Model Outooks: Winter 2008/2009

Snowaddict

Quite an output from the JMA (Japanese Model) this evening. Interesting setup for Stepehen's day... We miss out... just... according to the latest output.. Although 850 hPA temps of -8 getting into the UK...

Interesting, but I don't know if this model is in any way consistent or reliable. Plus this is for T+168. Interesting all the same..

JMA Output 18 December 2008 for 26th December 2008 @ 13.00

jma is rarely quoted in model threads in this side of the world, except for fun.
It usually overplays situations longer before falling into line with whatever the other models show when it enters a more reliable resolution ie sub 72hrs.

Deep Easterly

Snowaddict wrote: »

Quite an output from the JMA (Japanese Model) this evening. Interesting setup for Stepehen's day... We miss out... just... according to the latest output.. Although 850 hPA temps of -8 getting into the UK...

Interesting, but I don't know if this model is in any way consistent or reliable. Plus this is for T+168. Interesting all the same..

JMA Output 18 December 2008 for 26th December 2008 @ 13.00

Interesting SA. Believe it or not, it is not unlike the latest ECMWF 850's chart for the same period:



Colour repesentations of temps differ but 850's nearly spot on between both models. Note -5's in near continent on both charts!!!!

Snowaddict

Deep Easterly wrote: »

Interesting SA. Believe it or not, it is not unlike the latest ECMWF 850's chart for the same period:

Colour repesentations of temps differ but 850's nearly spot on between both models. Note -5's in near continent on both charts!!!!

Indeed DE. If we could only tap into that huge pool of cold air thats going to be over the near continent. Furthermore, although GFS operational was somewhat (although not a complete) cold outlier on the later part of the run tonight, it was also fairly close to this setup. At T+180 GFS was so close to a beast form the east... Very very close.

Some substantial agreement tonight amongst the ensembles for a clear blocking trend. From about T+276 onwards, an increasing number of members go for a colder outbreak / outlook.

Right out to the end of the run, there is a clear majority of perturbations going for a very cold and ever evolving pattern. Approx 75% suggest a clearly blocked pattern.

Colder incursions are modelled from both north of east and north of west.
This continuous blocked and ever interesting pattern is really grabbing my attention now tbh. There is some serious potential IMO if things continue to trend this way into the weekend. Lets just hope the models are not leading us up the garden path on this one.

Regards,
SA.

Deep Easterly

Snowaddict wrote: »

This continuous blocked and ever interesting pattern is really grabbing my attention now tbh. There is some serious potential IMO if things continue to trend this way into the weekend.

Regards,
SA.

Yep SA, nail biting times ahead with regards the next few runs. I woke up this morning worrying that all signs of block would be smashed in this morning's runs, but so far, models still holding onto something. I for one will be keeping finger's tightly crossed over the next few days.

Snowaddict

Good morning all.
Some cracking outputs again this morning.

ECM showing clear signs of extensive northern blocking, and an easterly flow appears to be setting up on the latter part of the run.

Below is the GFS operational eye candy from the 00Z run.

If, these trends countinue, then into the new year, Ireland could potentially experience sustained wintriness not seen in a long time.

Based on the currently consistent outputs, I would put this risk currently at approx 30%, to stay on the cautious side.

Note also, the NAO is forecast to go negative as we head into the new year, and there are clear signatures of this on the T+240 ECMWF chart.

But its still quite a bit out yet, and subject to change, although I do find this very encouraging.

IMO, its all to play for now. However, if, and its a definate if at the moment, we do see this continuous pattern developing, much colder conditions could be arriving on our shores as we head into the New Year period, with a possiblity of this becoming sustained.

This may be very optimistic, but it cannot be denied that at the moment, things are looking very interesting.

Once again, lets hope the models are not playing games.

SA.

