Model Output Discussion - 05/01/2016 18z onwards

[bluearmy]

It's worth looking at the NH plot on the ECM day 10. Not for any specific detail but note that only yesterday and the day before, we had a large angry p/v by the end of the run. 

[chris55]

Fascinating output again tonight as we move into the weekend and beyond, GFS and its ensembles go really mild. UKMO stays frigid but dry with much potential beyond, and ECM trends towards UKMO, but still has the Atlantic knocking on the door, albeit it in a much more favourable way.

Obviously as a Westcountry resident, watching the inbound Atlantic lows disrupt and head south-east is our holy grail if the front can get far enough inland before fading. 

So its a catch 22 really from an IMBY perspective, we need the front to produce the snow, but we really want the high to win out to keep the cold!!

And looking at the ECM both seem possible. And that's also good for everyone wanting to keep the cold in situ. The second attempt from the Atlantic only brings the 0c isotherm as far as the borders before the cold move back in, and going by recent trends that isotherm could well end up much further south!!

[northwestsnow]

7 minutes ago, bluearmy said:

It's worth looking at the NH plot on the ECM day 10. Not for any specific detail but note that only yesterday and the day before, we had a large angry p/v by the end of the run. 

Yes i noticed that Blue, any unsettled stuff doesnt look long lasting on ecm 12z at any rate.

Looks a bit colder than gfs for thurand friday too which im selfishly more interested in

Edited January 12, 2016 by northwestsnow

[Frosty.]

I spent most of December feeling punch drunk from the constant very mild blow torch mush but now I've recovered and really enjoying the fact that the wheel has turned in favour of the majority on here who are coldies! The Ecm 12z is now joining the ukmo party and it feels like a momentum shift to prolonging and intensifying the cold spell is now underway, the wheels are in motion and I like it a lot! The daffs won't like it though!

[Singularity]

Yep, that's a notable change of tune from the ECM det. with respect to the polar heights... turns out I was right to be suspicious of such a clean, fast influence from the stratosphere.

The biggest story of the evening does look to be UKMO once again though. Amazing that it and ECM are very similar indeed at +96, yet UKMO achieves so much better trough disruption by +120 which appears to be entirely down to the feature being weaker. Or it could just be the model physics disagreeing?

It seems it won't take much more in the way of adjustment for ECM to produce something similar to UKMO for Monday. As it happens, it currently sits remarkably close to GFS with respect to that stalling, tilting frontal boundary with heavy frontal snow on offer across a notable swathe of the UK.

Yet the two diverge considerably thereafter, as GFS goes momentum-happy while ECM has made another eyebrow-raising decision in holding that trough back in the mid-Atlantic while a ridge persists over Greenland. Talk about a change of tune with respect to that part of the world! I suppose it links well with the change across the polar regions in general, with the vortex unable to regroup in the face of continued strong ridging of high pressure from the Siberian and Pacific sides. Amusing how the run manages to give us a sliding low occurring in tandem with a strong high to our south - but of course that high is in fact centered way down in the western Med. so a bit of a difference there as well.

 

Essentially, we have ECM and to some extent GFS looking as if they're trying to make major corrections without throwing out their old ideas entirely, while UKMO remains generally consistent with its previous 6 to 8 runs. 

Let's have yet another look at that UKMO +144 from both the Atlantic and Polar perspectives, it's such a brilliant tease!

       

 

It would actually seem unfair for UKMO not to win out after this long battle. If only fairness came into it! 

 

[bobbydog]

19 minutes ago, Ed Stone said:

Let's just stick to what the models are suggesting?

well pete, does that mean we can post disagreement,  confusion and conflict??

lol!

[Timmytour]

14 minutes ago, Greenland1080 said:

BA you said a bird with wings (I could see that as something else) ....I do find many experts are really struggling as to the end Jan early Feb call right now due to the possible SSW an where that might leave us in UK.

 

I like the UKMO's headless bowler in Singulaity's post above!

Just at the time we have the PV where we want it, is it a possible an SSW could actually dispury the existing opportunity instead of providing one?

[bluearmy]

Interestingly, the 12z ECM op arrests a sequence of 4 positive AO/NAO runs with both indicators staying negative.

similarly, the GFS op managed to keep negative on both by the end of its 12z run.  These aren't particularly neg returns compared to where we are next few days but the fact that they have chucked a piece of wood into the cogs may promise more changes tomorrow in the fi output. 

if the ens reflect this later, it will be a shame that the earlier ec32 and ec46 ran with yesterday's data rather than running today. 

[Duane S.]

Posted 6 days ago from GP (can't forum quote as now an archive thread)

"Unless of course if the trough slides out through the Atlantic south-east being the catalyst for our proper -NAO flip......could well be our torpedo surfacing before it strikes its target."

I wonder if the UKMO, and now to a lesser degree most other models, is playing this out?

Certainly got a lot of similarities with jan 2013 ( or was it 2012?). The one with the meandering mid-high lat blocking that brought about decent snowfall for many via slider systems.

[Singularity]

The progress with the models in the space of 24 hours, from yesterday's 12z to today's, for Monday 18th at noon, starting with ECM:

11th:  12th: 

Oh dear ECM, that is a little embarrassing I'm afraid. From a strong NE jet with heights tanking near Greenland to a weak, disrupted jet with respect to the UK and a notable wedge of higher heights across Greenland.

As for GFS, well through stubborn behaviour it's only shown a typical reduction in eastward progression so far:

11th:  12th:  

Sigh...

Now the UKMO. Of course I can only use Sunday as a guide due to the earlier culmination of the runs we get to see:

11th:  12th: 

Even here we have actually seen improvements to the angle of the ridge and trough disruption. So the Euros are moving in tandem in that respect while the Americans and Canadians are on some other planet. I've not posted GEM as it's very similar to GFS overall.

