Model Outlook Jan 2009 --->

Snowbie

This thread is only for models and ensembles only.
No forecasts are to be produced in here.

As with the nature of recent runs from some of the big outputs ECMWF, GFS and UKMO there has been little agreement on a setup just outside the reliable timeframe that is T+120hrs.
None of these setups have come off.

The first bitter weather was expected here on New years Eve/Day modeled from last week and it is not going to happen. The upgrades and downgrades happen throughout the year not just in Winter.

The term FI or Fantasy Island, Fupping Impossible, Frequently Inconsistent is used in the last thread.
There is >10% of these models making it into the reliable timeframe.

As in the last thread, the mods mentioned it several times to stay on topic, this has been ignored and some posts where deleted.
Not only will your post be deleted you will receive a one day ban from the forum and if re-occurs a one week ban.

I will ask anyone who is posting up a chart etc to explain why that chart is significant and to post the health warning with it if in FI. There is no problem discussing that type of chart but remember the chances of this happening is very small.

There is no problem for a thread to be started about an upcoming event but make sure it is in the reliable timeframe and not hyperbole please.

Snowbie

LP moves down to the south of Ireland and down the North sea from 06Z next Monday 5th bringing a NE across Ireland. Ensembles not out yet.



ECM 00z not in agreement

forkassed

I was reading Steve Murrs thoughts this morning on NW this morning and what i gathered from it was how much the jet stream plays in that all elusive high getting up into Greenland.

The chart below shows @ T+84 the jet (yellowy/red line) trying to go up the eastern seaboard of the U.S and up and over the top of Greenland.This would allow pressure to rise in Greenland.










Unfortunately for us some of the latest models at T 108 and afterwards show the southern arm of the jet stream taking most of the energy and shooting straight across the atlantic. This prevents the heights from rising in GL and is a spanner in the works for our chances of snow.









If we want cold&snow, this is important to watch for in the models over the next couple of runs, as until the models pin down the orientation of the jet we are on a knife edge.

MUSEIST

If we want cold&snow, this is important to watch for in the models over the next couple of runs, as until the models pin down the orientation of the jet we are on a knife edge.[/QUOTE]

Yes and in recent runs the southern arm has looked strong and introduces the atlantic in FI, also I would tke into account the fact that the models both GFS and ECM have been all over he place and have struglled with the high pressure over the northern atlantic, a lot of ups and downs in the models to come - no real trend forming yet IMO;)

JanuarySnowstor

Is the atlantic really that bad
Surely what we have had the last 2 weeks (i.e. nothing) is a tad boring. I doubt very much if our interest in weather was borne out of weeks like these. At least the atlantic can throw the odd storm at us or maybe even cold zonal. In Cork today it's 8C and breezy. It doesn't get much milder than that in a strong southwesterly

Anyway let's hope the 12z cheers us all up:D

JanuarySnowstor

12Z GFS halfway out and it looks a complete mess.
We seem to be stuck in some kind of a col yet still miss out in the deep cold to our East
Looking more and more like the status quo continuing into next week i.e. nothing

I think we may welcome back the atlantic with open arms by the end of all this. A very poor few weeks and burning valuable heart of winter time

Villain

The latest models don't look good at all it seems the milder air from the west is going to win out rather quick.

It will be interesting to compare the 18z tonight with last nights I think sadly though we will see huge downgrades although the Models are struggling so things could yet change

MUSEIST

Well 12z gfs is a disaster for snow. It all seems to be going wrong now .What happend to those great charts of a few days ago and the general trend of greenland highs. Anyway if the ecm is similar to 12z then its the nail in the coffin i'm afraid:mad:

Pangea

hmm no one really posting any info here today.

Villain

The models are all over the place and no-one likes downgrades!

Snowbie

Majority of ensembles in favour of mild.

GFS and ECM near agreement. Near reliable timeframe and 2 more runs to change but by this time tomorrow, the cold spell could be dead. Looks to be cold and frosty but with the Atlantic about to break through.



ECM

JanuarySnowstor

There never was a "proper" cold spell in Ireland
As I earlier suggested earlier even atlantic type weather in early Jan gives maxes of 8-10
Was 8 here in Cork last few days with no frost since before Christmas.
I welcome the atlantic with open arms, anything better than the last 3 weeks of....................erm nothing

Snowbie

JS banned for a day for going off topic.

JS i am getting tired of your constant whining on this forum. You seem to want attention on here as your not getting it on Netweather as per your recent post about that forum.
Either post something relevant in this thread or just read. Your decision.

MUSEIST

Well at the moment it looks bad for a cold spell but I would 'nt be suprised if the 18z gave a upgrade. NOAA have been predicting height rises over greenland for early january for a while now(they have been consistent with this). The GFS and ECM can get it wrong especially in dealing with situations like this so its possible that this could upgrade.I dont want to get peoples hopes up but 18z coul d have something for us:P



They could be wrong but its unlikely they are completely wrong wheras you can disregard some GFS runs as some are just not plausible.