Thats a beautifull chart cold wise.
Pressures a tad too high though and I notice the next 2 charts kill the good of it by moving the hp closer killing even that very slack flow.
It would be dry apart from maybe a 10% chance of a few flurries right on the coast-nothing would go too far inland with pressure that high.

Regarding ECM.
It's still toying with our HP ridging into a SH but reluctantly and also unhelpfully with no or little flow.
And anyway whats out to our East is not cold enough for snow yet.You'd want a week of it sourced east of Moscow with surface temps sub minus 8c at the source.

Our best bet would appear to be a Northeasterly with a northerly source from the current output bringing down potent cold troughs from Western Norway.
Thats what you'd get with the above chart if the HP moved a little more NW-GFS doesnt want it to though.
All immaterial to the actual anyhow as it's off the scale FI.

Snowaddict

Deleted User wrote: »

Thats a beautifull chart cold wise.
Pressures a tad too high though and I notice the next 2 charts kill the good of it by moving the hp closer killing even that very slack flow.
It would be dry apart from maybe a 10% chance of a few flurries right on the coast-nothing would go too far inland with pressure that high.

Regarding ECM.
It's still toying with our HP ridging into a SH but reluctantly and also unhelpfully with no or little flow.
And anyway whats out to our East is not cold enough for snow yet.You'd want a week of it sourced east of Moscow with surface temps sub minus 8c at the source.

Our best bet would appear to be a Northeasterly with a northerly source from the current output bringing down potent cold troughs from Western Norway.
Thats what you'd get with the above chart if the HP moved a little more NW-GFS doesnt want it to though.
All immaterial to the actual anyhow as it's off the scale FI.

Yep, agreed, but no sign at all of raging southwesterlies on recent outputs and that has to be a positive.

If you like dry or relatively dry yes.
If you don't like cloudy highs though this has the potential to be yukky.

We had no raging southwesterlies for a good while last year too but nothing of much use in terms of cold apart from a few brief 12hr extravaganza's local to a few spots.

Anyhow.
There'll be no excitement from me untill (1) I see an actual northern blocking develop.
(2) I see where our high pivots...I think the fact that the high will be knocking around is a near certainty now.

As regards getting the fruits of a northern blocking should one materialise properly,I suspect Four things could happen (1) we get a more southerly jet so we are on the cold side of any atlantic precipitation so always the marginal hope of snow on high ground from them in the coming months (short waves will appear and push through you know) and of course there will be the obligitory wintry showers.
We wont need the snow ploughs in either scenario.
(2) This could go on for ages and eventually we get the dregs of an Easterly (with the UK getting the most of it) anytime during january or february.
(3) outside possiblity of a 1963.Not impossible.
(4) Hot hail contingent though on Lugnaquilla erupting which in itself is on a probability of zero or below*


*Thats just to show you that whilst 3 is a very low probability,there are things that are lower

Snowaddict

IMO, the GFS operational 06Z run is a major upgrade in the more reliable timeframe, and certainly for that ever dreaded FI.

A Greenland high of 1064 mb is develops on this run... And just look at what follows.

The positioning of the high is much much better IMO. Of course this is only one run, but its another one in which things are definately trending in the right direciton.

On Xmas and Stephen's day, we miss out on an easterly by about 350-400 straight line miles. Its that close to be honest. And as the run develops its simply fantastic.

I mean, we are covered in a cold to very cold airflow from about the 28th onwards on this run, and just look at what develops at the end of it.

I don't care that these are in FI, they are simply FANTASTIC. Furthermore, there is a clear trend for cold from T+180 onwards. Just look at that chart below.

Its a classic, no doubt about it. Sorry but I had to get excited when seeing this run, because it is truly a classic.

Just take a look at this chart, and the ten that go before it, by the end of this run Ireland is gripped by a severe wintry outbreak into the New Year.

A big health warning attached to it though, this is FI and is subject to substantial change and I would assume that this will be a cold outlier in the main...

kerry1960

BB and SA ye should have yer own thread /

enjoying the analysis though (i get colour blind looking at those charts )

things starting to look interesting again for later next week ?

