Model Output Discussion; into 2015

[karyo]

justifiable pessimism and scepticism i think but what are we always told? "ignore the details in FI, look for trends"

well i can see a very strong trend emerging from BOTH GFS models.

The trend of the stratospheric warming easing and the polar vortex reforming?

[sebastiaan1973]

Seems to me, it is a reflection of the MJO. We have to be careful, EC is not showing a development to phase 6 and 7. http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

Edited January 4, 2015 by sebastiaan1973

[IDO]

I'm being a tad pedantic ido but but last year wasn't a record breaking winter for the Conus. It was only 33rd coldest. Certain regions were very cold like the upper Midwest which had the 6th coldest.

 

Yes. I should have said 2013/14 was the coldest interequinoctial (equinox to equinox) winter in a 100 years. You have to go back to your days at the Met outposts, 1911/12, for a colder one.

[bobbydog]

The trend of the stratospheric warming easing and the polar vortex reforming?

thankyou for the timely example of pessimism.

[mulzy]

At least the FI eye candy is back on the 06z op runs,with the gfs op in particilar throwing up a very useful looking block to our North.

 

gfs.png

 

 

The parallel also with a cold flow from the East/Northeast.

 

gfsp.png

 

Day 15 charts...

[Woollymummy]

Is there a way of seeing what the Sun's activity at the moment could be doing to the very outer edge of the atmosphere? Maybe the models are difficult to interpret because of something that isn't being shown properly.

[Harsh Climate]

justifiable pessimism and scepticism i think but what are we always told? "ignore the details in FI, look for trends"

well i can see a very strong trend emerging from BOTH GFS models.

 

I'm quite optimistic regarding the recent output, only 3 days ago we was looking at an never ending zonal train with no end in sight. Now we are seeing continuity albeit in FI from both the GFS (OP) and GFS (PARALLEL) of a more polar continental or continental flow! 

 

I know it's way out of range where we have confidence that it will happen, but we have to start somewhere.

 

I'm also a believer that FI in gfs isn't as extreme/unlikely that it once was, I think due to the upgrades in the gfs 2 or 3 years back the model is a bit better in picking up future blocking trends and we seem to see less stellar runs out in FI that never come to fruition.

 

I thoroughly expect the ECM to start showing what the gfs is showing out at 216/240h in a day or two and then we really can start looking into the possibility of something of real interest for cold/snow lovers just over the horizon 

[karlos1983]

That's because metiociel has put some extra colours on the scale to accommodate extra low 850's

D'oh

Yes I'm seeing it a lot now. Oops

[knocker]

Yes. I should have said 2013/14 was the coldest interequinoctial (equinox to equinox) winter in a 100 years. You have to go back to your days at the Met outposts, 1911/12, for a colder one.

 

Oooh. I remember it well.

[Banbury]

I've personally not seen white on the 850's anywhere in my model watching time, never mind N America.

A reliable source informs me

 

winter 2013/4 and winter 2012/3 over the Arctic Ocean and/or North America

[karyo]

thankyou for the timely example of pessimism.

You are welcome but it is easy to focus on something positive on the output and ignore the rest of the picture. This is why LRFS so often fail and this winter is another example of that.

Edited January 4, 2015 by karyo

[nick sussex]

After the GFS 06hrs runs my optimism rating has edged up from 2/10 to 4/10!

 

Both outputs start to add a bit more amplification within T240hrs, you'll see the ridge building into Alaska this effects the movement of the PV and low heights.

 

In this type of set up its easy to correlate what happens over the central USA with any cold potential for the UK. The more dig south of cold into that region will pull the PV and low heights further to the nw, at the same time this should help develop a more nw/se jet track into the UK.

 

 

If the cold stays north of the Canadian border then its a no go for cold into the UK as the bellwether for any change is the digging trough into the central USA.

 

The will it won't MJO is looking absolutely crucial to cold chances in the UK, a short cold snap might be possible with just phase 6 but for any decent cold that can hang around I think we need to see this in phase 7.

 

The thing to look out for tonight is that upstream troughing but also does this increase in amplitude start coming forward or remain marooned well into FI.

 

 

 

[bluearmy]

the 06z gefs continue to show amplification around mid month but none are able to build a sustained greeny ridge. the best on show for coldies is the mid atlantic ridge getting into greenland but then being flattened whilst an undercut enables this ridge to become cut off around the iceland locale. that would be fine for cold (possibly one of the best places for a wintry evolution) but at this distance, already the trend is to flatten the ridge so as we tick down, you would expect this trend to gather some pace and a rerun of late december to come into view. to add here, that we were pretty unlucky late december with that cut off low in the w atlantic which prevented any proper retrogression of the iberian heights. i wouldnt expect that to repeat so we could look forward to a better incursion of cold flow this time. (should the amplified solution verify)

 

there remain opportunities to get a colder sustained period out of this mid month ridge so dont despair and write it off as a short sharp blast.  they are just outnumbered by those which indicate a return to mobility or MLB.  time for that to change.

