Model Output Discussion

[Winter Monsoon]

I have to say I am still totally unconvinced of the trend of a west based -NAO.

Heights over the Arctic will drop down more into the Iceland, Svalbard area with

the lows and troughs shunted further south and east.

I know some will say this is hope casting but looking at the stratosphere charts

and the warming over the Svalbard area at the 30hpa level I think we will see a

big shift east in the models over the next three days or so.

If by the weekend this is not the case then fair enough but this is how I see the

SSW playing out for our neck of the woods.

Just read Chino's post and it doesnt taly with what you have suggested will happen. It would seem that theres nothing to stop the westward movement?? Im no expert but thats the feeling i got fromt he post.

So northern areas are looking good for next week. Its funny but this whole easterly/northerly has been downgrading ever since it appeared. With 18 days left of this month will this be the last hurrar of winter? My gut feeling is that after this brief not so cold, cold period spring will be upon us. The sun is projected to wake up from its slumber according to the beeb today so we possibly may not see a winter like this for some time to come.

Of course im really hoping that the models are having a laugh on us and will switch and we see the mother of all northerly/eaterly, i can but dream.

[Climate Man]

I am going to put my neck on the block here. I think that past experience shows GFS eastward progression to occur in situations like this. It would still not take much change in the right direction for the majority to see some snow. For me, roll on this time next week. PS I have seen snow every day this week too!

[Optimus Prime]

Lets be honest though the models have downgraded within the reliable timeframe which is why the next few days are far less wintry than what the countryfile forecast suggested on Sunday. For some reason once an E,ly moves within +96 timeframe there is a tendancy in the models to shorten and slacken the E,ly flow.

Looking good from that LP spilling down from the north. It's not to be treated as being a non-event. It's coming down from the Arctic so there is already cold air embedded in it. Not like your usual Atlantic low sitting over us.

BTW the GFS has just overtaken ECM as higher Verification for the last few days...that means the GFS has been performing better than the ECM but not quite as good as the UKMO.

Edited February 10, 2010 by grab my graupel

[Snowyowl9]

Snowy next week? Still possible. But it's very marginal. However, the cold spell of February 2009 was very marginal and delivered a heck of a lot of snow here so I remain upbeat. Better than this damp squib of an easterly and FAR more interesting to watch!

I agree that northern areas look favoured for a pasting as things stand, particularly in places with a bit of elevation. As things stand southern England could see some snowfall as well from this, but it's a messy flow so rain turning to snow more likely here.

Last february was far from very marginal except at the end of the cold spell for low ground.

Have to say next week does look more like christmas again.

http://www2.wetter3.de/Animation_06_UTC/144_30.gif

This pattern is just repeating over and over again,this could well carry on well into March.

http://91.121.93.17/pics/Rtavn14415.png

With only milder blips,with the jet that far south.

[Lewis]

There was never really an easterly blast shown aside from you and a few other deluding us with number 24/50 parallel run that was showing a 1987ect. Good job I don't look at them otherwise I'd be miserable as well.

Looking good from that LP spilling down from the north. It's not to be treated as being a non-event. It's coming down from the Arctic so there is already cold air embedded in it. Not like your usual Atlantic low sitting over us.

I agree,

I said 2 weeks ago that the easterly was never going to materialize, and i was called from a pig to a dog, and that i have no idea blah blah.

Some people don't learn from mistakes, it's very easy to get sucked in to FI and a fair few members on here do and they swear by it.

As we got closer it went from a 3-4 days easterly blast, to a more ENE'rly for 24 hours. The models have always struggled with these type of setups and of course continue to over do them in FI. A few snow showers about giving a dusting at best for them away from the far Kent Coastline.

Come april, 99.9% of the members that are online won't be seen until the cold arrives this coming winter. One thing we can be sure of until then is that we will have simple discussions, its going to be warm or hot lol, them type of discussions, bring on the thunderstorms

Lewis

Edited February 10, 2010 by Storm Force Lewis

[Duane S.]

