Spring Model Discussion 21st March 2013 006z onwards...

[Cheshire Freeze]

Not surprised about the flip back to a colder 12z suite. Looks to be rinse and repeat to me. The latter stages of the ECM are interesting as it renews the -NAO/-AO combination and cold looks pretty locked in from there should we reach that point.

[Panayiotis]

Not surprised about the flip back to a colder 12z suite. Looks to be rinse and repeat to me. The latter stages of the ECM are interesting as it renews the -NAO/-AO combination and cold looks pretty locked in from there should we reach that point.

Is it too late though? Can we achieve snow for low lying counties for the start of the second week of April?

[Cheshire Freeze]

Is it too late though? Can we achieve snow for low lying counties for the start of the second week of April?

Given what we've seen this month, we start from a very good base. Low SSTs and ground temperatures below average....i'd guess it's as good a start point as we could wish to see.

[Joe Levy]

Since I am up writing a university essay analysing a song by Kirsty MacColl, I might as well wait here for the 0z... weather insanity at its best I wonder if the southward correction will continue? There is a very fine line between who gets snow, if any at all, and for those who want snow in the South, the concern is that the models are already showing snow at 5 days away - pray for not many more southerly corrections!

Edited March 25, 2013 by Joe Levy

[Kentspur]

How ironic is this piece of folklore! ;-)

Borrowed Days

The last three days of March were said to be borrowed from April.‘March said to April,I see 3 hoggs (hoggets, sheep) upon a hill;And if you’ll lend me dayes 3I’ll find a way to make them dee (die).The first o’ them wus wind and weet,The second o’ them wus snaw and sleet,The third o’ them wus sic a freezeIt froze the birds’ nebs (noses) to the trees.When the 3 days were past and ganeThe 3 silly hoggs came hirpling (limping) hame.â€

[snowking]

So then it's as you were really from the 0z outputs

GFS remains the most keen to bring the frontal incursions (and slightly less cold air) further north east, whilst ECM and UKMO disrupt the low as it heads in and keep the energy sliding south, meaning the UK remains in the colder air for the foreseeable

The ECM makes a second attempt on FI to bring the Atlantic back in and has more success....but as we saw yesterday a similar run from the 0z proved rather an outlier against the ensemble mean.

So it's cold through into the Easter weekend

SK

Edited March 25, 2013 by snowking

[That ECM]

So then it's as you were really from the 0z outputs

GFS remains the most keen to bring the frontal incursions (and slightly less cold air) further north east, whilst ECM and UKMO disrupt the low as it heads in and keep the energy sliding south, meaning the UK remains in the colder air for the foreseeable

The ECM makes a second attempt on FI to bring the Atlantic back in and has more success....but as we saw yesterday a similar run from the 0z proved rather an outlier against the ensemble mean.

So it's cold through into the Easter weekend

SK

At least the ECM gives hope of something warmer with plus 3 uppers at t 240 in the south!!! Kind of illustrates where we are in this cold spell. Searching fi for warmer which is still below av.

[SLEETY]

"As the days grow longer the cold grow stronger"

My take of the models this morning

[BLAST FROM THE PAST]

The face over Scandinavia looks shocked at the cold!

Munch's scream!!

I have to say I was gobsmacked at the tv footage of the massive snow drifts. I've been away for a few days off line. There seems to be no sign of change yet with the jetstream way way south, the country under energy threat, a hemispheric pattern that is snugly fitting with solar cycles currently. Look at the depth odf cold that's on display.... this is impressive

BFTP

Edited March 25, 2013 by BLAST FROM THE PAST

[mushymanrob]

Is it too late though? Can we achieve snow for low lying counties for the start of the second week of April?

yes.

hard to come by but why not if the atmospheric conditions are right?

tbh i dont know what there is to discuss, because theres full agreement within a reliable timeframe!

what was going to be the saviour low later this week is now going to become the enemy for those looking for an end to the cold. it slides into central europe allowing a ridge to nose down behind it thus strengthening and prolonging the blocking highs hold on the uk.

so bitterly cold and frosty all week and into the weekend. the gfs (as usual) suggests a gradual, earlier breakdown over the weekend, the ecm prolongs the cold all weekend, BUT does deliver a decisive blow to the cold in fi, temps could be very nice in two weeks IF the ecm fi becomes reality..... but it wont.... just saying....

Edited March 25, 2013 by mushymanrob

[Welsh_Weather]

Even mushy has given up on the anything warmer coming this way! I think there will be a gradual warm up from the second week of April, not necessarily from the Atlantic winning the battle, but the strength of the sun is bound to at some point modify these temperatures. But there could well be a lot of snow with quite a strong jet to our south bumping into the block, even if the uppers modify to -1 or -2 with the very cold dew points would still allow snow.

