The Hunt for Cold continues 02/01/19

[Optimus Prime]

44 minutes ago, Roger J Smith said:

Day ten on ECM looks very encouraging, everything starts to line up for a severe cold plunge. We take as they say over here. 

So winter isn't over now?

[northwestsnow]

ICON/EC/GFSP the pick this morning-

Encouraging that EC might be sniffing out the way forward perhaps?

Not much help from GEFS- seems to be a split mid term between cold zonal and rubbish zonal..

Non the wiser from where i'm sitting, hopefully EC leading the way..

edit: after viewing the precip charts i'm not entirely sure what GEFS are depicting mid to long term , would have expected more precip spikes in a conventional zonal set up..

Edited January 3, 2019 by northwestsnow

[Roger J Smith]

14 minutes ago, Optimus Prime said:

So winter isn't over now?

I don't think I have been in the winter is over camp at any point, maybe you read my comment about the GEM, just how I reacted to seeing its output, not an endorsement of its theme by any stretch. GEM is only a good tool when it seems to be in harmony with several other major models. A GEM outlier is like a bitcoin offer you can refuse. 

[Tim Bland]

GFSp whilst not synopticaly spectacular delivers plenty of snow as wedges allow southerly tracking lows ...

[Nick F]

1 hour ago, Ali1977 said:

Why no comments on the ECM - it’s a good one  144-168-192 below

Not exactly BOOM charts in terms of deep cold air advection and associated snow potential, but synoptically much better than what we have a the moment.

Day 10 00z EC chart screams potential with the potent reload from the north knocking on Scotland's door, too far off to have confidence, but do think there is a signal for colder reloads from the arctic as we head towards mid-month, interestingly the 00z GEFS z500 mean is signalling cross polar height rises (-AO) from the NAO region day 10 and then on which would help lock in the reloads of arctic air.

00z EPS z500 mean has the ridge out west (further west than GEFS at day 10) and deep trough down into E Europe - which suggests scope for Nly reloads.

All-in-all, positive signals ahead toward mid-month, though no wintry nirvana yet showing, the wait continues and so patience required ...

Edited January 3, 2019 by Nick F

[DanDorsetUK]

This from Forecaster Helen Roberts. Her comments were about the ssw: “That is why it is feeling much colder this week than before, and towards the middle of the month it will make conditions much more changeable, with more freezing fog patches and rain. “While it is technically possible that Beast from the East-style heavy snowfall will return, we just don’t know yet whether it will happen.” So I guess they have no clue where this is going to go as much as we don't. 

[Duane S.]

Another edge towards an initial Easterly this morning? I think so.

The Berlin EC charts show an increased appetite for reversed winds to downwell and at 150mb, why maybe we should be looking east... ?

[nick sussex]

Good and bad this morning .

Good that the main models keep separation between shortwave and upstream trough at the key timeframe .

The bad we’re not seeing enough north easterly push to the ridge bar the ICON which is hands down the best output of the winter so far .

Because of the expected split PV in a few days it might be wise to view the later output in light of that .

Overall I would have gladly taken today’s outputs if offered yesterday morning , today I think we’re in a holding pattern waiting for the next move .

[northwestsnow]

Just now, nick sussex said:

Good and bad this morning .

Good that the main models keep separation between shortwave and upstream trough at the key timeframe .

The bad we’re not seeing enough north easterly push to the ridge bar the ICON which is hands down the best output of the winter so far .

Because of the expected split PV in a few days it might be wise to view the later output in light of that .

Overall I would have gladly taken today’s outputs if offered yesterday morning , today I think we’re in a holding pattern waiting for the next move .

EC looks good again Nick

Just read an interesting post by Iceberg in the other model thread and its an encouraging read from a very knowledgeable chap who doesn't post very often but i personally always pay attention to his thoughts..

[SMU]

A big step west of the cold on the EPS overnight from yesterday-

00z V 00z is 168 > 192 is a good 3/400 miles adjusted with the -4c line

[bluearmy]

10 minutes ago, s4lancia said:

Another edge towards an initial Easterly this morning? I think so.

The Berlin EC charts show an increased appetite for reversed winds to downwell and at 150mb, why maybe we should be looking east... ?

