Model Output Discussions 18z 31/01/2016

[snow freak]

8 hours ago, snowray said:

Yes the uppers are not what we might of expected in mid February, theres a lot of cold though further East ready to pile in though if the Easterly could hang on for a while. Having said this I have seen my fair share of really quite mild Easterlies during Winter months in years gone by.

not sure even easterlies would be much good at the moment.  Even Russia is currently in fairly mild air so there is no huge cold pool over Europe for us to tap into even if we get an Easterly.

[Frosty.]

Gibby mentions a return of milder Atlantic westerlies beyond the upcoming cold snap but within that more mobile pattern I'm seeing polar maritime shots too, the Ecm 00z for example is showing a strong blast of cold zonality later..so a return to milder Atlantic driven weather doesn't mean prolonged long draw mild swly mush, it would have colder phases too.

[jvenge]

7 minutes ago, snow freak said:

not sure even easterlies would be much good at the moment.  Even Russia is currently in fairly mild air so there is no huge cold pool over Europe for us to tap into even if we get an Easterly.

Yep...unusually warm over here as well and next week might see some mid teens. Can't really see any trend to anything different for the next two weeks, with just a few wildcard ensembles showing a change.

Of course, you have a little more of a chance with a north easterly I guess? That doesn't really need cold over eastern Europe and Russia. Probably better for this time of year as well! 

 

 

[winterof79]

Snow showers from Saturday for the NE and central areas

 

[Polar Maritime]

The weekends snow risk from the 6z. 

Edited February 10, 2016 by Polar Maritime

[Frosty.]

8 minutes ago, Polar Maritime said:

The weekends snow risk from the 6z.

 

Yes PM I'm really looking forward to this cold snap, there is mention it will be feeling bitterly cold on Sun / Mon with snow showers, especially across northern and eastern areas and with widespread frosts...  a nice change!

Edited February 10, 2016 by Karl.

[Ben Sainsbury]

Along with the potential snowy spell this weekend, I'm looking forward to T+180 as we see a strong area of HP over the Atlantic, with a weaker area of HP over Scandinavia, this seems to push high pressure into Greenland and with the isobars indicating northerly/ne winds looks like a decent cold spell on the cards if this comes off!? Most likely will change but looks promising to my amateur eye. Then hopefully we see the low pressure off the coast of East Canada, advecting northwards, which should displace colder air. Jetstream makes its way into Spain.

Edited February 10, 2016 by Ben Sainsbury

[Tim Bland]

I have a feeling that this weekend is going to be a damp squid with snow reserved for the highest ground of northern England and Wales. Perhaps some snow showers in the north and east sun night and monday. What we are seeing though is an upgrade to the snow opportunity mid week as the energy slides south east. This time we have Cold air in place and cold ground so a better chance of settling snow for those who are yet to see any this winter....

 

[nick sussex]

The GFS still wanting to go for some trough disruption next week. The ECM after hinting it might do this yesterday evening isn't interested today.

The GFS is quite an unusual scenario with a cold nw flow heading into some surface cold left over from the ne flow.

Its a shame the earlier 850's aren't as cold and the models keep the deeper cold locked over Scandi and Iceland and this then only grazes the UK as the low clears away.

 

[MR EXTREMES]

good morning everyone.

well my ramp earlier in the week has now turned into a bottomless pit...

as we see the more exciting outputs decline day by day run by run.

the lack of post from the more experienced posters except a few shows that confidence is very low on anything substantial in regards to cold.

as I suggested most of winter we have suffered at the hands of a strong vortex and strong el nino west QBO but the lag effect of these teleconnections are still running the show now theres not much difference though from winter 2014/15 when we had displaced azores high and strong vortex to our nw around Greenland and Canada even though last winter was a la nina winter.

so where do we go from here well we certainly do see possible cold pm air from time to time but only really effecting the northern half of England and Scotland further on into the rest of feb looking at the weekend I suspect the slider low is more likely to cross the south with snow line south midlands wales and sw with elevation chilterns southdowns possibly to.

the jet is not able to track much further south than southern England maybe northern france.