Snowaddict

Hey all,

I haven't seen the latest outputs until now but I see that things have taken a dive in terms of the potential colder outbreak. One thing to note is that NOAA have already binned the 12Z GFS Operational run.

However, there is a clear trend there for no real wintriness, particularly on the operational outputs. Furthermore, ECMWF run is not really that good at all.

The model outputs have now certainly backed away from the potential wintry outbreak. The 850hPA temps ensemble mean out to the 6th looks quite good, however from a brief run through the outputs, thats the only positive that I can really see to be honest.

Unless there are dramatic changes over the next 24 - 36 hours, the potential of any wintry outbreak may unfortunately not be realised.

A few more outputs needed, but its a big change from what I saw on the 18Z last night.

Regards,
SA.

arctictree

OK, GFS 18z rolling out now.

The chart for Monday 12z is still very interesting. The high has intensified over Scandinavia and pushing cold air over Ireland as the Atlantic LP moves in. This is still bordering on FI at t+138 but the building blocks of it are appearing now at t+120

I'm keeping an eye on this as it is only a few runs away from the reliable timeframe.

danni2

The 18z is much better, looks like an easterly at T144

Snowaddict

This chart is usually reserved for the deep realms of FI. Now this run may be a false hope and is only one run, but the fact that these potently cold charts are appearing nearer the more reliable timeframe, its very interesting to say the least.

I wonder where the 18Z operational will stand in terms of the ensembles?

This still shows that the outlook at the moment is far from certain past T+96.

GFS 18Z T+144



T+150




A massive health warning attached to this chart, its still at T+159 and its totally out of sync with recent ECMWF outputs. Could this be a rogue run or does this set a trend for a potent easterly? Given the recent outputs, this run should be treated with a pinch of salt. IMO, the setup will flip flop right up to T+48. One thing I will say is that Jan 5th has always been shown to be very cold on GFS ensemble runs over the past 10 days. However at the moment, I'm taking this run with a pinch of salt.

Villain

I was just about to post the same charts, the Pub run is looking good but the pub run looked good last night too, Monday looks cold http://212.100.247.145/gfsimages/gfs.20081230/18/144/h850t850eu.png

arctictree

Snowaddict wrote: »

IMO, the setup will flip flop right up to T+48.

TBH, I have been comparing each chart to the previous run for the last few days and they have been very consistent to t+96. After that any variation causes a massive change in subsequent charts. So, I think this is the timeframe where we can start to give a reliable forecast.

Snowaddict

arctictree wrote: »

TBH, I have been comparing each chart to the previous run for the last few days and they have been very consistent to t+96. After that any variation causes a massive change in subsequent charts. So, I think this is the timeframe where we can start to give a reliable forecast.

Thanks Artictree. I haven't been able to view hardly any of the outputs over recent days. In this setup, very small changes will definately make the world of difference for us. However, I fear that this may be a rogue run given the latest ECM outputs.

Lets hope not.
SA.

forkassed

Promising but i would bring the reliable timeframe back to t48 with this situation as small changes in the jet upstream are causing massive variations at t72+.

Lets hope its a trend now because all this is getting exhausting.

Villain

If you dare to look into FI

Snowaddict

Last post from me, I will check in again as soon as possible. For comparison at the moment, here's the latest outputs from 4 models for T+144 or T+147 approx, which is still well outside of the more reliable timeframe and is subject to substantial and significant change.

JMA



GFS Operational



ECM



UKMO



Regards,
SA.

Danno

Dodgy data, unable to get a handle on the jet, retrogression, shortwaves... the models are getting some battering and don't know what way to go by the looks of it. The last two runs have been a disaster [according to posts on here - did not get to see them myself] - so what is going on folks? Do we look for something else to enlighten us on what the weather ahead is going to be?

I just don't know what to make of it. But my gut feeling says something big is on the way [and NO it's not a big fart after all the Christmas food and beer ]

I am off now to investigate tonights 18z and offer my opinions.

Just had a quick 500hpa look out to 102hrs and the low over Denmark is still there, though I did expect this feature to be showing stronger on the runs by now...

More in a while...

MUSEIST

[I just don't know what to make of it. But my gut feeling says something big is on the way [and NO it's not a big fart after all the Christmas food and beer ]

Better not be!:D

Anyway another good 18z run like 24 hrs ago it was similar and all runs in between were poor for snowlovers- models are all over the place - just dont trust them at the moment. Also interesting how on the 18z a ridge of high pressure comes into play from the azores- will be interesting to see if that trend continues in later runs.

Pangea

Snowaddict wrote: »

Hey all,

however, there is a clear trend there for no real wintriness, particularly on the operational outputs. Furthermore, ECMWF run is not really that good at all.

