Model Output Discussion 01/09/17

[feb1991blizzard]

SEVERE DOWNGRADE ALERT

Not only have all the ops now abandoned the Northerly, the GEFS are already showing a marked change as well only 100 hrs into the run.

[tight isobar]

'Downgrade' etc....

Its a days worth of suites(mainly 12z..

With theEC 12Z yet to trickle!

The main emphasis' should be a focus more on the tropospheric/stratospheric state' being modeled -cross suites-..

If its notable infer your looking for.

The potantcy and alignment was always in doubt...and quite frankly 'still is'....

The broader spectrum looks as good as it gets on the doorstep of november!

[Allseasons-Si]

1 hour ago, bobbydog said:

garden path? backtrack? misery?....

we have recurring modelling of wave 2 activity, throwing warm air into the arctic, battering the vortex at an important time in its development-

and people are worried about missing out on a couple of sleet flurries in the midst of autumn??

reality check - this is great stuff to see.

i like my snow in winter. 'deep and crisp and even' etc... and if these patterns keep showing up, we just might get some!

Good post Bobbydog

It seems people are wanting snow on there doorstep....in October and a repeat of Oct 2008,this is very rare in our neck of the woods and there is plenty of time yet

anyways,back on topic,i have been keeping an eye on strat proceedings and here is the 10 and 30 hpa temps over the north pole,yes not much of a warming as of yet but there is a slight uptick there

10 and 30 hpa zonal mean zonal winds and as you can see on the bottom right the oranges(if i am reading these charts right) marking a drop off in wind speeds but i would like to see reds in there but maybe not this early on into the season

http://ds.data.jma.go.jp/tcc/tcc/products/clisys/STRAT/

i will continue to keep monitoring these as we progress into the season

and just for a bit of fun,it's hotting up in the north pole...1216c

will the ECM follow the the earlier runs from the GFS or will it stick to the same old record it has been for the last couple of days,will the GFS switch to it's earlier runs with bites at the cherry,a cherry isn't very big

Edited October 25, 2017 by Allseasons-si

[coldwinter]

34 minutes ago, Allseasons-si said:

Good post Bobbydog

It seems people are wanting snow on there doorstep....in October and a repeat of Oct 2008,this is very rare in our neck of the woods and there is plenty of time yet

anyways,back on topic,i have been keeping an eye on strat proceedings and here is the 10 and 30 hpa temps over the north pole,yes not much of a warming as of yet but there is a slight uptick there

10 and 30 hpa zonal mean zonal winds and as you can see on the bottom right the oranges(if i am reading these charts right) marking a drop off in wind speeds but i would like to see reds in there but maybe not this early on into the season

http://ds.data.jma.go.jp/tcc/tcc/products/clisys/STRAT/

i will continue to keep monitoring these as we progress into the season

and just for a bit of fun,it's hotting up in the north pole...1216c

will the ECM follow the the earlier runs from the GFS or will it stick to the same old record it has been for the last couple of days,will the GFS switch to it's earlier runs with bites at the cherry,a cherry isn't very big

Reds would show strong zonal winds. Not what we’d want to see if you like cold! 

Ryan. 

[Allseasons-Si]

4 minutes ago, coldwinter said:

Reds would show strong zonal winds. Not what we’d want to see if you like cold! 

Ryan. 

Yes,my bad,i was thinking it was high pressure

forgive me,still learning about the strat

the ECM is following the GFS,still,i am looking forward to the frost's if nowt else.

[ANYWEATHER]

No charts to post at present , but the synoptic charts are really great for a big cool down over the UK and indeed for most of Europe. A few frosts even for southern Britain before Halloween makes it the first time in a few years  that we have some really seasonal weather .!  No point quibbling about record cold at this time of year.......I remember October 1997 picticularly the end of the month with record breaking cold frosts then November came along with some sickly mild weather..,..We should be happy with the model output.......

[NeilN]

If anything,it's seasonal and that's what I want! 

[damianslaw]

I said yesterday developments look ripe for scandi troughing and high pressure through mid atlantic, with coldest shots just to our east, and the models are showing this for next week, meaning hopefully much drier sunnier conditions for all, temps around average for the time of year, slightly below at times, with cold nights, widespread frost for northern parts Sunday night week.

Longer term, signs heights will build behind the scandi trough, continuing the drier cold theme. Frost and fog in early November is ideal in my book.

 

 

[knocker]

The anomalies of late have all been in the same ball park but struggling to come to complete agreement over the pattern in the Atlantic so need to still keep that in mind when making a quick assessment of the way forward from this evening’s outputs.