but with very little in the way of higher pressure to our west nw or ne theres not much scope for a decent wintry setup.

there have been some interest from the models at times to try wedge around Greenland even west into the atlantic but this has only been sporadic within the model outputs models do tend to struggle with depression placements and sometimes we have to await the actual event itself until we can once again look for the next pattern although I do feel now that the vortex has split but not favourably so there for continued copping and changing but certainly no northern blocking and the mjo is rather slow to move through the phases.

so really its more of the same but not as active as recently.

winter most certainly looks dead in the water here in the far south but further north and this weekend southern midlands across into wales and sw England with elevation southdowns perhaps but anything south of that id say close but no cigar.

[karlos1983]

It seems to me that the Scandi heights are doomed to failure, they aren't strong enough at a time when there is a lot of energy to our north west, and the Scandi Heights actually prove to be a hinderance rather than aiding our cold hopes, pretty much ending our chances of a northerly in fi.

 

[nick sussex]

5 minutes ago, karlos1983 said:

It seems to me that the Scandi heights are doomed to failure, they aren't strong enough at a time when there is a lot of energy to our north west, and the Scandi Heights actually prove to be a hinderance rather than aiding our cold hopes, pretty much ending our chances of a northerly in fi.

 

Unfortunately Karlos there wouldn't be much chance of a northerly even without the Scandi high as the PV is too strong. Indeed the Scandi high is the only thing stopping the pattern flattening out completely and it at least is trying to force the jet to angle more nw/se.

I'm still interested in next weeks prospects because the ECM looking at the ensemble spreads still has solutions that disrupt that troughing near the UK.

The UKMO is colder than the ECM/GFS at T120hrs with a strong ne flow so theres still some snow chances.

[MR EXTREMES]

29 minutes ago, Ben Sainsbury said:

Along with the potential snowy spell this weekend, I'm looking forward to T+180 as we see a strong area of HP over the Atlantic, with a weaker area of HP over Scandinavia, this seems to push high pressure into Greenland and with the isobars indicating northerly/ne winds looks like a decent cold spell on the cards if this comes off!? Most likely will change but looks promising to my amateur eye. Then hopefully we see the low pressure off the coast of East Canada, advecting northwards, which should displace colder air. Jetstream makes its way into Spain.

these charts most certainly have potential.

the 6z gfs has removed the snow risk even from the sw for the weekend but longer term has a gradual decline in850s and is colder in lala land but shouldn't be read into to much but cold is transferred more from the west side of the uk to eastern side if the 6z is to be correct.

but until the slider departs then we will know if this will be correct big dis placed azores ridge building to the west of the uk but would not be good enough to build into Greenland we also have a scandi ridge trying to take on the vortex but I suspect the CHAMP IE VORTEX will continue to dominate.

 

[karlos1983]

14 minutes ago, nick sussex said:

Unfortunately Karlos there wouldn't be much chance of a northerly even without the Scandi high as the PV is too strong. Indeed the Scandi high is the only thing stopping the pattern flattening out completely and it at least is trying to force the jet to angle more nw/se.

I'm still interested in next weeks prospects because the ECM looking at the ensemble spreads still has solutions that disrupt that troughing near the UK.

The UKMO is colder than the ECM/GFS at T120hrs with a strong ne flow so theres still some snow chances.

Cheers Nick for clearing that up. It just looked at face value that the Scandi high was causing the issue, but my mistake. 

[weirpig]

Straw clutch  alert!  the gfs control run will bring bands of snow from the northwest down through the country.  Im not giving up i will get my snow

[wishingforsnow]

Typical as when a cold spell is forecast for the UK the focus then shifts towards worry over when its going to end

I hope things overall are starting to look drier for the future even if it warms up after this cold spell. The Jet Stream showing possible signs of finally weakening significantly in the long range output today is promising.  

[karlos1983]

9 minutes ago, wishingforsnow said:

Typical as when a cold spell is forecast for the UK the focus then shifts towards worry over when its going to end

I hope things overall are starting to look drier for the future even if it warms up after this cold spell. The Jet Stream showing possible signs of finally weakening significantly in the long range output today is promising.  

