Model Output Discussion 01/09/17

[Mucka]

Well after last nights high this morning is a bit of a let down, GFS anyway.

Quite flat and very wet with cold uppers in short supply through to day 8.

UKMO looks odd the way it blows up the low at 96h so not putting too much faith in that but at least it turns out much more amplified than GFS

 

I don't have much faith in either run tbh, the models still all over the place.

Edited November 22, 2017 by Mucka

[ArHu3]

1 hour ago, Mucka said:

Well after last nights high this morning is a bit of a let down, GFS anyway.

Quite flat and very wet with cold uppers in short supply through to day 8.

UKMO looks odd the way it blows up the low at 96h so not putting too much faith in that but at least it turns out much more amplified than GFS

 

I don't have much faith in either run tbh, the models still all over the place.

From experience last 2 winters ECM overamplifies, GFS underamplifies and UKMO is the goldilocks model @ +144h

[terrier]

Well after last nights excitement the gfs brings us down to earth with a bang. Looks  very wet out to day 8 and lacking in cold uppers. Ukmo looks a little better. Still got niggling feeling that we will see fleeting cold shots next week. Which bbc outlook was hinting at last night. 

[That ECM]

Morning all. What an interesting period of model watching coming up. The ridge in the Atlantic is shown all of the big 3. Up to t144 we have a general theme but where do we go from there? One run suggesting it gets flattened and others suggestion that it rebuilds. Low confidence in making a forecast? For sure. 

[knocker]

Today and tomorrow can be best summed up as various low pressure areas and associated fronts will cross the country. The main features will be strong winds, gusts up 70mph in places, heavy rain with up to 100mm in places in the north, which will fall as snow overnight and tomorrow in Scotland.

So on to this morning's gfs. By 12 Friday the fronts and lows will all have cleared with a positively tilted upper trough which is deconstructing lying across the UK with main centre to the north east with Scotland within the circulation of the deep surface low giving snow showers in the north. At the same time high pressure is ridging north west of the trough. Over the next 24 hours a wave depression associated with front connected to the cut off low to the south west crosses France into northern Germany and thus initiates a cool northwesterly across the whole of the UK

Simultaneously another upper trough has been ejected from the Canadian vortex lobe (as can be seen) with the surface front orientated a long way south upon which waves are forming. So the progression over the weekend into Monday is for everything to move east with the ridge nudging into the UK on Sunday which is quickly suppressed by the front and depression tracking quickly east bringing snow to Scotland with perhaps some significant falls in the north. by 06 Monday

The low does not clear the UK quickly as two things occur, One it merges with the main trough to the north east and secondly the simultaneous amplification of the HP in the west forces the subsequent complex area of surface low pressure south briefly plunging the UK into a N/NE regime (unsettled but not particularly cold in the well mixed air) before the ridge topples across.

From here a strong westerly regime becomes the order of the day but this is looking way too far ahead.

Edited November 22, 2017 by knocker

[That ECM]

28 minutes ago, knocker said:

Today and tomorrow can be best summed up as various low pressure areas and associated fronts will cross the country. The main features will be strong winds, gusts up 70mph in places, heavy rain with up to 100mm in places in the north, which will fall as snow overnight and tomorrow in Scotland.

So on to this morning's gfs. By 12 Friday the fronts and lows will all have cleared with a positively tilted upper trough which is deconstructing lying across the UK with main centre to the north east with Scotland within the circulation of the deep surface low giving snow showers in the north. At the same time high pressure is ridging north west of the trough. Over the next 24 hours a wave depression associated with front connected to the cut off low to the south west crosses France into northern Germany and thus initiates a cool northwesterly across the whole of the UK

Simultaneously another upper trough has been ejected from the Canadian vortex lobe (as can be seen) with the surface front orientated a long way south upon which waves are forming. So the progression over the weekend into Monday is for everything to move east with the ridge nudging into the UK on Sunday which is quickly suppressed by the front and depression tracking quickly east bringing snow to Scotland with perhaps some significant falls in the north. by 06 Monday

The low does not clear the UK quickly as two things occur, One it merges with the main trough to the north east and secondly the simultaneous amplification of the HP in the west forces the subsequent complex area of surface low pressure south briefly plunging the UK into a N/NE regime (unsettled but not particularly cold in the well mixed air) before the ridge topples across.

From here a strong westerly regime becomes the order of the day but this is looking way too far ahead.

And the ecm says "no gfs, those coldies in the U.K. Have suffered enough of rain and wind from the west. Time for a change have some wind and rain from the north" joking apart the t192 for gfs and ecm illustrate the difference between the ridge rebuilding or not. Await shed loads of posts explaining why ecm is on the money t216 much to resolved!!!!

Edited November 22, 2017 by That ECM

[swfc]

Yes I and a couple of members did say ecm yesterday's evening ecm was a bit clean and progressive

Looks likegfs 0z this morning but subject to change . Tbh ecm looks ok but I guess you could toss a coin on the output!!!

Edited November 22, 2017 by swfc

[SMU]

Still stalemate this morning

UKMO / ECM / GEM v GFS

ECM is the best run of the season promoting an increasing cold picture with snow in the mix

GFS whilst poor initially still retains the heights over the pole past 192

Much to play for with the 'kick' of the jet very apparent in the euros now at 120 it wont be long before its all resolved...

S

[northwestsnow]

EC 0z although not as eye catching as the 12z is still below average after tomorrow right through to day 10 so not sure where the Beeb are getting mild with cold shots from?

Unless of course they place more stock in GFS? 

Saying that GEFS0z dont scream mild to me either- below average all the way through-

 

 

[bluearmy]

Ecm op is close to its previous ens majority cluster out to day 8. should give us some confidence. 

