Model Output Discussion - Into February

[phil nw.]

Will we ever know where the recent cold GFS runs came from ?

Yes there are signs of a weakening spv along with it's displacement now underway but the trop.vortex to our north remains stubbornly positioned.With the MJO showing in the warmer phases over the Pacific area an easterly was against the background signals really as well as most other model suites so those GFS runs came out of left field.

We now seem to have normal service with pretty reasonable agreement with a uk high which may well give frosty nights but compared to what GFS offered recently it is a bump back down to earth for cold  and snow fans.

[bluearmy]

12 minutes ago, Ali1977 said:

Two consecutive big ssw gfs ops 

still ultra cautious on this but signs on that 12z run that its a split beyond day 16.  Still early enough to bring a QTR back end feb 

[Kirkcaldy Weather]

Thought I'd revisit my previous outlook and do my next where I believe we will be headed

Really happy with how that outlook has played out and decent on the dates too

As we see the MJO phase 3 now extending into February here's where I'd expect to be by approx 15th Feb, Note the switch from higher to lower pressure near the Eastern Seaboard and the lower pressure in Greenland transitioning to higher heights 

 

Likely to continue to see Tropical Cyclone development across the Indian Ocean 

Roughly another week in phase 3 though the JMA is still persisting on an even further extention. 

 

 

 

[Stuie]

18 minutes ago, phil nw. said:

Will we ever know where the recent cold GFS runs came from ?

Yes there are signs of a weakening spv along with it's displacement now underway but the trop.vortex to our north remains stubbornly positioned.With the MJO showing in the warmer phases over the Pacific area an easterly was against the background signals really as well as most other model suites so those GFS runs came out of left field.

We now seem to have normal service with pretty reasonable agreement with a uk high which may well give frosty nights but compared to what GFS offered recently it is a bump back down to earth for cold  and snow fans.

Glad you didn`t mention the BFTE Phil as I haven`t read anyone saying that is what the GFS was aiming at. It was was just a much colder option to the other models, and to be fair, we probably do now have a cold middle ground.

[Mike Poole]

11 minutes ago, bluearmy said:

Two consecutive big ssw gfs ops 

still ultra cautious on this but signs on that 12z run that its a split beyond day 16.  Still early enough to bring a QTR back end feb 

And this one looks like the real deal, -20 m/s winds by T384:

Re the convergence to the middle ground in the early part of the run, I still maintain that GFS has moved less than some of the other models.  Where, for example, are the big Atlantic inroads of yesterday’s UKMO 0z?  The issue is not of one model being ‘wrong’ here, it is that the easterly option was on the extreme end of the GFS option, and a middle ground has unfortunately been found that excludes it. 

[Nick F]

4 minutes ago, Mike Poole said:

And this one looks like the real deal, -20 m/s winds by T384:

Re the convergence to the middle ground in the early part of the run, I still maintain that GFS has moved less than some of the other models.  Where, for example, are the big Atlantic inroads of yesterday’s UKMO 0z?  The issue is not of one model being ‘wrong’ here, it is that the easterly option was on the extreme end of the GFS option, and a middle ground has unfortunately been found that excludes it. 

Well hello, a reversal evident mid-month on 12z GFS  looking at the zonal mean cross section ...

 

[Rain All Night]

1 minute ago, Nick F said:

Well hello, a reversal evident mid-month on 12z GFS  looking at the zonal mean cross section ...

 

I saw bluearmy feels it may not be too late for any effects from this to affect winter rather than spring and assume you're on board with that based on the tone of your post!

[tight isobar]

The drag n, draw for nxt weeks colder incursion- should not be “ prematurely underestimated “!! There’s scope for a delve into much more notable upper inflows!!... watch this space out to the 00z suites!!

[Mike Poole]

1 minute ago, RainAllNight said:

I saw bluearmy feels it may not be too late for any effects from this to affect winter rather than spring and assume you're on board with that based on the tone of your post!

One thing that might aid a quick trop response here, is the warming that we had a week or so ago, the ‘nearly’ one.  I think it is agreed that this led to a flushing down of westerly winds from the previous very strong strat vortex that dominated the heart of winter.  This done, a full SSW now could potentially impact the trop with a running start.

[Nick F]

2 minutes ago, RainAllNight said:

I saw bluearmy feels it may not be too late for any effects from this to affect winter rather than spring and assume you're on board with that based on the tone of your post!