To be honest, I'm more worried about whether its going to get started, but I guess that depends on one's opinion of a cold spell. 

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=144&mode=1&carte=1

-4 850's with snow confined to high ground, doesn't really seem like a cold spell to me. Time of course for things to change.

 

[bryan629]

1 hour ago, nick sussex said:

Unfortunately Karlos there wouldn't be much chance of a northerly even without the Scandi high as the PV is too strong. Indeed the Scandi high is the only thing stopping the pattern flattening out completely and it at least is trying to force the jet to angle more nw/se.

I'm still interested in next weeks prospects because the ECM looking at the ensemble spreads still has solutions that disrupt that troughing near the UK.

The UKMO is colder than the ECM/GFS at T120hrs with a strong ne flow so theres still some snow chances.

I see what your saying about trough disruption .. or the possibility thereof...!!  

The CMA shows of quite nicely your line of thinking Nick

http://www.meteociel.fr/modeles/cmae_cartes.php?ech=12&code=0&carte=1&mode=0&archive=0

I hope the 12z ECM starts to sniff something along these lines 

 

 

[johnholmes]

Looking at the last 2 days or so from the 500mb anomaly charts and worries about a milder Atlantic, based on is it one or more synoptic runs, seems pretty unlikely to me. See links below showing quite marked north of west flow on all 3 models in the 6-10 day and further out with NOAA in the 8-14 day time frame.  Of course the synoptic models may have a lead on the anomalies but it is quite rare.

http://www.cpc.noaa.gov/products/predictions/814day/500mb.php

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

Certainly the 500mb air on NOAA originates from USA showing about 546DM in the far south of the UK on the 6-10 day with ECMWF-GFS showing lower values and the air from over Canada. These differences in origin and predicted heights do happen, maybe NOAA will move towards the other heights. Mostly the NOAA outputs do seem to verify more often but not always. Anyway none of them show milder weather as an AVERAGE over the 6-14 day period. Day to day may well have a milder slot as a low tracks east over the Atlantic towards/over the UK.

[Man With Beard]

1 hour ago, weirpig said:

Straw clutch  alert!  the gfs control run will bring bands of snow from the northwest down through the country.  Im not giving up i will get my snow

This is not a straw clutch at all. How many times have we seen disturbances pop up even at T24 once we get a northerly flow in low heights? This has good chance of verifying IMO.

So interesting to see how the tiniest of changes in the GFS over 48 hours has changed the forecasted drag of cold over the UK:

The dissolution of the first slider has not helped the cause of cold, as we now do not have a strong eastern flank to filter cold through. We really need two lows to slide in order to get the cold in. What would be really helpful is more developments to the SW of Saturday's low, which can combine with the colder air Sunday/Monday. Like GEFS permutation 12:

which, as the disturbances develop, become:

and even better, lead to low heights over Iberia/Corsica:

which then link up with the disrupting trough SW of Ireland to lock the cold in from the east:

What odds would you give it? Better than Leicester winning the Premier League??

 

 

[Severe Siberian icy blast]

23 minutes ago, Man With Beard said:

I thiThis is not a straw clutch at all. How many times have we seen disturbances pop up even at T24 once we get a northerly flow in low heights? This has good chance of verifying IMO.

So interesting to see how the tiniest of changes in the GFS over 48 hours has changed the forecasted drag of cold over the UK:

The dissolution of the first slider has not helped the cause of cold, as we now do not have a strong eastern flank to filter cold through. We really need two lows to slide in order to get the cold in. What would be really helpful is more developments to the SW of Saturday's low, which can combine with the colder air Sunday/Monday. Like GEFS permutation 12:

which, as the disturbances develop, become:

and even better, lead to low heights over Iberia/Corsica:

which then link up with the disrupting trough SW of Ireland to lock the cold in from the east:

What odds would you give it? Better than Leicester winning the Premier League??

 

 

I think you have really well illustrated the point well . 