I am going to put my neck on the block here. I think that past experience shows GFS eastward progression to occur in situations like this. It would still not take much change in the right direction for the majority to see some snow. For me, roll on this time next week. PS I have seen snow every day this week too!

I too have a feeling that despite the negative zonal winds trying to push everything west, we will soon see a shift to the East as is normally the case.

Just in the middle of an VERY beefy snow shower at the moment, very nice.

[NorthantsSnow]

Last february was far from very marginal except at the end of the cold spell for low ground.

Sorry but it was for here. I followed it very closely so I should know. The -5 line was way north of Northamptonshire but still we ended up with several inches of snow and then more the next day and continued topups for days after. A terrifc spell but very marginal and this is why the automated forecasts on Netweather were only predicting icy rain and a less than 10% chance of snow! (but it was snow all the way)

http://www.wzkarten3.de/pics/archive/ra/2009/Rrea00220090205.gif

[Frosty.]

Definately rather wintry looking charts from next monday onwards, snow in the north looks guaranteed, and lots of it but southern britain more marginal with a rain/sleet mix, that's how I read the 6z run anyway.

[Optimus Prime]

Definately rather wintry looking charts from next monday onwards, snow in the north looks guaranteed, and lots of it but southern britain more marginal with a rain/sleet mix, that's how I read the 6z run anyway.

06Z (and 12z) seem to have issues mapping the build up to the pattern but once it's underway they go top of the league of all the runs.

I'd say o6z and 12z will be the runs to watch for detail of the Northerly.

[noel]

well the lasted met office update looks like many might see snow next week, with some getting lots esp in north and on hills anywere

UK Outlook for Monday 15 Feb 2010 to Wednesday 24 Feb 2010:

Initially on Monday (15th) outbreaks of rain, sleet and hill snow in the north look likely to spread southwards, reaching all but the far south by the end of the day. Thereafter it currently looks likely that conditions across the United Kingdom will be cold and unsettled with further outbreaks of rain, sleet and snow, some of which are likely to be heavy. As usual the hillier areas are most likely to experience the largest amounts of snow, although there is also a fair chance that many lower lying areas will have some fresh accumulations at times. During the second week there is a chance that the main snow risk area will move towards the northern parts of the country. It will be windy at times, especially in the north.

Updated: 1256 on Wed 10 Feb 2010

[Frosty.]

06Z (and 12z) seem to have issues mapping the build up to the pattern but once it's underway they go top of the league of all the runs.

I'd say o6z and 12z will be the runs to watch for detail of the Northerly.

Just noticed the meto has updated and suggests a lot of snow in northern britain next week but less so in the south with snow becoming confined to higher ground of southern britain with rain/sleet at low levels but up north it could be severe although it depends now if the models halt the westward shift and start pushing things east like the gfs 6z showed yesterday.

[Snowyowl9]

Sorry but it was for here. I followed it very closely so I should know. The -5 line was way north of Northamptonshire but still we ended up with several inches of snow and then more the next day and continued topups for days after. A terrifc spell but very marginal and this is why the automated forecasts on Netweather were only predicting icy rain and a less than 10% chance of snow! (but it was snow all the way)

http://www.wzkarten3.de/pics/archive/ra/2009/Rrea00220090205.gif

Less marginal with this chart,overall it wasn`t marginal as it made the headlines.

http://www.wzkarten3.de/pics/archive/ra/2009/Rrea00120090205.gif

And it got below -10upper air with powdery snow and an easterly.

http://www.wzkarten3.de/pics/archive/ra/2009/Rrea00220090202.gif

MODS move this if off topic,which it is.

[Supacell]

Just noticed the meto has updated and suggests a lot of snow in northern britain next week but less so in the south with snow becoming confined to higher ground of southern britain with rain/sleet at low levels but up north it could be severe although it depends now if the models halt the westward shift and start pushing things east like the gfs 6z showed yesterday.

Yes, looks like the Meto longer range forecast agrees with what GFS is forecasting with snow being more likely further north. For me next week actually looks quite good, infact up here we could end up with a good dumping!

