Model Output Discussions 12z 08/03/17

[Frosty.]

Indeed, it's a massive snowfest in low res on tonight's Gfs 18z..and that's no exaggeration.

[knocker]

Morning campers, a quick overview of the GFS this morning some of which is unchanged from yesterday.

So we still have the trough disruption tomorrow and the new surge of the Azores NE on Sunday. Perhaps it's worth stopping and taking a closer look here and on Monday the ridge comes under pressure from the energy driven trough to the north west which actually forces some decaying fronts across the country Monday night before the high pressure reestablishes itself. But it's also worth noting the split energy upstream with some taking the more southern route and is to become a very familiar cut off upper low to our south west.

Moving forward to Thursday midnight and we have the high cell established just south of Ireland with energy shooting over the top and the cut off upper low in mid Atlantic This portends the quiet pleasant weather next week that has been indicated for a while now with the detail of cloud and geographical/diurnal temp variations still to be nailed down

From this position the scenario is not a million miles away that has been indicated by the anomalies with the high pressure continuing under pressure from the energy running east/south east but also in the Atlantic where the upper low is reinforced by the drip feed of energy emanating upstream But through all of this the HP manages to hang in there, albeit some cooler more unsettled weather may ingress from the NW on occasion

But this twin attack does eventually gain some traction and ends with a trough tracking SE to the west of the UK and the possibility of another large low pressure area with much cooler and unsettled weather setting up shop in the eastern Atlantic for a period. But this is getting a little ahead of ourselves for the moment.

So next week in a nutshell. Generally under the auspices of the high pressure so dry, apart from Scotland, with temps around average (usual caveats) but perhaps the odd much cooler unsettled spell late on for the north.

Edited March 31, 2017 by knocker

[Frosty.]

The Gfs 00z shows spells of unsettled and wintry weather during low res as arctic air digs south, especially across the north, cold enough for sleet and snow at times with overnight frosts / ice.

Edited March 31, 2017 by Frosty.

[I remember Atlantic 252]

let's have old Frosty back! want decent charts! good chart from ECM, hopefully better on GEM too as high drifts east, slight continental drift

[knocker]

The ecm does differ in the evolution from the GFS as it gets into the run and by T180 has a much more established upper trough mid Atlantic with no ridging into Greenland.and thus by midnight Sunday we find the trough deconstructing just to the west of Ireland which is not the case with the GFS. This shouldn't really be a great surprise because any variation of the phasing of cooler/warmer air is going to be exaggerated the further into the run we go 

All in all the overall picture with the ecm is not dissimilar to the GFS with the UK remaining under the auspices of the high pressure with some Atlantic ingress over Scotland at times and perhaps indications of the breakdown at the end. So dry with the usual caveats vis temps and cloud.

[Summer Sun]

Whilst GFS wants to bring some colder air our way next weekend ECM doesn't

Edited March 31, 2017 by Summer Sun

[Frosty.]

13 minutes ago, Summer Sun said:

Whilst GFS wants to bring some colder air our way next weekend ECM doesn't

More runs are needed I think.

[Man With Beard]

Bit of a mix-up this morning. 

By the 8th April, the ECM isn't as warm as yesterday's 00Z, but still very spring-like if the det/mean comes off

      

The GFS, on the other hand, makes a lot more of the Scandi low and reminds us that April can still bring a wintry bite. Take GEFS P5 for instance:

    

On balance, and bearing in mind the trends of the past 48 hours, you'd still have to say something more like the ECM is favourite, but you never write off the GFS, do you.

[Frosty.]

2 minutes ago, Man With Beard said:

Bit of a mix-up this morning. 

By the 8th April, the ECM isn't as warm as yesterday's 00Z, but still very spring-like if the det/mean comes off

      

The GFS, on the other hand, makes a lot more of the Scandi low and reminds us that April can still bring a wintry bite. Take GEFS P5 for instance:

    

On balance, and bearing in mind the trends of the past 48 hours, you'd still have to say something more like the ECM is favourite, but you never write off the GFS, do you.

I'm not sure about the Ecm, it led coldies up the garden path all winter, building dreams and then crushing them soon after.

[Man With Beard]

Just now, Frosty. said:

I'm not sure about the Ecm, it led coldies up the garden path all winter, building dreams and then crushing them soon after.

I think that was true of the op, but the mean wasn't so far off I think, at least up to D10?

GEM offers support to the ECM as well - looks BBQ ish, in fact

Interesting looking at the ECM monthly out to D18. The D4-D10 period looks nailed on for heights centred over the south and well above average temps for all:

  

But the D11-D18 flips to more of a GEFS style scenario. The temp anomoly doesn't look far off average but I'd guess the set-up would support a few very cold days for the time of year:

  

GEFS D15 heights anomoly is not exactly the same but you can see a sort of resemblance

A white Scottish Easter coming up, perhaps??