Still waiting to see some consistent agreement with gfs 

[bluearmy]

Ignore the Beeb forecasts if that's what they say. Clearly written by Ian brown ..........

 

[northwestsnow]

Just now, bluearmy said:

Ignore the Beeb forecasts if that's what they say. Clearly written by Ian brown ..........

 

LOL!!

I was a bit suprised by the comments Blue- i personally haven't seen a forecast of mild next week- again EC temp deviation plots look below avg all thr way thru after today?

UKMO/EC look far more amplified and although the block will of course come under pressure both look to extend the high far enough north to prevent a zonal setup returning anytime soon.

 

[northwestsnow]

Joker in the pack has to be the Euro low- while thats locked in its all gravy- for those saying Europa is mild, it isn't acc to the EC 00z deviation plots- couple of snapshots from next week..

mon

tu

fri

Only above avg temps  i can see are NW Russia, mainland Europa looks cold/below avg.

In fact by day 10 the cold seems to be intensifying across Germany/Benelux.

 

Edited November 22, 2017 by northwestsnow

[knocker]

The ecm in fair agreement up to the beginning of the week although it does take the wave on Monday a tad further north which would probably remove the snow threat in Scotland, but it also phases the low with the main trough to the north east and initiate high pressure amplification in the west

So by T168 there is also a complex area of low pressure in the vicinity of the UK generally centred in the North Sea being pushed slowly south, and the the UK in a northerly or northeasterly pretty well mixed airstream. Thus by midweek a wintry mix without anything horrendous.

From this point it differs drastically from the gfs as the ridge is strong enough to resist the east bound energy which is diverted to the trough in the south west which eventually promotes a high cell to the north of the UK. But again this is getting ahead of ourselves.

[Seasonality]

Still a decent ECM. Not as exciting as last night perhaps but a chilly outlook and with UKMO/ECM vs GFS (at the moment), we know who the odds favour. Nothing to moan about here. Have generated a gif of the run for fun, so please click on the image to see.

 

Edited November 22, 2017 by Seasonality

[feb1991blizzard]

24 minutes ago, bluearmy said:

Ignore the Beeb forecasts if that's what they say. Clearly written by Ian brown ..........

 

The long ranger didn't say that last night, it said cold with just temporary milder interludes as systems come through but said back edge and front edge snow likely.

[Team Jo]

Can I ask we keep BBC discussion in the relevant thread please  

I think we can comfortably say that there is a significant degree of uncertainty beyond t72 at the moment, so next week is anyone’s guess....

[SMU]

The updated 00z ECM mean at day 10 shows a further swing to cold-

- Residual high pressure over the pole

- weak high pressure over Greenland & Scandi

- The core of the jet running across the atlantic then bending south East towaards Spain

- Low Euro heights..

Thats a stella mean.

[northwestsnow]

2 minutes ago, Steve Murr said:

The updated 00z ECM mean at day 10 shows a further swing to cold-

- Residual high pressure over the pole

- weak high pressure over Greenland & Scandi

- The core of the jet running across the atlantic then bending south East towaards Spain

- Low Euro heights..

Thats a stella mean.

Yes steve if you go from day 9 to day 10 you can clearly see the azores high being dragged way out westwards- euro low in place= cold west europe . cheers.

[northwestsnow]

3 minutes ago, blizzard81 said:

I for one have not been thinking about beyond the weekend. First things first, this weekend is going to be COLD! Even just a few days ago this was looking very unlikely. Let's just be joyous about that for now ☺️ I won't be even thinking about events for early next week until Friday at the earliest. 

Thats a good post...dry and cold would be my hope to usher in December- As steve has posted, the EC  mean is really encouraging this morning.

Just look at the last two December and be eternally thankful we are not (as of yet) staring into a zonal barrel.

[Seasonality]

3 minutes ago, northwestsnow said:

Thats a good post...dry and cold would be my hope to usher in December- As steve has posted, the EC  mean is really encouraging this morning.

Just look at the last two December and be eternally thankful we are not (as of yet) staring into a zonal barrel.

Dry and cold gives a good base to build on, quite literally. If the air and the ground are already dry and cold then we increase the chances of wintry precipitation when moist air does arrive and also increase the chances of it settling.

[ZK099]

1 hour ago, northwestsnow said:

EC 0z although not as eye catching as the 12z is still below average after tomorrow right through to day 10 so not sure where the Beeb are getting mild with cold shots from?

Unless of course they place more stock in GFS? 

Saying that GEFS0z dont scream mild to me either- below average all the way through-

 

 

I'm pretty sure they don't haha. Gfs performance has been so poor over the past few winters and it was only last week it got it wrong only a couple of days out

[northwestsnow]

1 minute ago, Seasonality said:

Dry and cold gives a good base to build on, quite literally. If the air and the ground are already dry and cold then we increase the chances of wintry precipitation when moist air does arrive and also increase the chances of it settling.

still waiting for the EC mean to update on WZ but yes - i agree with you. In all honesty places locally need a dry spell its been dreadful this past few days, rain wise

[JeffC]

17 minutes ago, northwestsnow said:

still waiting for the EC mean to update on WZ but yes - i agree with you. In all honesty places locally need a dry spell its been dreadful this past few days, rain wise

I'd agree with you there NWS! Everything is fully laden water table wise, and I don't like the look of the rainfall predictions modelled for today.

[carinthian]

Following on from the above post, the latest US Navy model at 180t continues to show a stronger Mid -Atlantic block and differs from its GFS counterpart model at this stage. Its output looks more akin to the ECM/UKMO this morning. Still encouraging to see lower heights in the Azores location combined with persistent meridian  300mb upper wind keep out well into the North Atlantic.