Model output discussion - after the beast, what next?

[Chesil View]

1 hour ago, Summer Sun said:

The area where the ECM 12z Op takes the 850's down towards -20 or lower compared with the mean

Safe to say it has gone off on one

The thing is most cold spells start off as an op or ensemble run that appears to have "gone off on one" So I wouldn't dismiss it entirely.

[Man With Beard]

1 hour ago, bluearmy said:

It doesn’t ?

the day 8 cluster had the anomoly to our ne - the difference days 9/10 is the polar ridge which is notoriously difficult to model 

yesterday’s spreads had a ne Scandi  high 

whilst this is an unlikely solution, l I wasn’t surprised to see it emerging 

Damn you're right, it is supported by cluster 2 this morning - only 17% of members though.

Well if the op has crossed to that cluster, maybe there's a bit more in it tonight.

[bluearmy]

18 minutes ago, Man With Beard said:

Damn you're right, it is supported by cluster 2 this morning - only 17% of members though.

Well if the op has crossed to that cluster, maybe there's a bit more in it tonight.

The 12z mean/anomolys heading towards cluster 2 

could we see the mid Atlantic ridge growing to link over to a n scandi ridge of sorts ?? Euro trough getting cut off perhaps ?

[Methuselah]

I'm sure (well, almost sure) that I can recall March & April 1965 being cold and snowy, and dominated by mostly easterly winds...?

With the PFJ being so far south, this year, I don't think another incursion of very cold air can be ruled out... Late April 1981 was a bit odd, too...

[lassie23]

what does the gfs show, don't trust the ECM, having said that, which model picked up the beast first.

[bluearmy]

3 minutes ago, lassie23 said:

what does the gfs show, don't trust the ECM, having said that, which model picked up the beast first.

Gfs was playing with it beyond day 10 which doesn’t leave any room for the other models to get there first ...

Ecm was making a decent stab at the actual solution from day 10 apart from one mobile dodgy run

[EllyTech]

4 minutes ago, bluearmy said:

Gfs was playing with it beyond day 10 which doesn’t leave any room for the other models to get there first ...

Ecm was making a decent stab at the actual solution from day 10 apart from one mobile dodgy run

UKMO was on the money. Usually the model of modesty. 

[bluearmy]

11 minutes ago, EllyTech said:

UKMO was on the money. Usually the model of modesty. 

It’s never going to win a predictable race when it starts 4 days behind! 

[bluearmy]

Eps clusters out to day 10 are single which means the op, whilst not heavily supported in detail isn’t far away from the upper heights pattern. The difference between cold for March and potentially very cold for March is going to come down to the polar ridge on that basis. Still no sign of spring apart from the odd day.

[Daniel*]

Following that ECM op run interesting.

 

[Come rain snow or shine]

2 hours ago, Ed Stone said:

I'm sure (well, almost sure) that I can recall March & April 1965 being cold and snowy, and dominated by mostly easterly winds...?

With the PFJ being so far south, this year, I don't think another incursion of very cold air can be ruled out... Late April 1981 was a bit odd, too...

 

Yes, March and April '65 very much were.

[bluearmy]

The 00z suites continue to play with the wedges and amplifications - no strong idea of what to do with them although the gfs op shows good continuity from the ideas of yesterday’s ec 12z without the polar ridge getting involved whic makes more sense and fits the extended eps better. (Plus the predicted strat profile)

Edited March 8, 2018 by bluearmy

[Frosty.]

Nice FI cold blast on Gfs 00z..I still think we could see another wintry spell during the second half or last third of march..fingers crossed!

[Bob G]

There is a new moon on the 18th, I wouldn't be surprised to see a cold spell starting a couple of days either side of then.

[Summer Sun]

Once again the Op is on the colder side of the mean for the FI cold air

From tomorrow the London mean doesn't fall below 0 until at least the 16th with the colder blip at the end on the cold side of the mean

This was the mean on Tuesday morning

 

[Summer Sun]

Southeasterly winds from UKMO extended?

 

[Bradowl]

12 hours ago, Ed Stone said:

I'm sure (well, almost sure) that I can recall March & April 1965 being cold and snowy, and dominated by mostly easterly winds...?

With the PFJ being so far south, this year, I don't think another incursion of very cold air can be ruled out... Late April 1981 was a bit odd, too...

If I remember rightly in 1981 we had been dominated by high pressure for a few weeks which made it feel very much spring like in the sun though I remember it being chilly in shade, day before snow starting on the Friday we had a few snow showers early Thursday morning that came in from the west.

The low that brought the blizzards was the usual tracking from south west of us to south east. 

[Man With Beard]

This morning's clusters - still looking for a small height rise to the north, possibly NE or NW. Perhaps a little more encouraging that yesterday morning for bringing cold to the UK, but fairly weak so could go either way. Cold rain still the main dish on offer.

Towards the end of the month, like yesterday the focus on ridging is more towards the NW but still waiting to see how the trend will develop. Very unlike last week's cold blast which the ensembles shouted out loud 15 days before it happened!

[Frosty.]

