Model Output Discussions 12z 01/09/2016

[blizzard81]

On ‎26‎/‎09‎/‎2016 at 15:37, blizzard81 said:

But this is what the GFS was showing on most of it's operational runs for the same time frame. ECM now jumps on board only for GFS to jump ship - a familiar tale. I expect GFS to climb back on board soon. A fine, warm first half to October beckons.

Slowly but surely the GFS climbs back on board. Sometimes it's own worst enemy as it was the first model to spot the warmth of next week - quite a few operational runs showed this but yet again as the clock ran down, the GFS jumped ship. Very strange and something it has been prone to for as long as I have been model watching (13 years now).

[knocker]

A showery regime over the weekend as a shallow low traverses the country followed by the expected amplification but the trough spoils the party.

[Frosty.]

Nights look chilly this coming weekend according to the Gfs 12z with single digits celsius minima and ground / slight air frosts, especially in the north..good timing for the start of october.. as for the run overall, it's generally changeable / unsettled with temps close to average but with a few pleasantly warmer and fine days across the s / e with the most unsettled and coolest weather targeting the northwest of the uk which is normal for this time of year although later in the run it becomes cooler and more trough dominated for all areas. 

 

Edited September 27, 2016 by Frosty.

[Frosty.]

Well the Ecm 12z is pretty changeable / unsettled, more so than earlier today, especially further n / w  and not as warm as the 00z either, however, high pressure does build to the east for a time next week which holds the Atlantic at bay with at least a few days of pleasant weather, especially further east / south and also some influence from the Azores high too.. ..personally, I will be happy if we can get some more warmth in the short term but I'm now looking ahead to what winter will hopefully bring which is plenty of what we didn't get last winter. I.e... frosts and snow of course!

Edited September 27, 2016 by Frosty.

[blizzard81]

9 minutes ago, Frosty. said:

Well the Ecm 12z is pretty changeable / unsettled, more so than earlier today and not as warm as the 00z either, it's almost a repeat of what happened yesterday with a stonking 00z showing very warm weather across the s / e next week followed by a more mobile 12z run..personally, I will be happy if we can get some more warmth but I'm now looking ahead to what winter will hopefully bring which is frosts and snow of course!

ECM is actually warm and settled for the southern half of the UK in the mid to latter stages. It looks to me as though it blows that low up way too much at T192 but even that doesn't really spoil the subsequent two frames as the azores high exerts it's influence yet again.

Edited September 27, 2016 by blizzard81

[Frosty.]

Just now, blizzard81 said:

ECM is actually warm and settled for the southern half of the UK in mid to latter stages. It looks to me as though it blows that low up way too much at T192 but even that doesn't really spoil the subsequent two frames as the azores high exerts it's influence yet again.

Yes I edited my post to reflect that.

[knocker]

The ecm is not hugely different to the GFS as it also has a little glitch with the upper trough which is bit far hence to worry about at the moment.

Edited September 27, 2016 by knocker

[Matthew.]

The sunniest October on record had charts like these from the ECM tonight. High Pressure centred well for a southerly airstream. Warm sunny days bringing pleasant October weather. If only it lasts

Edit: October 1959, sunniest Uk, England.

Edited September 27, 2016 by Matthew Wilson

[blizzard81]

1 minute ago, Matthew Wilson said:

The sunniest October on record had charts like these from the ECM tonight. High Pressure centred well for a southerly airstream. Warm sunny days bringing pleasant October weather. If only it lasts

Which year had the sunniest October?

[damianslaw]

Its far from a zonal atlantic onslaught attack.. the models continue to show amplification in the flow over the coming week, thanks to the interaction of ex-tropical storm systems, lots of topsy turvy conditions, from a mild southerly tomorrow, to much fresher polar maritime air by the weekend, and a significant chance of seeing the first ground frost of the season come the early hours of Sunday, to something milder again early next week, with the trough amplifying and heights building strongly to the east.

What is also notable is the propensity for relatively strong heights to our north throughout the run, especially as shown by the GFS. All in all quite interesting charts.. 

[Allseasons-Si]

22 minutes ago, damianslaw said:

Its far from a zonal atlantic onslaught attack.. the models continue to show amplification in the flow over the coming week, thanks to the interaction of ex-tropical storm systems, lots of topsy turvy conditions, from a mild southerly tomorrow, to much fresher polar maritime air by the weekend, and a significant chance of seeing the first ground frost of the season come the early hours of Sunday, to something milder again early next week, with the trough amplifying and heights building strongly to the east.

What is also notable is the propensity for relatively strong heights to our north throughout the run, especially as shown by the GFS. All in all quite interesting charts.. 

And the 8-14 days too looking at the 500mb outlook,plenty of hp into the pole too and if we get that hp in Europe to retrogress north over the next few weeks then we could expect a cool down from the N/NE/E,one can only hope.

 

Edited September 27, 2016 by Allseasons-si

[knocker]

Today

The east and south east mainly dry and quite warm with the west cloudy with intermittent light drizzle in many areas, Later a depression tracks NE close to Scotland bringing strong winds and heavy rain with it.

Thereafter

The above depression continues to track east whilst another shallow low forms within it's circulation and proceeds to to track SE over the UK bringing cool showery conditions for the weekend. Meanwhile another depression in mid Atlantic is tracking slowly north and deepening as the upper air pattern amplifies with strong ridging to the east. Ergo the frontal systems associated with the depression to the west slow down and a warm southerly surface drift the order of the day at the beginning of next week.

The $64,000 question is how long will the high amplification last and is quickly answered. The Atlantic and the strong jet will not be denied and the best that can be hoped for is a N/S split for the rest of next week

.