Yes, in with a chance of a trop response of high lat blocking end of Feb and continuing into early March, similar to 2018. But we need to see this reversal showing continue in the GFS and also be interesting to see the EC weeklies update this evening showing hints of a SSW too later this month, the last update showed promise.

[January Snowstorm]

If the gfs charts are unreliable why do we trust its strat charts. Surely they are also subject to wild swings?

[Penicuikblizzard]

1 hour ago, Met4Cast said:

No worries, mistakes happen 

Chilly surface inversion under high pressure next week, temperatures below average but it's no -15C isotherm BFTE the model was suggesting only yesterday.

It was never going to be the model was out on it’s own with the crazy charts,,this looks more favourable for next week. Chilly with night frosts returning 

[Ali1977]

15 minutes ago, Mike Poole said:

One thing that might aid a quick trop response here, is the warming that we had a week or so ago, the ‘nearly’ one.  I think it is agreed that this led to a flushing down of westerly winds from the previous very strong strat vortex that dominated the heart of winter.  This done, a full SSW now could potentially impact the trop with a running start.

A running start would be good, but even early March can produce extreme cold with the right set up. The BFTE for example. 
Long way off but maybe a nice EC42 tonight to start the next chase 

[Nick F]

6 minutes ago, January Snowstorm said:

If the gfs charts are unreliable why do we trust its strat charts. Surely they are also subject to wild swings?

Compared to the troposphere the models display longer predictability timescales for variations within the stratosphere, so less wild swings high up, we've seen GFS predicting warming or a SSW for a while now mid-month. Besides, last EC weeklies was also hinting at a SSW later this month, the mean heading towards 0 m/s.

[January Snowstorm]

8 minutes ago, Nick F said:

Compared to the troposphere the models display longer predictability timescales for variations within the stratosphere, so less wild swings high up, we've seen GFS predicting warming or a SSW for a while now mid-month. Besides, last EC weeklies was also hinting at a SSW later this month, the mean heading towards 0 m/s.

Great thanks for the info.

Better chances so last third of Feb. 2018 certainly delivered here, gave the most snow for Southern Ireland in 50 years and the snow depths were unbelievable 1st March (storm emma)

[Stuie]

Last nights ECM 12z vs todays 12z.

 

Edit: Teleconnections still make sense for the US, no cold plunge for the time being, albeit skirting the North.

Edit 2: GFS teleconnections and ECM op.

Edited February 2, 2023 by Stuie W

[mulzy]

5 minutes ago, Stuie W said:

Last nights ECM 12z vs todays 12z.

Yes, some variance on the 850s but looks broadly similar from a synoptic point of view.

[snowray]

Dear me, what a pile of tosh!

 

[goosey007]

5 minutes ago, snowray said:

Dear me, what a pile of tosh!

 

The walls are closing in on winter at a rate of knots ! 

[January Snowstorm]

13 minutes ago, snowray said:

Dear me, what a pile of tosh!

 

It's as ugly as it could get really, that after weeks of dross. We can only hope the strat does us a favour!

[snowray]

2 minutes ago, goosey007 said:

The walls are closing in on winter at a rate of knots ! 

GFS is junk, it was last Winter too.

3 minutes ago, January Snowstorm said:

It's as ugly as it could get really, that after weeks of dross. We can only hope the strat does us a favour!

Winter for Easter? No thanks!

[Stuie]

13 minutes ago, snowray said:

Dear me, what a pile of tosh!

 

If we look at 9 days which is still way up for grabs.

The teleconnections are showing the US are not getting the blob of death so it has to go somewhere. ECM T216 tries to do this.

No faith in anything at 9 days but the models show this.

Edited February 2, 2023 by Stuie W

[mushymanrob]

IMHO the GFS 12z is now pretty much in line with what the NOAA anomaly charts have been suggesting.

[snowray]

10 minutes ago, Stuie W said:

If we look at 7 days which is still way up for grabs.

The teleconnections are showing the US are not getting the blob of death so it has to go somewhere. ECM T216 tries to do this.

No faith in anything even at 7 days but the models show this.

No forgiveness for the GFS model from me, it was a wind up last winter too. At least the other models correct themselves pretty fast, in fact it was ECM that first had more amplification a few days back back at T 240, but it was only one run.

I posted this earlier......this was the GFS Ens just yesterday, and I'll post it again, not even a half way house, what a joke!!!!!

Edited February 2, 2023 by snowray

[ItNeverSnowsInWindsor]

And it’s (the cold) all gone now in 12z GFS.