Model output discussion - mid-winter

[NickR]

25 minutes ago, doctor32 said:

Looking dam right ugly that deep low that intensifies over the uk, track still to the north and this will likely change over next 48hrs or so.

Timing of this low will be the main thing as a rush hour storm not good for people in affected areas.

These wind gusts inland are strong and will likely be very damaging!!!

As it stands snow to rain then back to snow as it clears into the north sea for NE England with the main concern those damaging winds on southern flank...

Meto forecast mention both rain,snow and strong winds in latest update too (which was not even mentioned this morning) so more support for low to be further north now??

Yes, I'm slightly bemused as to why so much of the talk in here remains about snow and spanners in said snow works. Surely the big story here is the potentially very worrying storm for Wed night. ICON has gusts of over 110mph for parts of N Eng, for example. Frankly, the prospect of some snow pales into insignificance in comparison.

[Frosty.]

Has the cold spell been cancelled?..nope, the Gfs 12z shows plenty of snow on the charts for most of the week ahead, especially further north and there are yellow warnings for Mon / Tues / Wed up north..and Thurs / Fri could be added soon!

Edited January 14, 2018 by Frosty.

[Jason M]

Still some good GEFS as Nick mentioned. The control is dire though, so if things go true to form these will start to drop away over the next 24 hours. There still remains enough scatter to suggest its not yet a done deal so a few straws to cling onto.

 

[bluearmy]

looking at the gefs T144/T168 and the ukmo/gem at day 6, don’t assume the trough will just push through without incident 

[January Snowstorm]

The gfs has been really good lately.

It was the first model to pick up the runner low as and also the first to pick up the cold spell not lasting....

[swilliam]

23 minutes ago, I remember Atlantic 252 said:

GEM rubbish model, but makes very little of the shortwave, doubt it's correct

GEM showed this change to no Northerly and Atlantic coming through yesterday  with the same kind of comments (about it being rubbish) - in this case the model picked this change out first if it happens like is shown at present.

[nick sussex]

Some news from NOAA re the upstream pattern and its key to what happens to the amplitude and the low exiting the ne USA.

TROUGH MOVING THROUGH THE EAST WEDNESDAY
SURFACE LOW SCOOTING BY NEW ENGLAND WEDNESDAY
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
PREFERENCE: NON-NAM BLEND; CONFIDENCE AVERAGE

THE 12Z NAM WAS DEEP/SLOW/SOUTHWEST WITH THIS SYSTEM WHEN COMPARED
TO THE OTHER GUIDANCE, WHILE THE 12Z GFS WAS THE QUICKEST -- BOTH
MODELS ARE DISPLAYING THEIR TYPICAL BIASES.  NORMALLY DOWNSTREAM
OF A RIDGE ONE WOULD FAVOR A SLOWER/DEEPER SOLUTION, BUT THE
MID-LEVEL LOW EXPECTED TO MOVE ACROSS MT IS A WILD CARD AND COULD
LEAD TO A LESS DUG IN AND MORE PROGRESSIVE SOLUTION.  THIS RULED
THE 12Z NAM OUT.  OTHERWISE, THE 00Z ECMWF, 00Z UKMET, 00Z
CANADIAN, 12Z GFS LIE WITHIN THE RANGE OF POSSIBLE SOLUTIONS
ALOFT.  A COMPROMISE OF THE ABOVE GUIDANCE IS PREFERRED WITH
AVERAGE CONFIDENCE.
 

We want the slower deeper solution but so far tonight we've got the more progressive ones.

[Man With Beard]

36 minutes ago, daz_4 said:

Yesterday

Today 

Same old story with the high pressure in the south. How many years now? This is a year without winter here in Europe. It's just November streched over three months.

The recurring problem to me is that weak Atlantic heights task don't get to Greenland almost always get overwritten by a shortwave when we get to D5/D6. This seems to happen at any time of the year, and they all do it.

I was looking at the charts yesterday and thinking that another low would get through, but I must admit I was thinking "slider" rather than complete disappearance of northern heights.

The crumb of comfort though, is that this kind of thing is often followed by a renewed ridge 48 hours later.

[Methuselah]

4 minutes ago, Frosty. said:

Has the cold spell been cancelled?..nope, the Gfs 12z shows plenty of snow on the charts for most of the week ahead, especially further north and there are yellow warnings for Mon / Tues / Wed up north..and Thurs / Fri could be added soon!

I agree with you, Karl. Whatever now happens (regarding model runs) we're still in for rather an exciting week...

[swilliam]

Just now, January Snowstorm said:

The gfs has been really good lately.

It was the first model to pick up the runner low as and also the first to pick up the cold spell not lasting....

As I just said GEM was first - not that it matters anyway really - the one model is better than another model is a rather wearisome discussion

[mountain shadow]

On 12/01/2018 at 11:05, Glacier Point said:

There is a suspicion here, advertised by the 06z GFS op, that the extended range modelling will be subject to the (false) tropical forcing signal, but which will not tend to get this beyond the day 8-10 range as the extratropical / tropical interactions become apparent to NWP.

