Model Output Discussion 12z 03/04/13

[Backtrack]

If the ECM monthly forecast for Birmingham is right temperatures would stay well below normal into May

A 10C average during May? I'd rather starve myself for the entire month than have a traditionally summery month some 5C below average!!

I'm getting the feeling that an above average month this year is going to be hard to come by, although the models do offer some light at the end of the tunnel but never in the form of a stable pattern. Here we just see the high getting squashed thanks to lower heights to the north, leading to that Northerly... unlikely but unfortunately it can't be ignored.

The ECM offers another solution, a rather strange pattern I must say, height linkups to the north east over Scandinavia. This one is looking dry although mostly cloudy due to the orientation of the high. Not as warm as the GFS but still pleasant.

Met Office's medium range forecast offers a little hope, but nothing to shout about with a north west/south east split..

"By the final week of the period, temperatures should be generally near-normal, perhaps warm at times inland. The north and west will then probably be on the unsettled side whilst the south and east stay drier."

[Summer Sun]

ECM ensemble for London

[phil nw.]

It still looks like the cold will ease into next week but it promises to be a gradual process especially further north.

The fax for Monday shows how the first approaching trough struggles to make progress with some energy disrupting SE.

However the overall signals from the medium range outputs including the NAEF`s 500hPa anomalies and the ECM means promise some warming as we go into the week after.

The NAEf`s day 10

and the ECM means compare day 5 and then day 10

Good indications, as John H as alluded to, of the pattern change later next week.A mean Atlantic trough to our west or north west and with heights building over the near continent is still the likely outcome after the transition period next week.

A NW-SE split with the more settled and warmer weather nearer the continent.

[Summer Sun]

Less cold air arriving into the SW by Wednesday according to GFS

Less cold air continues to spread across the country into Thursday

Rain moves in from the west preceded by hill snow in the north

By t144 we have high pressure to the north and edging up from southern Europe with the low in the middle over the UK

Less cold air over all but Scotland

t156 is almost perfect for warm south westerly winds

Edited April 5, 2013 by Gavin.

[Geordiesnow]

A NW-SE split with the more settled and warmer weather nearer the continent.

Exactly what the GFS 12Z is suggesting in the medium term but its nothing like this mornings ECM run so you can't get too carried away at the thought of temperatures reaching the mid-teens with the thought of some sunshine.

I agree with most that a pattern change to more wetter conditions will happen(even if the early part of the GFS run suggests Monday and Tuesday won't be as wet and mild as perhaps earlier indications suggested) but whether this in turn will result in significantly milder conditions is uncertain as of course we could see something like what this mornings ECM is showing and that for the most part of next week could remain cool and wet.

[Summer Sun]

GFS want to bring some cooler air across the Atlantic to us next weekend

Looking at the track the high would build over the UK once the low pulls away

+8 uppers incoming

Edited April 5, 2013 by Gavin.

[Purga]

Another edge southwards

Some of the higher ground in the Midlands or even furthers south could get a bit of wintrynes.

[Summer Sun]

Another edge southwards

Some of the higher ground in the Midlands or even furthers south could get a bit of wintrynes.

You need precipitation first and given the fact the UK is dry wintry showers will be hard to find

[Frosty.]

According to the Gfs 12z operational run, it will finally turn mild by next thursday with temps across southern britain hitting 15-16c, around 60f but less mild further north, until then it looks rather chilly this weekend with temps around 9c but cold overnight with widespread frosts, the first half of next week looks rather cold and fine at first but gradually turning unsettled, windy and milder as the week goes on but really taking until midweek for temps to reach double figures celsius but then becoming much milder but cold enough in northern britain for hill snow until later next week, the gfs 12z even looks on the warm side in parts of the south for a time, beyond that it looks mixed with low pressure crossing the uk but the trend being for the lows to be further northwest with pressure building towards the southeast so a typical NW-SE split developing but occasionally unsettled even in the southeast, towards the end of the run we see proper spring weather arrive with high pressure close to the southwest and temps reaching the magic 21c in central england.

[chris55]

Well after such a long spell of easterly winds, with the Atlantic failing miserably at every attempt to break through it does look like we will see a relaxing of the cold conditions (eventually) as we head through next week. However the Atlantic push early next week yet again gets forced further south and what was looking like a solid change is now a little less certain. UKMO tonight shows just how the colder air is hanging on and a snow event in places is not out of the question, when a few days ago that was looking unlikely.

http://www.wetterzen...ics/Rukm721.gif

http://www.wetterzen...ics/Rukm961.gif

As we move through the week GFS highlights how the milder air will most probably push through,

http://www.wetterzen...s/Rtavn1441.png

These synoptics of late have been remarkable, and oh to have had them in Jan and Feb rather than March and April. If things had been this stubbornly blocked in winter proper then conditions rivalling the "big winters" would have ensued.

But for all those snow lovers, prolonged cold conditions like this do show that we seem to have turned a corner since 2009 and the very mild period of the late 90s and 2000s, when we struggled to see even a northerly toppler, look like a distant memory. The potential for "proper" cold conditions have increased significantly and lets hope we see more of the same when it matters (like dec 2010) rather than in mid spring!!

