Model Output Discussions 18z 31/01/2016

[Nouska]

Yes Nick, quite an impressive ensemble mean beyond day ten - for those that don't have access to the premium sites, a wee snapshot of the local area.

Day 13 EPS.

850 temp     Z500  

[cheshire snow]

quite a contrast on the GFS06z by day ten(FI) Temperatures upto 12c,were as on the

06z we were just getting up to 5c.

And then to top it all of Day 11 shows Heavy snow spreading from the North

C.S 

[IDO]

With Feb CET anomaly after 5 days at +3.5c the theme of a very mild Winter continues. Looking at the temp anomalies for the next 10 days this will continue for most of Europe though the UK may just miss the anomalous warmth on this occasion:

  JMA w3-4:   CFS w3 & w4: 

The lack of cold to the east sums up this winter. The JMA week 3-4 anomaly offers little hope of a pattern change with a continuation of the Winter theme, +Euro heights anomaly dominating. CFS offers the same with the possibility of height rises over the UK in week 4^^^.

Potential for some cold air over the UK in the next 8 days but not great synoptics, away from the North and hills, for snow for most. I think when this Winter is summed up it will be storms, rain and warmth rather than cold. As others have said without a Major SSW, this winter was always likely to be rubbish for cold and snow and I see little hope of any pattern change to a blocked pattern for the rest of Feb. Best to look to Spring now and see what lies ahead there.

 

[nick sussex]

What actually verifies come T0hrs is up in the air.

For example take yesterday mornings ECM to T192hrs and compare it to todays at T168hrs in terms of 850 temps to the ne:

 

The slp chart for T168hrs shows why this deeper cold pool raises the stakes as it could deliver a snow event if theres more trough disruption with a westwards correction, this would result in this cold getting further sw and as the elongated low pressure to the west slips se'wards this would engage that colder drier air with lower dew points. And you'd be very much on then for some significant snow.

 

The models seem to be struggling with the detail for the UK and western Europe and exactly how much cold pooling appears between outputs seems to keep changing.

 

 

[winterof79]

51 minutes ago, IDO said:

With Feb CET anomaly after 5 days at +3.5c the theme of a very mild Winter continues. Looking at the temp anomalies for the next 10 days this will continue for most of Europe though the UK may just miss the anomalous warmth on this occasion:

  JMA w3-4:   CFS w3 & w4: 

The lack of cold to the east sums up this winter. The JMA week 3-4 anomaly offers little hope of a pattern change with a continuation of the Winter theme, +Euro heights anomaly dominating. CFS offers the same with the possibility of height rises over the UK in week 4^^^.

Potential for some cold air over the UK in the next 8 days but not great synoptics, away from the North and hills, for snow for most. I think when this Winter is summed up it will be storms, rain and warmth rather than cold. As others have said without a Major SSW, this winter was always likely to be rubbish for cold and snow and I see little hope of any pattern change to a blocked pattern for the rest of Feb. Best to look to Spring now and see what lies ahead there.

 

A fair proportion of the UK is hilly from the Derbyshire peaks upward. More than people realise

Even though the six nations is on I must include Wales as being hilly too

Edited February 7, 2016 by winterof79

[feb1991blizzard]

13 hours ago, nick sussex said:

Yes but we haven't seen the much vaunted major SSW which hit the buffers. The only remotely interesting spell for the UK which wasn't upto much but still better than the rest of the winter was that spell in January which was helped on its way by the MJO.  Unfortunately the PV has been relentless and together with the El Nino has made it an uphill struggle.

At this point I think our last hope is on the MJO gaining more amplitude and getting into a favourable phase.

True but when you get to the middle of winter and still have a rampant tropospheric PV, the only way really to Sustained HLB in the rest of the meteorological winter is likely to be through an SSW, its different at the start of winter because minor wave breaking events from the troposphere can be enough to stop the Vortex intensification high up in the stratosphere affecting the troposphere quickly, thus giving us a window of opportunity.