We have had snow showers of and on all morning and have the past 3 days. I'm personally enjoying this cold spell even if it is a much toned down version of what FI charts were showing last week.

[Cheshire Freeze]

Yes, looks like the Meto longer range forecast agrees with what GFS is forecasting with snow being more likely further north. For me next week actually looks quite good, infact up here we could end up with a good dumping!

We have had snow showers of and on all morning and have the past 3 days. I'm personally enjoying this cold spell even if it is a much toned down version of what FI charts were showing last week.

Yeah, I agree. There is a lot of potential in the charts for next week but we need to see the westwards shift of the trough brought to a halt in the models. As things stand lowland snowfall is possible from Birmingham northwards. If the trough heads further west, things wont be so pretty

[Weathizard]

Yes, looks like the Meto longer range forecast agrees with what GFS is forecasting with snow being more likely further north. For me next week actually looks quite good, infact up here we could end up with a good dumping!

We have had snow showers of and on all morning and have the past 3 days. I'm personally enjoying this cold spell even if it is a much toned down version of what FI charts were showing last week.

Good for you guys in the north, bad for us in the south/south east?

My part of the world seems to have a NE flow for Wednesday....

[Eugene]

http://www.wetterzentrale.de/pics/Rtavn122.png

Last time i looked on monday there was some doubt about the >-10C 850 hPa air and only reaching southeast england and east anglia , on this chart it reaches a larger area, nice upgrade since i last looked , the runs are looking very similar to when i last looked with less cold air getting into the mix from friday, not sure why the disappointment things went exactly as planned, there was never a mega cold spell on the way actually a mild wet week could of been on its way so we should all be happy with the pleasant february sunshine and crisp air

Come april, 99.9% of the members that are online won't be seen until the cold arrives this coming winter. One thing we can be sure of until then is that we will have simple discussions, its going to be warm or hot lol, them type of discussions, bring on the thunderstorms

lol yes bring on the convective thunderstorms in the spring with some snow mixed in

[Thundery wintry showers]

Don't know if I'm looking at different models to everyone else- it looks like the cold spell is still "on" for the longer-term, evolving similarly to the December spell with a west based -ve NAO but the jet staying largely away to the south. Sunshine and snow showers for most, but perhaps a bit less cold with frontal sleet/snow events in the south (rain near the south coast) and daytime thaws in any sunshine.

A lot of south-east bias is perhaps manifesting itself here but even towards the SE it would only require a very slight eastward shift from both GFS and ECM to leave the SE fully exposed to the coldest air.

[MR EXTREMES]

Definately rather wintry looking charts from next monday onwards, snow in the north looks guaranteed, and lots of it but southern britain more marginal with a rain/sleet mix, that's how I read the 6z run anyway.

to be honest i dont think none of the charts are good for anywhere in the south for this kind event.:wacko:

infact its possible we wont see even any rain hear in the south but still the weather gods are smiling down on northern britain which is not abnormal,

we had a different winter this year very exciting very stressfull but we had some fun thats the main thing.

winter continues next week for the north ive excepted its over for the south but everywhere that does get some of the white stuff enjoy it,

might well be a great event aswell.

[Nath]

Don't know if I'm looking at different models to everyone else- it looks like the cold spell is still "on" for the longer-term, evolving similarly to the December spell with a west based -ve NAO but the jet staying largely away to the south. Sunshine and snow showers for most, but perhaps a bit less cold with frontal sleet/snow events in the south (rain near the south coast) and daytime thaws in any sunshine.

A lot of south-east bias is perhaps manifesting itself here but even towards the SE it would only require a very slight eastward shift from both GFS and ECM to leave the SE fully exposed to the coldest air.

I agree totally. The short, medium and long term look full of real potential to me.

[Buzzit]

Hi All

I dont see why we can put much faith in any of the models at the moment apart from a very generalised trend - perhaps the reason comments have decreased on this forum is because there does not appear any point to doing so at the moment..

