Model Output Discussion - 5th December - 11th December

[rich1]

Seen the rest of the run pre-wetter and it doesnt 'quite' make it but perhaps Nick's punt is not as left field as it may appear at that range

one to watch perhaps...

[Thundery wintry showers]

I know some in southern England love their easterlies but I really don't see us being any closer to a full-on easterly than a full-on northerly. If the jet tracks much further south across the Atlantic in the future (not looking likely for the foreseeable, but possible in the longer-term) we would start to see pressure rises in the Greenland/Iceland area. Conversely, Nick Sussex's suggested evolution towards an easterly would require the jet to change configuration completely- a strong SW-NE tilt allowing pressure rises to extend west through Siberia and Scandinavia. The latter evolution is also fraught with danger for cold/snow lovers as a halfway house between what we have now, and a January 1987 type evolution, would lead us with mild zonality, with high pressure to the SE and the jet powering into northern Scandinavia. The other issue is that as long as we have a strong polar vortex to the north, any pressure rises over Scandinavia will struggle to head far west enough to bring cold continental air across and we will end up, most likely, with a dry cloudy stalemate over the British Isles like during last February.

On the other hand there is another possible evolution towards an easterly- a continued NW-SE jet with high pressure extending west from Siberia through Scandinavia over the top of the jet- this evolution, in the past, has quite often produced significant frontal battleground snowfalls, though the UK sometimes ends up with an average to cold zonal pattern with the very cold air held out east.

It's true that a dry Christmas would probably satisfy many people if it was bright and frosty but may not go down too well if it's anything like Christmas Day 2006, i.e. overcast and dark all day. I think there's a high chance that the probable northerly outbreak around the 20th may be followed by high pressure close to or over the British Isles, but it's too far out to say for definite.

Edited December 9, 2011 by Thundery wintry showers

[Jack Wales]

Still a very zonal pattern however I note that a developing feature on a few of the gfs runs for cut of lows to run through the channel around next weekend. That's still in FI at the moment as nearly all the models have been poor in the medium range lately, but with with uppers around -5 there this could be something to follow over the next few days!!

Edited December 9, 2011 by Jack Wales

[kold weather]

The GFS 06hrs run looks similar to the ECM at 240hrs with that mid Atlantic ridge and some troughing digging into Europe, this has a decent chance of verifying but what happens after that?

Well thats the tough question. It's a very hard pattern to sustain so I'd have thought given the generally +ve AO we'll probably seer the Azores High pull in towards the UK. Odds are with the PV still lingering a lobe nearby it'll probably become a milder set-up come Xmas but the 06z shows a possible way to evolve into a cold dry pattern.

Those sliders are interesting, but we'd probably need to pull down slightly colder air for things to get REALLY interesting...and of course its a long way off obviously!!

[Frosty.]

I hope we get a Northerly with some potency, even if it's only a 36 hour toppler, for cold fans it's been dire so far, especially in the south and southeast where temps today are at 6's and 7's which is not particularly cold and any snow across southern britain is above 500 metres, even the far northeast is only catching a few wintry showers when the experts were saying there would be blizzards! the week ahead looks unsettled with average temps and occasionally very windy but at least some welcome rain for the areas that need it.

Edited December 9, 2011 by Polar_ Low

[shedhead]

I hope we get a Northerly with some potency, even if it's only a 36 hour toppler, for cold fans it's been dire so far, especially in the south and southeast where temps today are at 6's and 7's which is not particularly cold and any snow across southern britain is above 500 metres, even the far northeast is only catching a few wintry showers when the experts where saying there would be blizzards! the week ahead looks unsettled with average temps and occasionally very windy but at least some welcome rain for the areas that need it.

Largely agree, especially with regard todays forecasted blizzards in the northeast... shocking call by the MO. Looked closely at the model outputs yesterday evening and again this morning, but I could find no evidence to justity anything other than some blustery, wintry showers, which to date is all that has transpired.

Edited December 9, 2011 by shedhead

[Frosty.]

Largely agree, especially with regard todays forecasted blizzards in the northeast... shocking call by the MO. Looked closely at the model outputs yesterday evening and again this morning, but I could find no evidence to justity anything other than some blustery, wintry showers, which to date is all that has transpired.

It's all very underwhelming for most of the uk, if I lived in the southeast I would be pulling my hair out in frustration at the lack of snow potential on the model output but a sharp frost even for london tonight at -3c 27f. The models don't show signs of any sustained wintry weather this side of xmas, just occasional cold zoneality with the 528 dam line making short visits.

