Model Output Discussion - 2nd March Onward

[SMU]

Must admit im struggling to figure out how much snowfall would result from this mornings GFS. I feel snow showers would be widespread pushing well inland but its the intensity im uncertain of due to the temps of the N Sea. If this output was being shown in Dec or early Jan then I would be predicting over 30cm in places.

TEITS the 1 or 2 c difference in gradient is much less significant compared with the instability of the air thats arriving-

sub 524 heights & towering cloud tops will produce heavy snow from the 00z & 06z run- big totals in the E & NE & parts of kent / Suffolk/ Norfolk if it all varifies.-

S

[BLAST FROM THE PAST]

Based only on the GFS 06Z Monday would be the only amazingly cold day. After Monday it's not very cold at all. It might be a case of blink and you will miss the very cold temps.

Looking at todays temps and current set up I cannot believe that with the deep cold air shown, the flow shown that temps will be +6c to +7c widely on the 06z run as a general rule come Tues/Wed.

BFTP

Edited March 6, 2013 by BLAST FROM THE PAST

[nick sussex]

Well judging by the latest BBC forecast they're not buying the GFS and look to be behind the UKMO output for the weekend.

I'm quite surprised that they even went out that far given the disagreements but certainly if you look at the GFS 06hrs run for Sunday and compare it to the latest BBC forecasts they are in different Universes.

Just been looking at the latest NAE and it does look to be developing a shortwave at T48hrs near southern Greenland:

Its not as developed as the GFS but is this a sign of some movement from the UKMO later.

Edited March 6, 2013 by nick sussex

[BLAST FROM THE PAST]

Well judging by the latest BBC forecast they're not buying the GFS and look to be behind the UKMO output for the weekend.

I'm quite surprised that they even went out that far given the disagreements but certainly if you look at the GFS 06hrs run for Sunday and compare it to the latest BBC forecasts they are in different Universes.

I bet they'll still be showing 5-6c for Monday Tues too. It'll take confirmation upto Friday with GFS and ECM with UKMO jumping on board before we see a shift IMO.

With the performance of the models this winter it would be NO SURPRISE if we saw a sudden backdown/backtrack from ECM or GFS....but for now the UKMO is slowing edging towards them and not the other way round. MOGREPS probably has the 'phantom' SW'ly flow that never occurred showing again? But more seriously, is slower?

BFTP

Edited March 6, 2013 by BLAST FROM THE PAST

[Radiating Dendrite]

Well judging by the latest BBC forecast they're not buying the GFS and look to be behind the UKMO output for the weekend.

I'm quite surprised that they even went out that far given the disagreements but certainly if you look at the GFS 06hrs run for Sunday and compare it to the latest BBC forecasts they are in different Universes.

Could be an egg on the face moment.................hopefully!

[SMU]

http://modeles.meteociel.fr/modeles/gens/run/gens-5-0-144.png?6

A couple of runs at the extreme end now bringing in the -16c line

S

[Purga]

The UKMO has been temperamental all winter really.

I just cannot believe that the GFS ensembles could suddenly switch to mild...............they are all cold and showing a level of agreement that I have never seen before. Add to this the ECM and I can only see a backtrack from the UKMO.

There was a notorious occasion back in 2008 / 2009 ? I can't recall exactly when (maybe somebody has it saved) when exactly what you described happened!

It was one of the biggest debacles in cold model watching I can ever recall and left a very nasty aftertaste to this day. But, please, I am NOT saying a decent cold shot won't happen, it is looking pretty good, just that without UKMO fully on song, I'm very cautious.

OK I'll shut up about now ...

.......until the 12z - LOL

Edited March 6, 2013 by Purga

[Radiating Dendrite]

http://modeles.meteo...s-5-0-144.png?6

A couple of runs at the extreme end now bringing in the -16c line

S

How often do you see -12c out to the west coast of Ireland!!

Not very.............evern less so in March.

[Dave Kightley]

Ian on twitter saus Mogreps agree on colder spell but later then Gfs and EC. Timing issue thats all.

[Shunter]

Could be an egg on the face moment.................hopefully!

Remember BBC use essentially delayed info ( t -12hours ) so they would still be forecasting on last nights MO output. Looking at IanF's recent twitters it seems that MOGREPS back the EC solution albeit with a delayed timescale. Therefore in essence I would lean more towards a slight delay in GFS/EC solutions with the UKMO making inroads to the same conclusion on the 12z output later this afternoon.