 

13 hours ago, Frost HoIIow said:

Hopefully. March 2013 was a rare event & I think anything close to that would be a monumental success after this awful "Winter"

 

13 hours ago, wishingforsnow said:

Personally I think our next best chance for potent cold is early Spring, tying in with Ian Pennell's thoughts, should the warming be as you described.

If we get a strong SSW in spring its likely to be a final warming.

 

Meanwhile the top of the strat is looking interesting again with a displacement type warming late on in GFS FI, round 2 of chase the SSW??

 

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2016020706&var=TMP&lev=1mb&hour=384

Edited February 7, 2016 by feb1991blizzard

[Banbury]

1 hour ago, cheshire snow said:

Whilst The GFS06z removes the snow risk for the South on Tuesday,i suspect it will be back

on the 12z to once again tease us,overall the 06z is a cooler run with overnight frosts increasing

as the week goes on,would not rule out snow falling almost any were  in the

next seven days(and not just the hills)

C.S 

I doubt it will be back, the Beeb are having nothing to do with it

[Nick L]

The GFS removing the snow risk for Tuesday is simply it moving into line with the rest of the model output. Don't really see anything to suggest it would bring it back.

Edited February 7, 2016 by Nick L

[J10]

 

Although any snow risk diminishing for Tuesday, it now looks much colder on Friday over the UK than than the 00Hz run, as shown in charts in link below.

Latest Ski blog, containing all of the GFS charts for this forthcoming week.

For those in need of a snow fix, these charts really look enticing for the Alps, with over 1m of snow possible over higher slopes/resorts.

 

[winterof79]

The ECM seriously needs to step up a gear if we are to see snow out of Scotland according to its latest run

 

http://en.vedur.is/weather/forecasts/atlantic/#type=temp

[Ali1977]

It'S been a pretty bleak year for coldies, however GEFS ens in FI have some fairly interesting outcomes - late Feb so would need a fairly good set up to deliver something decent - but you never know.

[ukpaul]

1 hour ago, winterof79 said:

The snow risk remains for central Northern England though

Or maybe Euro4 shows how GFS has a propensity to over do snowfall Mmmm

 

 

 

Posting a Europe view of the main GFS is pointless. There's a perfectly good high resolution chart available. for the same run, to post from the 0.25 GFS. Posting the very low resolution Europe view is misleading at best but then to compare it to the high resolution EURO4? What's the point?

Edited February 7, 2016 by ukpaul
Added 0.25 Chart for comparison

[nick sussex]

The next ten days is looking like one of those scenarios which will either bring some snow events or one in which turns out to be a damp squib.

Because the models are uncertain of how deep any cold might be its a bit of a lottery between outputs. Generally theres good agreement on the overall NH pattern at day 6 between the ECM/GFS and UKMO.

The key synoptic detail in displaced Azores high, deep cold PV chunk over the ne USA, Siberian high are all there.

The big difference today from the ECM is a big upgrade in cold pooling to the ne and that's why the stakes are raised because there is sufficient cold air to tap into, yesterday we had some good synoptics minus the cold air from it, today we have some almost very good synoptics and the cold air.

Because the Azores high is strongly signalled to  edge further west low pressure track into the UK will be more nw/se around the eastern flank of that.

And this is where the snow versus damp squib scenario plays out, if the track is further west with more trough disruption then the colder air to the ne will engage any precip readily turning this to snow, if we don't see this westwards correction its more marginal and an eastwards correction will remove any chance completely.

In that case there would be a further wait to see if this low pressure will clear se eventually allowing some colder air south and this relies on enough amplitude in the eastern USA to help push the Azores high further north.

At the moment we don't want to see the Siberian high pushing too far west as theres no cold air associated with it, we want something similar to the ECM at T144hrs which develops that separate weak high pressure lobe and cuts off that milder air from encroaching too far west.