Pangea

snowaddict what is that chart for? 2nd of january?
looks promising

Wibbler

Snowaddict wrote: »

Good morning all.
Some cracking outputs again this morning.
...
If, these trends countinue, then into the new year, Ireland could potentially experience sustained wintriness not seen in a long time.

Are you channeling Weathercheck?

nacho libre

Snowaddict wrote: »

IMO, the GFS operational 06Z run is a major upgrade in the more reliable timeframe, and certainly for that ever dreaded FI.

A Greenland high of 1064 mb is develops on this run... And just look at what follows.

The positioning of the high is much much better IMO. Of course this is only one run, but its another one in which things are definately trending in the right direciton.

On Xmas and Stephen's day, we miss out on an easterly by about 350-400 straight line miles. Its that close to be honest. And as the run develops its simply fantastic.

I mean, we are covered in a cold to very cold airflow from about the 28th onwards on this run, and just look at what develops at the end of it.

I don't care that these are in FI, they are simply FANTASTIC. Furthermore, there is a clear trend for cold from T+180 onwards. Just look at that chart below.

Its a classic, no doubt about it. Sorry but I had to get excited when seeing this run, because it is truly a classic.

Just take a look at this chart, and the ten that go before it, by the end of this run Ireland is gripped by a severe wintry outbreak into the New Year.

A big health warning attached to it though, this is FI and is subject to substantial change and I would assume that this will be a cold outlier in the main...

that chart is just too good to be true:(

Supercell

If that comes off we'd have another '63 or '47 on our hands...and the chances of that are...I'm hopeful

Lovely chart again.That chart is pretty much identical to jan 87 except the wind is direct North-so activity would be confined to most of Ulster,Connaught and west munster and maybe North Leinster.
I'd just have frozen pipes to deal with unless there was a slight NNE flow and if it persisted,then it would be shovel time :P

It's not in a reliable timeframe though-it's nearly 2 weeks away.
None the less,If and when I see stuff like that appearing on the ECM t-96 and less I shall be getting .... excited

Different evolution again-
I'd actually like the below chart if the high stayed in place for a week or two at least and if it was a bit further north.

You'd be kinda looking foward to after Chrimbo so see what actually does turn up!

Snowaddict

Further to my earlier posts.... Joe Bastardi chief meteorologist with Accuweather is forecasting the following for Europe from the post Xmas period and well out into the new year:

SEVERE COLD WAVE TO HIT EUROPE

''The development of a major blocking high pressure system over the north atlantic and its subsequent backing west is about to throw most of Europe into the coldest winter weather pattern in many a year. In fact, Temps over the next month or so are liable to average 6-10 degrees F below normal over the center part of the continent with the northwest coldest last, but still getting into the games. Intuitive with this is the likelihood of more than normal snow and ice. As the upper block backs west, arctic discharges from the north and east are liable to bring shots of severe cold back into England and with it enhanced snowfall''.

When he mentions England, that does include Ireland as well. I know its a long way out everyone, but the odds are increasing in favour of a classic wintry outbreak (not a transient one either but a sustained colder evolution) as we head into the new year and well out into Jan.

The above forecast is from an individual who up to two weeks ago was forecasting a much milder January from northwest Europe.

All things being equal, things are now looking quite favourable for a wintry outbreak, but with nothing certain as of yet.

Chart below from GFS at T+264 would be very interesting for those in eastern and southeastern areas in particular.

The overall pattern is for continued blocking, with possible retrgression of high pressure towards Greenland, as stated by Mr Bastardi... and we all know what happened the last time we had such a setup..:)

That ones nice SA albeit deep FI again..
-10 850 air is a definite snow fest in Eastern Ireland
The UKMO isnt as nice because it routes the siberian air via Rome..

