Model output discussion - 5th December 2016 - Into Winter we go

[booferking]

4 minutes ago, Snow Grain said:

Really?

Yep.

Edited December 18, 2016 by booferking

[Frosty.]

9 minutes ago, Snow Grain said:

It'll be rain with snow on highest ground in the north.

I disagree, I expect snow to low ground at times too in the n / nw later in the week, not confined to highest ground at all!

[Ravelin]

37 minutes ago, khodds said:

Thanks for that. I don't usually post on here, I won't bother in the future if I'm not entitled to an opinion. I was just excising caution - I'm a coldie like the majority on here.. shoot me down why don't you!!

It wasn't aimed at you even though it was you I quoted, that's why I specifically said "half the participants". All the emotions stuff should be in the 'model moans' thread, not here, so post away. 

35 minutes ago, mulzy said:

GFS has a clear model bias to underplay heights to the south.  We see it every winter in a zonal flow where it often pushes the jet too far south at day 5/6 only to draw it further north as day 0 is reached.

Also, a day 6 precipitation chart should have a "just for fun" label.

 

 

^^^^That's the way to shoot down day 6 charts. 

[I remember Atlantic 252]

13 minutes ago, Snow Grain said:

I wouldn't take much notice of Gfs snow projections from the west, they are always exaggerated.  It'll be rain with snow on highest ground in the north.

Can only agree sadly, from experience too, this chart is the way I think Xmas Eve will go, snow only on hills, north and west

Edited December 18, 2016 by I remember Atlantic 252

[Northern Sky]

Regardless of any chance of snow I think one thing is clear and that is we are in for a change of weather. I actually like wind and rain and the bonus is it will feel very cold in the wind. I'm just ready for a change of weather and if it feels cold I'll be happy.

I realise the models always overplay the depth of cold from NW'ly's but I have been following the 850 temps for a couple of days and really they don't seem to have changed a great deal. However as Multzy pointed out there is time for that to change for the worse yet. I know everyone wants snow but at face value I like the GFS 12Z, plenty of exciting weather and chilly Atlantic air about over the holidays.

[booferking]

Ecm colder air in quicker for Wednesday upgrade..

[Captain Shortwave]

Now before I potentially go on a bit of a rant, can we just call the upcoming week zonal, because it is not a cold zonal pattern, cold zonality comes from a suppressed jetstream over central/southern Europe with the polar vortex positioned mainly to our north/north east allowing the Azores high to be placed further north in the Atlantic. Hence a dominance of west to north west winds with the jet still blowing strongly.

To point this out for every colder shot, there is a milder slot following quickly behind.

    

    

Charts for Thursday through to Sunday, cool/mild/cool/mild, temperatures coming out near normal ,again perhaps siding a little above due to the wind preventing cold nights.

Edited December 18, 2016 by Captain Shortwave

[mountain shadow]

1 minute ago, Captain Shortwave said:

Now before I potentially go on a bit of a rant, can we just call the upcoming week zonal, because it is not a cold zonal pattern, cold zonality comes from a suppressed jetstream over central/southern Europe with the polar vortex positioned mainly to our north/north east allowing the Azores high to be placed further north in the Atlantic.

To point this out for every colder shot, there is a milder slot following quickly behind.

    

    

Charts for Thursday through to Sunday, cool/mild/cool/mild, temperatures coming out near normal ,again perhaps siding a little above due to the wind preventing cold nights.

Clearly, it is a matter of conjecture, but if the -5 isotherm is overhead, it is not cool but cold in my book, therefore your cool/mild/cool/mild translates to cold/average,cold average and is therefore cold zonal in my book. That's for the North West of course.

[A.J]

posts removed......no one-liners, off topic posts etc etc etc yadda yadda yadda......you know the drill *sigh*

[booferking]

4 minutes ago, mountain shadow said:

Clearly, it is a matter of conjecture, but if the -5 isotherm is overhead, it is not cool but cold in my book, therefore your cool/mild/cool/mild translates to cold/average,cold average and is therefore cold zonal in my book. That's for the North West of course.

Right off the Green ice sheet to pretty cold in my eyes for some..

[Frosty.]

The Ecm 12z shows a nice blast of cold zonality with 520-522 dam with blustery increasingly wintry showers with snow down to modest levels thru late wed / early thurs across the nw..opening salvo of wintry weather!

[gottolovethisweather]

49 minutes ago, Captain Shortwave said:

Now before I potentially go on a bit of a rant, can we just call the upcoming week zonal, because it is not a cold zonal pattern, cold zonality comes from a suppressed jetstream over central/southern Europe with the polar vortex positioned mainly to our north/north east allowing the Azores high to be placed further north in the Atlantic. Hence a dominance of west to north west winds with the jet still blowing strongly.

To point this out for every colder shot, there is a milder slot following quickly behind.