The ec op again downwelled above 75N ....... the latest op is neg 2/3 AO and  neg 2 NAO . imo, the mid month period is dependent on how the tpv arranges itself which could allow the arctic high to play a bigger part in the atantic sector 

[Weathizard]

1 minute ago, Steve Murr said:

A big step west of the cold on the EPS overnight from yesterday-

00z V 00z is 168 > 192 is a good 3/400 miles adjusted with the -4c line

Much better angle being depicted now also, not sure it will be enough to get a sustained wintry flow though, the ridge seems incessant on staying too close to us  , longer term the set up is getting better and better IMO.

[Ali1977]

2 minutes ago, bluearmy said:

The ec op again downwelled above 75N ....... the latest op is neg 2/3 AO and  neg 2 NAO . imo, the mid month period is dependent on how the tpv arranges itself which could allow the arctic high to play a bigger part in the atantic sector 

So a mid month swing is still possible going off that? 

[bluearmy]

Just now, Ali1977 said:

So a mid month swing is still possible going off that? 

the modelling is a little tricky at the moment  .........the big pieces of the jigsaw are known but the areas between the big pieces are proving tough to work out ..... wedges perhaps ......

[IDO]

Despite hopes for a QTR, I think we can safely rule this out. Some initial response to the SSW is still likely and we can see the models trying to grind some sort of cold from that, so that remains a possibility.

However, as I expected the SSW downwelling may be the make or break for this Winter. This is due in the third week of Jan and combined with possibly favourable Tropical forcing in the Pacific region, Feb should be interesting for some mid-latitude regions. I still believe that a long cold spell will be directly related to a Pacific Wave and its interaction with any HLB. The usual caveats for the UK.

The D16 nascent GEFS are still there but no current trend for any large scale flips to a blocky Atlantic sector; D16:

Of course with the GFS bias for over-egging the Atlantic, these GEFS may have little probative value, but an improvement would be helpful!

Seemingly no light at the end of the tunnel yet for wholesale changes to be reflected in the models so as we were...

 

 

[nick sussex]

Timing is so important .

What we want is to get the ridge sufficiently ne and low pressure developing over northern Italy before lobes of the PV start flying all over the place .

This is why the PV split could add a lot of uncertainty into the modelling .

[Roger J Smith]

We should also be aware that there is already a well-developed northerly flow around 20-30E at all levels, starting from around 70N and reaching the Med (north to north-northeast actually). Since retrogression is closely aligned with the SSW phenomenon, that's a good omen, if that would repeat in a week to ten days over the UK and turn a bit more to the northeast, then a sustained deep cold would develop. And that would happen just before an energy peak which suggests to me that troughs would form over France and the North Sea. 

[northwestsnow]

ICON rolling out- will be interesting to see if it maintains the nice trends observed on the 00z run- as it was one of EC's 'allies' this morning it would be a positive if it follows the 00z..

Edited January 3, 2019 by northwestsnow

[ArHu3]

2 minutes ago, northwestsnow said:

ICON rolling out- will be interesting to see if it maintains the nice trends observed on the 00z run- as it was one of EC's 'allies' this morning it would be a positive if it follows the 00z..

6z doesn't go past 120h unfortunately 

[northwestsnow]

1 minute ago, ArHu3 said:

6z doesn't go past 120h unfortunately 

Oh bugger i forgot about that, thanks Artur..

[karlos1983]

9 minutes ago, northwestsnow said:

Oh bugger i forgot about that, thanks Artur..

We should still get a good idea of where it’s heading by +120 though.

[SMU]

So, todays the day where the phasing of the 2 lows will be resolved as the timing edges towards the T69 Mark.

My personal forecast would be to expect significant upgrades across the piste in the day 6-8 timeline & a more uniform agreement across all the models inc GEFS & EPS

S

[shaky]

3 minutes ago, Steve Murr said:

So, todays the day where the phasing of the 2 lows will be resolved as the timing edges towards the T69 Mark.

My personal forecast would be to expect significant upgrades across the piste in the day 6-8 timeline & a more uniform agreement across all the models inc GEFS & EPS

S

Icon lookin even better at 102 hours!!more ridiging into greenland and shortwave dropping further south!!

[Duane S.]

Yep only goes out to +120 but a notable improvement 

[northwestsnow]

Well ICON is actually an improvement on 00z IMHO-

Dropping that trough nicely ..

6z

00z

Edited January 3, 2019 by northwestsnow