Model Output Discussion

[Mr.Plow]

It doesn't look perfect to me! I hope it does come off for you in the North of England / Scotland - for those that want it.

Large parts of the country look to me as though they will miss out totally and just get rain/sleet judging by those charts (Please correct me if I am wrong).

Personally hoping that things change soon and we perhaps get high pressure back in control. The GFS show very wet conditions but no snow right through til Saturday for much of England.

[TEITS]

Nothing very mild being shown on the ECM ensembles.

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

Quick word about the rest of this week. I would suggest being wary of the model output at the moment. The centre of the LP today is going to track along the S coast when only a few days ago this was supposed to exit Norfolk. The S trend of this LP has mean't the precip didn't even reach my location. For some locations to the S of me the NAE yesterday suggested heavy rain and temps of 7C and yet the reality is heavy snow and temps of 0C!

At the moment its looking as though the snow risk will move into N England before colder air moves back S towards the end of the week.

[Lewis]

Heres my view on latest models for areas in northern england:

Good GFS this morning, not perfect but good.

The last couple of runs had the lows/fronts pushing too far north wed-fri with scotland getting battered. Now its shifted further south again with northern most parts of england/border regions getting hammered . A little further south and we could be on the cusp of a major dumping!

http://charts.netweather.tv/ensimages/ens.20100222/00/t850West~Yorkshire.png

Also note the operational run on the esembles wed-thu was very much on the mild side according to other perpetrations, meaning most overs arent as keen to push lows too far north resulting in uppers of between -5hpa and -8hpa

Look at the ukmo 00z, also very good, 100 miles further south and PERFFFFFECT...

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

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

ECM

http://www.wetterzen...ics/Recm721.gif

http://www.wetterzen...ics/Recm961.gif

This is what were aiming for! SYNOPTIC HEAVEN!!!

So Good developements this morning, lets hope the 6z follows suit!

It's good to have a little shift south, but you don't want the center of the LP where it is on the above charts! Especially not for us.

In all honesty other than Northern most parts of N England, Scotland and parts of N Ireland, it will be dull with temps 3-5c for parts of the midlands and Yorkshire/Lincs, with some heavy bursts of rain, some sleet and snow falling for a time on higher ground.

Further south, heavy rain, temps at 6-8ºc.

Look at the 0c isotherm for Wednesday aswell on all subsequent runs.

The latest GFS 06z gives us this with the LP;

Even further North!

Edited February 22, 2010 by Storm Force Lewis

[Harsh Climate]

It's good to have a little shift south, but you don't want the center of the LP where it is on the above charts! Especially not for us.

In all honesty other than Northern most parts of N England, Scotland and parts of N Ireland, it will be dull with temps 3-5c for parts of the midlands and Yorkshire/Lincs, with some heavy bursts of rain, some sleet and snow falling for a time on higher ground.

Further south, heavy rain, temps at 6-8ºc.

Look at the 0c isotherm for Wednesday aswell on all subsequent runs.

The latest GFS 06z gives us this with the LP;

Maybe according the gfs 6z, but we have no verification yet of were this run sits with other perpetrations.

Also I think its a little early to be makin forecasts , look how wrong most people were on todays low, in the space of 36 hours has gone 100 miles further south than first expected..

[Lewis]

Maybe according the gfs 6z, but we have no verification yet of were this run sits with other perpetrations.

Also I think its a little early to be makin forecasts , look how wrong most people were on todays low, in the space of 36 hours has gone 100 miles further south than first expected..

I did a forecast for it the other day i'm so confident

That LP on Wednesday is a monster, and it will break through and push much further North than expected, there's only one way it can go and that's North.

[mickpips]

A bit of advice please , I have been following the GFS ensembles for the last few days and although there is a huge scatter on the 850's from around wednesday for my region ( and its been evident for a few days now ) ... the general trend is for positive figures 850's.

The question is , if this trend is for positive 850's then how come there is increasing confidence for further snow events in the latter part of the week and into the weekend.

I know there are many other factors that are needed for snowfall but i generally start with the 850 temp and then look at other factors to see if there conducive of snowfall.

[Lewis]

A bit of advice please , I have been following the GFS ensembles for the last few days and although there is a huge scatter on the 850's from around wednesday for my region ( and its been evident for a few days now ) ... the general trend is for positive figures 850's.