I hope I'm wrong though, but dont think i will be, I love the cold and snow but this is really getting to me now. Long daylight hours with no sun or warmth is more depressing than 17 hours of darkness in winter.

[bradymk]

Snow chance from the SW decreases this morning, on most outputs, the front does not make it much past cornwall before dying out. A shift north is needed if it is snow you want.

[mushymanrob]

Even mushy has given up on the anything warmer coming this way!

thats because theres no tangible sign within a reliable timeframe, theres no milder options until saturday at the earliest and probably much further off then that. i might prefer the milder weather over the cold, but if its not an option, its not an option!

[Average Joe]

Even mushy has given up on the anything warmer coming this way! I think there will be a gradual warm up from the second week of April, not necessarily from the Atlantic winning the battle, but the strength of the sun is bound to at some point modify these temperatures. But there could well be a lot of snow with quite a strong jet to our south bumping into the block, even if the uppers modify to -1 or -2 with the very cold dew points would still allow snow.

I hope I'm wrong though, but dont think i will be, I love the cold and snow but this is really getting to me now. Long daylight hours with no sun or warmth is more depressing than 17 hours of darkness in winter.

The thing is, the sun's got to come out in order for there to be any strength behind it!!

[mushymanrob]

The thing is, the sun's got to come out in order for there to be any strength behind it!!

its trying to break through here, think the west will be sunniest, at least its not looking as dull and overcast as i thought it would be (here at least).

[rory o gorman]

big scatter in the ENS this morning for Dublin, showing both a chance for cold to remain with undercutting or much more seasonal with Greenland heights eroding and unsettled but milder air advecting. A growing number of members show quite a fast transition to mild hopefully a developing trend.

[Gibby]

Good morning. here is today's report on the 00z output from GFS, UKMO, GEM and ECM for today Monday March 25th 2013.

All models shows the cold spell continuing throughout this week and much of the Easter break. A large High pressure area to the North feeds Arctic winds around it's Southern flank across the UK and little to change this pattern over the next 3-4 days. By Easter itself milder air will be trying to dislodge the cold pool over the UK but looks doomed to failure on this attempt probably only affecting the far South with rain or snow on Good Friday before receding away South again. Widespread sharp frosts look likely through the week.

GFS then shows the period from Easter Monday to stay cold with the next push of milder air making somewhat more progress North with the risk of snowfall for Northern England, the Midlands and North Wales again with less cold air staggering into the far South with rain. Thereafter the cold pushes back South again but all the time the cold is moderating as the source of cold air is diluted by seasonal change so that the very cold air will be replaced by just chilly weather with some bright spells and occasional showers, wintry on just the highest hills of the north later in FI though with winds still largely between SE and NE.

The GFS Ensembles show the continued pattern it's been showing for a while now of uppers warming over Easter to nearer to average levels as the cold source of air becomes diluted. Only normal values are achieved however and with continues Low pressure close to Southern Britain many areas may still maintain an east or NE feed making it feel cold with rain at times, especially in the South.

The Jet Stream continues to blow West to East at very Southerly latitudes close to Southern Spain and North Africa later this week, through the weekend and start of next week.

UKMO shows a sustained period of cold weather over Easter with slow moving Low pressure in mid Atlantic spawning breakaway Lows ESE towards the SW approaches. The UK lies under a ridge from an Arctic High way north of Greenland with continued very cold and raw winds from the north in the east and SE in the West with some scattered snow showers towards the East coast and rain or snow threatening the SW at times.

GEM shows very unseasonably cold weather right out to the end of it's run with a deep Low passing close by to the South and SE of the UK bringing strong winds, rain, snow and potential Spring blizzards as it passes just after Easter. The cold weakens somewhat at the end of the run though the pattern looks far from conducive towards bringing a warm spell to the UK anytime soon from it's day 10 chart.

ECM is a little more hopeful for those looking for milder weather after Easter as it changes the axis of mid Atlantic Low pressure after Easter bringing a spell of snow North over the UK just after Easter and pushing milder SSE winds up from more Southerly latitudes finally removing the coldest air away North and leaving rather cloudy conditions with temperatures staggering towards average in the South with rain at times, chiefly in the west and SW.

In Summary the cold spell looks almost certain now to last through this week and the Easter holidays. Thereafter there are mixed messages this morning with GEM and UKMO looking like locking the cold air in for rather longer while GFS (including it's ensembles and ECM moderate conditions through next week with rain at times rather than snowfall. High pressure pushing up from the Azores or SE Europe which would normally usher in Spring big time still looks a long way off though even with the longer term milder charts shown this morning.

