Model Output Discussion - 1st February Onwards 12z--->

[mushymanrob]

Im not sure I agree with Mushy comments.

 

Whatever your weather preference & model preference no output should ever be ignored. An open mind should be adopted to all model output. We know the issues the ECM has with regards to over amplifying but the GFS on the other hand tends to be the opposite.

 

At this stage I can see many options.

 

1. As the ECM output brings a very cold N,ly.

 

2. Again like the 0Z ECM but even more amplified with our HP being even further NW bringing an even colder more prolonged spell.

 

3. HP is centred across the UK.

 

4. HP drifts SE of the UK.

 

I can understand Mushy discounting the ECM though because he must be fed up with all these cold spells we nave seen these past 2 winters. :laugh:

 

 

 

Spot on.

 

lol, yeah i can see why youd think that dave and maybe i was abit too dismissive of that ecm chart. of course it might verify, or something like it.

but over the last year or so the ecm has amplified 'events' (hot spells in summer) at that kind of timeframe, hence my dismissal of it .

of course theres plenty of time yet for synoptics to change to support a northerly blast, and when/if they do ill post accordingly.

[mushymanrob]

The upper anomaly charts are a good guide on the basis that one interprets them in terms of factors that make them liable to change and doesn't take them at face value in the same way as happens with NWP output.

 

 

 i think of them like this...

you are traveling from a to b, a resonable distance. (no sat nav, lol) you read a map beforehand, remember the key roads to take... then set out... you know in your mind which way you are going, but every so often you miss an important turn off, so you head for a while down the wrong road until you realise your mistake and correct it by rejoining the path you were taking.

thats how i see the noaa anomaly charts. they usually run pretty smoothly, but every so often theres a sudden change as new data realignes the path. im a big 'fan' of these charts, as they are simple enough to understand in as much as they  dont swing so wildly as the ops do. and of course as john says (after his study of them), they are the most accurate resource (when in consistent agreement) for the time periods they cover.

[southbank]

Slightly off topic but model forecast related , I was reading how the ENSO hasn't actually materialise a El nino in the usual sense and this has knocked out some of the modelling . The ocean had periods of warming but there wasn't the feedback your expect in the atmosphere

It's left a lot of head scratching

[knocker]

lol, yeah i can see why youd think that dave and maybe i was abit too dismissive of that ecm chart. of course it might verify, or something like it.

but over the last year or so the ecm has amplified 'events' (hot spells in summer) at that kind of timeframe, hence my dismissal of it .

of course theres plenty of time yet for synoptics to change to support a northerly blast, and when/if they do ill post accordingly.

 

Perhaps it should be noted the ECM ens mean 850mb temp chart  for day ten as usual downplayed the ops.

Edited February 5, 2015 by knocker

[Mucka]

EDIT. Posted following after only reading this mornings comments, I now see this has already been discussed. I think this is the first time I have been in full agreement with you Mushy.  The World will now end.   (Or ECM be right and we will have a huge Greenland high by mid month)

 

Far too much hope being pinned on one ECM Op today IMO. Not only does it have virtually no support but it has already been shown up by GFS for doing this very same thing, pushing the pattern too far West and over amplifying from the mid range.

It is possible it is picking up on the overall theme of slowly backing the pattern West but it looks far too fast with that this morning based on all the other output.

I still think we will have to wait until the last 3rd Feb to be in a more favourable position to pull in some colder air again.

We could still see a very cold and blocked end of Feb and first half of March though, at lest that is what I think, but I fully expect a few people to feel let down by ECM again if they are chasing something akin to this mornings run only better.

Edited February 5, 2015 by Mucka

[Blake]

Potential for a Thames streamer tonight anyone? -6/-8 uppers, Easterly... as it would be more convective, should we be concerned that the thickness isn't great? We could still get snowfall I'm sure.

 

We've seen snow across Kent due to the more NErly airflow, with showers also forming through the channel falling over northern France, so I was wondering if tonight with marginally stronger and colder airflow from the East, might we get a little surprise south of the Thames/M4? Probably not quite a Feb 2009, though.

