Model output discussion 8th Feb - Cold for now, but then what?

[snowray]

1 hour ago, Frosty. said:

Hopefully this will bode well for the GEFS 12z with plenty of arctic shots to choose from..would love a potent mid March Northerly to put the winter to shame.

GFS looking a bit isolated though so far, here comes the all important ECM.

 

Pretty well agreement on turning a lot colder mid march, ensembles for London & Sheffield there. Can GFS be that far off the mark?

Edited March 4, 2017 by snowray

[Summer Sun]

t144 from the main 3

UKMO                                                           ECM                                                            GFS

[Summer Sun]

Cold air sweeping south at t192

[Summer Sun]

I know it's D10 etc but the difference between GFS and ECM is laughable

GFS

ECM

[Frosty.]

We could still be in for a potent cold snap or spell, the Ecm 12z draws Arctic  -10 850's well south briefly so it wouldn't take much change for a nationwide wintry outbreak rather than just scotland.

Edited March 4, 2017 by Frosty.

[snowray]

20 minutes ago, Summer Sun said:

I know it's D10 etc but the difference between GFS and ECM is laughable

GFS

ECM

Story of this winter, never any agreement, FI at around T120 if not earlier at times, in fact he models in winter months seem to have got worse to me over the years, not better.

What a bloody waist of time and energy!

[Frosty.]

7 minutes ago, snowray said:

Story of this winter, never any agreement, FI at around T120 if not earlier at times, in fact he models in winter months seem to have got worse to me over the years, not better.

What a bloody waist of time and energy!

I think I'm going to start looking for spanish plumes, much less stressful

Hopes of an Arctic outbreak haven't ended, we should have a better idea by tomorrow one way or the other.

[Frosty.]

Looking through the GEFS 12z there is plenty of wintry interest in the mid and longer range with arctic reloads, near misses etc..this is just a sample. I still think something wintry is brewing for mid month and perhaps later in the month too. 

Edited March 4, 2017 by Frosty.

[Singularity]

Strange to see GFS so insistent on inflating a Mid-Atlantic ridge, perhaps even with an omega block setting up, yet other models all persistent with cutting of a wedge of higher heights over Greenland with the jet stream just romping across to the south of it. 

The latter is a dire outcome as low after low is directed our way and March begins to look like a possible contender for one of the wettest on record. So it is that I very unusually find myself hoping for the colder GFS outcome as at least that should not be as wet!

[Summer Sun]

That cold plunge shown by ECM at t192 isn't really supported by the ens

Nothing desperately cold it must be said maybe -3 if we are lucky for the south

Even central Scotland fails to drop below -4

 

Edited March 4, 2017 by Summer Sun

[Frosty.]

I'm wondering if there is any real appetite for an arctic plunge or whether we are just so accustomed to downgrades nearer the time or complete failure?..maybe it's time to look instead for signs of proper spring.

[I remember Atlantic 252]

10 minutes ago, Frosty. said:

I'm wondering if there is any real appetite for an arctic plunge or whether we are just so accustomed to downgrades nearer the time or complete failure?..maybe it's time to look instead for signs of proper spring.

Exactly Frosty, Spring all the way for me! now if I lived on a hill oop norf, then I would be hoping for a northerly

[Ǝssex Ǝasterly]

IMO a "cold snap" is worthless in late march with the strengthening sun. Unless we can get some prolonged cold to chill the ground so that the snow will stick I find it utterly pointless ramping when we all know that even if were lucky to get snowfall it'll just about last until midday, whether it's a night time snowfall or day. In January I would love it, but having snow now and expecting to to become a winter wonderland we may as well be jaffa cakesing in the wind

[I remember Atlantic 252]

Just now, Essex Easterly said:

IMO a "cold snap" is worthless in late march with the strengthening sun. Unless we can get some prolonged cold to chill the ground so that the snow will stick I find it utterly pointless ramping when we all know that even if were lucky to get snowfall it'll just about last until midday, whether it's a night time snowfall or day. In January I would love it, but having snow now and expecting to to become a winter wonderland we may as well be jaffa cakesing in the wind

Even in January, nowadays lying snow is a struggle, especially past 11am, the usual 1cm normally thawed by then, at least at low levels in the south

I used to love winter

[snowray]

2 minutes ago, I remember Atlantic 252 said:

Even in January, nowadays lying snow is a struggle, especially past 11am, the usual 1cm normally thawed by then, at least at low levels in the south

I used to love winter

How very true.

