more springlike figure.

I stick to what I said, favoured spots could reach high teens celsius with a mild SEly airflow and boosted by any prolonged sunshine.