The hunt for cold - Model discussion (late November)

[northwestsnow]

Models seem to be putting more and more energy into the jet stream this morning.

Still confident of the UK turning dryer and colder as we move through next weekend,which as i look out of the window to more wind and rain suits me fine.

Lets see how the next few days evolve..

EC mean at day 10 is blocked..

Edited December 2, 2018 by northwestsnow

[Chesil View]

I almost knew before I switched on my phone this morning that there would posts saying the 0z ops are not as good as yesterday. The temptation to give knee jerk reactions or commentary purely on the ops is strong for cold and snow lovers and I do understand that this is the models thread ( cold biased) but a run is the whole package ens ect not just the ops and unless the models are viewed as such then just commenting on the ops does not give the whole picture.

It's very rare( apart from exceptions like last summer and the overwhelming model certainty of December 2010) for the ops not to differ and change often quite substantially on the way to a cold spell. 

I appreciate that we are on here because we are weather lovers of the cold variety but it does help to view the whole package and the direction of travel before passing judgement.

Rant over. Lol

Edited December 2, 2018 by Broadmayne blizzard

[mulzy]

De Bilt 2M ensembles are decent

Of course, De Bilt is ~250 miles to the east of London *and* in this particular scenario that is crucial!

Edited December 2, 2018 by mulzy

[ArHu3]

9 minutes ago, mulzy said:

De Bilt 2M ensembles are decent

Of course, De Bilt is ~250 miles to the east of London *and* in this particular scenario that is crucial!

The ensemble is actually better than yesterday and I'm only 50 km west from De Bilt

[Tim Bland]

GFS (00z) ensembles similar to yesterday’s (12z)

 

 

[northwestsnow]

UKMO looks the pick of the 3 at 144, ever so slightly less progressive with that low between 120-144..

Its fascinating model watching for sure, key time frame now 120-144, obviously the further north the azores ridge can get the better.

edit And i'm still of the opinion things look good for at the very least a cold high by next weekend.

Edited December 2, 2018 by northwestsnow

[Ladyofthestorm]

Looking the ensembles. I really don't think we can draw any conclusion from it. 

Anything beyond day 10 is really purely speculation. The models don't know where to place the highs either. Though I suspect the GFS is overplaying the role of the Atlantic. The GEM is  going for higher pressure over the UK. I suppose we can use this point as a benchmark to see which model verifies if any!! 

[bluearmy]

 seems that the obvious trend is that the ridge won’t get the traction to sustain far enough north initially - what happens in the Atlantic subsequently dictates if we drive another bout of WAA to form a proper scandi ridge 

currently looking messy but pretty confident that a nw European high is pretty solid ...... likely to be cold one but how cold dictated by whether we are generally cloudy or clear 

there remain many routes on the table re how this ridge sets up through week 2 (does it settle scandi?) and the puzzle solved eventually by how much goes into the northern arm and how low heights over se Europe are able to drift west.

the Atlantic jet in the extended continues to look pretty weak and the mean tpv still centred ne Siberia end week 2 on the eps. 

Glad Daniel got those cushions for my fence ..........

Edited December 2, 2018 by bluearmy

[carinthian]

46 minutes ago, carinthian said:

Morning all, remember in yesterdays post , I mentioned we now have to look for some consistency in the models and compared with the previous 24 hours projections. Looking at this mornings , it is there . The GEFS control at 192t picture below shows this. Also backed up by ECM . So I would expect strong ridging to develop to the NE by day 9 (216t). Obviously there will be variations during the interim operational runs but the trend to a colder outlook continues for most in Europe during the second week of December. Shown below is chart of the day at 240t produced by the Canadian Met NWP model ( now that would be something )!

The chart below from is the mean ECM run for 192t and kind of in sync with the GEFS control run for the same time, which is a good thing. So this time tomorrow we need to look at the 168T charts to get a comparison. What we are looking for is consistency in the outputs. If get the same development by 144t , we increase the chances of a sustained forecast to colder weather. Hang on to your hats but as I mentioned, so far , so good. Do not be put of by the variability of the various op runs as they can easily switch outcomes in the period 168t -240t .

C

[johnholmes]

Regarding the anomaly charts, the last 24 hours shows the ridge and +ve heights still there but, and this is important, to me they centre of gravity of both has shifted SE. Gone is the area over Greenland on both EC and GFS, now showing coming out of Europe.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

The NOAA charts from last evening, although the 6-10 does show contour ridging showing into Greenland, is also showing +ve heights coming out of Europe rather than more shown in the Greenland area. 

So my caution yesterday looks justified this morning. It remains to be seen if the pattern of yesterday will return or the Euopean  ridging be the main player. With the strength of flow out of North America it does suggest that the latter may predominate, at least for some time yet. As always I'll keep checking and analysing the charts daily.

