Model Output Discussion - 2nd March Onward

[Cloud 10]

Ensemble 4 has the -16 isotherm threatening the SE corner,which is incredible at any time

of year but doubly so for mid-march.

The one thing written in stone at the moment is that mid-march this year is going to be

very different to last year!

[Frosty.]

poor ukmo dragging its heels even more than its 0z if its snow your after.

Gfs solution is a nice and clean evolution for a change .but until we see a little bit more agreement.i wouldnt pull out the sledge yet.

cross model agreement should be here by tomorrow, bbc news 24 weather already talking up a freeze next week with lots of snow and severe frosts.

[weather eater]

they are wrong - it didnt. there are archive charts for you to look at to check.

the remainder of the gem 12z run post day 6 drops a depression just to our east and eventually the high sinks across us by day 10 with thicknesses around 520 dam. brrrr.

Your memory must be short BA the GFS certainly picked up the cold spell in 2010 way before the ECM which flopped about for quite some time before coming on board. Of course the GFS didn’t get it exactly right but was as good as could be expected. As an example check the GFS 12z on the 4^th Dec for 240hrs then check the ECM 12z for same date then look at the charts for the day, GFS not bad, ECM miles out.

[Derecho]

http://www.wetterzen..._London_ens.png

Ensembles looking superb once again. Just to er a slight note of caution aside the spectacular output...

UKMO does develop the shortwave but doesn't get the REALLY cold air towards us, it just goes for a slower progression towards some notable but not spectacular cold going past, either way it is missing out on the initial very potent blast. I've noticed in the ensembles 3 runs show this... only 3 runs but still only 1 in the 06z ens did I think...

The earlier the cold comes the better! I won't be getting truely excited about the output until T+72... but make no mistake the recent GFS runs are the perfect charts for very heavy convective snow for the NE especially. Astonishing charts being thrown out for Sunday night/ monday here.

Fingers crossed GFS has called it right.

Edited March 6, 2013 by Quicksilver1989

[Captain Shortwave]

ECM is backing gfs

GFS

[ITSY]

Talk about a windchill. If there are any snow showers (still iffy at this range) then they will travel fairly far inland i'd imagine.

[SMU]

http://www.meteociel...H1-120.GIF?06-0

& there it is- sub zero mazima & heavy snow across England- prolonged in the SE & E, this is after the NE gets a battering.

http://www.meteociel...F0-120.GIF?06-0

-12c uppers & 513 ~ thicknesses, 500 heights very low sub 524 DAM

S

Edited March 6, 2013 by Steve Murr

[Summer Sun]

The big 3 are in agreement now, its just a case now can they keep this agreement going till next week without downgrades

[Geordiesnow]

Getting more and more certain it will turn colder this weekend, how quickly the cold air floods in and whether the flow is enough to generate convective weather is uncertain at the moment so no doubt there be twists and turns to come whilst the theme does seem to be for easterly winds to turn colder.

If all goes to plan though, could be quite a noticetable cold shot for March.

[snowmadchrisuk]

http://www.wetterzen..._London_ens.png

Ensembles looking superb once again. Just to er a slight note of caution aside the spectacular output...

UKMO does develop the shortwave but doesn't get the REALLY cold air towards us, it just goes for a slower progression towards some notable but not spectacular cold going past, either way it is missing out on the initial very potent blast. I've noticed in the ensembles 3 runs show this... only 3 runs but still only 1 in the 06z ens did I think...

The earlier the cold comes the better! I won't be getting truely excited about the output until T+72... but make no mistake the recent GFS runs are the perfect charts for very heavy convective snow for the NE especially. Astonishing charts being thrown out for Sunday night/ monday here.

Fingers crossed GFS has called it right.

We will be at +T72 this time tomorrow, My concern would be what happens on Sunday , as there is some very Cold air undercutting some heavy precipitation in the South , Will the 2 areas meet and cause Heavy Snow in southern England Sunday night... or will it not be cold enough and Southern England would have to wait for Showers Monday.

[shaky]

Jheeez ecm agrees aswell!!boy i cant wait for next week!!looking forward to temps of 0 and dew points of -8! Oh and snow to boot!!

