Spring Model Discussion 17/3/13 6PM onwards....

[Ian Brown]

ECM just doesn't want to give up the cold does it?!

it should be dry and cold for many in the north at first next week

I'm not sure about the dry Gavin based on the ECM, snow showers possible virtually anywhere.

[ANYWEATHER]

Whatever way you look at it,the cold does not leave the Uk,Gfs the mildest, Ecm WOW!!!

[fatyido]

Im seeing, 'astonishing' and 'Dec 2010' again........remarkable charts don't usually come off with cross model agreement...we don't have that now......so skepticism is probably wise....

(tin hat on)

Exactly. I agree the latest run of charts look promising - but people - please, hold the bus.

We have been here countless times already this winter with 'epic looking charts', but do they verify ? Seldom.

Im seeing it and liking it, but wait a few more days...

[joggs]

Also bearing in mind,The sun can trigger showers off this time of year so dont know about it been dry on that chart.

[Methuselah]

Exactly. I agree the latest run of charts look promising - but people - please, hold the bus.

We have been here countless times already this winter with 'epic looking charts', but do they verify ? Seldom.

Im seeing it and liking it, but wait a few more days...

Aye, if the ECM had ever really, properly verified, Bozo the Mayor would be having frost fairs on the Thames...

[Severe Siberian icy blast]

Whatever way you look at it,the cold does not leave the Uk,Gfs the mildest, Ecm WOW!!!

I'm absolutely astonished by this march , what a brilliant month for reminding us all how cold the month can be , and next week looks colder than this week, potentially snowy aswell which is quite hard to believe actually .

The southward correction continues this evening , to be honest I expected it , it happens time and time and again , the midlands quite often is the place to receive the snow from these scenarios , I'm becoming more confident that it will be a midlands event , maybe as far as Manchester , Sheffield , southern northern England , so maybe turn to rain for a 12hr period in southern midlands before turning back to snow during Saturday . Of course nothing is set in stone , but the southward corrections is made year in year out . Either way it's a very interesting wkend coming up , with fascinating Synoptics for the time of year !

[noonoo418]

I am surprised by how full on and positive people are as regards forthcoming snow. Now I live north of the M4 corridor mentioned in certain posts as a boundary line. Now looking at the Met Office forecasts, it shows cold temperatures for March and a lot of rain. No hint whatsoever of snow. I would love them to be wrong and for a full blown blizzard outside my front door, but given the timescale and the resources available, sure the Met Office must be close to right?!

[Stuie]

The love it or hate it GFS precip info, imo after looking at the weekend front coming in, it gives a plausible outcome with EA getting some wintry showers.

From Saturday onwards the uppers get colder and colder:

If the cold air comes in quicker then maybe more southern areas than the Midlands could see something more than rain. It is only Tuesday and in January, Saturday would have been FI.

[Summer Sun]

Whoops still getting to grips with these sorry !

Re-posted here -

From Derek Brockway on twitter

More cold or very cold weather next week but as we approach Easter weekend some recovery of temperature is likely

Edited March 19, 2013 by Gavin.

[Cloud 10]

Those are the operational run charts Gavin,the 12z ensemble mean charts will be out in a few minutes.

[chris55]

I am surprised by how full on and positive people are as regards forthcoming snow. Now I live north of the M4 corridor mentioned in certain posts as a boundary line. Now looking at the Met Office forecasts, it shows cold temperatures for March and a lot of rain. No hint whatsoever of snow. I would love them to be wrong and for a full blown blizzard outside my front door, but given the timescale and the resources available, sure the Met Office must be close to right?!

As things stand our area is pretty much just outside the "snowline" and if you read through I doubt there is to many posts suggesting otherwise. We are seeing some subtle southward shifts of the pattern though and if this trend continues then Glos could come into the firing line for the initial front. But then we have the colder air digging back south through the weekend so that also gives those further south a chance of something.

[Summer Sun]

Those are the operational run charts Gavin,the 12z ensemble mean charts will be out in a few minutes.

Whoops still getting use to these here are the ensembles my apologies for the confusion

A relaxation of the cold seems likely in the south this weekend colder further north

The midlands north remains under the coldest uppers on Monday slightly milder in the south

Cold briefly moving further south dropping temperatures for just about all

By Thursday less cold air starts to push in from the south west

Good Friday is less cold for all temperatures close to double figures are possible in the south with cloud and rain quite likely

short term support is there long term onwards its a cold outlier especially for the south coast and south west by t192 (Wednesday) its a cold outlier for just about all

The message tonight appears to be cold for all at first next week but a recovery of temperatures starting in the south west at first before spreading across the country as we approach the Easter weekend

Edited March 19, 2013 by Gavin.

[Gibby]

Hi folks. Here is the report from the 12z output from GFS, UKMO and ECM for today Tuesday March 19th 2013.

All models show a slack Low pressure over the South of the UK moving slowly away East with a brief respite in low pressure tomorrow. By Thursday a new Low is deepening down to the SW with a freshening and cold SE flow developing across the UK. In addition cloud and rain from a complex trough will move slowly NE through the day into the SW of the UK. Over Friday and Saturday this slow Northwards progress continues with potentially blizzard conditions developing over the North as the wet weather engages with the cold East winds in the North. Saturday may become brighter in Southern England as the frost passes away to the North before on Sunday the trend reverses with the cold air in the North flooding back South to all areas as the Low slides away slowly Eastwards.

