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

[Nouska]

23 minutes ago, knocker said:

You weren't casting your eyes on this little fella by any chance ?

 

Nope.

The ECM did actually get one at four days out - you might remember? The mets were a bit at odds about it though.

Satellite and a beady eye nearer the time if upper air profile still the same.

PS - you can tell I'm missing the tropical season.

 

[northwestsnow]

Some very nice GEFS this evening!

Hopefully ECM continues with the cold pm intrusion in the mid timeframe this evening..

Edited January 5, 2017 by northwestsnow

[bluearmy]

4 minutes ago, northwestsnow said:

Some very nice GEFS this evening!

Hopefully ECM continues with the cold pm intrusion in the mid timeframe this evening..

overall it isn't a great suite imo. only a few members worth salivating over and too much variation to make over analysis. given the lack of tweeting from matt, I assume the eps are similarly varied which may generate a decentish mean but doesn't lead one to think anything particularly notable for January is on the horizon.

[The PIT]

Disappointing GFS again everything still well out in lala land and when it gets closer gets so watered down it ends up as plain average or a brief one day hiccup. Basically pesky shortwaves preventing any real cold air really filtering down.

[northwestsnow]

1 minute ago, bluearmy said:

overall it isn't a great suite imo. only a few members worth salivating over and too much variation to make over analysis. given the lack of tweeting from matt, I assume the eps are similarly varied which may generate a decentish mean but doesn't lead one to think anything particularly notable for January is on the horizon.

Blue a day or two snowcover is worth salivating over and the last two gfs ops have produced that IMBY, ukmo looks primed to bring a potent Nwr at 144 so im feeling optimistic.Granted i am fairly high up in the north west, then again so is matt so i thought he might have started making positive noises, fwiw bbc automated showing snow next wed thur imby..

[chris55]

That's a notably cold northwesterly then northerly on the GFS 12z. Often in these type of set ups the 528 line fails to even get to the south coast. But with -10 850s in the Bay of Biscay id say most of the UK would be at risk of some snowfall, though the details will vary, troughs and a potential true polar low could develop within the flow.

Personally im liking the kink at around 230h on the 12z, that would deliver snow to many western parts, though not to be taken as a forecast it highlights the potential in such a flow.

[feb1991blizzard]

1 minute ago, northwestsnow said:

Blue a day or two snowcover is worth salivating over and the last two gfs ops have produced that IMBY, ukmo looks primed to bring a potent Nwr at 144 so im feeling optimistic.Granted i am fairly high up in the north west, then again so is matt so i thought he might have started making positive noises, fwiw bbc automated showing snow next wed thur imby..

Runs like the GFS op could bring heavy snow to just about anywhere IMO, not just the North West, however, its on the cold side of the ens and there isn't the potency or longjevity in most members as per bluearmy's view.

[Frosty.]

That's one hell of a cold snap on the Gfs 12z which would produce much wanted snow for some parts of the uk, needless to say I hope the Gfs is on the right track regarding next week, especially the second half when the arctic air arrives!

A nondescript weekend coming up but next week could become very interesting / exciting hopefully!

Edited January 5, 2017 by Frosty.

[northwestsnow]

2 minutes ago, feb1991blizzard said:

Runs like the GFS op could bring heavy snow to just about anywhere IMO, not just the North West, however, its on the cold side of the ens and there isn't the potency or longjevity in most members as per bluearmy's view.

Absolutely, and i agree esp longevity but beggars cant be choosers.At any rate ukmo looks better than gfs to me at 144 but i would take a 48 hour pm shot after whats gone before, happily..

[IDO]

2 minutes ago, chris55 said:

That's a notably cold northwesterly then northerly on the GFS 12z. Often in these type of set ups the 528 line fails to even get to the south coast. But with -10 850s in the Bay of Biscay id say most of the UK would be at risk of some snowfall, though the details will vary, troughs and a potential true polar low could develop within the flow.

Personally im liking the kink at around 230h on the 12z, that would deliver snow to many western parts, though not to be taken as a forecast it highlights the potential in such a flow.

That GFS 12z op looks a rogue run and is an outlier from very early in the run. I would ignore. 

Looking at the GEFS, the general theme maintained though in the nearer term compared to the 0z, the mean uppers are getting warmer rather than colder:

0z   12z

So I would be wary of anything after D7 viz cold air, as it keeps getting delayed! 

See what the ECM does but that GFS op run looks suspicious.

 

[bluearmy]

for you guys oop north (especially with a bit of altitude), i'm rather hoping the pattern stays amplified long enough to bring a runner down in the flow. then you may have something really worthwhile to remember the first half of winter for (just about!). an 36 hour toppler may only bring showers to the usual suspects.

