Model Output Discussion - 05/01/2016 18z onwards

[ANYWEATHER]

Evening All, Yes its gonna get cold , even very cold ,the devil will be in the detail, but just dust off youre winter woollies , get out your sledgies out some places will get Plastered with snow in just a few days

[karlos1983]

4 minutes ago, Ali1977 said:

I've lived at my house for 3 years and haven't had a flake of snow....missed the 09/10 winters as was overseas with work...an I finally going to get some by next weekend, surely it's looking possible, and some severe frosts especially looking possible!!

The signs are positive. There is nout warm about those ECM ENS. Fact

[Frosty.]

The Ecm 12z ensemble mean tonight is easily as good as last night or better if you are a coldie like me, it's showing rock solid support for arctic air to become entrenched as time goes on with a scandi trough and Atlantic high building north...so, no downgrade from 24 hours ago, indeed it looks synoptically better to me!..Good riddance mild mush

[nick sussex]

Not much support for the UKMO output upto T120hrs in the ECM postage stamps:

http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2016010712!!/

I'd be surprised if the UKMO doesn't modify their raw output in the fax charts.

[Paul]

Please folks, if you want to chat generally about the weather / winter etc, don't do it in here. Head over to the general chat thread and do it there. The vast majority of people are fine with this and have no problems with where to post, just a small minority who don't seem to want to...

 

 

[phil nw.]

Pretty good gefs tonight and a consistent message for the colder air sinking south over the UK by the 13th.

Compare the mean from the 4th to this evenings chart

and the 2mtr temperatures for Warks

possible freezing days in there with the cold extending into the following week.

It seems based on these we are looking at at least a week of cold and with the 12z Op.run going mild against the set at the end who knows,maybe longer.

 

[Deep Snow please]

Oh Fantasy Island my master you never disappoint. If that verifies I'll eat some of the foot-long icicles we'd get.

Firstly the strip of double digit minuses across from Wales to Norwich or Nottingham whichever one it is:

And then the double digit minuses around the Pennines and Northumberland:

[CI Weather]

1 hour ago, Steve Murr said:

Dont hate the azores low - love it ( dont hate it )

- as long as it doesnt get to far north ...

its a snow bringer ....

These 2 charts never get a mention in the archives but the second one had the most fierce easterly ever..

its what happens when you spike the subtropical jet north out of spain against high pressure over greenland -

s

 

 

As I'm sure there will (hopefully) be plenty of posting of charts over the coming days.  If you press and hold on the chart you can save the image rather than screen shots

Hopefully we can see a better interaction with the low to bring an easterly element into play!

Edited January 7, 2016 by CI Weather

[winterof79]

ECM control making the running

[Nick F]

Ever wondered why the GFS can't decide which direction to head in the medium to long range? Just take a look at its bias-corrected MJO forecast, though at least it gets into phase 8

The ECM confidently ploughs on through 8/1, gaining more amplitude with each day. It's been top dog with the MJO while the other models play catch up, the same is probably true with the medium range pattern ahead. 

 

The 12z EPS mean days 10-15 does again show retrogression of the Greenland +height anomaly though, this could lead to a more west-based -NAO, but there is the potential for the deep cold pool building over Scandi and NW Russia to retrogress toward the UK too, keeping any milder intrusion from the SW at bay over France.

 

 

Edited January 7, 2016 by Nick F

[Cheshire Freeze]

1 minute ago, Nick F said:

Ever wondered why the GFS can't decide which direction to head in the medium to long range? Just take a look at its bias-corrected MJO forecast, though at least it gets into phase 8

The ECM confidently ploughs on through 8/1, gaining more amplitude with each day. It's been top dog with the MJO while the other models play catch up, the same is probably true with the medium range pattern ahead. 

The 12z EPS days 10-15 does again show retrogression of the Greenland +height anomaly though, this could lead to a more west-based -NAO, but there is the potential for the deep cold pool building over Scandi and NW Russia to retrogress toward the UK too, keeping any milder intrusion from the SW at bay over France.

Yes I keep noticing this cold pool and wondering whether it will eventually come into play. Would certainly put the cherry on top.

[Catacol]

Excellent charts - very exciting. But I would second what RJS said yesterday - there is heat in our locale that needs to dissipate. The north sea is warm, the ground is warm - and experience is telling me that when the cold arrives midweek for many parts in the south modification will take the edge off the cold. We need 3 - 5 days of the cold to take that residual heat out of the system and allow greater chances of something substantial and long lasting.

Way out at 240h on ECM I like what I see - namely a feed of the cold air from deep in northern Russia. The flow is rather slack over the UK, but time for this to change. 

However the key here is the longevity (hopefully) of air from a very cold source. I see the spell as a slow burner therefore. For the north it will kick in early - for the south my gut is telling me we may have to endure marginality until week 2 brings embedded cold. Steve said as much earlier this evening - I agree.

