Model Output Discussion 29th December - Into mid-Winter.

[SMU]

25 minutes ago, Rob K said:

That is the ECM 168 chart, Steve.

 

This is the UKMO 168 chart:

 

Still easterly apart from the far SW until the low clears

 

ECM mean @ 144 homing in ...

[winterof79]

Status Quo short ensembles......?

Down Down

Edited January 10, 2017 by winterof79

[SMU]

19 minutes ago, Unleash the Beast said:

Fantastic ECM again but can anyone remember which Model was most on the money when the 2010 cold/snow spell when it started counting it down from about 10 days out I believe?? 

ECM 100% modelled the vertical advection better & earlier in Nov 2010

[doctor32]

Matt Hugo on twitter...

12Z EC ENS steadfast with the blocked outlook next wk, still some members not building the high far enough to the NE otherwise E'ly is on.

[SMU]

& last post before the 18z

UKMO PPN depth for T60

-6 uppers & what appears to be 1280 thickness.. DPs marginal

S

 

[Summer Sun]

 

 

[Ali1977]

7 minutes ago, Steve Murr said:

& last post before the 18z

UKMO PPN depth for T60

-6 uppers & what appears to be 1280 thickness.. DPs marginal

S

 

Where would have the best chance for snow on this chart down south ?

[Seasonality]

Just to note. According to latest ECM output based update on yr.no even tropical London will have an ice day on the 19th. A rare beast indeed for the balmy capital.

Edited January 10, 2017 by Seasonality

[SMU]

14 minutes ago, Ali1977 said:

Where would have the best chance for snow on this chart down south ?

The NE quadrent & in the heavier bursts which lower the ZDL towards the surface--

[phil nw.]

Please only post model related discussions in here.We are constantly removing off topic content -remember the other threads for chat and banter.

Thanks

[chris55]

4 minutes ago, A Frayed Knot said:

ECM for USA still incredibly mild for the time of year in the mid term, days 9/10

 

[Weather-history]

13 minutes ago, Summer Sun said:

 

 

GFS 12Z ensembles go for an anticyclonic block next week as well, as does GEM 12z.

The question is becoming more and more where does the centre and axis of anticyclone lie?

[Frosty.]

4 minutes ago, chris55 said:

ECM for USA still incredibly mild for the time of year in the mid term, days 9/10

 

It's about time they had some mild mush..I have no sympathy!

[Cheshire Freeze]

Just looked at the mean pressure anomalies of the ECM ensembles...note the retrogressive signature between 216-240 hours. 

[bluearmy]

Extended eps continue the theme of retrogressing the high anomoly west towards the east Canadian ridge and the low height anomoly to the northeast backs sw to meet the Azores low height anomoly headed ne 

the result is a general low anomoly covering the east Atlantic and into nw Europe which covers a huge envelope of solutions, some of which would be zonal mild and some of which would be zonal cold, and some which could be troughy cold. I suspect the key remains low heights over Europe to our south which is unconvincing either way 

[cheese]

3 minutes ago, Frosty. said:

It's about time they had some mild mush..I have no sympathy!

Probably won't be mild mush for them, more like clear skies and temps over 20C.

[Summer Sun]

 

[snowking]

T2M 12z EPS for Heathrow:

Pretty solidly behind the cold at least in the mid range, though also relatively dry it must be said (EPS Average <1mm after the 15th)

[AWD]

Just pinched this from Judah Cohen's Twitter feed;

Reminds me of those CFS charts @CreweCold has been posting for the last couple of months.  

[Frostbite1980]

Also remembering that uppers are not everything, you can have them at -1/-2 if the dew points are at freezing or below and with a continental feed this is more than likely so any precipitation should fall as snow especially away directly from the coast. Looking at the ECM ens the op is in the colder catergory but the mean is more than cold enough for snow. Although the colder the uppers the better as the North Sea convective machine ramps up especially with SST's at around 9/10 degrees. All in all things are looking good tonight and hope to see another shift in the 18z GFS......fingers crossed.

[stewfox]

Eyes down

GFS 18Z updating. 0% complete - up to +00 (approx 90 mins remaining) -

Edited January 10, 2017 by stewfox

[Captain Shortwave]

2 minutes ago, Frostbite1980 said:

Also remembering that uppers are not everything, you can have them at -1/-2 if the dew points are at freezing or below and with a continental feed this is more than likely so any precipitation should fall as snow especially away directly from the coast. Looking at the ECM ens the op is in the colder catergory but the mean is more than cold enough for snow. Although the colder the uppers the better as the North Sea convective machine ramps up especially with SST's at around 9/10 degrees. All in all things are looking good tonight and hope to see another shift in the 18z GFS......fingers crossed.

You need the airmass as cold as possible to generate the showers in the first place as well as low heights throughout the atmosphere. The ECM ens are cold or very cold at the surface with 850s still below average as well, but convection is capped by high pressure and the thermal gradient is too shallow. Hence conditions remain mostly dry.

That said in my opinion if we get the easterly feed then I suspect we will drag an area of low heights towards France as per the ECM operational which would lower the heights near the UK with the risk of more prolonged precipitation moving out of the continent. The ECM ens are moving in the right direction with the mean edging north each run and well as the 850s having been edging lower each run as well. Hopefully we should continue to see this trend continue over the next 24 hours to cement this cold spell. 

[winterof79]

Longuns for those of that persuasion and a few little rogues in and amongst

Edited January 10, 2017 by winterof79

[mhielte]

8 minutes ago, stewfox said:

Eyes down

GFS 18Z updating. 0% complete - up to +00 (approx 90 mins remaining) -

Looking solid so far then...

[Frostbite1980]

3 minutes ago, mhielte said:

Looking solid so far then...

At 24hrs it should be.....patience grasshopper patience 

the bdifferences at 72 hrs between the models is where I am interested.....we want more amplification from the GFS this time round 

Edited January 10, 2017 by Frostbite1980