In the ten day period the overall pattern is strong ridge Alaska (continuing WAA into the Arctic), The main vortex lobe N. Canada/NW Greenland (and becoming the main player) with cold trough south through N. America  with subsidiary lobe Franz Joseph and  a negatively tilted trough into eastern Europe. Associated with this is less amplification in the Atlantic so we are looking at an upper flow possibly just north of west and changeable weather over the UK with temps around average, maybe a tad below.

Moving into the later period the trend continues with an intensification of the Canadian vortex, a weakening of the Euro trough and with low pressure over Greenland a more westerly upper flow with perhaps the Azores HP taking more interest in the vicinity of the UK albeit NOAA is not really on board with this. Thus remaining changeable but perhaps more inclined to a N/S split with temps around average perhaps a tad below.. Can't post the EPS but it's not a million miles from the GEFS. A Nina pattern?

[Singularity]

Not without interest how the trop. vortex falls apart days 8-10 of the ECM 12z.

Some very, eh, interesting discoveries while working today have got me paying more attention to this winter season at last. Most long-range models still seeing something different dominating the pattern forcing though, and it remains elusive as to what exactly.

Anyway - I'd not worry too much about missing out on a few early northerlies, and in any case, we should after the past few winters be very used to the light being at the end of a tunnel that seems capable of suddenly changing length without any warning .

If the vortex can be kept dishevelled in the troposphere and lower levels of the stratosphere, that's as good a place to start as any. IF.

[knocker]

Further to my post above MV has tweeted this. Just N. America but you get the drift

"It doesn't get any more La Nina (pattern) than this 11-15d period forecast from the ECMWF EPS"

 

[East_England_Stormchaser91]

5 hours ago, booferking said:

GFS up to its all tricks again backtrack city lol,  first Northerly clips Scotland which was modelled and now the second Northerly which modelled to hit for days goes pete tong another clipper for Scotland and east coast

Up the GARDEN PATH WE GO

Even if we do miss out on the northerlies, they are prepping up cold pooling to our east, which would then be a vital ingredient further down the line if the patterns open up a scandi high and an easterly shot. So many easterlies have failed in the past due to lack of sufficient cold pooling over the near continent. 

[blizzard81]

46 minutes ago, Singularity said:

Not without interest how the trop. vortex falls apart days 8-10 of the ECM 12z.

Some very, eh, interesting discoveries while working today have got me paying more attention to this winter season at last. Most long-range models still seeing something different dominating the pattern forcing though, and it remains elusive as to what exactly.

Anyway - I'd not worry too much about missing out on a few early northerlies, and in any case, we should after the past few winters be very used to the light being at the end of a tunnel that seems capable of suddenly changing length without any warning .

If the vortex can be kept dishevelled in the troposphere and lower levels of the stratosphere, that's as good a place to start as any. IF.

Yes, I noticed that too in the latter stages of the ecm. As a result, things look very sluggish in the northern hemisphere. Surely a good sign for cold to build in the mid latitudes. 

[tight isobar]

The theme continues'angular volocity'..continuing to look very favorable...

Alaskan/eastern seaboard flux continues to tap into the pole.

Pv-is under enormous pressure...run to run..

And looks a defined instrument in continuation ' of stratospheric response!

The punch-load of waa' @above mentioned..(alaskan eastern board ridge)..

And is'nt without aiding arms' of russian pennisula' warmth.... 

Leaving aside'(again)..the seasonal infering/cool/cold northerly. North westerly flow (immenent).  Which will indeed be more 'seasonal'..

The clocks appear'and cogs are most certainly winding in the correct amp...

If your looking for notable cold ...... 

 

Edited October 25, 2017 by tight isobar
Add.

[tight isobar]

Eastern-seaboard/alaskan'ridge 2010-NOVEMBER....

#ARCHIVES

gfs.....#suite....

Favorable eastern lobe pv.

.....

Edited October 25, 2017 by tight isobar

[Geordiesnow]

Think once again, the hunt for cold just starts too early, i see no benefit/relevance of the PV being smashed up so early on, if anything that has been the problem at times, WAA heads into the Arctic so often, the PV struggles to form and we don't see the deep cold like it would in the 70's/80's heading to lower latitudes.

Regardless though, it does look like we will see WAA heading into the Pacific side of the Arctic by the end of the month and at the start of November, history seems to suggest too me it will have no real affect on our weather if cold is your after if the PV heads into Canada and down the Eastern seaboard, if I was looking for cold, the best to hope for is for the WAA to head up to the Arctic via the Atlantic side as that would at least suggest some sort of blocking towards Scandinavia.