[Timmytour]

Do the damned shortwaves that keep cropping up in the models to scupper nice looking previous runs/potential in the current run disappear as readily as they seem to appear?

Can't remember reading too much of shortwaves that have disappeared on a following run once they have appeared on a run as the catalyst to scupper potential, though I've no doubt that if there were shortwaves that actually assisted in bringing in the cold, they would disappear readily!

[Paul]

2 minutes ago, IDO said:

That GFS 12z op looks a rogue run and is an outlier from very early in the run. I would ignore. 

 

I'm assuming you're basing your 'rogue run' theory on the fact that the GFS is quite different for 2m temperatures than the GEFS members, as you've used that to illustrate your point.

If so, you're not correct. Virtually every run has that discrepancy because the GFS is run at a different resolution to the GEFS which is always more notiecable on the ground as that's where local variations with height / coasts / towns & cities etc play a much larger part. 

For instance - 6z and 00z runs for Cumbria (a hilly part of the country for illustration), the same discrepancy...

 

 

[Richard Fisher]

21 minutes ago, The PIT said:

Disappointing GFS again everything still well out in lala land and when it gets closer gets so watered down it ends up as plain average or a brief one day hiccup. Basically pesky shortwaves preventing any real cold air really filtering down.

 

 

12 minutes ago, Frosty. said:

That's one hell of a cold snap on the Gfs 12z which would produce much wanted snow for some parts of the uk, needless to say I hope the Gfs is on the right track regarding next week, especially the second half when the arctic air arrives!

A nondescript weekend coming up but next week could become very interesting / exciting hopefully!

Not helpful for newbies with totally different posts regarding GFS 12z

[frosty ground]

9 minutes ago, IDO said:

That GFS 12z op looks a rogue run and is an outlier from very early in the run. I would ignore. 

Looking at the GEFS, the general theme maintained though in the nearer term compared to the 0z, the mean uppers are getting warmer rather than colder:

0z   12z

So I would be wary of anything after D7 viz cold air, as it keeps getting delayed! 

See what the ECM does but that GFS op run looks suspicious.

 

Non of those graphs show the Op to be a rouge run to be fair.... on.the colder side of average yeah but not without support.

[radiohead]

GEFS mean and GFS op run look a pretty good pattern match to me at T192. Exact detail will obviously change from run to run at that range. And it is still FI. The broad picture looks positive though.

[Frosty.]

22 minutes ago, Richard Fisher said:

 

Not helpful for newbies with totally different posts regarding GFS 12z

Sorry if it wasn't helpful but it's what the Gfs 12z shows from 7 / 8 days ahead, our first stonking arctic outbreak, especially severe in northern uk..please verify!

Edited January 5, 2017 by Frosty.

[chris55]

34 minutes ago, IDO said:

That GFS 12z op looks a rogue run and is an outlier from very early in the run. I would ignore. 

Looking at the GEFS, the general theme maintained though in the nearer term compared to the 0z, the mean uppers are getting warmer rather than colder:

0z   12z

So I would be wary of anything after D7 viz cold air, as it keeps getting delayed! 

See what the ECM does but that GFS op run looks suspicious.

 

From day 7 the 12z is colder than the 00z?

With both the Op and Control going cold and the scatter is trending the same way.

The fact the Op looks like an outlier early on is more to do with timing and location than any rouge influence.

 

 

Edited January 5, 2017 by chris55

[snowice]

ECM seems to be following Gfs at 168

[radiohead]

If anything the 12Z ECM looks even better than the 12Z GFS at T168. But T192 will tell the tale....

Cold air already sweeping in at T168 on the ECM

[tight isobar]

Ecm 12z following path gfs 12z..expect v-similar synoptic s..

The gfs 12zwas a whole 'not an outlier!  Strolling through the full suite.

[Gustywind]

Wonder if that little wedge of heights just east of Finland on the ECM can stop the west to east progression and keep us under a cold N/NW flow longer?

[nick sussex]

Good agreement overall tonight at T144hrs, the ECM though looks like developing another wave of amplification upstream at T168hrs so a difference between it and the GFS at that stage.

Yes just what we wanted the main PV chunk pulling nw at T192 hrs! this though helped by that amplification upstream.

If we want to see deeper cold this is the only route within the current overall set up.

Edited January 5, 2017 by nick sussex

[northwestsnow]

Showers turning to snow in the north west at 168? Posibly some altitude needed but interesting anyway..

[radiohead]

T192...ECM follows the GFS. ECM slightly more amplified south of Greenland so maybe a chance the cold will last a little long in FI here?

Uppers not quite as cold as on the GFS here but at 192 hours there's no way of predicting the uppers accurately.

Edited January 5, 2017 by radiohead