The model outputs have now certainly backed away from the potential wintry outbreak.

Unless there are dramatic changes over the next 24 - 36 hours, the potential of any wintry outbreak may unfortunately not be realised.


Regards,

Snowaddict wrote: »

This chart is usually reserved for the deep realms of FI. Now this run may be a false hope and is only one run, but the fact that these potently cold charts are appearing nearer the more reliable timeframe, its very interesting to say the least.

I wonder where the 18Z operational will stand in terms of the ensembles?

This still shows that the outlook at the moment is far from certain past T+96.



A massive health warning attached to this chart, its still at T+159 and its totally out of sync with recent ECMWF outputs. Could this be a rogue run or does this set a trend for a potent easterly? Given the recent outputs, this run should be treated with a pinch of salt. IMO, the setup will flip flop right up to T+48. One thing I will say is that Jan 5th has always been shown to be very cold on GFS ensemble runs over the past 10 days. However at the moment, I'm taking this run with a pinch of salt.

SA. [/quote]

wow what a contrast in the space of one hour from both of your posts , thats why i think all these models are a waste of time, they change constantly from highs to lows


is this the dramatic change u hoped for?

Snowaddict

Pangea wrote: »

SA.
wow what a contrast in the space of one hour from both of your posts , thats why i think all these models are a waste of time, they change constantly from highs to lows


is this the dramatic change u hoped for?

Hey Pangea. I'm away at the moment so I can't keep up much with the outputs, but when I viewed the 12Z Op it was not good at all, as is the latest ECM 12Z.

The 18Z GFS Op would be the dramatic change that would be needed, however this is one run and as I said, it really needs to be taken with a pinch of salt. From what I can breifly see, there is huge uncertainty at the moment.
Treat all of the outputs with caution at this time. However, we need to see continuous cross model agreement at a very close timeframe before we can contemplate any change back in favour of a cold outbreak.

I will try check in tomorrow again if possible.

Regards,
SA.

To be honest (yes It's me) model reading past 144 especially in complicated set ups is not meant to be forecasting,never is,never was and never will be.

The current set up is Very complicated.I've never seen anything like it in terms of model confusion or professional forecaster cautiousness and I've been looking at this stuff I suspect since before a lot of the new posters here were born as has the likes of snowbie,Supercell and certainly mothman.

Where are we at this point? Well leaving the rather peachy 18z aside [its a snowfest] we've got a strong signal from the UKMO forecasters tonight that this is going in the right direction..
When you see the likes of Peter Gibbs putting up maps of the whole of Europe and hinting thats where our weather will be coming from for the foreseeable,then theres little cause for concern folks.

We are always on the edge of anything coming from that direction so we are always looking for more intensity than our friends across the water and we are always at the risk of dipping out of the cold while they stay in etc but lets see what happens.

Deep Easterly

Welcome back BB!!!

Danno

Welcome back BB! Hope ya had a good Christmas and that the few tipples have helped you unwind and relax!

I agree with you about anything after T+144 (Current Time + 144 hours), but the sheer persistance of the models about this cold spell has caught everyone's attention I am sure you will agree.

As I said earlier, we have the theme in place, now we are looking for the detail, and as you rightly pointed out, the reliability of these models to be so fine tuned in detail from such a far off time is almost impossible.

The best thing we can do is discuss the T+144 era in the theme of things to come, but to suggest snow showers in Dublin and not in Belfast from these FI charts is a complete waste of time.

Hope to see you online more over the winter [a REAL winter hopefully!]

Hmmm I would suggest that the alternative GFS run tonight would bring heavy snow showers into Dublin...in about a week

-12 850 air right down the East...

Pity we cant freeze that and impliment it!

danni2

The 00z has downgraded the cold from the 18z, cold air does clip the east of Ireland next monday but nothing major cold. Overall nothing exciting really.

LEIN

Welcome back BB.

I must reply to your pm...

Meanwhile,theres a good chance will hand will be wrong.

http://groups.google.co.uk/group/uk.sci.weather/browse_thread/thread/da4fa7d86fdb7e50?hl=en

200motels

According to Accu Weather next week is going to be mild and wet, Sky News 3 day forecast gives rain moving in from the west on Sunday. Yet some models say easterlies for next week, it's all a bit confusing.

Snowaddict

Afternoon all.

I'm delighted to see BB back on here, Welcome Back!

I see from the latest GFS operational and ECM operational outputs (for the more reliable timeframe at least) that things are not looking very good in terms of potent cold.

There is still a huge amount of uncertainty at this point and there may yet be a turnaround. Some of the GEFS ensembles (06Z) are still very encouraging, with the mean 850hPA temps remaining below -5 from the 5th to the 9th of January. GFS Control was also very wintry for the more reliable timeframe on the 06Z. However we need to see a fairly big turnaround if there is to be proper potential from the 5th onwards and it may very well be that the operational outputs are picking up on signals that the other ensembles have not yet picked up on.

