Model discussion - Warm spell ending as Spring begins

[feb1991blizzard]

2 minutes ago, Mattwolves said:

Yep, London has a big anti cold dome around it! The 12s look pretty good up north, still waiting on the 18s

Yes, you have to take into account that even if there were snow showers for London at this time of year, you would expect the temps to drop to just above freezing during the showers but that won't show on the graph, you would still expect max temps to be around 5 or 6c, that said, i am not saying that many eps are showing the N'ly as i haven't checked them

[MATTWOLVES 3]

Can you imagine what the daily express headline would be if they went by this chart!!! Millions of Britain's to face avalanche risk!!! 

Edited February 27, 2019 by Mattwolves

[Frosty.]

7 minutes ago, Mattwolves said:

Can you imagine what the daily express headline would be if they went by this chart!!! Millions of Britain's to face avalanche risk!!! 

Imagine being stuck in that little blob with no snow while 99.99 percent of the uk gets buried!...let the cold chase begin again..there are grounds to be optimistic about March snow judging by some of today's / tonight's model output.

[MATTWOLVES 3]

6 minutes ago, Frosty. said:

Imagine being stuck in that little blob with no snow while 99.99 percent of the uk gets buried!...let the cold chase begin again..there are grounds to be optimistic about March snow judging by some of today's / tonight's model output.

Yes frosty, some poor bugger from the Dundee area is gonna be well gutted by that chart tonight!

[knocker]

outlook - unsettled and very windy at times and, not surprisingly, not as warm as recently

The NH 500mb and surface analysis for midnight and the 0400 surface chart

A fairly cloudy start to most p;aces this morning with plenty of mist/fog around and some showery rain, associated with the frontal system pushing in from the south west, already into that area. This will spread north east during the day over Wales and England, with any breaks in the cloud probable confined to the south east. Remaining dry further north but still predominately cloudy. Temps still above average but some regional variations as can be seen

The showery rain will gradually clear to the south east overnight but low cloud with mist and fog will again be a feature in many areas

Tomorrow much brighter than today after early mist/fog clears but cloud may be more of a feature in western regions where a fading cold front resides. Temps still a tad above average. Bur note the developing low away to the south west

Overnight Friday and through Saturday morning the low tracks north east and undergoes rapid cyclogenesis and by midday saturday is 968mb north west of Ireland, Thus strong winds and rain rapidly effect  the whole of the country through Saturday, but particularly Scotland late on as the low continues to to track north east.

By midday Sunday the low is 964mb north of Scotland in what is now a complex area of low pressure over Scandinavia and complications are afoot as another wave is forming on a front trailing away to the south west from that region. This tracks north east across Wales and England on Sunday bringing more heavy rain as it goes

By Monday the low has cleared east to Denmark but by now the UK is under the influence of a general area of low pressure with plenty of showery activity around  in western and southern regions, perhaps some snow on high ground, as temps finally descend to around average or a tad below.

Edited February 28, 2019 by knocker

[knocker]

To continue with the gfs albeit frm this point the evolution is quite messy and I suspect the detail quite liable to change. By T156 another low that has formed in the baraclinic zone off the eastern seaboard over the weekend, has tracked north east and finally deepened to be over the UK bringing more rain through Tuesday night and Wednesday

from this point we are arriving into the area that has been discussed previously, with events upstream dictating matters, so just a reminder as it's best left here I feel

 

Edited February 28, 2019 by knocker

[knocker]

Broadly speaking the ecm is along the same lines as the gfs next week so quite wet and windy Weds/Thurs

[stodge]

Morning all

In stark contrast to the past few days, the coming week is increasingly disturbed for us all with periods of rain, lowering temperatures and snow likely for northern hills and mountains with a particular chill set for Monday which was 21c in parts of London this week and may struggle to reach 10c next week.

Beyond that, plenty of options as you'd expect - the majority call is to keep the unsettled theme going toward mid month but there's more than a hint of heights rising from the south as the Azores HP ridges NE and even a suggestion of some heights rising from the north. We'll see.

The PV looks as dominant as ever but one thing working in our favour is a weak warming from the Canadian side - it's not substantial but it seems to be enough to knock the core of the PV over to the Siberian side by the middle of the month.  The GFS 00Z OP, Parallel and Control all show a distinct lifting of heights through northern Canada toward the Pole.