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

[johnholmes]

Just now, johnholmes said:

Regarding the anomaly charts, the last 24 hours shows the ridge and +ve heights still there but, and this is important, to me the centre of gravity of both has shifted SE. Gone is the area over Greenland on both EC and GFS, now showing coming out of Europe.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

The NOAA charts from last evening, although the 6-10 does show contour ridging showing into Greenland, is also showing +ve heights coming out of Europe rather than more shown in the Greenland area. 

So my caution yesterday looks justified this morning. It remains to be seen if the pattern of yesterday will return or the Euopean  ridging be the main player. With the strength of flow out of North America it does suggest that the latter may predominate, at least for some time yet. As always I'll keep checking and analysing the charts daily.

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

 

[Met4Cast]

20 minutes ago, bluearmy said:

 seems that the obvious trend is that the ridge won’t get the traction to sustain far enough north initially - what happens in the Atlantic subsequently dictates if we drive another bout of WAA to form a proper scandi ridge 

currently looking messy but pretty confident that a nw European high is pretty solid ...... likely to be cold one but how cold dictated by whether we are generally cloudy or clear 

there remain many routes on the table re how this ridge sets up through week 2 (does it settle scandi?) and the puzzle solved eventually by how much goes into the northern arm and how low heights over se Europe are able to drift west.

the Atlantic jet in the extended continues to look pretty weak and the mean tpv still centred ne Siberia end week 2 on the eps. 

Glad Daniel got those cushions for my fence ..........

If the fence fell down which side do you think you’d fall on?

The deep cold side made of hopes & dreams or the wet, mild & muddy side where Christmas is ruined?

[northwestsnow]

Looking at the EC mean again there is a big neg pressure anomaly over Europe by day 10, this will assist the high not sinking -i wouldn't be suprised if we see heights being sucked back into the Atlantic and a big northerly just in time for christmas..

Edited December 2, 2018 by northwestsnow

[Summer Sun]

The ECM op might have a very mild spell around the 11th but it's got no support from the ens

[Weathizard]

19 minutes ago, Summer Sun said:

The ECM op might have a very mild spell around the 11th but it's got no support from the ens

That’s a true outlier if ever I saw one! Realistically i’d take a dry spell out of this considering the zonal train that was being progged a few days ago, been a real deluge here recently

Edited December 2, 2018 by Weathizard

[bluearmy]

16 minutes ago, Daniel Smith said:

If the fence fell down which side do you think you’d fall on?

The deep cold side made of hopes & dreams or the wet, mild & muddy side where Christmas is ruined?

Somewhere inbetween ..................

Edited December 2, 2018 by bluearmy

[northwestsnow]

2 minutes ago, bluearmy said:

Somewhere inbetween ..................

Blue you really should be a politician!!

Joking aside its the prudent approach, personally i feel there is lots of scope for wintry weather post this coming week.

I think we will see a better EC det this evening, temps dropping away by next weekend..

Exeters musings again will be interesting reading and i don't think they will deviate from a cold high mid term..

[Met4Cast]

4 minutes ago, bluearmy said:

Somewhere inbetween ..................

You should be a politician!

EPS days 10-15 not without interest, good support for Scandi height rises, one worry for me is the lack of low heights being signalled over the Med 

[January Snowstorm]

While the models have remained fickle jumping from cold to mild in the long term the musings from Exeter have remained exceptionally accurate. They were the first to mention blocking to our northeast in November and first to mention a return to westerly's 

I often wonder if we didn't look at the models at all and just looked at the met office daily updates would we save ourselves a lot of heart ache.

[northwestsnow]

2 minutes ago, January Snowstorm said:

While the models have remained fickle jumping from cold to mild in the long term the musings from Exeter have remained exceptionally accurate. They were the first to mention blocking to our northeast in November and first to mention a return to westerly's 

I often wonder if we didn't look at the models at all and just looked at the met office daily updates would we save ourselves a lot of heart ache.

Agreed, although their updates have been fluid recently , only two days ago they were signalling a wet mild wet and windy December, yesterday they put the brakes on that in response to the NWP..

I know were my money is, and it isn't a mild wet and windy Dec!

Edited December 2, 2018 by northwestsnow

[Methuselah]

It'll be interesting to see whether the PM runs keep coming up with the goods; early-day doom and gloom (relatively speaking) is becoming a habit, of late?

Edited December 2, 2018 by Ed Stone

[Penicuikblizzard]

Surely with the mass of fridgid air going to hit NE America, will this not fire up the jet and send lows our way off the Atlantic??

Normally America is milder when we have a easterly blast ??

[Stuie]

3 minutes ago, Penicuikblizzard said:

Surely with the mass of fridgid air going to hit NE America, will this not fire up the jet and send lows our way off the Atlantic??

Normally America is milder when we have a easterly blast ??

Milder like this?

 

[Weathizard]

More amplification trending early again...

 

0z 

6z

Edited December 2, 2018 by Weathizard

[pdiddy]

3 minutes ago, Weathizard said:

More amplification trending early again...

 

0z 

6z

Not so sure, think we're relying on the second low to drive up warmer air west of us and it's less potent at this stage...