Model Output Discussion 01/09/17

[Daniel*]

I’d go as far as calling it unprecedented you could not get a better synoptic for ridiculously abnormal high temperatures on the cusp of November. An interesting outlook by GFS 06z.

[ICE COLD]

The op right at top of the ensembles again . Just look at the spread . 

[Scorcher]

The GFS 06z is almost as warm as the 00Z. I wouldn't disregard it at all. The odds are certainly favouring warmth for late next week and into the weekend.

[ICE COLD]

12 minutes ago, Scorcher said:

The GFS 06z is almost as warm as the 00Z. I wouldn't disregard it at all. The odds are certainly favouring warmth for late next week and into the weekend.

I wouldn't say the odds are favouring warmth next week . It's only been 2 GFS op runs . It will probley be completely different on the 12 z run . This is the GFS Lol 

[Marcus71]

11 minutes ago, Scorcher said:

The GFS 06z is almost as warm as the 00Z. I wouldn't disregard it at all. The odds are certainly favouring warmth for late next week and into the weekend.

The ECM tells a different story at the same time...

[knocker]

And this could also indicate the pattern and nod towards the ecm

Edited October 20, 2017 by knocker

[ACCOUNT DELETED]

1 hour ago, NorthernRab said:

Both the GFS 00hz and 06z are quite bullish about this, beginning at 150 hrs or so - something to keep an eye on and quite interesting if it materialises.

For southern England it would be notable, but for the Scottish Highlands exceptionally so. Main pulse isn't until 200 hrs but this is an interesting chart nonetheless

Bring on the beach weather lol what a cracking start to half term here in Wales that would be! 

[Man With Beard]

Hmmmm ... at T192, the main cluster in the ECM ensembles is not a million miles away from the GFS 06Z op (that's the first cluster on the top-left, which represents 18 out of the 51 members). However, alternative clusters vary considerably. Hard to see a clear way forward for the UK. 

  

With a strong signal in both GFS and ECM ensembles to build heights between Canada and Iceland, I can see heights to our west rather than east as the slightly more likely influence on our weather at this stage.

Edited October 20, 2017 by Man With Beard

[Scorcher]

3 hours ago, Marcus71 said:

The ECM tells a different story at the same time...

Picking and choosing there though- closer to the reliable time frame and the ECM isn't far off the GFS at the same stage for Thursday- 

 

 

Still a lot of exceptional warmth on offer over Spain which could well come our way with a very small adjustment to this chart.

[knocker]

The gfs has nodded towards the ecm with energy nipping around the top of western ridge after the initial amplification next week. Thus tending towards a N/S split but temps still very respectable. But as the ridge to west surges NE and the cut off low sinks south what next

Edited October 20, 2017 by knocker

[feb1991blizzard]

Cracking NH profile on GFS 12z, its almost a perfect 3 wave pattern - the cream logo!!

[phil nw.]

No sign yet of any real cool down as we enter the last third of October as an Atlantic trough becomes slow moving against building continental blocking next week bringing sub-tropical air northwards towards the UK. 

 

The latest Gefs C.England temp graph highlighting the warm up on the latest charts after Brian exits right early next week.

Temperatures look to remain well up day and night for the time being with no sign of any frosts in this mild setup.

 

[ANYWEATHER]

28 minutes ago, phil nw. said:

No sign yet of any real cool down as we enter the last third of October as an Atlantic trough becomes slow moving against building continental blocking next week bringing sub-tropical air northwards towards the UK. 

 

The latest Gefs C.England temp graph highlighting the warm up on the latest charts after Brian exits right early next week.

Temperatures look to remain well up day and night for the time being with no sign of any frosts in this mild setup.

 

Yes, but you are basing your view on GFS only.........

[phil nw.]

13 minutes ago, ANYWEATHER said:

Yes, but you are basing your view on GFS only.........

...and the UKMO charts posted.

Pretty good trend amongst the ens members on the graph AW and in recent runs and day 4/5 overall pattern in the charts posted.

Just for you the ECM day 4 and 5

The full set.

Edited October 20, 2017 by phil nw.

[knocker]

Another interesting example of explosive cyclogenesis in the western Atlantic.

At 06 tomorrow the depression is 982mb to the west of the Atlantic ridge. 24hours later it is 938mb south east of Greenland having just departed from the strong jet running NE along the flank of the aforementioned ridge.

Edited October 20, 2017 by knocker

[Captain Shortwave]

Good agreement on a southerly flow developing during the second half of next week as said above we see a highly amplified pattern develop with an Atlantic trough digging far south towards the Azores allowing warm air to pump northwards over western Europe.

GFS/UKMO/ECM

      

How long this pattern lasts is unknown and could breakdown quickly with a lot of options on the table with a spell of unusually warm weather, westerlies returning on possible retrogression with much cooler weather developing. I would suggest that an amplified pattern looks more likely to verify at the moment with the potential for blocking to set up and be maintain suppressing the development of the polar votex as we end the month.