Edited March 25, 2013 by Gibby

[stodge]

Morning all

As Rory and the other mildies opine, a step away from the very solid cold 12Z output of last night but a considerable divergence of opinion and option going into April.

http://www.meteociel.com/modeles/ecmwf/runs/2013032500/ECM1-216.GIF?25-12

A nice chart for the mildies this morning. With a ridge disrupting the flow of LP into central Europe, the cold SE'ly feed is cut off. I suspect from this you'd see an anticyclonic evolution in the Scandinavia area and a more traditional SW/NE split with the SW'ly winds prevailing, Rory suggests a split in the numbers for Dublin and that wouldn't be surprising off this chart but again it's at T+216 so a long way from reality.

http://modeles.meteociel.fr/modeles/gfs/runs/2013032500/gfs-0-216.png?0

GFS OP at the same point doesn't want to know. The ridge is much weaker and fails to disrupt the passage of LP from the Atlantic into Central Europe. That train keeps the bulk of the British Isles in an E'ly flow

http://modeles.meteociel.fr/modeles/gfs/runs/2013032500/gfs-0-300.png?0

Another attempt here but this also fails. The OP keeps the North of the British Isles throughout and at no point do we get a SW'ly flow. Amazing synoptics for the time of year.

http://modeles.meteociel.fr/modeles/gem/runs/2013032500/gem-0-216.png

GEM at T+216 - nothing for the mildies there.

http://modeles.meteociel.fr/modeles/bom/runs/2013032500/bom-0-210.png?00

BOM at T+216 - another awful output for the mildies.

So it's down to ECM's Iberian HP - if they've called this right, major plaudits but otherwise we stay somewhere between the fridge and the freezer for the foreseeable.

[Summer Sun]

It still looks like the cold air will moderate next week once the coldest uppers start to ease precipitation is now looking low for all of us

The Birmingham ECM ensemble also shows temperatures moderating next week with the high going from 2c to 3c this week to between 6c and 11c with the average running at 7c to 9c

Still below the seasonal average but better than what we have now

The average minimum also rises next week

Edited March 25, 2013 by Gavin.

[Captain Shortwave]

I've not got the temperature charts but I wouldn't be surprised if the op was once again a mild outlier. ECM ens are as cold if not colder than yesterday afternoons run.

GEM/UKMO cold throughout.

GFS is the one lifeline but with the mild breakdown already delayed by several days, who is to say it wouldn't happen again.

[AWD]

I've not got the temperature charts but I wouldn't be surprised if the op was once again a mild outlier. ECM ens are as cold if not colder than yesterday afternoons run.

GEM/UKMO cold throughout.

GFS is the one lifeline but with the mild breakdown already delayed by several days, who is to say it wouldn't happen again.

That's what I'm thinking too;

Can't be bothered to check the individual EPS, probably depressing viewing!

[Summer Sun]

One thing GFS and ECM both go for this morning is milder uppers as we go into April

Starts in the south first before spreading north

GFS for the same dates

Don't worry folks an April heatwave is coming - http://www.dailymail...ite-Easter.html

But, according to the three-month forecast from the Met Office, the same pattern may also bring a heat-wave towards the end of Spring if – as is likely – it shifts slightly south.

[stodge]

It still looks like the cold air will moderate next week once the coldest uppers start to ease precipitation is now looking low for all of us

With respect, Gavin, it would be astonishing if we kept daytime maxima of 2-3c well into April in the south. Some form of recovery in temperatures is inevitable and has been persistently predicted by the modles for the last week to ten days and yet it hasn't yet materialised. Checking my records here in lowland East London, we reached 16c on March 5th and 13c on March 6th and haven't been above 8c since. All winter, we have recorded three ice days (one in mid-December, one on January 20th and one on March 11th while we reached the dizzy heights of 0.6c yesterday). The maxima numbers for this time of year are extraordinary but I know it will change sooner or later.

I think this morning's output suggests that the way out of the cold is less likely to be from a direct Atlantic onslaught as from a re-orientation of pressure systems which will moderate and eventually cut off the cold air so gradual warm-up rather than rapid thaw which may be no bad thing in its way.

[-uksnow-]

Colder uppers remain in place longer on the 06z

compared to 00z

Gavin, i simply dont think spring will happen this year!

[londonsnow]

Colder uppers remain in place longer on the 06z

compared to 00z

Gavin, i simply dont think spring will happen this year!