[Essan]

We will be at +T72 this time tomorrow, My concern would be what happens on Sunday , as there is some very Cold air undercutting some heavy precipitation in the South , Will the 2 areas meet and cause Heavy Snow in southern England Sunday night... or will it not be cold enough and Southern England would have to wait for Showers Monday.

That's something I don't think we'll know for sure until Sunday - or Saturday at least

[chionomaniac]

Been too busy with work to enjoy the run in to this forthcoming spell, but the ECM chart for Monday is truly spectacular if it verifies.

Not a spot left out on the UK from under the -10ºC 850's.

Even over Cork, Carlisle and the Scilly Isles.

Now where are those hen's teeth.....

[SMU]

http://cdn.accuracyproject.org/Celsius.bmp

Assuming monday midday around london -1c at the surface & 50 mPH gusts = -10 Windchill...

http://www.meteociel.fr/modeles/ecmwf/runs/2013030612/ECH1-144.GIF?06-0

144 looks very much like the GFS -- however uppers are STILL -10c from HULL to Wales & -13c in the SE !!!!! big east kent streamer at 144!!!!

reload lining up at 168!

S

[Summer Sun]

t144

John Hammond on the BBC 6 o`clock news it does look like turning much colder this weekend and through the early part of next week we see the return of frost and MAYBE some snow

Edited March 6, 2013 by Gavin.

[Summer Sun]

T168 snow showers in the east

The coldest uppers ease slightly

Edited March 6, 2013 by Gavin.

[Frosty.]

Been too busy with work to enjoy the run in to this forthcoming spell, but the ECM chart for Monday is truly spectacular if it verifies.

Not a spot left out on the UK from under the -10ºC 850's.

Even over Cork, Carlisle and the Scilly Isles.

Now where are those hen's teeth.....

[That ECM]

On many times this winter I have been up at stupid o'clock to watch the output come out hoping to see charts like we have now. Then when I am looking forward to some warmth we get these charts. You have got to love the weather! Oh we'll back to being a coldie for a couple of weeks.

[johnholmes]

the gfs picked up on the breakdown of the cold in dec 10, it was insistant for several runs over two days before the ecm and ukmo conceeded.

UK Met predicted this severe cold from about mid November if you look at the forecasts 16-30 day outlooks, the predictions on here using 500mb charts suggested the start 15 days ahead

[Snowmaggedon]

Has this expected cold spell came as a result of the SSW earlier this year, or has that had no bearing on it?

[cooling climate]

Regardless of what UKMO is showing the met office are on board now no doubt about it

UK Outlook for Monday 11 Mar 2013 to Wednesday 20 Mar 2013:

Much colder conditions are expected to develop early next week. Rain, sleet and hill snow in the southeast at first on Monday clearing away with brighter conditions elsewhere spreading south. Snow showers are likely to increasingly affect northern and eastern regions through next week, but all areas are at risk of seeing sleet, hail and snow showers at times. There is a risk of some significant and disruptive amounts of snow in places, but there is currently uncertainty regarding which areas are most at risk. There will however, also be some sunshine, particularly further west. Widespread overnight frosts returning with a risk of icy patches. Signals are that it may gradually become slightly less cold by the following week as bands of rain edge eastwards, perhaps preceded by further snow.

They get there in the end. Not very good really when you consider all the data and models at

their disposal. May be that is the problem they have to much data coming in and they can not

see the wood for the trees.

[Summer Sun]

Has this expected cold spell came as a result of the SSW earlier this year, or has that had no bearing on it?

As far as I know this has nothing to do with the SSW I think this is more the case of sods law you wait all winter for it to arrive then spring comes and hey presto

[Evening thunder]

They get there in the end. Not very good really when you consider all the data and models at

their disposal. May be that is the problem they have to much data coming in and they can not

see the wood for the trees.

Not sure what you mean - their forecast is similar to the models - and before yesterday there was too much uncertainty and it was too far off to make a confident forecast.

if the latest GFS and ECM come off, these will be the coldest uppers and daytime temps on Monday I have experienced in March that's for sure.

[bradymk]

Atlantic completely blocked tonight on ECM, colder air moving back from the East at 216 with the low to our west moving SE and deepening.

[Mucka]

This would be a tad exciting if it verified, channel low moving into very cold uppers and cold feed.