Model output discussion - deep cold inbound?

[ITSY]

Wrong thread I know but the Meto are bullish in their PR today and in the 16:00 update. Easterlies, Snowfalls and Wintry Showers galore starting this weekend and continuing into mid-month. It's clear the professionals back the GEM, UKMO and ECMWF (00z) solution. The GFS is at odds with those models and the professional forecast so if the American model (GFS) proves itself correct for the South, it will be a real coup for the model even if a real let down to us southerners. It's a question of waiting and seeing I fear for at least another 48hours...

[Snowman.]

Just now, Penicuikblizzard said:

There is a Easterly in the North, there will be plenty snow in the NE going by those charts 

Short lived affair however. By next wednesday you have mild air heading north.

The further south east low those lows are the longer we stay in an Easterly feed. Plain and simple.

[Uncertainty]

One for the South here...

The Arpege has had absolutely no interest in this cold spell and has kept the low plonked over the U.K. throughout, think ECM a few days back...

Now it piles snow showers into SE England 

 

All this On Sunday!

 

The GFS and GEFS got storm Christopher’s ejection point way wrong 2 days out. They have had countless other calamities whilst, obviously, the EPS haven’t as much. At this short range and with the hi res models now coming into line you have to go with a GEM/UKMO/ECM blend here. 
Expect more GEFS members to be more like the present GEM which, btw, is seriously cold for almost the whole of the UK

 

Edited February 2, 2021 by Uncertainy

[Mizzle]

1 hour ago, Cold Winter Night said:

Well, you might find learning material in the "Learning & research" section here on Netweather.

About the terms you mention, in short:

- An Op = Det = Operational: This is the main run of a model. It is run at the highest resolution, so the atmosphere is divided up in smaller blocks. This gives these runs finer detail, they are less likely to miss nuances that might be important later on.

- The mean is the mean of the ensemble runs. These are a number of extra runs, apart from the Operational runs. These are at a lower resolution, so the supercomputers can handle more of them in a short term.
It includes the control run which has the same starting data input as the operational (but run on that lower resolution) and a number of perturbations (P1, P2, P3 etc) or members that have slightly altered input at the start, so we can see if the starting data has much influence on the outcome or not.

- The EC or ECM is the model that is run by the ECMWF (European Centre for Medium-Range Weather Forecasts).
- The UKMO is run by the UK Met Office
- GFS (Global Forecast System) is run by the American NOAA-NCEP
- GFS parallel (GFS //) is the newest update for GFS, that is being tested alongside the old one.
- The GEM is Canadian.

@Cold Winter Night you are a star! Thank you so much.

[The Enforcer]

5 minutes ago, danm said:

So where are we so far?

GFS - still not great, but small steps in the right direction in the short term.

UKMO - excellent, again.

ICON - Very good.

GEM - sensational.

ARPEGE - excellent.

Let's see what the ECM has to say in a couple of hours. 

*Added Arpege, which came out just after ICON.

Edited February 2, 2021 by The Enforcer

[supernova]

Can't take my eyes off the GEM. Slider incoming, robust Greenie high, Easterly firmly established with notable convective snow showers/streamers and bloody cold!

Edited February 2, 2021 by supernova

[Singularity]

 

FWIW the GEM 12z suggests that 850s may not be as low as one might think for snow showers making it well inland off the North Sea - the relatively low sea level pressure, compared to many easterlies, may do the trick for the south with 850s around -8°C, maybe even a tad higher.

[tight isobar]

12z fare in overall... model miss-manage as we’d expect!! Model related or not.. rest in eternal peace mr moore  over to this evenings others........

Edited February 2, 2021 by tight isobar

[sheikhy]

Gfs looks a massive outlier for the midlands from day 5?!!

[Lukesluckybunch]

2 minutes ago, sheikhy said:

Gfs looks a massive outlier for the midlands from day 5?!!

So your saying that it should be colder with the ensemebles?

[Updated_Weather]

3 minutes ago, sheikhy said:

Gfs looks a massive outlier for the midlands from day 5?!!

Even more so for the south

[Updated_Weather]

Just now, Lukesluckybunch said:

So your saying that it should be colder with the ensemebles?

Majority are colder than the OP.

[East_England_Stormchaser91]

I find that anything East of the UK and modelling over the continent, the GFS can be woeful. It’s much better at forecasting the Atlantic behaviour. With a forecast so volatile and unorthodox, its inevitable that there is swings and bizarre runs happening! 