In a way, I don't mind the current outlook as we hopefully see the other side of Autumn appearing in terms of dry weather and chilly nights with chilly days despite the sun shining, unfortunately it seems this Northerly is not going to produce too much in the way of cold air for the UK so with milder air, I suspect there could be more cloud around than I would like but if the first widespread ground frost does occur, then Monday morning looks the best bet. The Northerly will hopefully be the start to help cool SST's down as yet again, they are above average quite widely.

[knocker]

Pretty much a north south split today as the front that briefly cleared to the south yesterday reverses and tracks north.Thus the south and midlands cloudy with the odd patch of drizzle in places with temps still on the plus side of normal whilst the north will be clearer and fresher with the odd shower, mainly in western Scotland. Quite windy in the north of Scotland at first with the low still in fairly close proximity to the north.

Tomorrow as high pressure builds in from the west will generally be fresher for all as the front finally clears and perhaps even some more sunshine as the wind generally veers the north west.

On to this morning's gfs. The aforementioned high pressure quickly comes under pressure from the trough to the north and small disturbances the track south east into Scandinavia thus increasing the surface wind and veering it north westerly on Saturday. This trend continues over the next 24 hours and by 12 Sunday the UK finds itself sandwiched between a deep area of low pressure to the east and ever present Atlantic low which is becoming more active. Thus far a time some very light winds leading to a widespread air frost Monday morning.

From this point the trough to the east takes closer order and a channel opens up the main trough area to the N/NE Thus by 12 Monday a shallow surface low lies to the north west of Scotland with a trailing front, and rain, from Scotland to points south west with the high pressure hanging on in there to the south. The fronts then track south east across the UK but by 12 Wednesday we appear to be repeating the pattern from when we started with high pressure surging to the west and a new cut off low to the south and this time the energy/troughs to the north are forced further east into central and eastern Europe. As has been mentioned frequently before slight alterations to this pattern can drastically alter the surface analysis vis the UK

I don't feel inclined to take this much further but by Friday a familiar picture has emerged with the next trough poised overIceland. One thing to note through all of this is that there is very little precipitation apart from SW Scotland and NW England

A quick reflection on the vortex and looking at last night's anomalies and this morning's GEFs a much quoted thought of Samuel Clemens springs to mind.

Edited October 26, 2017 by knocker

[biggreyface]

1 hour ago, knocker said:

Pretty much a north south split today as the front that briefly cleared to the south yesterday reverses and tracks north...

Continued  improvement  is better than delayed  perfection  

Edited October 26, 2017 by Polar Maritime
Snip quote.

[knocker]

The ecm predictable differs from the gfs at the end of next week. By 12 Wednesday it starts to develop a low on the trailing front mentioned above and by 12 Friday there is a shallow low NW of Coruna with the southern half of the UK in a col sandwiched between the two trough areas.By the end of the run the whole of the eastern Atlantic is under the influence of low pressure with what appears to be a large convective area to the south west of the UK. Fairly obviously none of this detail is close to being nailed down

Edited October 26, 2017 by knocker

[Sperrin]

Model 240 trolls out in force today. The 1st Nov northerly gets ditched only to be replaced with another next weekend. 

Are weather models the first sign of computers displaying an AI-type consciousness? 

[carinthian]

The 3 main forecast models have a similar run out to 120h. Below the UKMO still holds the upper low still in situ out in the Mid Atlantic. Thereafter, looks like ECM wants to develop and advance the circulation towards the SW of Britain bringing milder conditions back into Europe with a colder flow down its western flank. UK sort of in between.  All a bit messy past 120h. As Knocker has mentioned scope for change is rather high in this type of set up. May I suggest we still have to look between Iceland and Greenland for developments than can quickly change the forecast synoptics post day 5. 

C 

[Singularity]

It is interesting how the models seem to have this recurring idea of putting one of those mid-Atlantic ridges up toward Greenland, but with seemingly no real clue when this will actually take place, assuming it even does at all. Then again, I remember far too many of these 'dangling carrot' situations in recent winters. It just seems to be how NWP modelling tends to go.

[blizzard81]

38 minutes ago, Singularity said:

It is interesting how the models seem to have this recurring idea of putting one of those mid-Atlantic ridges up toward Greenland, but with seemingly no real clue when this will actually take place, assuming it even does at all. Then again, I remember far too many of these 'dangling carrot' situations in recent winters. It just seems to be how NWP modelling tends to go.

Worth remembering though that even during the classic winters it was often the case that the first couple of attempts at a Greenie block failed only for it to succeed on the third or fourth attempt. 

[karlos1983]

Why can't i see images being uploaded? all i see is links?

[Polar Maritime]

6 minutes ago, karlos1983 said:

Why can't i see images being uploaded? all i see is links?

Will look into it Karlos.