Model Output Discussion 29th December - Into mid-Winter.

[Gael_Force]

4 minutes ago, Johnp said:

What on earth is a QTR?

Not another acronym, I can't keep up.

Wondered this too: maybe 'quick tropospheric response' seeing as all eyes are on the strat at the moment.

[summer blizzard]

Euro shows most of England making it to at least day 8 before low pressure finally breaks through. 

[shane303]

Looking at the models Another cold dry week ahead for us in the south and east overnight frost and fog especially at first , milder and more unsettled in the far west and across Scotland Northern Ireland and NW Wales. 

[bluearmy]

8 minutes ago, Gael_Force said:

Wondered this too: maybe 'quick tropospheric response' seeing as all eyes are on the strat at the moment.

Seeing as it might need to be posted a few times thought it easier to 'acronyse' it

it won't be a well used acronym though! 

[IDO]

1 hour ago, Panayiotis said:

Just to add the spread on that D16 mean, which shows almost all of the NH middle latitudes to have some sort of uncertainty, 20 dam difference just to the NW of Britain

Yes I would expect in a zonal setup the most spread in the Iceland region as that is where the boundary of the jet fires through.

We need scatter in the regions that are drivers, that is the PV lobe over NE Canada, the Euro high and the Azores Ridge. They all remain solid, in line with the mean. 

I know that there are a lot of posters that dislike the mean at that range, but as guidance to long wave pattern it remains useful, especially when the pattern is more stable as the upcoming period will be. Compared to the EC46 which is taken very seriously when cold is showing the D16 mean will obviously be many times more instructive than the latter stages of the EC46 means/anomalies?

I do look at the clusters and scatter when I post, as I always like to backup any comments, be they misguided or not, but it would be arduous to post my musings on them every time I wanted to comment on the FI mean.

The zonal period is now heading towards the more reliable, so we should get more details as to where the jet crosses the UK and whether southern areas can get less unsettled weather. The GFS normally over does the Atlantic in FI, so the jet normally edges north as we enter the reliable. This could mean drier and feeling warmer the further SE you are. The EPO ridge appears to be oscillating which could slow down the PV journey from Siberia to our NW; the knock on effect would be less pressure on the euro high, maintaining a jet from the SW to NE, so cooler and wetter the further NW you are. These are the variations within the theme that may give some spread around the Iceland region, but what it doesn't mean is that there is much chance of a cold pattern materialising on current output which is what I assume your post was about?

[northwestsnow]

Well the models ' at ground level' continue to look hopeless for cold out to lala land but meanwhile the 6z strat forecasts look really good with the PV sent packing away from Greenland!

[Gowon]

Little area of hp starting to build around Iceland in FI

 

Edited January 22, 2017 by D.V.R

[stodge]

Morning all

Not much really to add - the Atlantic breaks through to most of the British Isles by Thursday though there may be a brief continental interlude once again for the SE for 24-48 hours before by this time next week we're all in a SW'ly Atlantic flow.

It's hard to argue with the man on top of Reigate Hill - I got slated for suggesting a 14 day zonal spell a few days ago but here we are. 

Some GEFS members sniffing the early signs of a pattern change but very early days.

It's perfectly possible to get settling lowland snow late February and early March if the synoptics are right.

The stratosphere has to play ball though and there were no guarantees.

[bluearmy]

8 minutes ago, stodge said:

Morning all

Not much really to add - the Atlantic breaks through to most of the British Isles by Thursday though there may be a brief continental interlude once again for the SE for 24-48 hours before by this time next week we're all in a SW'ly Atlantic flow.

It's hard to argue with the man on top of Reigate Hill - I got slated for suggesting a 14 day zonal spell a few days ago but here we are. 

Some GEFS members sniffing the early signs of a pattern change but very early days.

It's perfectly possible to get settling lowland snow late February and early March if the synoptics are right.

The stratosphere has to play ball though and there were no guarantees.

Well we're not there yet with clarity so how you can hang your hat on a two week duration is odd stodge.  

Espcially for the southern half of the uk which could conceivably hold onto the euro ridge 

was just looking at the latest London eps graph and wondering if we wil actually see any appreciable rainfall within the fortnight in the se

[shane303]

People keep going on about no cold spell in sight when here in the south we are in the coldest spell of weather for over 4 years with overnight lows of -9°c and daytime highs of 0°c to 5°c lower in freezing fog this week with the models showing this weather staying at least to Friday in the south 

[John Badrick]

1 hour ago, northwestsnow said:

Well the models ' at ground level' continue to look hopeless for cold out to lala land but meanwhile the 6z strat forecasts look really good with the PV sent packing away from Greenland!

When would you expect the models to start picking up any signal from the strat developments in terms of blocking from PV split?

[damianslaw]

1 hour ago, D.V.R said:

Little area of hp starting to build around Iceland in FI

 

I know talking about charts at such range is rather futile, its the kind of synoptical evolution we might expect to see should the repurcussions of forecasted changes in the Stratosphere and implications for position and strength of PV occur - building of heights over Greenaldn/Iceland regions nosing into central pole and westwards into NE Canada - end result a more NW-SE aligned jet and a lobe of the PV dropping into scandi.

In the meantime, I'm fully expecting the models to show a dominant westerly airstream over the next few days for the latter part of the month/early Feb, but longer range GFS models continue to suggest/hint at height rises to our north. 