    

    

Charts for Thursday through to Sunday, cool/mild/cool/mild, temperatures coming out near normal ,again perhaps siding a little above due to the wind preventing cold nights.

 

 

 

A perfect analysis of how things currently stand, the good Captain I thank you muchly.  At least that's a posting I've managed to take something from, given all the private conservations between individuals in public in here previously. However, I do believe wintriness is likely to feature more within the media forecasts as we approach the big day. The 23rd/24th December remains of interest for coldies away from my back yard, as does post Boxing Day. With forecasts hinting at even the remotest chance of a few people seeing some magic white crystals, I'd grasp that opportunity with vigour giving the far from perfect stratospheric conditions right now, so enjoy it as and when it does come about. How's the ECM unfolding anyone?

Edited December 18, 2016 by gottolovethisweather

[Iceberg]

People are right to say don't look at precip charts. Where the precip falls will not be known for days. 

However you can look at the general trends and the model predictions. Despite temps that many think will be to high. The pm air flow shows exactly the right characteristics. It's modified mainly in the lower layers 925mb to surface. This means that the thicknesses in the all important layers are suitable for snow for many. 

This is particularly so in the heavier  precip where the 900-925 layer will be dragged down to surface. With the freezing level of 300m or lower for most without precip. Anywhere with even a bit of altitude could see snow given the meto and gfs for Christmas Eve. 

The predictions might change but they might change for the colder as is the current trend. 

 The Christmas Day winds are another story. 

[frosty ground]

Wintry showers in the north west

[Iceberg]

Ecm keeping up with the trend to make the air colder for Christmas Eve. Midday 850s so colder than this come the afternoon. 

[Captain Shortwave]

Well the ECM doesn't give the Christmas day storm

Instead a lot of low cloud and temperatures in the low or even mid teens, a real opposite to the cold polar maritime air on the previous day. Still windy but nothing too damaging.

Edited December 18, 2016 by Captain Shortwave

[IDO]

4 minutes ago, Iceberg said:

Ecm keeping up with the trend to make the air colder for Christmas Eve. Midday 850s so colder than this come the afternoon. 

That is fleeting and Christmas day looks mild to me, especially the south. The ECM uppers:

  London ENS

And GFS suggests Christmas Eve and Christmas Day highs 3c above average and I believe they are being too progressive with the Atlantic and will have mini-ridge trough combo rather than stormy come the day, more like ECM and GEM.

[bobbydog]

26 minutes ago, ajpoolshark said:

posts removed......no one-liners, off topic posts etc etc etc yadda yadda yadda......you know the drill 

Edited December 18, 2016 by bobbydog
Apologies

[snowice]

2 minutes ago, Captain Shortwave said:

Well the ECM doesn't give the Christmas day storm

Instead a lot of low cloud and temperatures in the low or even mid teens, a real opposite to the cold polar maritime air on the previous day. Still windy but nothing too damaging.

Well no cool weather on 24th proper cold uppers at 144 on ecm Even if it is short lived

[booferking]

Could we see high pressure rise late on in the ECM. Atlantic greenland area would be preferred location for me to be honest..

 

Yep the 216 chart says so

Edited December 18, 2016 by booferking

[bradymk]

192 ECM chart a lot better than what we've seen the last couple of days! 

[Iceberg]

Ido you are right. But I was talking about Christmas Eve not Christmas days. Many folks would be happy just to see a few flakes around Christmas. Nobody thinks it will last for days. And we are know that the pm air is transitory. 

Re the gens it shows almost every solution if you look at the tabular form. But the trend in the operational is clear and in the ens members   

[LRD]

11 minutes ago, IDO said:

 

And GFS suggests Christmas Eve and Christmas Day highs 3c above average and I believe they are being too progressive with the Atlantic and will have mini-ridge trough combo rather than stormy come the day, more like ECM and GEM.

How predictable that when the models show the possibility of the Atlantic throwing something at us that you don't want, you down play the Atlantic's influence... when you build its influence up at all other times.

As it happens, I think the Christmas storminess will get down graded. That was a really good point made by someone else earlier - that the GFS underplays heights to the south

Edited December 18, 2016 by LRD

[MR EXTREMES]

im pretty certain the models really dont know how to deal with the intense burst of vortex energy but what is clear the depth of cold air to our west and northwest.

i think that theres going to be some pretty stormy and cold conditions and shorter milder ones.

its not boring thats for sure right on christmas more chaos to come.

[bluearmy]

2 minutes ago, LRD said:

How predictable that when the models show the possibility of the Atlantic throwing something at us that you don't want, you down play the Atlantic's influence... when you build its influence up at all other times.

As it happens, I think the Christmas storminess will get downplayed. That was a really good point made by someone else earlier - that the GFS underplays heights to the south

I thought so too (of course that could just increase the baroclinity and hence storminess!)

cold ridge on the ECM day 9. Another variation available form the wide envelope that is fi. 

Edited December 18, 2016 by bluearmy