Model output discussions pm 31/12/15

[Frosty.]

10 minutes ago, knocker said:

I wasn't referring to the cold Frosty just the snow as the cold interlude looks quite dry.

Fair enough knocks, I just think the Ecm 12z has potential wintry reloads beyond T+240...I'm more optimistic it will amount to more than just a cold interlude as you put it. For the first time this winter there is realistic hopes for nationwide cold!

[bradymk]

Some rough estimates of temperatures from tonight ECM. This site uses ECM data for its forecasts.

Glasgow and Birmingham attached. This would be delightful after what we have had to endure so far

[That ECM]

3 minutes ago, weirpig said:

but in your summary of the ecm  you said that there may may be harsh frosts  as the uk is under the influence of a brief northerly. Now i maybe very ignorant here but the later frame of the ecm suggests something more sustained. Is there any reason by looking at the ecm charts ypu believe it will on be a brief northerly?

Clearly I am not knocker but if you take the gfs, the met outlook and ecm tendency to over exaggerate heights then a 2/4 day cold spell/snap is a strong possibility. Time will tell and cross model agreement would be useful but any cold and a break from wind and rain is welcome. Hoping it becomes prolonged but at the moment I would like more evidence.

[Singularity]

I'm impressed by how similar GFS and ECM are in terms of how their 12z det. runs handle the general hemispheric pattern out to some 8 or 9 days ahead.

The usual differences in the placement and orientation of the Arctic High for sure, but with respect to the UK we see both runs advertising a diving trough, that first mid-Atlantic ridge not quite getting the WAA needed for the linkup with the Arc.H, and the potential for another go at getting that WAA angled south to north in the 9-11 day range. 

It's with that last point that the two models diverge, as GFS goes into classic 'flatten the ridges' mode while ECM entertains the idea of attempt #2 being more successful.

 

The signs are there that residual disturbances may make the route to a more sustained Arctic incursion a bit of a messy one - which may mean rather more in the way of marginal rain/snow events that some would like to deal with. Though I imagine many would still consider it better than having no chance at all.

This has yet to reach a point where those in the south can really get their hopes up for much in the way of snow; such developments remain largely beyond the 10 day range and are based on extrapolation from the 12z ECM, or the unreliable reaches of the 06z GFS det. It's starting to look more than a little interesting for the north though - but a lot of details to be resolved yet and who knows, something more organised could pop up for the south.

For now it's about getting that broad pattern of mid-Atlantic ridges, troughs into Europe, and a strong Arctic High into place. The 12z output is very encouraging in that respect 

[weirpig]

2 minutes ago, That ECM said:

Clearly I am not knocker but if you take the gfs, the met outlook and ecm tendency to over exaggerate heights then a 2/4 day cold spell/snap is a strong possibility. Time will tell and cross model agreement would be useful but any cold and a break from wind and rain is welcome. Hoping it becomes prolonged but at the moment I would like more evidence.

Yes  i understand that  but he was giving an overview of the ecm  in isolation based on just that one run,  Anyway academic will change between now and then. However ive just seen Knockers reply . 

[M1245]

So with the models looking as they are at the moment, when would we start to see/feel a difference in regards to cooler/colder weather?

[Eskimo]

1 minute ago, M1245 said:

So with the models looking as they are at the moment, when would we start to see/feel a difference in regards to cooler/colder weather?

When the cold weather comes in. 

[M1245]

1 minute ago, PerfectStorm said:

When the cold weather comes in. 

Thanks but for a rookie not helpful at all. 

[booferking]

26 minutes ago, i luv snow said:

And of course, the ECM shows 4 days of temperatures cold enough for snow, and as we all know, any finer details (if this evolution or something similar came to fruition) would not be known until much nearer the time. We have all been caught out/pleasantly surprised by unexpected snowfall in the past, so just getting the cold is the first big step!

Ecm Ensembles look decent again.

[Cheshire Freeze]

3 minutes ago, PerfectStorm said:

When the cold weather comes in. 

When will my dinner be ready to eat?

'when it's cooked'

[booferking]

Ecm Ensembles look decent again.

