Model output discussion - 7th January onwards

[chris55]

ECM fridgid this morning with a very cold surface high and hardly a breath of wind from day 5 out to the end. The cold would really begin to build with harsh frosts. Chance of some disturbances moving in at the end as well. 

Brrrrrrrr

 

[ptow]

1 hour ago, carinthian said:

The ECM proceeds to build a block of very cold air to cover most of Central and East Britain out to day 10.

C

Is -9 actually that cold though?  Wouldn’t that equate to 1-3 degrees above. 

[snowice]

Oh what a surpriseThat ECM is could be a great model watching day for us all looking forward to the 12z.If 12z is similar and repeats 00z it will settle the nerves. 

[SMU]

10 minutes ago, ptow said:

Is -9 actually that cold though?  Wouldn’t that equate to 1-3 degrees above. 

No- colder.

This is about the column of air - & how much 'modification' there is down to the surface-

The cold gets mixed down (-6) at day 5 then the cold air keeps decending day 6/7/8.

Once that column has got the polar air all the way to the surface then the lapse rate in terms of warming are really low - so -9 850 might only get a warming of 8 or 9 degrees. ( possibly less in the most prone spots )

The temps between 4-8pm would drop by about 4-5 degrees indicating that -10c could be available quite widely, which again the next day take a long while to recover.

The 192 ECM if you look at the europe version shows the optimal conditions for deep surface cold which are-

- Snow cover

- Low sun Angle

- Stationary air

- deep cold upper air mixed down to the surface.

To replicate the same daytime Maxima from a polar NW flow London would need uppers of around -16c to start with...

Continental air has the ability to sustain much colder surface conditions generally due to the much lower humidity-

Wait for the london ENS but to me they look like Ice days (192 > 240 ) & CET around -2.5c

But the 192 chart needs to get to about T48 first !

Debilt ENS just in

days 8-10

1c - -5c

0c - -6c

-1c - -7c 

We would have the same air as them !

Edited January 13, 2019 by Steve Murr

[Ben Sainsbury]

9 minutes ago, ptow said:

Is -9 actually that cold though?  Wouldn’t that equate to 1-3 degrees above. 

850hpa is approx 1km up into the atmosphere. According to environmental lapse rate as temp declines by about 10’c per km. I’d expect temperatures to struggle to get above 1’c at a max, if there is snow cover temperatures wouldn’t get above freezing. All depends on air flow too which affects lapse rate.

Edited January 13, 2019 by Ben Sainsbury

[ICE COLD]

Morning haven’t even looked at the GFS or read the forum yet . 

Just looked at the ECM and UKMO and all looking very good this morning ? 

This = Good mood this morning

[Ice Day]

1 hour ago, feb1991blizzard said:

Look at the cold pool over Norway building at 240 though!!!

That really caught my eye as well Feb  That's the coldest pool to our east all winter, now if we could just tap into that.....

 

[ptow]

18 minutes ago, Steve Murr said:

No- colder.

Thanks 

Edited January 13, 2019 by Polar Maritime

[Weather-history]

Looks a real possibility that January will be drier than average for many parts

 

Edited January 13, 2019 by Weather-history

[BLAST FROM THE PAST]

1 hour ago, carinthian said:

That just crazy. I know that location in Obertauern.  Its even worse there this morning. Parts of Austria not seen this amount of snow for many decades.

C

It’ll take decades to thaw it!  Very dangerous conditions out there, I hear many ski resorts closed as even chair lift stations are buried!

 

Re the runs, any run that builds temp surface heights towards Scandi over 7-10 range is on the money. Lots focused on the ECM but UKMO looks mighty good to me too.  

If we get that cold in and then we have the PV displacement shift SE across us into Europe, then there’ll be some very disruptive weather

 

BFTP

Edited January 13, 2019 by BLAST FROM THE PAST

[ICE COLD]

Also the GEFS looking great today . Lot of flat lining. Happy days . I feel we are gonna get a stonking easterly within the next few weeks with some seriously cold uppers .