 

Edit: Just to add, precipitation has edged further west this afternoon and showers starting to pop up across coastal fringes of Suffolk and Essex.. airflow has started to veer from NE towards the E...

 

Edited February 5, 2015 by GUWeather

[warrenb]

GFS getting a little interesting for us South Easterners again, with more of a Continental influence later in the run.

[warrenb]

Well if nothing else, if it isn't a cloudy high we will certainly have some cold nights.

Edited February 5, 2015 by warrenb

[carinthian]

Evening all, that's one hell of a mid-latitude block at day 6. Cannot see a removal from a westerly at that stage. Maybe, first indications of a pressure weakness to the southwest at this time next week . See what ECM shows from 144-240 hours run.

C

Edited February 5, 2015 by carinthian

[knocker]

Evening all, that's one hell of a mid-latitude block at day 6. Cannot see a removal from a westerly at that stage. Maybe, first indications of a pressure weakness to the southwest at this time next week . See what ECM shows from 144-240 hours run.

C

 

It appears to be pushed east by another of the east coast storms ending up 1045mb over the UK.

[shaky]

Well if nothing else, if it isn't a cloudy high we will certainly have some cold nights.

well looking at it on wetterzentrale it looks a pretty clean high most of the time!! So expect frosty nights and also temps during the day time only get up to 5 or 6 degrees throughout so pretty chilly!

[Day 10]

GFS and ECM 168

 

 

[mushymanrob]

well looking at it on wetterzentrale it looks a pretty clean high most of the time!! So expect frosty nights and also temps during the day time only get up to 5 or 6 degrees throughout so pretty chilly!

Thats not what the local tv people are predicting. It clouds over on saturday as we import less cold moist airoff the atlantic circulating around its northern flank with temps not far off normal. We lose overnight frosts too IF it remains cloudy.

[polar vortex]

Runs this afternoon and evening have definitely toned down the amount of northern amplification that they were showing 

yesterday. Only had a quick flip through the GFS ens but they look no where near as amplified either. I did say that they 

could be over reacting to a MJO signal and that may well have been the case but the MJO signal remains strong and the 

models could well have been to progressive with this. Best to see how the models behave over the next few days rather 

than speculate on rinse and repeat cycles etc.

Edited February 5, 2015 by polar vortex

[Man With Beard]

Not posted on here much this week as there aren't many ways to describe a UK high! Perhaps one interesting thing is that the westerly train will find it hard to hit the UK in the near future. However, subtle adjustments allowing a southerly (taste of spring) or a northerly (seriously cold) seem more possible. Maybe next weekend will bring something more noteworthy!

[ANYWEATHER]

Well the model output may be as dull as dish water, but perhaps around the T+168 + period may at least hold something of interest....talk about slim pickings and looking for gold at the end of the rainbow    

Edited February 5, 2015 by ANYWEATHER

[mcweather]

Probably best to do as Tamara suggests and not read to much into the intra run differences in the short term, Patience will be required in order to find out which way the HP finally moves but with some runs hinting at retrogression and the ECM 32dayer suggesting a quick move northeast to Scandi at some point there is still plenty of scope for a few more shots at winter weather for the UK.

Edited February 5, 2015 by mcweather

[phil nw.]

The 12 z runs continue to model an Atlantic blocking high close to or over the UK for the next 10 days.

http://modeles.meteociel.fr/modeles/gens/runs/2015020512/gensbcnh-21-1-240.png

 

The pattern looks pretty slow moving with only limited changes wrt positioning of the block from day to day.

As i have commented before the cold air is nearby but it all tends to move over the block and then into E.Europe,even as far south as the Balkans and the middle east !

 

 

Maybe another brief injection of colder air from the north around day 7 as AW showed above but it looks like we will have a repeat with any real cold being pushed east quickly as another High cell moves in from the west.