Northern Blocking in late March and April - hardly unknown - does happen and it's part of the struggle between the warmer and colder airmasses which characterises spring in the NH. The other aspect to this is the Final Warming which I suspect will be very late this year (well into April) and the nature of it in terms of whether it's quite a sudden sharp event or it's a more gradual diffusion - something else to watch.

[knocker]

The occlusion west of Ireland quite marked on the 0900 WV image

[Iceaxecrampon]

False sense os security and all that......

06z

 

[stodge]

The 06Z OP isn't without interest in the medium term as the jet remains over or just to the south of the British Isles so little sign of any ridging from the SW in the medium term. Indeed, a lobe of PV drops from the Pole to NW Russia encouraging weak heights to the NW and keeping the Atlantic LP tracking to the south. 

Parallel and Control are less extreme so it's only one to watch for now. I certainly think we have a minimum of 10 days of disturbed and often chilly weather in front of us and signs of a relaxation of that are tentative at best.

[MATTWOLVES 3]

Potentially a bit of interest early next week, especially up north! One to watch perhaps. 

[Jonathan Rhodri Roberts]

While the weather has turned cooler it'll be a much warmer and drier St David's Day this year in Wales and the rest of the U.K. & Ireland compared to last with temperatures up to 12C or possibly 13C, ideal weather for me and and others who are taking part in the parades as well as the spectators ️

Edited February 28, 2019 by Jonathan Rhodri Roberts

[Methuselah]

My interest in the models has been piqued: the blob of 15C+ uppers, way down south, is growing - albeit erratically...

[MATTWOLVES 3]

Some very juicy 12z charts coming out all be it in fi, come on gfs let's do this!!!!! 

[Polar Maritime]

Much more seasonal/interesting weather to come starting with Sunday/Monday as two lows pass the UK North and South off the Atlantic bringing severe gales for some. And a risk of some snow but this mainly over high ground.

Edited February 28, 2019 by Polar Maritime

[MATTWOLVES 3]

Ecm at 144hrs pulling down some real cold uppers! Could we be looking at an increased snow risk! 

[SLEETY]

Azores high spoils this run again,just about sums up why it’s gone wrong this winter.

[MATTWOLVES 3]

9 minutes ago, SLEETY said:

Azores high spoils this run again,just about sums up why it’s gone wrong this winter.

I've seen worse, the cold uppers keep on coming from a cold Atlantic! 

[The PIT]

GFS pretty naf tonight and never really brings in any cold uppers. ECM does manage to do this a little better but too far out to take much notice off.

[winterof79]

9 minutes ago, The PIT said:

GFS pretty naf tonight and never really brings in any cold uppers. ECM does manage to do this a little better but too far out to take much notice off.

144z? too far out

[Tim Bland]

1 hour ago, Mattwolves said:

Ecm at 144hrs pulling down some real cold uppers! Could we be looking at an increased snow risk! 

Only lasts for a few hrs though before uppers go back above -5

[stodge]

The 12z suite of output does nothing to amend the general trend of a first half of March dominated by Atlantic LP on quite a southerly track so plenty of much-needed rain coming.

The Azores HP remains suppressed to the SW and with ridging into Iberia there's a slight negative tilt to the trough which keeps the British Isles very much in the firing line. It's worth noting GEM and JMA keep the jet further north which brings the Azores HP more strongly into play by the end of next week.

Further into FI, the hint of raising pressure from the NE (OP) and from the SW (Parallel) around mid month coincides with some of Exeter's thoughts while P15 ends where many coldies would like but we have to admit it's on its own. Control keeps an unsettled theme so lots to be resolved at that time frame as you would expect.

 

[MATTWOLVES 3]

9 minutes ago, Tim Bland said:

Only lasts for a few hrs though before uppers go back above -5

A few hours Tim! My god we are highly honoured this winter.

[MATTWOLVES 3]

Regardless of some of the posts regarding blink and you will miss it type cold, the ensembles ain't that bad, tbh they was far worse in the middle of winter! Snow will be a continued risk in places, and up north to even low levels!! There is actually a better chance of snow this coming march, than at any point in December or the bulk of January. A lot of folk on here have now given in the chase for anything cold, I can understand it on the basis of the winter that's been, but come on folk we dont need - 10 or - 15 uppers to deliver snow! Expect quite a few surprises during the upcoming fortnight. And if things don't pan out to your liking, then not to worry it will soon be summer!!! ITS a WIN WIN SITUATION!!