[Stu_London]

A period of surface cold with less moisture (per the ECM) would be preferable to many of the operational runs delivered by the GFS which whilst looking pretty would have in reality been a bit of a sleety mess away from Scotland and northern hills. Marginal situations (should they arise) rarely deliver if arriving directly from a period of average or above average temperatures.

My concern is that the ECM has form with Armageddon type output that either evaporates or gets watered down nearer the event.

[nick sussex]

The greater uncertainty moving forward is less to do with the overall NH pattern but how far east the jet will be before it tracks se .

The signal for the displaced Azores high has been constant for days even when the models have been chopping and changing in terms of detail for Western Europe .

A good way to view this is with the ECM pressure ensembles, a good guide is to check London versus nw Scotland  , both show any incursion from the nw will be shallow , so after midweek when we have that low moving se the lowest pressure from 18 to 21 January is around 1005 , with a top of 1020 for Nw Scotland and around 1025 for London. It’s not till after this we see bigger spread .

Snow prospects are always better with shallower low pressure , this type of set up with shortwave energy heading se and cold air in place ahead often produces some good snow totals .

One word of caution though , where exactly will the track se in the jet occur .

This is why although the NH pattern looks solid the crucial more local detail which is so important is still to be determined .

[Purga]

Yes another great shift towards cold with the GEFS

18z                                                                 00z

 

[karlos1983]

Finally!!! A start to the day with a smile! Seems a long time ago we had great runs pretty much across the suites on the 00z !

ECM is an absolute beaut, getting cold in to the UK and locking it in! Get the cold in first  

Ok yes it’s a cold outlier, but it’s a totally feasible outcome. GEFS much better as well. Great start to the day

Edited January 13, 2019 by karlos1983

[winterof79]

3 minutes ago, ICE COLD said:

Also the GEFS looking great today . Lot of flat lining. Happy days . I feel we are gonna get a stonking easterly within the next few weeks with some seriously cold uppers .

Looking good and the sister vortex continues to be forecast to drain our way

[feb1991blizzard]

21 minutes ago, Weather-history said:

Looks a real possibility that January will be drier than average for many parts

 

That always looked a strong possibility - thats what i went for in the rainfall competition.

[Cannonfoda]

Is there anywhere that tracks the accuracy of the models?  Simple offset of the images against actual result would be cool and would let everyone see what model works best.  

[winterof79]

Am I reading these wrong or is it trending milder in the extended? I see cold clusters though.

Shows winds possible from any direction you prefer

 

[SMU]

ECM daytime maximas at day 10

Widely -2c but further North -3/-4 ( 28F is -4.5c )

 

[nick sussex]

Good start to the 06 hrs runs .

The ICON better upstream at T120hrs hrs and moving closer to the Euros .

We’re looking for small incremental changes early on which later on will help in the bigger picture .

Edited January 13, 2019 by nick sussex

[northwestsnow]

1 minute ago, Steve Murr said:

ECM daytime maximas at day 10

Widely -2c but further North -3/-4 ( 28F is -4.5c )

 

That is incredibly cold and my 1st thought was what about the poor homeless people...

I hope authorities and people with influence are watching things closely as a -3/-4 in the day could easily translate to a -8/-9 in the night..

 

[PeteG]

4 minutes ago, Steve Murr said:

ECM daytime maximas at day 10

Widely -2c but further North -3/-4 ( 28F is -4.5c )

 

28F is actually -2.2C

[Snowyowl9]

43 minutes ago, Weather-history said:

Looks a real possibility that January will be drier than average for many parts

 

Dry as 2005-06 winter so far ? drier even.

But winter looks like its aroud the corner with the Nly digging in further even this week now,can still mean very dry though.

Edited January 13, 2019 by Snowyowl9

[Methuselah]

5 minutes ago, Steve Murr said:

ECM daytime maximas at day 10

Widely -2c but further North -3/-4 ( 28F is -4.5c )

 

-2C= 28.4F Steve...