To make a point the GEM would get us close to Halloween 2014 levels of warmth for late October by next weekend.

   

   

 

Edited October 20, 2017 by Captain Shortwave

[knocker]

The ecm is not a million miles from this morning's run even out to T192, Thereafter it is not keen to drop the depression down into the North sea. So after the initial amplification surge the energy makes headway around the ridge again to initiates the N/S split over the UK but temps still very respectable particularly in the south

[LRD]

Well, the Azores High/Euro High combination of boredom is looking dominant next week as it has for much of this month. But the models are looking blocky to our north and north west. It could be (wishful thinking perhaps) that we see some unusual warmth in late October followed by some unusual cold in early November

http://www.wetterzentrale.de/de/topkarten.php?map=1&model=ecm&var=1&run=12&time=240&lid=OP&h=0&mv=0&tr=24#mapref 

 

Edited October 20, 2017 by LRD

[summer blizzard]

Looking at tonights Euro i think that again out to day 8 the Euro is very plausable. The only thing i disagree with is that day 8 it suddenly strengthens the Icelandic Trough. I think it's more likely that that trough would remain weak (if anything the one behind should strengthen) and so the Bermuda High would probably move east a bit and amplify the downstream flow (in turn probably nudging the Euro High East). Other than that though i think it looks very plausable around Greenland and how it mostly handles the Azores Low. 

The GFS has a stronger flow out of Canada which prevents the Azores Low properly cutting off quickly enough to amplify the flow and looks plausable in its own right. Indeed when it does cut off the low, it then retrogresses the Euro High. 

So both models look correct tonight but they show different solutions. 

[bluearmy]

First predictions for early December from the ec 46 show heights rising to our south and low to our north after a troughy cool back third of November - bucket loads of salt as per usual ....... (and unlikely to be of the rock variety!)

[knocker]

I think that it is reasonably apparent that there is a fair amount of uncertainty about the evolution in the medium term. The overall pattern is pretty much agreed on, Cold trough down eastern N. America; ridging in the western Atlantic; trough and cut off low to the W, SW of the UK and the Euro high pushing north in the vicinity of the UK. The problem arises because it only requires small adjustments to the orientation of these components to quite significantly alter the surface analysis. Basically will the trough/Euro HP combination override energy nipping around the HP in the western Atlantic or vice versa? The percentage play is to say a bit of both resulting in a N/S split over the UK with the south remaining dry and warm with any troughs impacting the north.

Back to the here and now. Not to spend too much time on today as this will be covered in other threads.

At midnight Brian was just west of central Ireland 964mb and by midnight Sunday it will be east of Aberdeen 986mb where it become stationary and continue to slowly fill. So a broad band of strong SW/W winds in the south west and south during this morning and afternoon gusting in the F7-9 range and spreading further north during the day when winds will also veer somewhat. These winds accompanied by very squally showers which may combine to form longer periods of rain.which could also produce rogue gusts.

So on to the gfs. After some very transient ridging the front from a very deep low in mid Atlantic that has already undergone explosive cyclogenesis is impacting the UK on Monday bringing some more rain. This soon fizzles out to be quickly followed by another that tracks east into Scotland as a wave that has formed on it scoots NNE to be east of Iceland.by 12 Tuesday. This too fizzles out against the burgeoning  HP as the amplification gets underway.

And this where we came in and the gfs is in no doubt on it's position. It promotes the high pressure, both to the east and west, which isolates the trough in mid Atlantic and initiates some quite extraordinary WAA, not only over the UK, but also over Greenland. The result of this has the UK remaining dry with temps above average though the end of the week and over the weekend and into the following week. Keeping in mind that confidence is very low vis detail in this time frame it best to stop here as this is miles away from a done deal

All of this creates an intense thermal gradient and pushes the 170kt jet up over Greenland.

Edited October 21, 2017 by knocker

[knocker]

No great surprise that the ecm differs quite drastically from the gfs. it's okay with the amplification and a southerly drift Weds/Thurs but not with the blocking in the western Atlantic.Thus by Friday energy has skipped around the HP and with a trough to the north west there is a westerly flow over the northern half of the UK whilst the south remains under the influence of the HP  Classic N/S split. The trough moves east to be way north of Scotland over the weekend creating a quite fresh NW flow over the UK.  It then proceeds to plunge the trough south east as the high pressure once again surges west of Ireland veering the flow over the UK to a cool northerly Oh what a complicated web we weave.

The weekend and after remains firmly in the pending file.

Edited October 21, 2017 by knocker

[summer blizzard]

Euro evolution is nearly perfect. Game over at day 7 for the Euro High..

 

 

[feb1991blizzard]

Here comes the -5c isotherm.

[ACCOUNT DELETED]

12 minutes ago, feb1991blizzard said:

Here comes the -5c isotherm.

Big change there, yesterday it was showing temperatures up to a balmy 21C in the south next Sunday