 

A predominantly dry and quiet outlook then with the current cold easing in the next few days although still with some night frosts where skies clear enough.

Edited February 5, 2015 by phil nw.

[ANYWEATHER]

Looks unfortunately to be a cloudy high according to NMM12, so little difference in daytime and night time temperatures ,so 2c/36f to 6c/43f  looks the mean temperatures, unless we get some clear spells. So not mild or even cold ..Yuk    

Edited February 5, 2015 by ANYWEATHER

[bluearmy]

i'll leave the ecm spreads to nick s this evening. safe to say that this mornings op is unlikely to be forgotten as quickly as some might expect. 

[damianslaw]

As others have said, not a lot to discuss at the moment with a very static picture on the cards - high pressure in full charge and a significant one, been a long time since we have seen one of these..

 

February can be a dry month with high pressure in charge.

 

Not expecting much change until mid month.

[joggs]

Well what to say.As Tamara says,patience,as with this winter.A very stubborn high that sets in and hopefully sneak a few clear days in!.

Just wish we had one of these highs in summer

Anyway I think personally im going to take a few days off model watching and just keep an eye on the metoffice updates.Been pretty draining at times in this thread

Big up to you hardcore!

[ukpaul]

Whilst things are quiet, it's been interesting to see what model has predicted the snowfall accurately here in Guildford (three separate events, the most since 2010, including Tuesday morning which caused complete chaos!). Ahead of the pack comes the much maligned GFS snow charts on the new 0.25 model. They got this morning correct, with falling snow for a couple of hours (if not sticking), the heaviness and extended nature of Tuesday morning and even the massive hail to heavy snow shower of last Thursday. At the bottom of the pack has been the EURO4 whose performance has been woeful - the one time it showed significant snow it didn't happen and it missed two of the above three events completely by overegging dewpoints, when in reality they were lower. The different WRF models come somewhere in the middle with the NMM 0.05 maybe the only one to come close to the GFS. I would think different areas of the country might have another view but, for here, it's thumbs up to the new GFS model.

[bluearmy]

Whilst things are quiet, it's been interesting to see what model has predicted the snowfall accurately here in Guildford (three separate events, the most since 2010, including Tuesday morning which caused complete chaos!). Ahead of the pack comes the much maligned GFS snow charts on the new 0.25 model. They got this morning correct, with falling snow for a couple of hours (if not sticking), the heaviness and extended nature of Tuesday morning and even the massive hail to heavy snow shower of last Thursday. At the bottom of the pack has been the EURO4 whose performance has been woeful - the one time it showed significant snow it didn't happen and it missed two of the above three events completely by overegging dewpoints, when in reality they were lower. The different WRF models come somewhere in the middle with the NMM 0.05 maybe the only one to come close to the GFS. I would think different areas of the country might have another view but, for here, it's thumbs up to the new GFS model.

Seriously ? The most since 2010? I'm astonished that you a) had so much this week or b) had so little in 2011/2012 or 2012/2013

Still waiting for Nick to sort the ECM spreads!

[mulzy]

Whilst things are quiet, it's been interesting to see what model has predicted the snowfall accurately here in Guildford (three separate events, the most since 2010, including Tuesday morning which caused complete chaos!). Ahead of the pack comes the much maligned GFS snow charts on the new 0.25 model. They got this morning correct, with falling snow for a couple of hours (if not sticking), the heaviness and extended nature of Tuesday morning and even the massive hail to heavy snow shower of last Thursday. At the bottom of the pack has been the EURO4 whose performance has been woeful - the one time it showed significant snow it didn't happen and it missed two of the above three events completely by overegging dewpoints, when in reality they were lower. The different WRF models come somewhere in the middle with the NMM 0.05 maybe the only one to come close to the GFS. I would think different areas of the country might have another view but, for here, it's thumbs up to the new GFS model.

 

I doubt it - you would have got more in 2012/13 - at least 2 significant snow events in SW London must have affected you.

Edited February 5, 2015 by mulzy