Model output discussion - into the last third of January

[nick sussex]

Typically as the UKMO improved on its 12hrs run the ECM then decides to go the other way !

Its a complex set up with the Azores high wanting to push ne in response to the upstream pattern and the Arctic heights trying to push sw .

So how much trough disruption occurs upstream and with it shortwave energy ejecting east se is a difficult balancing act for the models .

Edited January 20, 2021 by nick sussex

[Chesil View]

 We are in a sort of limbo at the moment. 

It is as I write snowing  heavily in the northwest of England and parts of north wales in association with Storm Christophe.

Scotland both north and south will soon be getting a dumping as well.

Mean while with a downhill run and a following wind parts of the south  may even see something over the weekend.

However we also know that after these few days it will get somewhat milder again.

We await  for the potential snow chances as we head towards and into Feb.

I would reiterate what I have been saying since the turn of the year however and that is not to look too far ahead and not to take any output beyond 144 too seriously whether it shows a beast from the east like the GFSP has for a few runs or raging southwesterlies driven by Iberian hieghts.  The current state of the polar vortex and the continuing ssw effects mean that the modelling can and very likely will change at quite short notice so pinning anything down at 144 and beyond is a mugs game.

I am not for one moment saying that there is going to be a mega beast come February but it is always worth going back through the NOAA reanalysis archives  on wetterzentrale and looking at the charts say seven days before most of the major cold and snowy spells of the last century and in most cases. you would say that you would never  have thought what followed would develop from the charts seven days prior to those historic spells. 

 

Edited January 20, 2021 by Broadmayne blizzard

[sebastiaan1973]

I count 15-20 EC members with N blocking, Scandihigh. Not every member is cold. Cherry picking.

Model charts for Europe (Mean Sea Level Pressure) | ECMWF IFS HRES (10 days)

METEOLOGIX.COM

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ECMWF IFS HRES (10 days) - Current forecast valid for 02/03/2021, 01:00pm of parameter "Mean Sea Level Pressure", model chart for map "Europe"

 

[Tim Bland]

Looks like after 5 days of snow potential it’s 5 days of average before another shot at cold from 1st Feb...which is outside of ECM range. Pattern has been this way according to GEFS for a while so as long as it doesn’t keep getting pushed back then I’m happy with that. 

[Frostbite1980]

12 minutes ago, Tim Bland said:

Looks like after 5 days of snow potential it’s 5 days of average before another shot at cold from 1st Feb...which is outside of ECM range. Pattern has been this way according to GEFS for a while so as long as it doesn’t keep getting pushed back then I’m happy with that. 

The concern i have is the sense of deja vu when there was trend to something colder a few weeks back and then it all backed away to what we have now. I just hope lightning doesnt strike twice on this occasion and agree the beginning of Feb looks interesting based on those ensembles.

Edited January 20, 2021 by Frostbite1980

[Matt H]

ICON 18z still looks snowy on Sunday. Looks great for those in the south that haven’t seen much snow so far this winter.

[Tim Bland]

Most places see some snow early Sunday on the Icon

[Griff]

GFS Arctic heights doing something different down the pub? 

[damianslaw]

Sticking to the UK Fax charts at present, no point in looking beyond 120 hrs I say.. lots going on. Outlook is cold, most of UK under 528 dam air, trough and frontal features hard to predict, but the flow is unstable, plenty of opportunities for snow and sudden developments. Always a nowcast situation, as proven this evening with the heavy snow in parts of lowland NW England - completely unforecast!

[Griff]

Much colder nearby than 12z if it can get to the UK rather than the Atlantic sweeping through... 

Edited January 20, 2021 by Griff

[MATTWOLVES 3]

18z keeps with that snow risk over the coming 5 days...while I'm at it...rain as turned to heavy snow here...im so happy I could do the 3rd act from singing in the rain.

[Tim Bland]

3 hours ago, feb1991blizzard said:

Not sure how any snow could have fallen over Manchester by that stage when the purple missed..

You can probably look out your window now for the answer to this!

[Griff]

Para also more amplified... 

[nick sussex]

The day 5 into 6 forecast is looking very hard to call with each run having a different view of any shortwave energy ejecting off the upstream troughing .

 

[Captain Shortwave]

Surprised to see the sheer stubborness from the ECM to develop something more interesting. Instead keeping the jetstream pretty solid through the UK with further spells of wind and rain.

GFS op - First hints of toying with a split flow by day 7.

We will have to see going forward, but if the idea of a wedge of heights to our north develops for week 2 then we could end up with a significant shift towards a colder outlook. 

 

Edited January 20, 2021 by Captain Shortwave

[Griff]

Para might have had one too many. Might go off on one

Edited January 20, 2021 by Griff

[Griff]

4 minutes ago, Captain Shortwave said:

Surprised to see the sheer stubborness from the ECM to develop something more interesting. Instead keeping the jetstream pretty solid through the UK with further spells of wind and rain.

GFS op - First hints of toying with a split flow by day 7.

We will have to see going forward, but if the idea of a wedge of heights to our north develops for week 2 then we could end up with a significant shift towards a colder outlook. 

 

Parallel is much more keen

Edited January 20, 2021 by Griff

[Jayfromcardiff]

GFS still going for snow across southern areas during Sunday, it'll be interesting to see if the Met Office make anything of it.

[Ice Day]

6 minutes ago, Griff said:

Para might have had one too, many. Might go off on one

You're not wrong - at 174 it's lining up some fun and games

No inter-run consistency though, perhaps a positive!?

[Frostbite1980]

3 minutes ago, Ice Day said:

You're not wrong - at 174 it's lining up some fun and games

No inter-run consistency though, perhaps a positive!?

Thats got sliders written all over it.

[Rocheydub]

I'm taking huge positives from this. Look at the state of the Vortex! It's all over the place, like BJ's hair!

[Griff]

Just now, Rocheydub said:

I'm taking huge positives from this. Look at the state of the Vortex! It's all over the place, like BJ's hair!

GFS op isn't interested

[IDO]

I said a little while ago I would be shocked if the para takes over next month. My shock is even more shocking seeing its current output! 

I went back 10-days to see how it fairs against the soon to be junked gfs; these were their predictions...

para>gfs>

...and the reality>

Shocking! It may have just been random bad luck it was so wrong at d10 for now, but it seems that when it predicts heights it has a greater propensity to be wrong and vice versa! It will be a feast of d10 charts on the scale ecm could never serve up, a gourmet meal every winter evening around 7pm. I cannot wait!

[Ice Day]

Para at 210 v the 216 from earlier - the NH profile is significantly different by this stage.  FI back to 72/96 at the moment.

  

[snowy36]

Even when it gets slightly milder the cold is never far away.