The question is , if this trend is for positive 850's then how come there is increasing confidence for further snow events in the latter part of the week and into the weekend.

I know there are many other factors that are needed for snowfall but i generally start with the 850 temp and then look at other factors to see if there conducive of snowfall.

Spot on Mick, you should come in the Yorkshire thread and post that too.

I have a new msn now mate, i'll pm you it.

With regards snowfall it's practically a no no with what the models are showing at the moment, people in far N england, Scotland and maybe Ireland will be looking forward to it

Edited February 22, 2010 by Storm Force Lewis

[TEITS]

A bit of advice please , I have been following the GFS ensembles for the last few days and although there is a huge scatter on the 850's from around wednesday for my region ( and its been evident for a few days now ) ... the general trend is for positive figures 850's.

The question is , if this trend is for positive 850's then how come there is increasing confidence for further snow events in the latter part of the week and into the weekend.

I know there are many other factors that are needed for snowfall but i generally start with the 850 temp and then look at other factors to see if there conducive of snowfall.

Looking at the ensembles and I feel some of them are rather slow at picking up the colder N,ly flow towards the end of the week into the weekend. The 0Z was one of the colder runs for this period but the 06Z is equally as cold. When the operationals continue to show this the ensembles slowly start to agree.

[bluearmy]

Looking at the ensembles and I feel some of them are rather slow at picking up the colder N,ly flow towards the end of the week into the weekend. The 0Z was one of the colder runs for this period but the 06Z is equally as cold. When the operationals continue to show this the ensembles slowly start to agree.

the weekend interaction between the shortwave runner(s) to the southeast and the colder n flow will be interesting to focus on for us in the 'south' after tomorrows front has pushed the less cold uppers through and our snow risk has gone. the conveyerbelt may well have run out of steam by then with pressure beginning to rise.

[Harsh Climate]

All at 72 hours, some quite big differences

No gaps

http://www.wetterzen...ics/Rngp721.gif

ECM

http://www.wetterzen...ics/Recm721.gif

GEM

http://www.wetterzen...ics/Rgem721.gif

UKMO

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

JMA

http://www.wetterzen...ics/Rjma721.gif

ENS

http://www.wetterzen...ics/Rz500m3.gif

GFS

http://www.wetterzen...cs/Rtavn721.png

Edited February 22, 2010 by Jed Bickerdike

[Weather-history]

To me, the Manchester 2m temps look chilly, chillier overall than past runs, no immediate sign of some welcome spring warmth

http://www.wzkarten3.de/pics/MT2_Manchester_ens.png

Edited February 22, 2010 by Mr_Data

[johnholmes]

I've decided to keep a note of the first date that GFS predicts my temperature exceeding 10C-on the 06Z run its Saturday 6 March

mind you the 06z run on Thur 4 Feb predicted it for Fri 19 Feb-in fact I got 5.1C

the 12z decided it would be the next day-I got 7.1

So we shall see!

[SP1986]

I do not foresee any return to Spring weather for a while. There doesn't appear to be any viable signals from the model anyway with any milder weather usually kept past 200 hours or so. I imagine it will be nearer April before the majority of the country records +10C or higher. I cannot remember the beginning of a year with such a lack of 10C temperatures locally.

[Michael Winston]

I cannot remember the beginning of a year with such a lack of 10C temperatures locally.

I can, Stephen. 1963! I'm getting too old for all this!!

Looks like an interesting few days but I think it's too marginal to call here in the Midlands.

Kind regards,

Mike.

[nick sussex]

Looking at the ECM ensembles for London, the operational run is at the top end of members for the 25th to the 27th with quite a few colder runs. Again the problem of where these lows track is evident.

http://www.meteogroup.co.uk/uk/home/weather/services/ensemble_forecast.html

http://www.meteo.psu.edu/~gadomski/ECMWF_0z/hgtcomp.html

The mean height comparisons show the ECM reducing the troughing near the UK with the deepest negative anomaly further sw into the Atlantic, , a chance we might see the deep troughing in the Atlantic forcing a ridge building ne'wards with a rerun of the pre Xmas set up as this built ne followed by an easterly if we can get the right trough alignment with WAA.