I suppose it seems bizarre to be talking about milder air to the east at this time of year but we need air drawn from the ne to get into the circulation. The Siberian high can help though to lock in that colder Euro troughing later.

Its really quite a complicated set up because of that milder air over Russia and that's why today we've seen such a big change in the ECM 850's because that high lobe has managed to tap some colder air to the ne.

Edited February 7, 2016 by nick sussex

[alexisj9]

1 minute ago, nick sussex said:

The next ten days is looking like of those scenarios which will either bring some snow events or one in which turns out to be a damp squib.

Because the models are uncertain of how deep any cold might be its a bit of a lottery between outputs. Generally theres good agreement on the overall NH pattern at day 6 between the ECM/GFS and UKMO.

The key synoptic detail in displaced Azores high, deep cold PV chunk over the ne USA, Siberian high are all there.

The big difference today from the ECM is a big upgrade in cold pooling to the ne and that's why the stakes are raised because there is sufficient cold air to tap into, yesterday we had some good synoptics minus the cold air from it, today we have some almost very good synoptics and the cold air.

Because the Azores high is strongly signalled to  edge further west low pressure track into the UK will be more nw/se around the eastern flank of that.

And this is where the snow versus damp squib scenario plays out, if the track is further west with more trough disruption then the colder air to the ne will engage any precip readily turning this to snow, if we don't see this westwards correction its more marginal and an eastwards correction will remove any chance completely.

In that case there would be a further wait to see if this low pressure will clear se eventually allowing some colder air south and this relies on enough amplitude in the eastern USA to help push the Azores high further north.

At the moment we don't want to see the Siberian high pushing too far west as theres no cold air associated with it, we want something similar to the ECM at T144hrs which develops that separate weak high pressure lobe and cuts off that milder air from encroaching too far west.

I suppose it seems bizarre to be talking about milder air to the east at this time of year but we need air drawn from the ne to get into the circulation. The Siberian high can help though to lock in that colder Euro troughing later.

Its really quite a complicated set up because of that milder air over Russia and that's why today we've seen such a big change in the ECM 850's because that high lobe has managed to tap some colder air to the ne.

Which is what is making this period interesting to me, watching what unfolds and whether we end up with snow or rain is nether more fun then in situations like this. Now just fingers crossed it goes the right way.

[nick sussex]

2 minutes ago, alexisj9 said:

Which is what is making this period interesting to me, watching what unfolds and whether we end up with snow or rain is nether more fun then in situations like this. Now just fingers crossed it goes the right way.

I really hope that finally in this crxp winter the cards will fall kindly for the UK. I mean how much bad luck can cold and snow lovers have in here, enough is enough!

The way the outputs are developing suggests to me that the MJO is playing some role here and yesterdays signal was quickened up aswell as increasing in amplitude.

I'll be interested to see the update on that from NCEP later this afternoon.

[Catacol]

18 hours ago, Tamara said:

 

Its turned out to be a case of all or nothing. Either a continued disconnect of the trop/lower strat with the upper strat, or a full blown SSW would have been preferred. Not something in between which has left us with the worst of all worlds in terms of any seasonal cold weather that resembles proper winter.

Couldnt agree more. Of the 3 options on the table we got the worst... and my goodness it has been bad. The weather in the SW yesterday was absolutely horrendous... as my wrecked garden gate, trashed garden shed and ripped off dome skylight can attest to. Fields flooded, roads blocked.

Next time I see a powerful El Nino forecast I'm booking foreign holidays.

On the up side - after all the rain and mild dross of the last 2 - 3 years 2016_17 surely cant be any worse. I hope.

[Ali1977]

1 minute ago, Catacol said:

Couldnt agree more. Of the 3 options on the table we got the worst... and my goodness it has been bad. The weather in the SW yesterday was absolutely horrendous... as my wrecked garden gate, trashed garden shed and ripped off dome skylight can attest to. Fields flooded, roads blocked.

Next time I see a powerful El Nino forecast I'm booking foreign holidays.