As regards Mr Bastardi-he's ok but he often gets it wrong with the longer range stuff

Snowaddict

Deleted User wrote: »

That ones nice SA albeit deep FI again..
-10 850 air is a definite snow fest in Eastern Ireland
The UKMO isnt as nice because it routes the siberian air via Rome..

As regards Mr Bastardi-he's ok but he often gets it wrong with the longer range stuff

Yep, agreed pretty much there, however if things continue to trend in the same manner (The upgrading of the colder synoptics in the nearer timeframe), which is highly possible IMO, then I think that its not beyond the realms of possibility that cold and snow may potentially arrive into the east of Ireland by the 27th...

At the moment I would put a 20-30% chance on that happening, with a 50% chance on at least some parts of Ireland seing snowfall out into January. Now I may be wrong, but as I've been saying for days, things have been trending this way with quite a while, and the net gain from this northern blocking setup, if continued, has to be at some point for Ireland a wintry outbreak of very notable nature. IMO this is probably more likely during the first 10 days of January as opposed to before the New Year, although as I said above I wouldn't at all be surprised to see snowfall on or around the 27th, however I think anything severe may be reserved for the first half of Jan... After that, theres no knowing what will happen.

Regards from the ever optimistic Snowaddict.

Supercell

Deleted User wrote: »

Different evolution again-
I'd actually like the below chart if the high stayed in place for a week or two at least and if it was a bit further north.

You'd be kinda looking foward to after Chrimbo so see what actually does turn up!

That is one awesome chart!! Lets hope it plays out like that.
These FI easterlies are soo tempting..

Indeed they are.
I'm not over awed by them though as the Rule that the continent must go into deep freeze first comes into play and thats not showing at the moment.

Great for annamoe and roundwood though,I'd expect ice days and snow there alright were some of these charts to verify.

No point getting excited though

Snowaddict

Supercell wrote: »

That is one awesome chart!! Lets hope it plays out like that.
These FI easterlies are soo tempting..

Very much agreed there Supercell. Things are looking very encouraging as it stand tonight.

An absolutely fantastic run from the ECM again this evening.
Retrogression towards Greeland is again delayed to T+240, but this is better in my opinion, as it gives time for the pattern to become set.

If these outputs continue to show, then there is only one net gain to be had at the end of all of this, and it may not be far out from Joe Bastardi's forecast.

Wonderful and possibly classic times ahead.



Furthermore, I know many don't rate JMA, but just take a look.



And take a look at NOGAPS:



I would still remain cautious to be honest, because we could be in for a major letdown, but I will say that this is look more interesting by the hour. I will endeavour to do regular updates on this now.

SA.

Deep Easterly

Deleted User wrote: »

Indeed they are.
I'm not over awed by them though as the Rule that the continent must go into deep freeze first comes into play and thats not showing at the moment.

Great for annamoe and roundwood though,I'd expect ice days and snow there alright were some of these charts to verify.

No point getting excited though

Great for all parts of Ireland! and more especially the west with regards temps. Snow for Wicklow maybe, but keep it, I want dry cold weather. We will get our snow in time.

I disagree to an extent that the continent needs to be in a deep freeze, because the continent won't freeze until the right synoptics are in place, one must follow the other. Surface cooling could happen quite quickly as height temps become less important when a continental flow is in operation.

Interestingly, ECMWF 12z 850's at 216 hrs hours look ok!



Still painfully far out, and caution is well advised as SA points out, but I can't help feeling excited. I know BB is excited too, he is just too macho and Wicklow to admit it!! :)

arctictree

Just had a look through the ECM 12z. Its looking good for cold weather from XMas day onwards. The next 48 hrs should hopefully confirm this.

The problem is that there seems to be a lot of HP around and very little precip. We need some sort of breakdown with an Atlantic front hitting that or some LP developing locally.

Snowaddict

Deep Easterly wrote: »

Great for all parts of Ireland! and more especially the west with regards temps. Snow for Wicklow maybe, but keep it, I want dry cold weather. We will get our snow in time.