GFS then moves us through next week with a cold and windy start with a renewed surge of wet weather pushing NE again by Tuesday with snow on its leading edge. This time though the milder weather wins the battle as the front crosses all the way to the NE bringing a spell of rain and strong winds to lead us up to Easter. Easter itself looks really inclement with stormy weather with severe gales across the UK and further heavy rain and showers at times. towards the end of the run the weather becomes a little colder again as High pressure slowly builds in the North Sea.

The GFS Ensembles show a clear warm up in the South briefly at the weekend before things turn colder for a time again next week. Longer term the trend for rather milder weather is still a favoured option with rather firmer agreement on things trending milder between the members than recently. It should also be noted that precipitation amounts in the far NE amount to little until the second mild pulse arrives here late next week.

The Jet Stream shows the flow continues to flow West to East to the South of the UK although it does show signs of moving North somewhat towards northern France later next week.

UKMO for the start of next week sees a cold and windy Easterly flow over the UK with low pressure moving away East to the South of the UK and a ridge stretching down from the Arctic towards Scotland. A lot of dry weather in the North but with some showers possible in the East and SE, wintry over hills.

ECM shows a cold week next week too with wintry showers early in the week enhanced by the risk of further snowfall as a new Low runs East across northern France on Wednesday followed by sunshine and wintry showers to take us into Easter with widespread night frost.

In summary GFS is the only offering of any milder weather from the big three tonight with both the Euro's keeping us locked in colder than average conditions with showers or rain at times and snow on the hills and frost at night all unseasonal ingredients in the mix tonight. As far as Easter goes GFS makes sure if it's not desperately cold then it will be wet and potentially stormy for a time while ECM looks like it could give a renewed attack from the SW over the Easter weekend with thee potential snow risk once more on the fronts leading edge.

[bluearmy]

how is the ECM op an outlier Gavin! Have you seen the graphical representation of the members?

[snowice]

Whoops still getting use to these here are the ensembles my apologies for the confusion

A relaxation of the cold seems likely in the south this weekend

The midlands north remains under the coldest uppers

After briefly moving further south

Less cold air starts to push in around easter time from the SW pushing the cold away NE wards

Good Friday is less cold for all

short term support is there long term from t144 (Monday) onwards its a cold outlier especially for the south at first and for all by t192 (Wednesday)

The message tonight appears to be cold for all at first next week but a recovery of temperatures starting in the south west at first before spreading across the country as we approach the Easter weekend

well Good Friday is well FI,this time last week the mildies were shouting spring!going by ecm ukmo gfs its still a long way off!goes to show you how strange the seasons are becomming!

[winterof79]

http://www.knmi.nl/exp/pluim/Data/pluim_06260_0_12_60.png?1363727049519 Edited March 19, 2013 by winterof79

[Snowman.]

Northern France low Number 2?

[Summer Sun]

how is the ECM op an outlier Gavin! Have you seen the graphical representation of the members?

This is the ensemble run

And early we got this

I would have thought thats classed as a cold outlier?

Edited March 19, 2013 by Gavin.

[bluearmy]

This is the ensemble run

And early we got this

I would have thought thats classed as a cold outlier?

it can only be an outlier if it is has little ens support. you are looking at a mean chart there gavin. impossible to tell if it is an outlier. it certainly wasnt an outlier in holland

i also have to break the bad news to you that your assessment of the good friday weather based on the ens is incorrect. only cornwall pokes out of the 0c isotherm. as it happens, there is a spread cluster that supports higher uppers than the mean in the southern half of the uk but at that range at the end of march, anything else would indeed be shocking.

Edited March 19, 2013 by bluearmy

[mcweather]

This is the ensemble run

And early we got this

I would have thought thats classed as a cold outlier?

Sorry Gavin you are incorrect. Take a look at the graphical representation of the 12z ecm and nowhere on the graph is the op a cold outlier.

It is on the cold side of the runs but not an outlier at any point.

[Summer Sun]

it can only be an outlier if it is has little ens support. you are looking at a mean chart there gavin. impossible to tell if it is an outlier. it certainly wasnt an outlier in holland

Ah right thanks, still learning this ECM ensemble

[Gustywind]

Dictionary definition of an outlier, from maths is fun.com !

A value that "lies outside" (is much smaller or larger than) most of the other values in a set of data.

For example in the scores 3,25,27,28,29,32,33,85, both 3 and 85 are "outliers".

[Snowman.]

Dictionary definition of an outlier, from maths is fun.com !

A value that "lies outside" (is much smaller or larger than) most of the other values in a set of data.

For example in the scores 3,25,27,28,29,32,33,85, both 3 and 85 are "outliers".

Gave gets it I'm sure he means just on the cold side.

Would be helpful if you disable the mild outliers as that probably messes with it all.

[No Balls Like Snow Balls]

Gave gets it I'm sure he means just on the cold side.

Would be helpful if you disable the mild outliers as that probably messes with it all.

You are joking arnt you?

[in the vale]

Interesting that the GFS and ECM seem to have come full circle to show (for N Wales) a similar outcome for this weekend that they were showing four days ago - with much movement in between. Suggests more movement still to come, albeit less as we are nearer than we were. Personally, I would bank the GFS out until 168 and ECM thereafter. Oh, and by the way, N Wales is a real place. Rarely gets a mention, even in the Regionals.