Edited January 4, 2015 by bluearmy

[Harsh Climate]

Just looking at the gfs again and it's good that the time frame in which the real change happens, has moved from t320h+ a couple of days ago to t276h, we need this trend to continue as once the models start pushing things further and further back time and time again it doesn't happen or becomes watered down.

 

GFS 276h

 

 

GFS parralel 276h

 

[bobbydog]

You are welcome but it is easy to focus on something positive on the output and ignore the rest of the picture. This is why LRFS so often fail and this winter is another example of that.

but it is positive. the output has looked bleak for a good few days and now we are seeing signs of colder weather on the horizon. we're not just talking about one or two runs toying with a slight atlantic ridge, occasionally throwing in one decent chart,both GFS models have clearly and consistently modelled a (building) greenland high at long range. normally we would dismiss this as FI but the strength and consistency of all models up to the mid range means we can have slightly higher confidence as to what happens afterwards

Edited January 4, 2015 by bobbydog

[Jason M]

GEFS are better in FI with a fairly coherent signal for some sort of pressure rise across Iceland and Scandi. Obvoiusly to be taken with a truck load of road salt (and there's plenty of road salt going spare). If we could get HLB centered on Iceland then we really would be in business.

[karyo]

but it is positive. the output has looked bleak for a good few days and now we are seeing signs of colder weather on the horizon. we're not just talking about one or two runs toying with a slight atlantic ridge, occasionally throwing in one decent chart,both GFS models have clearly and consistently modelled a (building) greenland high at long range. normally we would dismiss this as FI but the strength and consistency of all models up to the mid range means we can have slightly higher confidence as to what happens afterwards

I agree there are positive signs in the outlook but I fear there won't be a sustained change. We have seen last months the models overamplify the pattern and all we got was a sinking high.

[bobbydog]

I agree there are positive signs in the outlook but I fear there won't be a sustained change. We have seen last months the models overamplify the pattern and all we got was a sinking high.

that may well be the case but at least for now, we've got something positive to look at!

[nick sussex]

I agree there are positive signs in the outlook but I fear there won't be a sustained change. We have seen last months the models overamplify the pattern and all we got was a sinking high.

At this point Karyo a re-run of late December might be the best on offer,although we could squeeze out keeping the high further north for a bit longer which would make a  difference to those areas that missed out on the snow.

 

I think unless something bizarre happens then a Greenland block is out of the question, generally if one of those was on the cards the signal would be pretty strong and the best possible scenario out of the pattern might be high flattened but slower this time, with a lower probability cut off high over Iceland.

[london and south east kent]

GEFS is much better in F1 with a pressure rise to the north of the uk some where.With low pressure pushing south I do think other models will start to pick up on this later but for the next 10 days will stay in this westerly ..

[Frosty.]

It's a very volatile outlook shown by the latest models, I notice the MO are now firming up on very stormy conditions later in the week ahead across the far NW although we will all feel some impact from it. As for temperatures, milder and colder air will continue to trade blows with milder wet and very windy spells interspersed with brighter, colder and showery conditions with the showers turning wintry and frosty nights when calmer interludes occur.

[Lord Baltimore]

Zonal all the way. May be cold/cool in the latter stages, but no real sign of anything sustained. Unlikely to see anything white in the SW this winter.

[nick sussex]

Zonal all the way. May be cold/cool in the latter stages, but no real sign of anything sustained. Unlikely to see anything white in the SW this winter.

Sustained cold in the UK is rare anyway, however I certainly wouldn't give up hope of seeing some snow.

 

Even in some of the crappiest winters you get the odd surprise. I'll be the first to admit I'm hardly shouting from the rooftops at my excitement over the outputs.

 

I'm underwhelmed but there might be a window of opportunity in the second half of the month.

[Chris K]

but it is positive. the output has looked bleak for a good few days and now we are seeing signs of colder weather on the horizon. we're not just talking about one or two runs toying with a slight atlantic ridge, occasionally throwing in one decent chart,both GFS models have clearly and consistently modelled a (building) greenland high at long range. normally we would dismiss this as FI but the strength and consistency of all models up to the mid range means we can have slightly higher confidence as to what happens afterwards

 

I'm still wary of searching for trends in operational outputs in FI even if it is repeated - it reminds me of a time last year where high pressure was shown to block over SC Europe for at least 2 weeks and the models were showing this in FI for days...until a Low Pressure developed at relatively short notice and actually kicked us into an unsettled phase within a week. (think it was late Sept/Early Oct..don't have the archived charts to hand)

 

So for me yes it's nice to see and the positive for me is knowing whatever the charts are showing in FI, things can happen before then that can change FI dramatically...as its the nature of the charts at that range.

 

Of course if more models and ensembles and associated means start backing it up, then that's better!

Edited January 4, 2015 by Chris K

[meathead]

It's maybe a positive the models aren't showing cold. Least we won't be let down again and we'll all be happy if they flip to cold