Edited September 28, 2016 by knocker

[mb018538]

ECM holds the Atlantic mainly at bay, though it starts to edge in towards the very end of the run - with the SE coming under the influence of some warmer continental air once more. As we will be into October by then, I'd expect temps to maybe get around 21c, which is warm by any means. More unsettled towards the north and west.

[Frosty.]

The GEFS 6z mean shows support for quite a blocked pattern developing next week with height rises to the east / south and the Atlantic held at bay.. so, eastern / southern parts of the uk in particular look like becoming largely fine next week and with temperatures above average to warm, especially further s / se, still with a risk of some rain but most of the unsettled weather gradually becoming more confined to northwestern uk.

[Scorcher]

2 minutes ago, Frosty. said:

The GEFS 6z mean shows support for quite a blocked pattern developing next week with height rises to the east / south and the Atlantic held at bay.. so, eastern / southern parts of the uk in particular look like becoming largely fine next week and with temperatures above average to warm, especially further s / se, still with a risk of some rain but most of the unsettled weather gradually becoming more confined to northwestern uk.

It's looking better and better for those of us wanting the warmth to hold on for a bit longer- the Atlantic is really struggling to break through at the moment. And with high pressure to the east it only means one thing- above average temperatures.

[northwestsnow]

11 hours ago, knocker said:

Today

The east and south east mainly dry and quite warm with the west cloudy with intermittent light drizzle in many areas, Later a depression tracks NE close to Scotland bringing strong winds and heavy rain with it.

Thereafter

The above depression continues to track east whilst another shallow low forms within it's circulation and proceeds to to track SE over the UK bringing cool showery conditions for the weekend. Meanwhile another depression in mid Atlantic is tracking slowly north and deepening as the upper air pattern amplifies with strong ridging to the east. Ergo the frontal systems associated with the depression to the west slow down and a warm southerly surface drift the order of the day at the beginning of next week.

The $64,000 question is how long will the high amplification last and is quickly answered. The Atlantic and the strong jet will not be denied and the best that can be hoped for is a N/S split for the rest of next week

.

And less than 12 hours later the Atlantic domination vanishes into cyber space

[knocker]

The rest of this week remaining unsettled with the shallow showery low crossing the UK on Saturday before ridging replaces it on Sunday.

We then arrived at the synopsis of a deep low that has wandered north to be east of Greenland and associated fronts lying across Ireland with pressure rises to the east. In other words the predicted upper air amplification.

The evolution from here is quite interesting as the trough makes a partial breakthrough

But this is foiled by a resurgence of the Azores HP ridging into the UK and moving east in the quite mobile pattern which realigns the jet SW/NE and diverts the more inclement weather to effect the NW

 

Edited September 28, 2016 by knocker

[stodge]

Evening all

One or two interesting trends starting to show up on the evening output. Both GFS and GEM 12Z OP runs show the LP stalling and recurving NW in the Atlantic causing pressure to rise over Scandinavia and both have a spell of E'ly winds setting up.

Here's GEM at T+216

GFS at the same time:

I suspect for all the talk of warmth, it might be quite chilly on eastern coasts though it certainly would be dry for the south.

[knocker]

Really portending to be a tale of NW/SE split with systems tracking NE and the drier warmer conditions in the south and east being under the influence of the HP

Edited September 28, 2016 by knocker

[Frosty.]

The GEFS 12z mean is really going with the idea of an intensifying scandi high next week with our weather pattern becoming very blocked, the Azores high also looks like coming into play and lending a hand according to the 12z output so far meaning the Atlantic threat is snuffed out..it looks increasingly as though next week and even further ahead towards mid october could become very benign and pleasant with only the far northwest corner of the uk at risk of atlantic influence as time goes on.

Edited September 28, 2016 by Frosty.

[phil nw.]

14 minutes ago, Frosty. said:

The GEFS 12z mean is really going with the idea of an intensifying scandi high next week with our weather pattern becoming very blocked, the Azores high also looks like coming into play and lending a hand according to the 12z output so far meaning the Atlantic threat is snuffed out..it looks increasingly as though next week and even further ahead towards mid october could become very benign and pleasant with only the far northwest corner of the uk at risk of atlantic influence as time goes on.

(Images removed in quote to save space)

Yes Frosty after a pleasant September another burst of warmth from the south seems on the cards as we go into next week.

Day 5 on the UKMO looking promising too    

Looking at that and the Gef charts you posted signs that there's little activity from the Atlantic jet over the next week to 10 days with a stalling Icelandic trough and building heights to the east leaving the UK in a warm southerly based flow.

The ens graph for central England underlining the dry Anticyclonic outlook

Away from the far north west, where there will some effect from nearby fronts at times,it looks very pleasant for early October with temperatures approaching high teens/low 20's C maximums on some days-after the week end.

 

 

 

[ACCOUNT DELETED]

1 hour ago, knocker said:

Really portending to be a tale of NW/SE split with systems tracking NE and the drier warmer conditions in the south and east being under the influence of the HP

Where can I find these charts please? They look very interesting.

[Man With Beard]

Early October looks warmish - but just a few days in and we have a quandry. Will we keep a southerly draw, or will something colder encroach from the east?

  

  

[Frosty.]

3 minutes ago, DJ RY said:

Where can I find these charts please? They look very interesting.

I think they are behind a paywall, quite an expensive one.

[ACCOUNT DELETED]

2 minutes ago, Frosty. said:

I think they are behind a paywall, quite an expensive one.

 

2 minutes ago, Frosty. said:

I think they are behind a paywall, quite an expensive one.

Ah that's a shame, thanks anyway for the reply