And whether RJS is right or not about a comeback from the atlantic in 2 weeks time, I'm also in line with thinking pointing to a sustained period of cold winter. I cant see any teleconnection or signal for anything else right now. For all us amatuers those such as Tamara and GP laid this all out very clearly from the end of December. All there for us to read and learn from. Funny how EC32 and other tools were unable to see the same!!

So - Human 1, Computer 0.... and things are happening rather ahead of time too so that the coldest centre of the changing global and regional pattern may land on our doorstep right slap bang in the heart of winter.

I couldnt be happier.

Edited January 7, 2016 by Polar Maritime
To move discussion on..

[bluearmy]

The extended eps offer a more convincing route out of the cold by the end of week 2 as the -NAO becomes very west based and the Atlantic comes back in at our latitude. the control run is progressive and brings the Atlantic in just after day 10

 

 

 

[inghams85]

24 minutes ago, phil nw. said:

Pretty good gefs tonight and a consistent message for the colder air sinking south over the UK by the 13th.

Compare the mean from the 4th to this evenings chart

and the 2mtr temperatures for Warks

possible freezing days in there with the cold extending into the following week.

It seems based on these we are looking at at least a week of cold and with the 12z Op.run going mild against the set at the end who knows,maybe longer.

 

One trend I've been monitoring for 5 to 6 runs is to our North East. That cold pool has been building and building closer. I think our cold pool will receive an injection from days 8 onwards which is where our real cold is coming from. I have a sneaky feeling via undercut under a west based NAO and an easterly dow the line...

[bluearmy]

The extended eps offer a more convincing route out of the cold by the end of week 2 as the -NAO becomes very west based and the Atlantic comes back in at our latitude. the control run is progressive and brings the Atlantic in just after day 10

 

 

 

[Spah1]

1 hour ago, Theresnoway said:

Please can someone link to the model timetables, I cannot seem to find them.

TIA

 

 

 

Edited January 7, 2016 by Spah1

[feb1991blizzard]

Just now, bluearmy said:

The extended eps offer a more convincing route out of the cold by the end of week 2 as the -NAO becomes very west based and the Atlantic comes back in at our latitude. the control run is progressive and brings the Atlantic in just after day 10

 

 

 

It would just prove that the MO are getting better and the data we see almost seems like it reacts to MO forecasts rather than how it used to be (the other way around), just out of interest does it look like a reload is possible week 3 (meridional pattern continuation) or does it look like an atlantic driven spell will re-establish itself on the EPS, be interesting what the EC32 says tonight.

[nick sussex]

Looking at the US forecasters fax charts. The T144hrs one is more like the UKMO for the eastern USA, the T168hrs more like the ECM.

The GFS 12hrs run doesn't look like either.

[shaky]

Just now, nick sussex said:

Looking at the US forecasters fax charts. The T144hrs one is more like the UKMO for the eastern USA, the T168hrs more like the ECM.

The GFS 12hrs run doesn't look like either.

So 12z is an outlier maybe?

[lambgregg1977]

Would still want the cold entrenched into North Africa to be certain lol. Can't wait!

[Allseasons-Si]

Pretty supressed temps there

dew points looking good too,although could be a bit lower,but this is Netherlands

as for wind direction,someone give me heads up on this as i am getting splinters in my fingers

 

[booferking]

 

1 minute ago, nick sussex said:

Looking at the US forecasters fax charts. The T144hrs one is more like the UKMO for the eastern USA, the T168hrs more like the ECM.

The GFS 12hrs run doesn't look like either.

Fax chart & UKMO @72hrs the low looks like it has cleared into North sea and 528 dam line down through half the country,

[nick sussex]

12 minutes ago, shaky said:

So 12z is an outlier maybe?

Both the UKMO and ECM develop a coastal low near New England at T144hrs. The GFS takes another 24hrs to develop that. So at this point I'd say yes because that also effects the ridge coming out of the ne USA at the T144hrs timeframe.

Then of course at T96 and T120hrs the UKMO seems to be an outlier over the UK with its troughing so still a lot to be resolved.

I don't mind its outlier though becoming the right trend!

Indeed if you follow the likely evolution on the UKMO   we'd have a better chance at tapping the colder pool to the ne.

 

Edited January 7, 2016 by nick sussex

[bluearmy]

The gfs para holds the Atlantic trough so far back to the west for so long that the second system coming off the eastern seaboard at day 8 phases with it and it's game over for any lengthy cold spell. 

 

 

 

[Allseasons-Si]

Did anyone notice that secondry hp cell forming off the eastern seaboard on the ukmo 144 hrs chart with the trough digging south(red circle) and a bit of WAA ahead of it,one to watch on the 18z 138

ECM has it but the gfs and gem doesn't.

Edited January 7, 2016 by Allseasons-si