On the up side - after all the rain and mild dross of the last 2 - 3 years 2016_17 surely cant be any worse. I hope.

Next winter has much more going for it, let's hope for a great Summer followed by a 1963 winter!!

[Catacol]

1 minute ago, Ali1977 said:

Next winter has much more going for it, let's hope for a great Summer followed by a 1963 winter!!

Well - I certainly dont think it will be an early summer.... but agree that very long term teleconnections at this stage point to more optimism for winter. eQBO should be just about right... and current ENSO pointing perhaps to neutral or slight Nina conditions. Fingers crossed.

 

[Duane S.]

I am not convinced there will be anything of note this week for lowland UK.

However, I am looking at the D8 / Mid-month onwards period as when things could start getting interesting, potentially very interesting. Increasing agreement of energy diving SE into Europe...

+ with a small westwards correction, some serious fun and games for us whilst it does so, This is likely to encourage pressure build around 65N(ish). The Azores High could then very well become our friend as it will be handily placed to ridge and build something more noteworthy. Could be a second bite of the cherry scenario. It does seem that the worst case likely outcome will be airmass from a predominately W-NW direction. Still far enough out for this signal to be watered down but conversely (and hopefully) upgraded as well.

Timing is always a huge factor but I am wondering could we get lucky this around with tropical convection heading into the Pacific at the same time?

[Faronstream]

19 hours ago, Daniel* said:

Comparing to yesterday 192 it seems increasingly looking that the big old block of HP is going to exert some influence on Western Europe retrogressing westwards....

 

[Faronstream]

850 hpa temp below average for much of W/C and North Europé during middle Feb, long time time no seen

[winterof79]

1 hour ago, ukpaul said:

Posting a Europe view of the main GFS is pointless. There's a perfectly good high resolution chart available. for the same run, to post from the 0.25 GFS. Posting the very low resolution Europe view is misleading at best but then to compare it to the high resolution EURO4? What's the point?

Wow....sorry.I wasn't trying to mis lead anyone and leave it to you in future.

[Mucka]

Good to see the signal for trough disruption SE from the mid term strengthen through today, particularly within GFS ensembles.

As usual my post will aimed at the more casual readers who follow along with developments. (or lack of)

I posted yesterday how GFS some ensembles were picking up on this and bringing in an Easterly flow with height rises pushing out NW toward Greenland as troughs disrupt SE into Europe - this is a true cold zonal pattern so not a true Easterly although if low pressure is far enough South much of the UK can stay in a cool/cold E/NE flow.

This pattern is unlikely to sustain itself too long without pressure rises to our North keeping the cold air to our NE and forcing jet South but there is a small possibility that the zonal conditions can be slowed enough to force an Atlantic ridge. This is similar to a recent failed effort to build blocking where height rises from SE move NW and link up with Atlantic ridging toward Greenland.

I will use p20 as an example although this is a failed attempt as the pattern is not far enough West.

 

I think this is currently what the models are moving toward (more especially GFS) so it will be interesting to see if this afternoons runs build on that or go back to a flatter more mobile pattern.

At least it isn't deep FI so worth following for now with a very rough time guide

Step one (120); good trough disruption SE into Europe.

Step two (144); undercut and height rises NW out of Scandinavia - this can also be WAA toward Icelend or combination of both (the stronger these are and the more they can extend toward Greenland the better)

Step three (168); Atlantic ridge and high pressure building over Greenland.

Step four (216) Cut off Greenland high and Winter wonderland and the winning lottery ticket.

 

Okay forget step 4 for now but the rest is quite feasible though there are infinite variations within that synoptic of cold and less cold.

Edited February 7, 2016 by Mucka

[The Enforcer]

1 hour ago, Catacol said:

.... but agree that very long term teleconnections at this stage point to more optimism for winter. eQBO should be just about right... and current ENSO pointing perhaps to neutral or slight Nina conditions.

It's only a forecast, of course.

[bobbydog]

"nothing of note for lowland UK"....