Model Output Discussion

[Thundery wintry showers]

UKMO has also upgraded the easterly relative to this morning's 00Z though not by as much as GFS. 17th/18th December would be pretty snowy in the SE but less so in the NE relative to GFS, I think, with the high pressure closer by to the north earlier on.

Worth noting that the GFS 12Z gets so cold on the 18th December that east Scotland and NE England could expect lying snow right out to the sea front- quite a rare event in a December easterly.

[kold weather]

Scotland would get some VERY cold temps if the 12z GFS paralell is right by 180hrs, wouldn't be that far from the record IMO in one or two places given the very heavy snowfall, the weak high pressure at 1020mbs and obviously long nights and cold upper air.

Still from a personal point of veiw, I'd hate the 12z paralell to come off from a personal point of veiw as there'd be very little snow...though I still think it's rather underdoing precip from that second easterly.

[Neilsouth]

Not quite sure why there is so much excitement here.

The 12z sees a bit of a downgrade in the reliable timeframe. I don't think a lot of snow would come from this in the next 5 days. FI looks tasty but lets remember it is FI.

Basically what i said aswell , but someone said i need to Get real... hmmm

Again people this is all FI still , i'd wait till atleast monday before getting ultra excited !. Just as i waited till friday before getting excited over monday night , glad i did

[John Snow]

Slight ramp?

Just a bit but I really do seeing the blocking hard to shift as the Atlantic just does not have the strength to shift that stuff above us so yes I can see the cold spell lasting till the spring

As for your area you are going to get hammered unless downgrades occur, am really looking into the idea of travelling up to Newcastle and staying in a Travelodge to watch the action unfold but I will watch the charts till Monday before deciding on that

[Duncan McAlister]

Another bit of optimism - there hasn't been any serious prospect of a breakdown yet on any of the models. It has all been in deep FI

[i luv snow]

Just a bit but I really do seeing the blocking hard to shift as the Atlantic just does not have the strength to shift that stuff above us so yes I can see the cold spell lasting till the spring

As for your area you are going to get hammered unless downgrades occur, am really looking into the idea of travelling up to Newcastle and staying in a Travelodge to watch the action unfold but I will watch the charts till Monday before deciding on that

EA always does well in these situations, us jotting out into the North Sea as we do, we tend to pick up snow even when the rest of the country is snow starved. Fingers crossed!

Edited December 11, 2009 by i luv snow

[azores92]

as has been said folks, 6 days is still a loooong way off, and we still have many model outputs to go through before we are anywhere close to that day. so much can change within that timeframe, so looking at specifics at this stage is still pure speculation. at the moment, we are receiving cool weather i would say, slightly below average, and it looks like it will continue this way through next week, with any snow staying marginal for the time being. i think its a dangerous trade being dragged into model outputs, so im keeping my expectations low, and will not get into ramping mode until we see these sorts of runs entering the +72 hour timeframe. we have potential for snow, dont get me wrong, but it is still a fair way off, and things are very likely to change. getting cold in the uk was never easy.

[cooling climate]

UKMO is excellent, just the little ol ECM to go.

There should be no quibbles about the run we have just seen.

From wednesday onwards the threat of snow is there for everyone.

[liltbrockie]

GFS parallel run shows practically no ppn for the south from Thursday onwards :-(

[Harry]

I am not getting excited until Wednesday night! At the end of the day, all it takes is one area of high or low pressure to nudge slightly, orientating the wind from a slightly different direction and we could get nothing. Also, just because it might be bitterly cold, does not necessitate that there will be much in the way of snowfall at all. Conversely, there may be tonnes - who knows.

Either way, as with the thundery setups we get through the Summer months, you are ill-advised to get overly excited until its a few miles away and approaching fast.

Am also quite surprised at how many snow lovers there are!! For me, thunderstorms are far more exciting - that's just me though - who knows though, with the still relatively very high sea temps and a rapidly falling upper air temps - THUNDERSNOW!!!

Edited December 11, 2009 by Harry

[Geordiesnow]

UKMO has also upgraded the easterly relative to this morning's 00Z though not by as much as GFS. 17th/18th December would be pretty snowy in the SE but less so in the NE relative to GFS, I think, with the high pressure closer by to the north earlier on.

Worth noting that the GFS 12Z gets so cold on the 18th December that east Scotland and NE England could expect lying snow right out to the sea front- quite a rare event in a December easterly.

Yep, if i wish to be selfish then i would hope the UKMO is being over-progressive regarding sinking the easterly for the potential Northerly reload.

However the 12Z looks like a slight upgrade from the 00Z run. Hopefully the ecm will show some nice charts aswell.

[kold weather]

UKMO has also upgraded the easterly relative to this morning's 00Z though not by as much as GFS. 17th/18th December would be pretty snowy in the SE but less so in the NE relative to GFS, I think, with the high pressure closer by to the north earlier on.

Worth noting that the GFS 12Z gets so cold on the 18th December that east Scotland and NE England could expect lying snow right out to the sea front- quite a rare event in a December easterly.

That 12z UKMO utterly screams thames snow streamer, thats a very good chart from a personal veiwpoint and also a bit more progressive with getting rid of that shortwave.

Anyone on the northern side of the shortwave is looking at 4-6 inches probably, locally upto 7-9 but its still early days in that respect!

[Duane S.]

And now the METO has followed suit. Better ones than even I was hoping for. Not perfect but what is. A great way to start the weekend. Plenty more upgrades to follow. ECM likely to follow on from a very good 00z.

Although I suspect the GFS will be one of the cooler members when the ensembles come out in 20 minutes or so.