Edited April 5, 2013 by chris55

[chris55]

According to the Gfs 12z operational run, it will finally turn mild by next thursday with temps across southern britain hitting 15-16c, around 60f but less mild further north, until then it looks rather chilly this weekend with temps around 9c but cold overnight with widespread frosts, the first half of next week looks rather cold and fine at first but gradually turning unsettled, windy and milder as the week goes on but really taking until midweek for temps to reach double figures celsius but then becoming much milder but cold enough in northern britain for hill snow until later next week, the gfs 12z even looks on the warm side in parts of the south for a time, beyond that it looks mixed with low pressure crossing the uk but the trend being for the lows to be further northwest with pressure building towards the southeast so a typical NW-SE split developing but occasionally unsettled even in the southeast, towards the end of the run we see proper spring weather arrive with high pressure close to the southwest and temps reaching the magic 21c in central england.

That 21c look very inviting!! Id be really interested to know how long it was since we reached 21C, thinking about it 6+months seems feasible, as I dont think we saw a 21c in October last year? That's 6 cold months, bring on the summer!!!!

[J10]

Latest Ski Blog now out, showery again over the weekend, but more appreciable snowfall expected over higher slopes this week, but rain is expected lower down.

As ever, GFS synoptic charts for the week are included.

[Summer Sun]

The GFS ensemble run continues to promote south westerly winds later next week

[Frank Trough]

much as i would love it to be right, i can't believe the GFS scenario because of the complexities of the situation in the early part of next week. No doubt that any really mild push is being pushed back again. are we now looking towards the end of another week before that happens? a lot of hoops to jump through before then.

can anybody say with any certainty what would happen if the UKMO 144 verified? more trough disruption....more delays?

The NAVGEM is very groundhog day...

i'm cold and fed up. hoping for a heroic ECM tonight to smash the cold away...not holding my breath though.

[Purga]

much as i would love it to be right, i can't believe the GFS scenario because of the complexities of the situation in the early part of next week. No doubt that any really mild push is being pushed back again. are we now looking towards the end of another week before that happens? a lot of hoops to jump through before then.

can anybody say with any certainty what would happen if the UKMO 144 verified? more trough disruption....more delays?

The NAVGEM is very groundhog day...

i'm cold and fed up. hoping for a heroic ECM tonight to smash the cold away...not holding my breath though.

What a chart from NAVGEM for the 12th April !

Could the new model on the block be leading the field - again?

[Summer Sun]

ECM continues with the cold east to SE'ly winds up to Tuesday

Edited April 5, 2013 by Gavin.

[Tim Bland]

ECM continues with the cold east to SE'ly winds up to Tuesday

Snow midlands northwards on that .. What's the betting it shifts south a further 200 miles by T0 !

[Summer Sun]

Wet, less cold and windy by t144

Cooler air tracks south again at 168

Pressure is rising to our SW pressure could rise over the UK once the low pulls away

Edited April 5, 2013 by Gavin.

[shaky]

Snow midlands northwards on that .. What's the betting it shifts south a further 200 miles by T0 !

another snow event for the midlands!!!!!!!!😳.this winter has just been practically continuous snow for the midlands since january!!

[weather_it_will]

Wet, less cold and windy by t144

Much colder again by T168

[Summer Sun]

And less cold again at t192 as pressure builds

The high takes charge at t216 as the low is forced north breaking up the northern blocking

Edited April 5, 2013 by Gavin.

[Summer Sun]

A very settled high pressure dominated end to ECM tonight

[chris55]

ECM FI looks great, this easterly continental influence continues but the bonus is that when we get this far away from winter the continental flow is rather warm and pleasant. Much better than wet and cool eh!

Edited April 5, 2013 by chris55

[stodge]

The high takes charge at t216 as the low is forced north breaking up the northern blocking

I don't know about the thumbs-up. That still looks a very blocked chart to me albeit with the HP now over Scandinavia and at T+240:

http://meteociel.com/modeles/ecmwf/runs/2013040512/ECM1-240.GIF?05-0

Yep, that looks pretty blocked too.

Without time for a full analysis, the thing that strikes me from the 12Z chart is how GFS, UKMO and ECM have all stayed firm to their morning evolutions. GFS and ECM do an undercut which UKMO doesn't but UKMO is more unsettled at T+144. The lower-res periods indicate a strong return of HP but while GFS builds from the south offering warmth, ECM brings the same in from the NE which while not cold wouldn't be as warm as some on here would like.

[mushymanrob]

well, in all this evenings runs dont worry me at all, the cold is stubborn but is expected to go. even the ecm in fi might look menacing with more easterlies coutesy of a scandi high...but the uppers are much warmer, so whilst it might be cool under the inevitable north sea stratus, if the sun breaks through as it will from the west, itll be nice ala april 1974.

looking pretty dry though... as a whole, and the ground is actually getting quite dry now, surprisingly.