The Gfs 6z is generally unsettled and shows a colder spell during the last third of march with snow for some, especially further north. I don't think we will see anything wintry as such during the next 10 days or so, indeed, there is some very mild weather on the way for the weekend and at times next week but beyond that..there is a chance!

[stodge]

Morning all

The annual battle between colder and warmer air masses that is called spring advances and while last night's ECM 12Z looked very interesting in its latter stages, it's clear some people are done with cold and want something warm.

Spring tantalises delivering warm and then very often a final burst of cold. Let's see where the models are taking us on Sunday March 18th:

ECM 00Z OP at T+240:

A complex trough is aligned north-south through the British Isles with centres close to the north of Scotland and the coast of Brittany. A ridge follows from the west while pressure is high to the north of Scandinavia. Light winds for most of the British Isles with a slack N'ly over Ireland. Rain or showers for some northern and southern parts but some drier spells as well.

GEM 00Z OP at the same time:

A complex trough covers the British Isles with a main centre over the North Sea and a small secondary feature in the Channel. Pressure is higher over the Canaries, Greenland and Scandinavia. A slack W'ly air flow covers southern parts but winds are light elsewhere. Rain or showers continue to affect some eastern and south western parts but there is a hint of a weak ridge moving in from the west.

GFS 00Z OP at the same time:

A LP is filling in situ to the south west of the British Isles . Another LP is moving slowly east into Scandinavia forcing a HP which developed to the NE of Scandinavia south west toward Denmark. There is a ridge extending SE from another HP over Greenland. Overall, it's a slack and messy picture with a light SE'ly flow over the UK. Rain and showers becoming increasingly restricted to south western areas and drier elsewhere. Further into FI the ridging from Greenland becomes more influential with brief N or NE'ly flows over the British isles but the jet remains well to the south, the trough in charge and spring on hold.

GFS 06Z at T+234:

LP to the NW of the British Isles dominates the weather with a trough extending SE. A light WNW'ly flow covers Ireland with light winds elsewhere and showers for many with longer spells of rain (snow to hills) to the north west. Mid-Atlantic ridging looks to be squeezed out by the next LP coming off the eastern seaboard. Further into FI and with the jet kept well to the south areas of LP continue to cross southern Britain with plenty of rain and showers. Occasionally colder spells as well with wintry weather can't be ruled out with significant blocking over Greenland persisting.

GFS 06Z Control at T+240:

Close to the OP in all honesty with perhaps more defined ridging in mid-Atlantic. Further into FI and like the OP the Control remains very unsettled with LP held well to the south crossing the British Isles and the threat of cold Arctic air never far away.

The GEFS at T+240:

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240

Plenty of LP in charge but a hint of blocking from both the NE and NW at this time and further out into FI that hint grows with by T+360 two or three very tasty options for fans of cold but all that is a long way off.

To conclude, the trough rules supreme for the next 7-10 days with any transient milder interlude this weekend likely to be accompanied by a lot of rain and the pattern throughout next week suggests rain or showers will never be far away with the south and parts of Scotland catching the most rainfall. Transient ridges at best and more than a hint as we move into the last third of the month of a return of wintry conditions which, while nothing like last week's events, would be a shock to the system for many expecting something more spring like. In truth, I can see almost no sign of prolonged warmth this morning - some of the options yesterday flirted with a draw of warmer S'ly air but they have faded and winter has taken a step forward in my view this morning.

 

 

[SMU]

The UKMO 144 has teased me out if hibernation - for a comment.

144 shows a very meridional flow across 50N with deep cold filtering into Scandi-

could be a sharp transition from mild to cold across the UK across day 7/8

Edited March 8, 2018 by Steve Murr

[chris55]

1 hour ago, Steve Murr said:

The UKMO 144 has teased me out if hibernation - for a comment.

144 shows a very meridional flow across 50N with deep cold filtering into Scandi-

could be a sharp transition from mild to cold across the UK across day 7/8

Even though it's March, and even though we just experienced one of the coldest, snowiest periods of recent years thanks to a proper easterly flow. I can't help but look for the last chance saloon when it comes to winter weather. We are still in March and after the record breaking SSW, colder more blocked conditions are surely more favourable than milder springlike ones, whether we like it or not!

UKMO did catch my eye this evening when checking the runs, coupled with the ECM from yesterday, and the general background signal, it would not surprise me if we did end up seeing one last hurrah from winter 17/18 which overall has been pretty darned good.

It will be interesting to look back on March as a whole when it's done and see if that record SSW had the legs to deliver more than the initial beast....

 

[Frosty.]

Interesting Gfs 12z in low res with a chance of a Easterly / Beasterly evolving and even something from the Arctic towards the end, something which will hopefully keep cropping up and eventually heading towards high res..coldies can at least hope for another wintry blast before March is over!

[ANYWEATHER]

Evening...It looks as though the jet stream will be to our south for a while yet, hints from the 12z suite from gfs shows ridging from the south ,could it be the old adage March in like a lion and out like a lamb

[Summer Sun]

This could be a named storm if ECM were on the money

Don't hang around for long with things soon calming down