Still time for major changes and possibly changes in favour of more substantial colder weather. Things are still very uncertain at this point and this is in evidence in several of the online media weather forecasts.

I will try check in again later.

Regards,
SA.

There will always be turn arounds.
Meanwhile it's mild today here,it's +7c
This is fast losing it's title as a cold spell.

-5c to -7c 850 air would deliver rain here by the way without strong surface continental advection.A slack flow won't produce that.

Effectively the last 10 days of model output has been useless in terms of determining where our weather goes from here ie from being influenced by our meandering high pressure cell.
The scientists should think about that one.

My own personal feeling at this stage is we wont get any cold advection from either the continent or scandi because this block isnt able to block the atlantic from Ireland when push comes to shove.
It's at the pin of it's collar to keep it out of the rest of Europe.

Slight turn there by the GFS 12z again but of not much consequence for Ireland even past 120 I think with circa -5c 850's.

Huge uncertainties.There hasnt been a GFS certainty sub 144 for a while now.

Trogdor

Ensembles aren't that bad really, all dip to -10C (bar the operational) on the 6th on the 12z
http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=113&y=33

shamwari

John Eagleton delivered the forcast after the 6pm news on RTE1. He never once mentioned the magical "S" word, but at the end of the bulletin, the weather graphic for next Monday showed what look like snow down the east side of the country.....:eek:

Snowaddict

Hey all.

Well in the more reliable timeframe, the GEFS ensembles are what I would describe as very good. The ensemble mean now drops to -10 between the 5th and 7th of Jan and remains at or below -5 between the 5th and the 11th.

Regarding the 12Z GFS operational, it certainly has toned down somewhat in terms of being a mild outlier compared to previous runs and offers a halfway house type scenario from what I can see which would potentially deliver some marginal snow to more favoured areas. This run again needs to be taken with a pinch of salt, but is encouraging. Furthermore, the 12Z GFS parallel run is very good, as is the 12Z GFS operational run. This is interesting IMO because the 12Z Operational GFS run is usually the most progressive of runs. However, we must note that NOAA are not happy with the 12Z GFS run.

I'm not by any means suggesting that any potential colder outbreak is going to happen because at the moment there is simply huge uncertainty in the model outputs, but it certainly cannot be ruled out at this point. However, if the ensembles were to be correct and if they verified, a sharp drop will still occur in upper 850 hPA temps between the 3rd and 5th of January over Ireland, as has been shown for many days now.

The drop to -10 is most impressive but is still approx 138 hours out and there are still plenty of chances for significant changes.

ECMWF 12Z is not excellent, however from what I can breifly make out, its somewhat better than previous runs, up to T+144 at least.

The bottom line at this point is that the potential is still in evidence for a potential wintry onset, (even slightly more strongly when compared to previous runs) beginning around next Monday, 5th of January, on some model outputs at least. However, due to the large degree of uncertainty at this point, all options are on the table and it may yet be a case of so close but yet so far for Ireland, equally the cold outbreak could potentially materialise.

Things have trended somewhat in the right direction on the latest suite of GFS outputs, but there's a long way to go yet.

Happy new year to all.
I will check in again as soon as possible.

Regards to all,
SA.

arctictree

OK - Obviously everyone is out celebrating!

18z GFS seems like a major upgrade to me.

Wintry event still on for Monday and getting colder after that.

Interesting, GFS showing maxes in the midlands of -4c next Wednesday!

Happy New Year!

A

BigCon

Wow, seems to have turned around again, look good for Monday and getting even better after that (to my untrained eye anyway). Hope it stays that way...

danni2

Happy new year everyone!!:D

Speaking of happy I'm happy with the 18z, looking good for monday and after that we have a true northerly wind.

j1979p

Wow, what an upgrade. According to GFS now, T150 and it's snowfest across the country! Why do i feel i have to take this with a pinch of salt? :rolleyes:

Hal1

Hmm interesting chart, tis a week out wait and see. Happy new year an all that.

danni2

The 00z gfs run has downgraded from the 18z but still looking cold, met eireann has mention the word snow.

Latest from met.
Sunday looks like turning cloudier with some rain or sleet affecting the north and west. On Monday this will affect other areas as well and there is a possibility that it may turn to SNOW in places

nacho libre

It'll be interesting to see what the BBC forecast shows for Monday. I have a feeling the midlands will likely see snow out of this if the met eireann forecast is correct.

Snowbie

Very interesting charts and at less than T+120hrs. Cold air very much in place and an eye catching feature approaching from the north.:)



but could slip into the continent.

Snowbie

Not very often we get -11C 850mb air in Ireland.