[Weathizard]

Looking at the models this morning, I'm surprised the UKMO is still showing the same as it has consistently for the past few days, its a worry if you're looking for cold, it would be nice for it to get on board with the 12z, I trust the UKMO over all over models at 120 however the MOGREPS, EC and GFS ensemble suites are not supporting its evolution. If you're looking for cold that's a good thing, however for me now its spring for my location I'd far prefer to have some lovely spring weather but given the uppers sinking into Europe I think that's the long shot bet at the moment! Some serious cold for the time of year, normally happens in February from my experience.

[BLAST FROM THE PAST]

There was a notorious occasion back in 2008 / 2009 ? I can't recall exactly when (maybe soebody has it saved) when exactly what you described happened!

It was one of the biggest debacles in cold model watching I can ever recall and left a very nasty aftertaste to this day. But, please, I am NOT saying a decent cold shot won't happen, it is looking pretty good, just that without UKMO fully on song, I'm very cautious.

OK I'll shut up about now ...

You are talking Jan 2008.....the mother of all Scandi HPs developed from High Latitude and just as it was about to strike it retreated SSE'wards as trough developed towards Greenland preventing retrogression. Yes it was very disappointing and was quite 'last minute'.

BFTP

[The Giant Daddy Jackpot]

Well well well, just when we thought that winter was over there could be a real punch at the end. GFS looks pretty sure of itself so all eyes on the models for this one because it could well deliver a real energetic NE'y and put the East of the country into standstill mode.

The METO are keeping tight lipped at the moment but maybe they realise the 'egg on the face' value if they call it wrong either way!

[SomeLikeItHot]

Looking at the ECM ensembles, there is still a minority cluster going for cold, but 1-2 days later than the bulk of the ensembles, mean and Op do.

So if Mogreps is going for it later (as per the twitter referred to easier). It wouldn't be without some support on the ECM ensembles. I imagine that Mogreps is more biased towards the top group and that is where the UKMO has fallen.

However as people have pointed out Mogreps was suggesting SW ly flow well after the ECM op and majority ensembles were predicting a biting easterly during the late Feb cold snap, so it has been wrong before.

Edited March 6, 2013 by SomeLikeItHot

[nick sussex]

Ian on twitter saus Mogreps agree on colder spell but later then Gfs and EC. Timing issue thats all.

Any chance it arrives before we break out the Easter eggs? The problem I have with the delay is that its essential the UK taps the coldest source of air and its debatable whether the UKMO would do that.

If I was in the UK I'd swap longevity for a noteworthy cold snap, two days of snow showers and very cold upper air, then high pressure with some very cold nights and a chance to enjoy the snow compared to possibly 5 days or more of slush.

It would just be great to see a convective easterly finally verify, sometimes quality is better than quantity.

Of course it would be great to see a long cold spell but if I had to choose I'd go quality rather than too much marginality coming into the equation.

There might be another reload anyway but when you've got such a great cold pool to the east and ne it would be a shame to see that sitting there diluting whilst the UKMO dragged the whole drama out.

[Captain Shortwave]

GFS ensembles really wanting the cold in by day 5 (monday)

NASA Hi res model agrees

of course the reliability of this model is still up for debate as it's new.

Edited March 6, 2013 by Captain shortwave

[Frosty.]

In Summary the weather will take a sharp turn colder early next week as High pressure over Greenland pulls very cold Arctic winds South over the UK. With Low pressure close by to the UK there looks to be plentiful opportunities for snowfall, more especially but not exclusively to Northern and Eastern Britain but maybe in the South and SW too should Low pressure close to the SW push troughs up into the cold air from the South. Frosts will be widespread and sharp so Gardeners beware the last few days of mild Spring weather was a false dawn and we will have to wait quite a while for anything remotely Springlike temperature wise looking at this morning's output and Jet Stream profile.

Another top summary from Gibby, seems to have been almost entirely overlooked on here!

[bluearmy]

the 06z gefs are a bit more spread on the drop in temps with a cluster of runs now going into monday. given ecm ens mean having monday as onset of the cold uppers + ukmo being slow, i wonder if we will see the entire ncep suite move back 24 hours whilst ukmo catches up to bring the really cold uppers in mon/tues.