[ANYWEATHER]

1 minute ago, M1245 said:

So with the models looking as they are at the moment, when would we start to see/feel a difference in regards to cooler/colder weather?

Hiyer! We should Feel a change by this time next week, of course subject to some changes.....

[gottolovethisweather]

36 minutes ago, booferking said:

Is there no chance people in the north will see snow on day 7,8,9,10??

From the 11th/12th January onwards, I'd give it 30 to 40% perhaps slightly higher chance of verifying at this stage. A trend is a trend is a trend though and Phil NW's post from earlier and Singularity's above in particular highlight what to look for from a NH perspective I feel. Give things another few days and the colder trend might be in the bank.

[Eskimo]

I didn't mean to sound arrogant, but that's generally what happens, you will see/feel a difference when the cold weather comes in. It's part and parcel. 

[That ECM]

4 minutes ago, M1245 said:

So with the models looking as they are at the moment, when would we start to see/feel a difference in regards to cooler/colder weather?

With your location soon. If you have access to the models then click on the 850s and move down the different time scales. You will see the cold air coming from the north and you will start you learning. That's how we all started. Word of warning tho, it's very addictive!!!!!

[knocker]

6 minutes ago, weirpig said:

Yes  i understand that  but he was giving an overview of the ecm  in isolation based on just that one run,  Anyway academic will change between now and then. However ive just seen Knockers reply . 

This may clarify it a bit. If the HP to the SW continues it's recent movement I suspect the WNW flow to the north would encroach but this is still quite cold.

[Ali1977]

Anyone got a link to the ECM ensembles?

[A Frayed Knot]

4 minutes ago, M1245 said:

Thanks but for a rookie not helpful at all. 

Yes i agree M1245 All you asked for is when it will get colder ' i for one am still learning and it's nice to know when a talented member comes up with a Answer like that ..Tut Tut .

[shaky]

4 minutes ago, booferking said:

Ecm Ensembles look decent again.

Any pics?!

[Bobafet]

As someone who is still trying to learn I must say I am royally confused with the posts tonight, normally I get the jist of what  is going on! But there are so many conflicting posts Tonight I haven't got a clue what to expect!! I would appreciate a bit of clarity!! 

Although I must say this is one of the best forums on the net and makes winter even more magical.

 

[booferking]

3 minutes ago, shaky said:

Any pics?!

Sure here they are.

 

 

 

Edited January 4, 2016 by booferking

[BARRY]

1 minute ago, bobafet said:

As someone who is still trying to learn I must say I am royally confused with the posts tonight, normally I get the jist of what  is going on! But there are so many conflicting posts Tonight I haven't got a clue what to expect!! I would appreciate a bit of clarity!! 

Although I must say this is one of the best forums on the net and makes winter even more magical.

 

don't worry, just enjoy all the ups and down that model watching brings it is addictive

 

[booferking]

Sorry uploaded doubles here they are again.

[Captain Shortwave]

ECM ens

Trough moves eastwards with a mean ridge to our west, the result a northerly flow.

Scotland seeing a mean as low as -7C at 850 level. Not bad at all.

In general the pattern suggests a ridge in the Atlantic northerly rather than one triggered by a cut off high, that said a cold snap looks to be more of a 3-5 day northerly rather than a quick toppler. One other thing would be that we see a big positive anomaly even at day 10 over the pole.

So lots of options down the line with that pattern in place.

So in the end the odds of something colder developing from the middle of next week is increasing. This is before we see the ramifications of these probing ridges further down the line (End of January/February where most have their money on a significant cold spell).

[Shuga ice]

4 minutes ago, M1245 said:

Thanks but for a rookie not helpful at all. 

I agree, that was not helpful.  The colder weather looks like setting in during next week according to the latest charts, though I must stress that the excitement on this thread is because of the mild weather that we have had up to now.  The charts are showing a rather cold spell as opposed to cold or very cold.  This could upgrade to a colder solution if we end up with a continental feed.  Northerly winds generally disappoint the majority on here if it is snow and longevity of a cold spell that is wanted.