Edited December 9, 2011 by Polar_ Low

[BLAST FROM THE PAST]

I'm strangely optimistic! and if you read through the lines of GP's post he is too but obviously he had the good sense not to mention any easterly. If pressure lowers over Europe especally towards central and southern areas then thats a big first step.

I am, even moreso, look east or NE is correct and in early Jan, I think things are moving faster than GPs excellent thoughts.

Cracking ECM again, great model watching IMO and the channel LP or secondary LP is a more likely than not scenario.

BFTP

[Gavin Hannah]

Would be nice to see a "deep freeze" at Xmas and new year. In the short term, I def see the continuation of this pattern right up to Xmas. Can't see the Atlantic High moving into Europe, especially with the Jet going on a southern vacation.

[phil nw.]

The trend in current output to extend low pressure into Europe shows up well on the latest T84hrs. fax.

More wet and windy weather moving in to the UK followed by yet another incursion of Polar air behind the fronts.

This seems to be the picture going out to week 2 with Low pressure digging ever Southwards bringing more Polar air into the mix at times.

http://www.wetterzen...s/Rtavn1802.png

http://www.wetterzen...cs/Recm2402.gif

Looking beyond this a trend is starting to appear of the energy starting to ease off the Atlantic allowing mid-latitude heights closer to the UK.

it will be interesting to see where these heights build but probably we will have to see the jet realine to a less favourable tilt for a period for this to happen.

We often go from cold zonal to a milder version when pressure builds from the SouthWest and any Euro troughing becomes cut off and warms out.

We can still get surface cold with frost and/or fog in spite of milder uppers-depending on where the High centres itself.

Yes maybe something from the East beyond the current modelling horizon but imo we wont get there in one easy stage with that vortex still very dominant to our North.

[Don]

Unfortunately today's Metoffice 16-30 day outlook doesn't look good for late December/early January with unsettled conditions continuing but becoming mild or very mild with only brief cooler spells with snow possible in the north. So it sounds like they expect a more 'typical' zonal pattern to set up. It also predicts that the driest weather will be in the SE hinting high pressure moving more into Europe. Obviously there is time for this forecast to change but certainly not the outlook I was hoping for!

Edited December 9, 2011 by Don

[lorenzo]

Some upstream outlook..

NOAA updated winter outlook article discusses La Niña and also impact of Arctic Oscillation.

http://www.climatewatch.noaa.gov/image/2011/2011-2012-winter-outlook

Undecided on the AO and a negative phase - Will leave the implications to minds better than mine !

[Frosty.]

very poor meto update out to T+30 days with a tendancy for mild weather to dominate in the later stages especially, it's a kick in the teeth for cold fans of southern britain with only transcient frost risk and negligable risk of snow. For northern britain it's more average with snow for hills at times which is normal but there is no sign of anything cold as such, this indicates a green christmas and new year for the majority of the uk. The operational runs so far today don't show any sustainable wintry weather, it just looks very unsettled and rather cool but sometimes mild or very mild.

[bluearmy]

very poor meto update out to T+30 days with a tendancy for mild weather to dominate in the later stages especially, it's a kick in the teeth for cold fans of southern britain with only transcient frost risk and negligable risk of snow. For northern britain it's more average with snow for hills at times which is normal but there is no sign of anything cold as such, this indicates a green christmas and new year for the majority of the uk. The operational runs so far today don't show any sustainable wintry weather, it just looks very unsettled and rather cool but sometimes mild or very mild.

the naefs and ecm 32 day runs have consistently pointed to higher heights to our south or southwest and lower to our north. thats means a more sw/ne tilted jet than we currently see. however, this has been the case for a while now and we dont seem to be getting any closer to it becoming reality.

[BLAST FROM THE PAST]

very poor meto update out to T+30 days with a tendancy for mild weather to dominate in the later stages especially, it's a kick in the teeth for cold fans of southern britain with only transcient frost risk and negligable risk of snow. For northern britain it's more average with snow for hills at times which is normal but there is no sign of anything cold as such, this indicates a green christmas and new year for the majority of the uk. The operational runs so far today don't show any sustainable wintry weather, it just looks very unsettled and rather cool but sometimes mild or very mild.

Karl

Calm down mate, its only early winter. MetO outlook for mild end to month is probably a good call, as compared to last year we had nothing to occupy us when the switch came to les cold and mild conditions. At least Christmas can take your mind off it a little with the thought of potential proper cold to arrive. In the meantime some great weather to enjoy over next ten to 14 days.