Phase 5 of the MJO is where the modelling will want to go, but this idea of ridging to out south is false IMHO.

GPs post a couple of days ago alluded to the models picking up false ridging to the South, so lets not throw in the towel yet.

[SLEETY]

42 minutes ago, blizzard81 said:

And just to rub a whole shovel of salt into the wounds, GFS brings in blow torch south westerlies towards the end. Oh well, chins up! It's Monday tomorrow lol. 

And if any fl chart will verify ,it’s nearly always the mild charts isn’t.RIP uk cold winters

[carinthian]

13 minutes ago, nick sussex said:

A few GEFS survive the bloodbath and show what’s possible however the problem is it starts to go pear shaped as early as T96 hrs.

Its really the issue of upstream phasing and amplification.

There are still differences with how this happens even between the GFS and UKMO.

I think the priest is about to give the last rites but is waiting for the ECM to confirm whether there’s a pulse!

Not long to wait now if it’s a no then donations rather than flowers to the NW Lapland Fund!

 

 

 

That's so funny Nick. You have to laugh at such despondency and to end it all GFS comes up after such a deflated run a chart from hell that inflates right above my head ( 1040mb) in Euroland.  Sunshine ski-ing in the Alps and tropical gloom into blighty Of course at 372h the charts hardly verify, so clinging to hope. You have to laugh , its just not flipping fair for snow starved fans back home or indeed for much of Euroland who still wait.

 C

 C

[karlos1983]

The 10hpa warming signal has been significantly watered down now as well. Oh bother.

What a 24 hrs it’s been. 

Edited January 14, 2018 by karlos1983

[bluearmy]

my post following the 06z gefs applies again after the 12z - if not moreso with the potential transition at day 6/7 looking uncertain. whilst the 00z runs were rather a flat surprise (ecm apart), the subsequent output has put my tax return in danger .........

[shaky]

28 minutes ago, nick sussex said:

A few GEFS survive the bloodbath and show what’s possible however the problem is it starts to go pear shaped as early as T96 hrs.

Its really the issue of upstream phasing and amplification.

There are still differences with how this happens even between the GFS and UKMO.

I think the priest is about to give the last rites but is waiting for the ECM to confirm whether there’s a pulse!

Not long to wait now if it’s a no then donations rather than flowers to the NW Lapland Fund!

 

 

 

Is this a good thing or bad thing!!i think we might just see more changes!!

[shaky]

7 minutes ago, karlos1983 said:

The 10hpa warming signal has been significantly watered down now as well. Oh bother.

What a 24 hrs it’s been. 

How does it look 72 hours before that chart!!

Edited January 14, 2018 by shaky

[Severe Siberian icy blast]

2 minutes ago, bluearmy said:

my post following the 06z gefs applies again after the 12z - if not moreso with the potential transition at day 6/7 looking uncertain. whilst the 00z runs were rather a flat surprise (ecm apart), the subsequent output has put my tax return in danger .........

Blue, that's what having a good accountant is all about boy! I have a tax bill bigger than last year, and I can't afford last years!!!!

[karyo]

4 minutes ago, karlos1983 said:

The 10hpa warming signal has been significantly watered down now as well. Oh bother.

What a 24 hrs it’s been. 

There were some expectations in the strato thread for a SSW around the 20th Jan. I guess this date will now have to be pushed back significantly. Hopefully better luck in February.

[Chris K]

1 hour ago, offerman said:

Scientific evidence was on a BBC science program a few years ago. Very very  good enthusiastic  black female presenter . Was a  great program.  

Likely to be the research into climate change effects on the Hadley cell and it's projected expansion northward. Anyway, probably discussion for another part of the forum but there are plenty of research papers online to read up on it.

Edited January 14, 2018 by Chris K

[karlos1983]

3 minutes ago, shaky said:

How does it look 72 hours before that chart!!

Still watered down, 

there’s no sugar coating it, it’s not what we’ve been used to seeing for days and days anymore. 

[nick sussex]

Just now, shaky said:

Is this a good thing or bad thing!!i think we might just see more changes!!

The GEFS look a bit better than the earlier ones.

But the ops are still flat upstream. You'll know by T96hrs  regarding what sort of ridge you might get to the nw as the behaviour of the Pacific originating shortwave will be an excellent guide to whats to come.

I'll be publishing my exit poll at T96hrs!

 

 

[shaky]

5 minutes ago, karlos1983 said:

Still watered down, 

there’s no sugar coating it, it’s not what we’ve been used to seeing for days and days anymore. 

Where have the reds gone??!!bloody useless!!

[ACCOUNT DELETED]

I'm hoping the ECM 12z takes this storm system much further north or south just to keep the worst of the winds away from the populated areas, fingers crossed 

[Chesil View]

Just now, January Snowstorm said:

The gfs has been really good lately.

It was the first model to pick up the runner low as and also the first to pick up the cold spell not lasting....

That'll be the cold spell that hasn't arrived and the one we don't yet know the length of then.