Looking at the UKMO further outlook that suggests the current status quo to continue but i'd be surprised not to see at least some weak height rises to the north slowly sinking south as low pressure near the UK weakens with a slacker pattern.

Although recent days have seen some snowfall it has been marginal away from much higher elevations, people have mentioned how quick the thaw has been, unfortunately we're seeing quite a moist flow so the dew points have been relatively high and hence the quick snow melt.

Theres still some more snow to come with the risk slowly transferring north, some uncertainty regarding the end of the week as to whether there will be a change back to snow as the rain heads back se.

Overall then the wintry mix to continue with a very messy synoptic set up.

Edited February 22, 2010 by nick sussex

[Eugene]

Looks like i may see 10C on wednesday, if it does it would be the first time since mid Dec

Only brief though before turning colder again.

[Rollo]

Looks like i may see 10C on wednesday, if it does it would be the first time since mid Dec

Only brief though before turning colder again.

10c-sounds great but I would not be so sure as the movement of these lows is so mobile that things can virtually change at the last minute. Even the North-East could see some of the milder temperatures or get a dumping later in the week.

[Guest]

I do not foresee any return to Spring weather for a while. There doesn't appear to be any viable signals from the model anyway with any milder weather usually kept past 200 hours or so. I imagine it will be nearer April before the majority of the country records +10C or higher. I cannot remember the beginning of a year with such a lack of 10C temperatures locally.

The majority of Scotland, Northern Ireland, Isle of Man and parts of Northern England have already recorded 10C or more this year Ste (27th January).

In fact a lot of the UK has had temps at or above 10c, try the 18th of Jan as well for max temps of 10C and 11C:

http://www.weatheronline.co.uk/ukukstdf.htm

But twice in two months is still pretty exceptional :)

[Timmytour]

Saw some snow this morning which I presume was due to the low being further south than modelled a couple of days this morning.

assuming that is the case, how will this impact upon what was being modelled for later this week? Does a significant shift of one system from what was actually modelled make a big difference to how further systems coming along have been modelled?

[Harsh Climate]

After looking at the gfs output again, wednesdays low doesnt go too far north afterall, it goes south.

centre of low about 350miles southwest of ireland

http://www.wetterzen...cs/Rtavn421.png

now over the iberian peninsula

http://www.wetterzen...cs/Rtavn541.png

the low has now wound itself out near denmark

http://www.wetterzen...cs/Rtavn721.png

What happens is that a small low developes out of nothing from our low and pushes towards scotland as shown here:

http://www.wetterzen...cs/Rtavn541.png

http://www.wetterzen...cs/Rtavn721.png.

This isnt shown on any other model.. Hopefully the gfs is overplaying these possible developing lows/depressions and untill t24 wont be able to even correctly model the exact track of these, nor where they will develope.

http://www.wetterzen...ics/Recm721.gif

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

The 12z charts should be v interesting indeed

Edited February 22, 2010 by Jed Bickerdike

[MisfitDog3]

OK, the model runs towards the end of the week and the weekend are enough to actually get me out of my recent slumber down here on the Surrey/Hants border. There is only so much cold rain that the excitement can take.....

Spring certainly seems to be on hold for the time being and the trend (excluding the next few days) suggest this Winter may yet have a sting in it's tail for some of us down sarf!

[Matty M]

The 12z will be interesting, some parts of Northern Ireland could see some decent falls tomorrow night.

12z will firm up slightly where is most exposed.

[Harsh Climate]

looking better so far

http://www.wetterzentrale.de/pics/Rtavn481.png

not that the lows further south, but that little **** of a low pressure doesnt look like devlopeing and pushing north..

[MR EXTREMES]

after looking at the models tonight both gfs and ukmo it would seem more of the same.

north midlands north always more favourate for anything wintry although good upper air does drift slowly more north than midlands as week rolls on.

but i will add nothing truely brillant from the models tonight although scotland could tap into some of the colder air from the east on the northern edge of systems passing through the uk.

what is intresting they dont make much of an impact and seem to die out over the northsea.

over all always colder more north you go milder in the south or should i say average in the south but very wet and windy but feeling cold in that wind.

[Thundery wintry showers]

The GFS 12Z probably shouldn't be taken too seriously- to my mind it's overdeepening those lows to an implausible extent.