[Tim Bland]

Op is on the mild side again...surprise surprise. Snow ensembles starting to ping from Sat eve..

[BurwellWeatherWatch]

The direction of travel looks pretty good to me.

GFS coming back in the right direction, so even a meeting point wouldn't be a disaster, albeit less memorable for the south.

But I remember seeing all the memorable spells evolve in the last 10 years: Dec 2010, Jan 2013, March 2013, Feb 2018 etc, and every time there has been much gnashing of teeth from doom-mongers who want to write it off before it's begun ("the -25 uppers won't reach Cornwall", "there won't be glaciers coming through East Anglia", "there won't be perma-frost in my bed" etc)

so we need to take these with a pinch of salt and broadly speaking things look good - with some absolute belting possibilities such as the GEM and, fundamentally, UKMO.

Fingers firmly crossed for the ECM

[Lukesluckybunch]

Let's wait and see that the ECM is showing later..if is still there from this mornings runs then the chances increase massively and if it's still showing the same in the morning then is almost certain! Also the GEM is a beauty UKMO remains pretty decent also!

[Battleground Snow]

Shame not to have the para run so far, hopefully it trickles out soon.

[Lukesluckybunch]

1 minute ago, Vadoseflame said:

Majority are colder than the OP.

Well that's good news isn't it!

[Guest]

Midlands north event by the look of things, 12z is continuing the new trend away from the cold easterly (more for the south as things stand).

Lots of rain following behind with a an awful SW flow.

I expect the ECM and UKMO will follow the GFS soon. 

[kold weather]

Just now, DCee said:

Midlands north event by the look of things, 12z is continuing the new trend away from the cold easterly (more for the south as things stand).

Lots of rain following behind with a an awful SW flow.

I expect the ECM and UKMO will follow the GFS soon. 

You do know the GFS is literally on its own at the moment?

As it stands its:

GFS OP with about 30-40% of the ensembles vs the 60-70% of GFS ensembles, UKMO, GEM, ICON, ARPEGE.

The further south you are the more chance of thing indeed not getting cold enough, but the models so far are far from painting the picture your trying to paint there.

Mind you, watch the ECM smash this reply down in about 90 minutes! 

[bumpydogz]

3 minutes ago, DCee said:

Midlands north event by the look of things, 12z is continuing the new trend away from the cold easterly (more for the south as things stand).

Lots of rain following behind with a an awful SW flow.

I expect the ECM and UKMO will follow the GFS soon. 

Cheery. Based on what evidence?

[Lukesluckybunch]

1 minute ago, DCee said:

Midlands north event by the look of things, 12z is continuing the new trend away from the cold easterly (more for the south as things stand).

Lots of rain following behind with a an awful SW flow.

I expect the ECM and UKMO will follow the GFS soon. 

Well I sort of agree with you here it doesn't look particularly prolonged but Sunday through to Wednesday could be very cold,but at the moment more especially for the North country.having said that if the ECM and UKMO remain like this then would be hard to bet against a proper nationwide freeze up

[Notty]

3 minutes ago, DCee said:

Midlands north event by the look of things, 12z is continuing the new trend away from the cold easterly (more for the south as things stand).

Lots of rain following behind with a an awful SW flow.

I expect the ECM and UKMO will follow the GFS soon. 

Only if you think the GFS Op is correct

[snowking]

31 minutes ago, bluearmy said:

Help me out kris - how do the uppers match the thickness ??  Never seen this before ?? 

Trying to figure that one out myself Nick - given the flow on the +144 chart we must be missing something between +120 and +144 to end up with those 850mb temps. I'm not complaining about it, but was a bit of a head scratcher.

I think Nick S is right in as much as on this particular run the +168 chart would show trough disruption - but it's a far less comfortable scenario for many south of the Humber to be faced with (vs what was previously modelled), particularly given we don't get the very coldest air fully across the UK and certainly into much of France before we see the attempted Atlantic intrusion.

Anyway all too much detail for +144 given the current levels of entropy. But still we wait for some consistency

[Blessed Weather]

A few posts about preferences and wishes that contained no model output discussion have been moved to the Chat/Moans thread. Expressing your weather preference is absolutely fine, but without reference to current model output is nevertheless off-topic in this thread. Thank you.