BFTP

[Frosty.]

the naefs and ecm 32 day runs have consistently pointed to higher heights to our south or southwest and lower to our north. thats means a more sw/ne tilted jet than we currently see. however, this has been the case for a while now and we dont seem to be getting any closer to it becoming reality.

It basically looks like a continuation of the cool to average zonal and sometimes mild but becoming harder for even the north to get low ground snow as time goes on, IB is probably right about the sw/ne tilted jet being the likely outcome, it's very sad as I was hoping steve murr would be right about a more widespread cold zonal outlook.

[snow drift]

very poor meto update out to T+30 days with a tendancy for mild weather to dominate in the later stages especially, it's a kick in the teeth for cold fans of southern britain with only transcient frost risk and negligable risk of snow. For northern britain it's more average with snow for hills at times which is normal but there is no sign of anything cold as such, this indicates a green christmas and new year for the majority of the uk. The operational runs so far today don't show any sustainable wintry weather, it just looks very unsettled and rather cool but sometimes mild or very mild.

I would agree with what you have said and would add this: The reality of this current pattern was and is that this has been the case for some while.

With fear of being shot down from every angle, untill things change to the north/northwest of us and we get some pressure rise it will continue in the same vain.

May well be wrong, Tin hat at the ready!!!!!!!!!!!

[Frosty.]

Karl Calm down mate, its only early winter. MetO outlook for mild end to month is probably a good call, as compared to last year we had nothing to occupy us when the switch came to les cold and mild conditions. At least Christmas can take your mind off it a little with the thought of potential proper cold to arrive. In the meantime some great weather to enjoy over next ten to 14 days. BFTP

Hi Fred, i'm very disappointed with what's happened so far but i'm still hoping for proper cold in the new year but no sign of it yet.

I would agree with what you have said and would add this: The reality of this current pattern was and is that this has been the case for some while. With fear of being shot down from every angle, untill things change to the north/northwest of us and we get some pressure rise it will continue in the same vain. May well be wrong, Tin hat at the ready!!!!!!!!!!!

no need for the tin hat, you are only stating the reality rather than offering false hopes.

[Harsh Climate]

Hi Fred, i'm very disappointed with what's happened so far but i'm still hoping for proper cold in the new year but no sign of it yet.

Don't look too much into what the met office are saying. They are basing there 15-30 day forecast simply on the models. If by sunday the models start hinting at bitterly cold easterlies in FI, I guarantee by tuesday the met office would hint at 'possibility of it turning much colder from the east later in the month'...

The charts aren't showing us exactly what we want to see, but its early days and this time next week we could very well be looking a classic set-up developing Not saying it will, but the models can change very quickly.

[Frosty.]

Don't look too much into what the met office are saying. They are basing there 15-30 day forecast simply on the models. If by sunday the models start hinting at bitterly cold easterlies in FI, I guarantee by tuesday the met office would hint at 'possibility of it turning much colder from the east later in the month'... The charts aren't showing us exactly what we want to see, but its early days and this time next week we could very well be looking a classic set-up developing Not saying it will, but the models can change very quickly.

I agree with what you are saying, for coldies it's just a case of looking for wintry weather to appear in FI, a bit of eye candy would be nice!

[Harsh Climate]

I agree with what you are saying, for coldies it's just a case of looking for wintry weather to appear in FI, a bit of eye candy would be nice!

Ye it certainly would.

Hopefully FI will start showing some good blocking or even a nice easterly, would be nice to see what could happen!

[nick sussex]

It's amazing how one meto update can harpoon the mood in here!

Let's just wait and see what the models do in the coming days, I mean how many times have those updates in the past promised colder conditions which imploded.

[johnholmes]

It's amazing how one meto update can harpoon the mood in here!

Let's just wait and see what the models do in the coming days, I mean how many times have those updates in the past promised colder conditions which imploded.

rarely

[legritter]

dont get down over any weather forecast for 20/30 days away , if what ever models they are using are 20miles a day out thats 400 miles just for starters 600 miles for a month . move yesterdays synoptics around by this amount and look at the difference . i have a feeling that a blosk will set up ,block ,sorry in middle of listening to snooker behind me . back to block ,where it sets up will be important just basing my feeling on what i said a couple of weeks ago i think this winter will be full of surprises A QUICK CHANGE ARTIST IS THE WEATHER SOMETIMES , tues/sat next week looking very interesting ,model watching will be fun ,after that euro high drama ,anything is possible ,we are nearly there , lets hope we all get our dream charts at some stage ,regards

[nick sussex]

rarely

Of course as a former member of staff you would say that! :smilz38:

Given the changes we saw during the last week then we should just wait and see what develops.