[suffolkboy_]

GFS parallel run shows practically no ppn for the south from Thursday onwards :-(

The hard part is getting the cold here in the first place, so that is all we need to be looking at to start with. Once the cold has arrived, then that's the time to worry about where any moisture will come from. Looking at this forum, most moisture looks to be in people's pants at the moment!

[Duane S.]

mark, so john hammond saying on tuesday that this time next week we will be in siberian air ,was all in my imagination . and carol kirkwood saying the same

too far away for me to be interested , what happended to sun nite /mon snow ? were taking 2 steps forward and 8 steps back .imho

No we're not Have patience, it is all coming together VERY nicely.

The Sunday 'event' always looked to be being a result of some models being a tad over-progressive.

[kold weather]

What is very impressive from the GFS is it looks like a real old school set-up again in FI, would be a very sustained cold set-up if that run came off, but much depends on the upper low over Scandinavia dropping far enough south to keep us in a northerly airflow.

[liltbrockie]

The hard part is getting the cold here in the first place, so that is all we need to be looking at to start with. Once the cold has arrived, then that's the time to worry about where any moisture will come from. Looking at this forum, most moisture looks to be in people's pants at the moment!

Very true... I honestly don't see what all the fuss is about here re: massive snow...As we all know that actual location of snow is something that can only be forecast in the +72 hours time frame... BUT the point is... from these charts I don't see the potential for much snow anywhere .. its not even on the radar... Maybe I am being a bit pessimistic!

[Frosty.]

Not quite sure why there is so much excitement here.

The 12z sees a bit of a downgrade in the reliable timeframe. I don't think a lot of snow would come from this in the next 5 days. FI looks tasty but lets remember it is FI.

Downgrade for the south and upgrade for the north but we all end up very wintry by this time next week. Honestly, after that dire ecm yesterday, I am just glad we are still in with a good chance of a proper wintry spell which could last until the end of the year.

[stewfox]

IMO next week is fairly nailed on now with sleety stuff on Mon / Tues (In East) and Snow showers from most areas to end the weeks. How heavy the showers are and if they merge to more prolinged snow is yet to be decided. IMO it won't be acurately forecastable until Tuesday at the earliest. Certainly charts to savour though!

How can it be nailed if it cant be nailed ??

[doublebarrel]

ok. surely this is all F.I. stuff, i think it has been said on here 2-3 days,ok maybe 4 after that forget it !! i sat here wed thurs night reading the OMG its happening mon/tuesday posts. Friday now !! OMG its happening wed/thurs now. slow down boys !! like someone has said the meto aren`t breaking their necks to warn us are they ? and you know if god forbid london should be getting anything the world is ending!! one person has said upgrade another downgrade and thats just this run the ecm comes out later and then there`ll be more up / downi suppose. ok now can somebody tell us just what is happening now with this run thankyou!!!!

[John Snow]

Very true... I honestly don't see what all the fuss is about here re: massive snow...As we all know that actual location of snow is something that can only be forecast in the +72 hours time frame... BUT the point is... from these charts I don't see the potential for much snow anywhere .. its not even on the radar... Maybe I am being a bit pessimistic!

The shortwave is going to hit us on a direct hit if the GFS comes off, well hit the NE and Scotland and that will result in massive snowfalls, even I as anything but an expert can see that

Thursday and Friday next week is filled with snow for NE and Scotland

[Guest North Sea Snow Convection]

We are kind of back to where we were earlier in the week when we we focussing on the cold spell starting after the weekend and the GFS and UKMO were pretty well agreed on snow potential from early in the week, but the ECM was much more cautious. The potential for that as we now know is much smaller and pretty low. However, here we are again looking ahead at 5/6 days again at what is a colder still scenario and thus far the GFS and now UKMO have given indications of a pretty wintry scenario for the post mid week period. Again 5/6 days. We wait for the ECM again to give its verdict.

The proper cold air relies on timing/phasing of the system to the north moving south quickly enough, and this will continue to play on the modelling through the weekend and start of next week before we can be much more certain what is going to happen. So assuming full agreement at 5/6 days away is achieved then this needs to hold through the weekend without any further glitches arising as the models play with this feature and what it is likely to do and how and where the cold advects to etc.

Getting past the 'jam tomorrow' situation remains the ever present hurdle atm - but the carrot is a huge reward for Thurs/Fri

Edited December 11, 2009 by North Sea Snow Convection

[Mark Bayley]

mark, so john hammond saying on tuesday that this time next week we will be in siberian air ,was all in my imagination . and carol kirkwood saying the same

too far away for me to be interested , what happended to sun nite /mon snow ? were taking 2 steps forward and 8 steps back .imho

The first wave of cold from the east has always forecast to be around around Monday, then there was going to be a milder interlude with the main cold arriving around Thursday from the North East. This is what the models have been showing for a good few days now. The first wave from the east has upgraded and downgraded over the past few days. It was always favouring further south. It may upgrade again on the next few runs. I still think some in the South East will see some snow showers Monday night into Tuesday. But the rest of us will have to wait till the end of the week

[grab my graupel]

Don't want to spoil the party folks, but the ramping thread seems to have been forgotten

Please remember, this is the 'Model' Discussion thread

[SP1986]

If you think the synoptic setup is rife for snow, you might be disappointed.. the setup indicated will always bring drier air and lower dewpoints, of course if a precipitation event were to occur, then yet it would inevitably be as snow.

I'm not convinced hugely cold temperatures are going to occur from this though.

0 to -2C as night minimum is not conducive to an easterly of old.