 

Edited January 22, 2017 by damianslaw

[Summer Sun]

A few bits from Ian on Twitter (replies to questions)

"However, later in Feb, UKMO model suggests risk of cold wx increases via block in Atlantic with resultant NE/E flow. However: that's wk5 from now (!) & whether it's related to SSW is unclear. In short: low confidence"

[rain_shadow]

3 hours ago, shane303 said:

People keep going on about no cold spell in sight when here in the south we are in the coldest spell of weather for over 4 years with overnight lows of -9°c and daytime highs of 0°c to 5°c lower in freezing fog this week with the models showing this weather staying at least to Friday in the south 

It is because the people going on about don't live in the South.  We had 1 frosty morning on Sat corresponding to 1,3 days of sunshine until 11am on Sat, otherwise ugly low cloud and 3-5 C and the models forecast this for the coming days too. Very exciting indeed.

Edited January 22, 2017 by rain_shadow

[bluearmy]

16 minutes ago, rain_shadow said:

It is because the people going on about don't live in the South.  We had 1 frosty morning on Sat corresponding to 1,3 days of sunshine until 11am on Sat, otherwise ugly low cloud and 3-5 C and the models forecast this for the coming days too. Very exciting indeed.

I can send you a photo of a frosty table if it helps 

ever since those 10hpa warming charts came into focus, all I've been able to picture is a cold spring like last year. 

[shotski]

3 minutes ago, bluearmy said:

I can send you a photo of a frosty table if it helps 

ever since those 10hpa warming charts came into focus, all I've been able to picture is a cold spring like last year. 

Checks Calendar, and it's the 22nd January. 

[terrier]

Well not a single comment on the ukmo or gfs12z tonight. Think that sums it up really. 

[The Weather Dragon]

14 minutes ago, terrier said:

Well not a single comment on the ukmo or gfs12z tonight. Think that sums it up really. 

It's called model fatigue - i'm suffering as well 

[Polar Maritime]

Just sensible discussion on the Model outputs please, For everything else there will be another thread.

Thanks. 

[Ali1977]

Without clogging the feed up with pictures the latest ENS in FI have a fair few with a block forming to our East or North East - it'll be interesting to see if this gathers pace in the next few days. The PV still sits in Northen Canada however.

[nick sussex]

This thread seems more quiet than last year which shows how underwhelming the output is. Its been a bizarre winter so far with hardly any storms but although the Atlantic has been less energetic its still managed to harpoon those windows of opportunity where things could have turned out more interesting.

After the colder conditions leave the scene its looking pretty grim with a flat upstream pattern and low heights to the north. I hope the ECM can deliver something but its a long shot, at this point I'll even take something thats unlikely to verify if only to give us something to talk about!

Edited January 22, 2017 by nick sussex

[Gael_Force]

I went to Instant weather maps to get a strat chart for response to a post that has since been moved. This looks more promising on the 12z output.

That's good separation along the meridian .... opportunity for cold surely if that burrows down to trop.

[CK1981]

3 minutes ago, nick sussex said:

This thread seems more quiet than last year which shows how underwhelming the output is. Its been a bizarre winter so far with hardly any storms but although the Atlantic has been less energetic its still managed to harpoon those windows of opportunity where things could have turned out more interesting.

After the colder conditions leave the scene its looking pretty grim with a flat upstream pattern and low heights to the north. I hope the ECM can deliver something but its a long shot, at this point I'll even take something thats unlikely to verify if only to give us something to talk about!

I'm no expert at all, but with a potential SSW, and subsequent reduction in zonal winds, do you think the models will adjust accordingly? Maybe we'll see a reversal in early Feb and more promising charts as we move forward? I guess if or when it happens, changes in the model output will be seen. I guess we're in a holding pattern.

[Steady Easterly]

17 minutes ago, nick sussex said:

This thread seems more quiet than last year which shows how underwhelming the output is. Its been a bizarre winter so far with hardly any storms but although the Atlantic has been less energetic its still managed to harpoon those windows of opportunity where things could have turned out more interesting.

After the colder conditions leave the scene its looking pretty grim with a flat upstream pattern and low heights to the north. I hope the ECM can deliver something but its a long shot, at this point I'll even take something thats unlikely to verify if only to give us something to talk about!

Its been an extremely dissapointing and highly frustrating Winter, all the signals seemed to suggest cold or deep cold, but it just hasnt worked out that way, to me it just goes to show that you just never know, the weather will do as it wants, and all the teleconnections and stratospheric suggestions dont mean zip, until you see that powdery drift building nicely on your doorstep.

However it may still come yet, we are entering the part of winter that traditionally produces the goods, and ive seen worst patterns than we see now looking forward to the remainder of Winter.

[nick sussex]

9 minutes ago, CK1981 said:

I'm no expert at all, but with a potential SSW, and subsequent reduction in zonal winds, do you think the models will adjust accordingly? Maybe we'll see a reversal in early Feb and more promising charts as we move forward? I guess if or when it happens, changes in the model output will be seen. I guess we're in a holding pattern.

Well if it does land it depends whether you see a quick initial response or whether you have to wait several weeks for that to happen. Generally theres a stronger response if the AO is positive at the time of the SSW in terms of impact on the NH pattern. If some HLB does pop up then its a bit of a lottery though where that sets up.