Traditionally, the Euros eat the those on the other side of the pond for breakfast when it comes to split jets and trough disruption (which is why ECM of late has seemed very strange), so we're in a good place this evening IMO.

[Methuselah]

6 minutes ago, bobbydog said:

well pete, does that mean we can post disagreement,  confusion and conflict??

lol!

Well if we couldn't, what would we do? Just so long as the 'arguments' are both model-related and polite...

[nick sussex]

Good news from the NCEP New York State forecast.

The GFS is seen as an outlier solution upstream over the ne USA for next Sunday/Monday, they prefer the ECM operational run.

It develops this low circled red, which neither the ECM/UKMO have.

The GFS is also the flattest and pushes that eastern USA troughing further east.

 

 

 

[ANYWEATHER]

Evening All! Well at last we can welcome in proper Winter weather the big question is how long can we keep it?  Gfs is the spoiler of the party , Ecm keeps the party going on for longer. It looks like the age old battle between mild and cold, but before any defeat some very nice snow surprises, which wont be forecast even down to the zero hour. Tomorrows Gfs  and Ecm will be pivitol in giving us some guidance in which direction we will be going......

[phil nw.]

I am wondering if the expected tightening of the Stratosphereic vortex pre warming will fail to stop the continued disruption of the tropospheric vortex caused by the continued wave breaking on 3 areas of the NH on both models.

As BA has alluded to the the polar profile still shows a disrupted vortex at 500hPa level even at day 10.

Meanwhile UKMO up to day 6 remains consistent with the amplified block and low pressure angled underneath.

This i think is the 3rd day running where it has shown the best pattern for a cold extension and last night it made me sit up when the late fax's came out agreeing with the earlier raw output.At that time of course it was the only major run to keep the ridge into the weekend.

Good to see the ECM moving that way this evening.

GFS well again ok up to day 4 then it continues on to lose the ridge as it has been doing for a few runs.It tends to keep finding the amplification as it get's closer again.
While there is still the differences in the models around day 5 on we still can't be sure that at some point we may see an Atlantic breakthrough but as each day passes any change in the short term becomes less likely.

 

 

[Singularity]

Just noticed JMA wants to trash the party too, but that low bottom-left is the same extra one that GFS develops and which NCEP don't like the look of. The run basically combines that with the dramatic lowering of polar heights that ECM has now let go of, to produce an outcome quite similar to the ECM 00z det. but with HP more in control. Meh.

Shows the idea of a quicker strat influence isn't dead in the water yet, but the movement by ECM is about as heavyweight as it gets so I remain of a positive mindset this evening.

[chris55]

A freezing Sunday morning wake up for most if ECM is correct. Double digit negative temps for some and a very hard frost for the masses! Get out and about for a crisp early morning walk with the dogs id say

 

Edited January 12, 2016 by chris55
added to post

[nick sussex]

The ECM postage stamps show a lot more support for the UKMO view tonight:

http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2016011212!!/

Theres still some which I'd rather not talk about! but overall they're not bad at all.

[Mark Bayley]

32 minutes ago, Dreamnine said:

No real (deep) cold in sight according to the models that I can see. Southern England will be 5C and raining. Here it will remain at 2 to 4C maxima a day which it's been the past week. But expect 8 to 9C widely next week.

I can't remember our last double digit maximum. But 10C quite likely in Edinburgh next week

Looks quite cold on the ECM. 3-5c across the south of the UK (i.e. south of the midlands) till Sunday, 0-3c the Midlands north. Colder still on Monday and Tuesday, with possible ice days further north! Very cold at night, with minus double figures in the North over the weekend and early next week. Wednesday and Friday maximum temperatures in the south are about 6c (9c in the south west), although tbf it does show double figure maximums on Thursday! Not a deep freeze, but notably quite cold with snow for some. I'm willing to wager that 'milder' temps shown Wednesday onwards continue to be pushed back... (i.e. the ukmo solution)

Also, as stated by Steve four posts down, the ensembles seem keen to retain the cold longer!

Edited January 12, 2016 by Mark Bayley

[SMU]

Updated ECM mean at a mere 120 hours away -

shamazing..... Looks at that undercut

s

[booferking]

1 minute ago, Steve Murr said:

Updated ECM mean at a mere 120 hours away -

shamazing..... Looks at that undercut

s

Looks really good big turn around.

[chris55]

5 minutes ago, nick sussex said:

The ECM postage stamps show a lot more support for the UKMO view tonight:

http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2016011212!!/

Theres still some which I'd rather not talk about! but overall they're not bad at all.

Cluster 1 and cluster 4 look best, and cluster 1 includes the op and control.

Edited January 12, 2016 by chris55

[SMU]

& to add a very mild outlier at the end with significant cold clustering redeveloping....

00z

 

& 12z

 

solid swing over a period of 18 hours to the UKMO....

s

[northwestsnow]

3 minutes ago, Steve Murr said:

& to add a very mild outlier at the end with significant cold clustering redeveloping....

00z

 

& 12z

 

solid swing over a period of 18 hours to the UKMO....

s

LOVE it steve boy

Excellent 120 mean- the milder options will vanish by 00z runs im sure

[Nick L]

I wouldn't call the EC op a mild outlier at all. It's on the mild end of the suite but it is not an outlier by any stretch of the imagination.

[northwestsnow]

1 minute ago, Nick L said:

I wouldn't call the EC op a mild outlier at all. It's on the mild end of the suite but it is not an outlier by any stretch of the imagination.

it pretty much is on the bottom set nickster, updated one