There is a genuine chance of more trough disruption next week and once the low pressure gets into Europe then the over scandi will have a decent breeding ground and should in time push deep cold west.  Certainly more interesting weather coming up over the next week or so. 

Personally I'm disappointed with the loss of the snow risk the weekend had . Not a complete no goer but chances seem slim in comparison to the other day . Maybe some will be in for a surprise ? 

[wishingforsnow]

1 hour ago, johnholmes said:

Looking at the last 2 days or so from the 500mb anomaly charts and worries about a milder Atlantic, based on is it one or more synoptic runs, seems pretty unlikely to me. See links below showing quite marked north of west flow on all 3 models in the 6-10 day and further out with NOAA in the 8-14 day time frame.  Of course the synoptic models may have a lead on the anomalies but it is quite rare.

http://www.cpc.noaa.gov/products/predictions/814day/500mb.php

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

Certainly the 500mb air on NOAA originates from USA showing about 546DM in the far south of the UK on the 6-10 day with ECMWF-GFS showing lower values and the air from over Canada. These differences in origin and predicted heights do happen, maybe NOAA will move towards the other heights. Mostly the NOAA outputs do seem to verify more often but not always. Anyway none of them show milder weather as an AVERAGE over the 6-14 day period. Day to day may well have a milder slot as a low tracks east over the Atlantic towards/over the UK.

Great point here. No point getting hung up on individual model upgrades and downgrades when there is still uncertainty over the weekend and beyond.

and NOAA isn't showing anything mild/milder than average

Edited February 10, 2016 by wishingforsnow

[Purga]

1 hour ago, Man With Beard said:

This is not a straw clutch at all. How many times have we seen disturbances pop up even at T24 once we get a northerly flow in low heights? This has good chance of verifying IMO.

So interesting to see how the tiniest of changes in the GFS over 48 hours has changed the forecasted drag of cold over the UK:

The dissolution of the first slider has not helped the cause of cold, as we now do not have a strong eastern flank to filter cold through. We really need two lows to slide in order to get the cold in. What would be really helpful is more developments to the SW of Saturday's low, which can combine with the colder air Sunday/Monday. Like GEFS permutation 12:

which, as the disturbances develop, become:

and even better, lead to low heights over Iberia/Corsica:

which then link up with the disrupting trough SW of Ireland to lock the cold in from the east:

What odds would you give it? Better than Leicester winning the Premier League??

 

 

Well said but you in Portsmouth and me and many others in the south of the country really aren't likely to get anything much more than cold rain or a bit of sleet throughout the next 7-10 days - if we're lucky - are we?

In the meantime the GEFS 06z seem to paint an increasingly milder picture in the longer term.

apart from one lone straggler that is!

Edited February 10, 2016 by Purga

[nick sussex]

I sense a feeling of model fatigue and frustration from NW members. It does seem to have been like a long arduous slog through much of the winter. With very little reward in terms of cold and snow. This pretty well sums up most winters that I spent in the UK.

Looking forward I'm still not willing to throw the towel in although I was close to it a few times early last week. I'd like to see what the models do with the deepish trough which heads se from Greenland and any Scandi ridge that might develop.

Before then theres still uncertainty with any any shortwave low and how much cold gets pulled sw into the UK.

Admittedly its not the deep freeze that many would hope for and we are to a degree left with the cold scraps which seems to be the way of things this winter.

Hopefully the models will make the best of those scraps!

[Daniel*]

The weekend is still up for grabs IMO south of the M4 it is not looking great quite wet - expect changes to T24. 

It is not resolved I sense the model fatigue as well, it has been a long winter but hopefully our efforts are rewarded before the doors slam shut on winter 15/16.

Weekend aside a flow from the NE, quite unstable I'd reckon with low heights in Low Countries squeezing a ne'ly flow. Driving in sleet/snow showers from the east perhaps merging into longer spells of s thing not a bad synoptic. Hopefully the quite warm SST in North Sea will help compensate for the lack of very cold 850's which are typically needed to allow convection. 

It is not an ordinary winter that's for sure..it's not over yet. 

 

Edited February 10, 2016 by Daniel*
Note to self do not post while working