I disagree to an extent that the continent needs to be in a deep freeze, because the continent won't freeze until the right synoptics are in place, one must follow the other. Surface cooling could happen quite quickly as height temps become less important when a continental flow is in operation.

Interestingly, ECMWF 12z 850's at 216 hrs hours look ok!

Still painfully far out, and caution is well advised as SA points out, but I can't help feeling excited. I know BB is excited too, he is just too macho and Wicklow to admit it!! :)

Yep, and if that ECMWF chart above verified, it kinda ties in with my suspicion of snow flurries arriving in the east by possibly the 27th into the 28th. No certainty yet, but the potential is there for something severe and going on the latest runs I would definately put the risk at between 40 and 50%.

Deep Easterly

arctictree wrote: »

Just had a look through the ECM 12z. Its looking good for cold weather from XMas day onwards. The next 48 hrs should hopefully confirm this.

The problem is that there seems to be a lot of HP around and very little precip. We need some sort of breakdown with an Atlantic front hitting that or some LP developing locally.

I wouldn't worry too much yet Arctictree, those local lows would be hard to pinpoint on charts that far out anyway. Even with that chart I posted above, the potential for even a small trough to develop to the near south of the high looks quite plausible IMO. Fine tuning as we near the time, but looking good I think!:)

Snowaddict

Deep Easterly wrote: »

I wouldn't worry too much yet Arctictree, those local lows would be hard to pinpoint on charts that far out anyway. Even with that chart I posted above, the potential for even a small trough to develop to the near south of the high looks quite plausible IMO. Fine tuning as we near the time, but looking good I think!:)

Yep DE, and if things became very well established into the new year, we could even be looking at lake effect snow off the Irish sea. The thing about this possible cold spell, is that there is the potential for it too last for a very long time, ie.. more than one week at least... It does appear that it won't be a one day cold spell anyway...

I'm trying to contain the excitement at the moment, but its clear things are getting very interesting.

Regards,
SA.

Snowaddict

I want to add one more piece from Joe Bastardi's latest lrf update.
Because, if it is to be believed, this cold spell could potentially cause severe disruption.

IMO, I think it will be safe to make a fairly safe call on the general setup for this side of the new year in about 4 days time, until then we have a danger for backtracking of the pattern, quite a high danger to be honest. Post Xmas is still far out, but there is every potential for this cold to continue out to then (if it arrives before the New Year as suggested by the models in recent outputs). So tentative steps in the right direction and if Joe B's forecast is in any way correct, we are heading for something historical:

''NOAA had a December forecast for a warm central US for November that they were forced to revise and the UKMET forecast for a rather bland winter for Europe speaks for itself. Its anything but bland, whether it averages out near the average or not, because what is coming has not been seen in years''.

Snowbie

OMG have i been the only one busy in work today.:eek:
Not a chance to view them charts until now.

When it comes to weather, i be more of a realist instead of an optimist but these charts do look very good i have to admit.
I would not even consider snowfall just yet as dry cold air off the continent over the warm SST's of the north sea and Irish sea could create a cold inversion or the stratus muck we like to call it in HP situations. This results in flurries at best. We need a destabilising of the air mass or LP to get something special but as always with an easterly these surprises to crop up.

Lets just stick to getting the cold in place first as i just checked in depth into the models and it does indicate, a block, high pressure over our shores dry air with a typical stratus cover. This is still a bit away but if we get some sort of moderate breeze to break up the cloud, it would be a start. Nowcasting for snow if pressure remains high would be best as the upper air would be cold enough for any precip to be of snow at lower levels if there is truth to the runs. We then need lower pressure to stir things up a bit.

GEFS (ensembles) does not want the mid level cold to stick around for too long.



Lack of precip but is too early to call




I do very much hope we get more potentially spellbinding runs tbh