[Frosty.]

1 hour ago, Man With Beard said:

I think that was true of the op, but the mean wasn't so far off I think, at least up to D10?

GEM offers support to the ECM as well - looks BBQ ish, in fact

Interesting looking at the ECM monthly out to D18. The D4-D10 period looks nailed on for heights centred over the south and well above average temps for all:

  

But the D11-D18 flips to more of a GEFS style scenario. The temp anomoly doesn't look far off average but I'd guess the set-up would support a few very cold days for the time of year:

  

GEFS D15 heights anomoly is not exactly the same but you can see a sort of resemblance

A white Scottish Easter coming up, perhaps??

Good post MWB..sounds a fair assessment of how things currently stand. :- )

[mb018538]

I wouldn't worry too much about the charts 10+ days away at the moment.....vary different outcomes showing up!



Seems to me that the key period is around the 7th April, where some runs carry on with the mild theme, where as others plunge some pretty cold air south! One to keep an eye on without taking OP runs at face value.

[Summer Sun]

The ECM weekly temperatures which updated earlier in the week are free from blue which means one thing above average temps

[knocker]

It would look quite likely that a pattern change is on the cards in around 8-10 days time but how that evolves is far from certain and at this stage one can really only play rough percentages IMHO. the EPS 6- 10 anomaly shows this transition with the HP and weak Atlantic trough moving east whilst heights build in the western Atlantic.

So moving forward from this the EC46 11-18 has the vortex over Russia, secondary lobe over Canada, trough over the UK and positive anomalies mid Atlantic which actually is not a million miles away from the GEFS 10-15 this morning whilst the EPS merely nods in that direction NOAA 8-14 certainly has height building and ridging in the Atlantic but is somewhat more complex further east.

So without anything being close to being pinned down vis the detail the percentage play would appear to be a return to a much more zonal regime with the usual interplay between the warm/cool airmasses. This portends a period of more unsettled weather, with systems tending to swing SE in the W/NW flow with temps fluctuating but tending a little below average.

Edited March 31, 2017 by knocker

[snowray]

Well what a difference 12 hours makes with the GFS, Palm Sunday now looking very mild and sunny, and there was me thinking about a Scottish skiing break Easter week too.

[Frosty.]

15 minutes ago, snowray said:

Well what a difference 12 hours makes with the GFS, Palm Sunday now looking very mild and sunny, and there was me thinking about a Scottish skiing break Easter week too.

Just a final kick in the teeth for the Scottish skiing industry who have had their worst season in years..unless the latest run is wrong of course.

[snowray]

21 minutes ago, Frosty. said:

Just a final kick in the teeth for the Scottish skiing industry who have had their worst season in years..unless the latest run is wrong of course.

I doubt its wrong, GFS just starting to fall in line with the ECM as per usual these days. 

[jvenge]

Ohhhh the control from the GEFS 06z is a thing of beauty for my location and not terrible bad for the UK either. Only a few of the members showing cooler outcomes for the UK, which is encouraging. 

[I remember Atlantic 252]

3rd one down, my favourite Frosty!

[snowray]

1 hour ago, Frosty. said:

Something for everyone..for the sake of balance.

Well I'm hoping that the mild runs verify because any half baked cold blast like the halfway house between ECM and the colder GFS runs in April will just be miserable after all this lovely weather, and with the prospect of more of the same and even better to come its just too mouth watering, I got a taste for it yesterday I'm afraid. So I will stick to being a mildy, for now anyway.

[I remember Atlantic 252]

2 minutes ago, snowray said:

Well I'm hoping that the mild runs verify because any half baked cold blast like the halfway house between ECM and the colder GFS runs in April will just be miserable after all this lovely weather, and with the prospect of more of the same and even better to come its just too mouth watering, I got a taste for it yesterday I'm afraid. So I will stick to being a mildy, for now anyway.

Yes, don't fancy single digits and rain, dunno how anyone can like that weather, in any month of the year

[cheshire snow]

41 minutes ago, I remember Atlantic 252 said:

Yes, don't fancy single digits and rain, dunno how anyone can like that weather, in any month of the year

Indeed,however we seem to get the single digits and rain from November through too February 

C.S. 

[snowray]

4 minutes ago, cheshire snow said:

Indeed,however we seem to get the single digits and rain from November through too February 

C.S. 

Iv'e seen single digits and rain in June CS!

 

[Sky Full]

The Jetstream is here predicted to form a perfect arch to the north of the UK next week allowing a lovely high pressure to become established directly over us, hopefully bringing some more warm and settled Spring weather with only light winds to most places, and with minimal cloud cover It is to be hoped...... (but don't go there again    )

  

  

 

[Frosty.]

12 minutes ago, Sky Full said:

and with minimal cloud cover It is to be hoped...... (but don't go there again    )

 

 

Hopefully there won't be as much high cloud next time making the sunshine milky / hazy.