Whats the point on commenting on FI when there has been zero consistancy in the models week to week. Model verification although high in the short term (3 day) has been particularly worse than usual in the longer time frames (out to 7 day) and reinforces the view that some members hold with regards to post +72 conversations.

In addition i think that splitting the technical and general model output discussion has probably done more harm than good as it has given more airtime to rampers, winders, and moaners on this thread. I think they should be put back together again and the mods should take a much harder stance on what gets posted on the resulting thread (its not like more than half of the technical thread gets posted in here anyway...)

I also assume that the NMM is based on the data from GFS, which is fine but you take a look at the NMM forecast for right now versus the radar... and I ask if the variance can be so horribly wrong... then there is not much to have faith in at the moment... apart from general trend (ie. LP will eventually head south) I dont see the point in any specifics for next week.

I have renewed respect for the difficulties the Meto face...

Edited February 10, 2010 by Buzzit

[Nick B]

Lets be honest though the models have downgraded within the reliable timeframe which is why the next few days are far less wintry than what the countryfile forecast suggested on Sunday. For some reason once an E,ly moves within +96 timeframe there is a tendancy in the models to shorten and slacken the E,ly flow. Back to the models and the GEFS control run shows what I referred to last night. I agree with Nick S, I doubt the pattern will suddenly shift much further E and our only hope is something like what the GEFS control run suggests. I will add I have seen snow fall every day this week so maybe im just getting greedy!

Interesting point you make about the tendency I have highlighted above. I am concerned whether, even if the placement of next week's potential LP system were further east, there might be there a significant chance that exactly the same scenario could apply to systems originating in and sweeping down south from the Arctic?

i.e. As we move closer towards the reliable (for me well within 72 hours atm) might we see the penetration of the cold air to the South held back, keeping this as a feature only for mid-Scotland and further north? I'm not sure at all, but I wonder if this has previously happened. Also, the seas to the north of Scotland are not as cool as the North Sea, so if flow was slacker, surely we will then see more moderation and end up with a week of sleet, cold rain and the occasional wet snow flurry melting away? Trying not to be downbeat, but I see this as another distinct possibility, and am therefore curbing my enthusiasm with a healthy dose of realism / pessimism - therefore anything we receive after this point I now view as an unexpected bonus.

In mid-Northamptonshire we may possibly have seen less lying snow - about 5cm at most - than almost anywhere this winter (except maybe for SW Cornwall, or did they get some?) and I would rather like a winter wonderland for a good week! Yes, there's bags of potential but I look at these charts and with the good stuff potentially heading a bit too far west for most of us, I am again looking at what I see as very marginal set-ups, and feel time is now beginning to run out for a real dumping of deep long-lasting powder snow for all, which, let's be honest, is the jackpot most of us addicts are particularly interested in! Btw, if Ireland get everything and we get nothing I am still happy for you guys over there! Could you just nudge it our way though?!

Edited February 10, 2010 by Nick B

[Rollo]

The truth is we have been spoilt this winter(save for mushy who has had a bad time if it),the charts still hold out immense potential for most of the country-sometimes they come right and other times not so, the way things have worked out so far this winter we probably have a 50/50 chance of worthwhile snowfall over the majority of the country next week.

[FENDER.]

All down to the 12z, if the high moves any further west, its game over I think

[grab my graupel]

Just time to mention, before the 12z begin to appear, that the latest Model output can be viewed on Netweather http://www.netweather.tv/index.cgi?action=nwdc;sess=

The Netweather charts are in a higher resolution than those on Wetterzentrale, and they are in English too

[Eugene]

All down to the 12z, if the high moves any further west, its game over I think

LOL maybe game over in your head but the weather will have other idea's thankfully

Just to show to those who say the cold never ends up in the reliable timeframe well those charts below should be a reliable timeframe enough for you and that is cold no matter what you say

http://www.wetterzentrale.de/pics/Rtavn062.png

http://www.wetterzentrale.de/pics/Rtavn1210.png

http://www.wetterzentrale.de/pics/Rtavn1217.png

http://www.wetterzentrale.de/pics/Rtavn123.png