[Dave Kightley]

Any chance it arrives before we break out the Easter eggs? The problem I have with the delay is that its essential the UK taps the coldest source of air and its debatable whether the UKMO would do that.

If I was in the UK I'd swap longevity for a noteworthy cold snap, two days of snow showers and very cold upper air, then high pressure with some very cold nights and a chance to enjoy the snow compared to possibly 5 days or more of slush.

It would just be great to see a convective easterly finally verify, sometimes quality is better than quantity.

Of course it would be great to see a long cold spell but if I had to choose I'd go quality rather than too much marginality coming into the equation.

There might be another reload anyway but when you've got such a great cold pool to the east and ne it would be a shame to see that sitting there diluting whilst the UKMO dragged the whole drama out.

I think going by Ian post the difference is a few days maybe as he said about snow possible for horse racing. He sounds confident on a colder spell which is fine by me..

[Glacier Point]

It has the worst verification but only just. What though is potentially important is that its not off on one and continues the 'elongation' cold theme of 00z that has moved towards the ECM elongation. So on that basis it possibly isn't a bin it run.

I have to say, Cheltenham Festival at this rate WILL be postponed IF GFS comes to fruition...and so will my trip to Swansea...these temps are supportive of laying snow remaining as laying snow.

BFTP

Don't forget Fred we have four days and opportunity to make up any losses with 10 race cards, and 13.30 starts so that should allow for temperatures to get above 0 by around 11 to enable covers to be removed.

Wednesday into Thursday looks interesting with both ECM and GFS picking up the potential for a shortwave to slide SE.

It's not going to be a warm Festival, infact I think we'll be calling it the 'Frigid Festival'. Long johns already packed !!

The key consideration being state of the ground and with Clerk of the Course not watering (and probably prevented from watering from Saturday onwards due to frost covers being in place), should enter the Festival with a mix of good, good to soft in places.

On a more serious note, lots of alcohol and temperatures this low are going to lead to some serious risks to health.

[nick sussex]

I think going by Ian post the difference is a few days maybe as he said about snow possible for horse racing. He sounds confident on a colder spell which is fine by me..

Well if its two days I'll stop moaning! but I'd still prefer the GFS solution to verify. In terms of cold that has the best chance of getting in those sub -10 uppers in a strong flow.

I suppose I'd just like to see the convective easterly jinx broken hence I'm cheering on the GFS solution.

[be cause]

gfs solution today for next monday on .. is little different from that of 8 days ago .. having faith for once looks worth it .. if we are looking for Cold !!!

[Severe Siberian icy blast]

Well I have to say , I'm sure everyone can remember my negativity lately , and Iv been watching the models insesently recently before I jump on bored , but Iv reached a point now where Im confident of a very cold and possibly snowy spell developing early next week , we'v saw this go wrong before which is why I suppose Iv been negative of late but this looks its growing support from all major models now . The ukmo has took baby steps this morning to the others , and the ECM has moved things to the gfs again after having the blip a couple of days ago , with the gfs been a day early to bring in the cold in my opinion, and we have seen a slight shift now from the gfs in delaying it ever so slightly , so I think Monday into Tuesday is the key days to bring very cold air in .

Then maybe a slight wane in the cold toward next wkend , before a renewed push from the north ?

We all know that march can deliver the goods , and as others has pointed out , statistically it's snowier than December , so with deep cold been forecast , (and by that it looks possibly record breaking) along with the stronger sun , we have the "potential" for some super cells developing and some thunder snow and blizzards , that's with upper air of -13,14 , that's know exaggeration given the thickness levels and off the North Sea .

So maybe 2 or more significant snow events this season isn't out the question going by the chars?

Very interesting !!

[Snowman.]

Would I be right in saying the ensembles below never got that low during winter for what its showing on the 11th

t120 and 126 brrrrrr

You have to laugh folks wait all winter for this and it don't happen as soon as the coldies leave the forum and spring arrives bang it arrives in the height of winter this place would have been in melt down

I drawn between cold and warmth been outside today and its amazing!

Lovely sunshine right on your face.

[Met4Cast]

Until the UKMO comes on board I'm not buying into it.

There's no doubting the GFS and ECM show some excellent synoptics, but all winter we've seen these two models throw out absolutely cracking runs only for them to gradually get watered down into practically nothing. To be honest, all models have performed quite poorly this winter with lots of amazing charts but none of them actually verifying.