I would not be in the slightest surprised if we get the Arctic plunge for Easter, I have known a fair few cold and snowy easters in April, so mark your diaries, Easter is 2nd week of April this year, good Friday around the 14th.

Although If could choose I would certainly prefer a plume and a sunny mild easter so don't blame me if it does snow and we end up with a pile of slush.

[Fourty Point Three Degrees]

22 minutes ago, Essex Easterly said:

IMO a "cold snap" is worthless in late march with the strengthening sun. Unless we can get some prolonged cold to chill the ground so that the snow will stick I find it utterly pointless ramping when we all know that even if were lucky to get snowfall it'll just about last until midday, whether it's a night time snowfall or day. In January I would love it, but having snow now and expecting to to become a winter wonderland we may as well be jaffa cakesing in the wind

You get a 35C "hot snap" in mid-September 2016 with a weakening sun dipping over the equator so why shouldn't the opposite happen? Never under-estimate our climate.

[Frosty.]

The cold snap has all but gone from the Gfs 18z, complete downgrade..just cool and breezy with cold rain and a bit of wet snow on hills for a time next weekend.  More interesting is the 3 pleasantly mild days on wed / thurs / friday, especially in the south with temps climbing into the low teens celsius and feeling warm in any sunshine. Any cold potential has been shunted back into the murky depths of FI.

Edited March 4, 2017 by Frosty.

[snowray]

Really?

Its just been delayed slightly.......to D13!

GFS turning rapidly into a junk model like NOGAPS used to me in my opinion.

[snowray]

[snowray]

And re-load right at the end of the run. I wonder what the chances are of getting a second half of March thats colder than the 1st half of the month, and colder than February too maybe? mm 

[Frosty.]

3 minutes ago, snowray said:

And re-load right at the end of the run. I wonder what the chances are of getting a second half of March thats colder than the 1st half of the month, and colder than February too maybe? mm 

Yea a T+384 tease for wintry reload..excited..nope

[snowray]

9 minutes ago, Frosty. said:

Yea a T+384 tease for wintry reload..excited..nope

Never know, might be the start of a new late March trend.

[Frosty.]

8 minutes ago, snowray said:

Never know, might be the start of a new late March trend.

Fingers crossed snowray  all this cold chasing is very tiring.

Edited March 4, 2017 by Frosty.

[bluearmy]

Perhaps a drift towards a Russian/Atlantic block combo holding the trough in w Europe mid month onwards? Not a pleasant outcome but given the dry nature of the previous months something which I guess is inevitable at some point. 

[knocker]

I didn't post the anomalies last evening because the difference between the GEFS and EPS was so stark ( little wonder the difference with the det. outputs) I couldn't think of anything useful to say. I will post the two relevant charts this morning just to illustrate the point and settle for the comment that the ecm was still not having the strong Atlantic ridge, That may, or may not, be relevant having looked at this morning's GFS output.

So keeping that in mind the gfs this morning has the ridge building behind the upper trough at the beginning of this week but, as can be seen, by Thursday it nods in the direction of the ecm and has the energy pushing east from North America cutting it down and creating the cut off upper cell over Greenland. Thus a different ball game.

From this position out until T240 it essentially comes down to the handling of the interaction, and phasing, between the cooler and warmer airmaases (or the  troughs tracking east and northward surges of the Azores high pressure). Thus we have some weak ridging during the week with the odd Atlantic system making  inroads (generally effecting the north more) with temps above average. Until Saturday when the next upper trough breaks through and a quite a deep surface depression tracks east to be 978mb east of Scotland by midnight bringing some strong winds and plenty of rain.

This low runs rapidly east giving way to some brief ridging before the Atlantic begins an assault in earnest. Or does it?

The GEFs anomalies this morning are definitely paying lip service to the ecm but not that the Atlantic is becoming a major player with perhaps HP still being influential in the vicinity of the UK stalling too much ingress from the west. Temps above average but trending below later. Now I wonder whether the ecm wil suddenly produce an Atlantic ridge,

Edited March 5, 2017 by knocker