Model Output Discussion

[Methuselah]

Good forecast, JH...Maybe the Highlands' snow won't be about to vanish, afterall???

[weather eater]

Interesting post from GP, who has so far been spot on the money, however by Christmas and New year regular model thread members might just have gone stir crazy.

[carinthian]

Aren't you expecting some fresh snow during this week, the models all seem to push fronts well into europe. Here the resorts were supposed to open last Saturday but this has been put back to this Saturday, of course with this type of pattern since the weekend the Pyrenees especially the western ones often do better than further east into the Alps, i'm sure everything will be open this weekend here with huge amounts of snow forecast this week, i have everything crossed for you C that things improve over there in Austria, keep us posted on things.

Hi Nick,

Yes, The Klagenfurt Met Centre are predicting heavy rain below 1200m tomorrow with a gradual lowering of the freezing level in this part of the world. Snow level is expected to be as low as 600m further west in the Voralbourg and Western Tirol by this time tomorrow.

Keep your reports coming from the Pyrenees and I do like your model reviews as much as I am finding it all very frustrating. At my age I should know better ! However, I love snow and even walk up 2500m mountains to find it in the summertime.

C

[Eugene]

however by Christmas and New year regular model thread members might just have gone stir crazy.

Yes in other cold winters they would have also

Poor models today no point in saying they are not as HP blocking to our east is blasted away by the jet eventually bringing in mild TM air by early next week.

As GP says though christmas onwards is when the real interest begins.

[nick sussex]

Hi Nick,

Yes, The Klagenfurt Met Centre are predicting heavy rain below 1200m tomorrow with a gradual lowering of the freezing level in this part of the world. Snow level is expected to be as low as 600m further west in the Voralbourg and Western Tirol by this time tomorrow.

Keep your reports coming from the Pyrenees and I do like your model reviews as much as I am finding it all very frustrating. At my age I should know better ! However, I love snow and even walk up 2500m mountains to find it in the summertime.

C

Now that is dedication! I do hope things change over in Austria. Unfortunately that limpet trough seems to be in a constant love in with the UK!

We see here some trough disruption to the west with a shortwave running se wards, will be interesting to see whether we can keep the jet tracking nw/se wards. Possibly we could develop something more interesting but this is the gfs and has been doing poorly over the last few days.

If the other models back this run which IMO is a big if expect the shortwave to take centre stage, no shortwave no deal, this runs ese here and helps anchor the weak height rise to the north.

Edited November 30, 2009 by nick sussex

[Eugene]

http://www.wetterzentrale.de/pics/Rtavn1501.png

Much better GFS 12Z run with temps about 5C colder than 06Z for sunday, could be an outlier though.

[patneve]

GFS 12Z...wow what an improvement, lets discuss!! high pressure building to the north after 130 hrs!

[nick sussex]

What do you make of this Kold W? i fear we're about to embark on yet another model drama led by the gfs, its not the most implausible thing the gfs has come up with but everything rests with that shortwave.

[492]

12Z GFS appears to be an upgrade however the ridge to the north is quite weak and GFS pressure shown for 06Z over Greenland appears around 10 mb too high compared to the actual at 12Z. However every slight upgrade is welcome.

[SP1986]

GFS most likely an outlier however if it isn't it could either be the GFS reverting back to it's inconsistency or it could be a new trend (that's doubtful if it's showing inconsistency from one run to another though)

[cooling climate]

At least this run should lift the spirits in here, even if its only temporary. The rest of the

run from t240 onwards should be a corker.

The main difference with this run is that it has moved the main part of the vortex over to

the north of Hudson Bay and Baffin Island, allowing better heights to the north of us.

[karyo]

I think the GFS is having another crazy moment with its 12z output! The Euros are unlikely to show anything similar although I'd love to be pleasantly surprised!

Karyo

[nick sussex]

I think the GFS is having another crazy moment with its 12z output! The Euros are unlikely to show anything similar although I'd love to be pleasantly surprised!

Karyo

Yes you're right the ukmo not going with the gfs so its upto the ecm now.

[Iceberg]

It's not often I laugh out loud at model output (promise), but this 12Z run is comical beyond 120Z, almost to the point of squirmingly embarrassing.

[weather eater]

Does the GFS have any clue what so ever, or is it on to something that no other model can see?

[azores92]

Yes you're right the ukmo not going with the gfs so its upto the ecm now.

i think its unlikely that ecm will go with gfs on this one, the fact its chopped and changed so much in the last few runs, shows the amount of uncertainty the model has. i think honestly, the outlook is fairly average, at times mild, with spells of rain, and cooler weather interspersed. i would be surprised if the 12z is anywhere near right tbh.

[karyo]

Yes you're right the ukmo not going with the gfs so its upto the ecm now.

It reminds me of the easterly it showed a couple of days ago and got people excited! It makes me wonder why the gfs has gone so downhill lately?

Karyo

[azores92]

It reminds me of the easterly it showed a couple of days ago and got people excited! It makes me wonder why the gfs has gone so downhill lately?

Karyo

its the same old story most winters. the addictive element of getting a rush from seeing a colder outlook means more and more seek the models, and then it inevitably leads to disappointment. im guilty as hell for this, but in reality, the best thing to do is to read the experts analysis, follow noaa discussions, and take the models with a sense of reality. imho, the 12z is going a little OTT, i doubt the temperatures will stay as suppressed as are being shown, temperatures will likely reach high single figures by the end of this week. also, chances are the atlantic is likely to stay in charge for sometime yet, as gp has shown by well backed up analysis.

[Thundery wintry showers]

Also, that easterly would not be cold enough for snow away from high ground until past T+180.

[phil nw.]

The common theme of the trough over the UK remains in both GFS and UKMO up to T120hrs.

Certainly differences from there though with GFS pushing the trough well into C.Europe.

http://www.wetterzen...s/Rtavn1441.png

http://www.wetterzen...cs/Rukm1441.gif

More heights up north from GFS.

Recurring Easterly theme further on again,could it be onto something in view of this?

Fax for T120hrs.

http://cirrus.netweather.tv/fax/PPVO89.png

Could that be an Easterly in the pipeline?

Edited November 30, 2009 by phil n.warks.

[The PIT]

Also, that easterly would not be cold enough for snow away from high ground until past T+180.

Yeh even though we're getting good setups the cold air either isnt there to drawn on or doesnt want to get pulled down. Still should get some snow out of those setups but no deep freeze.

[shuggee]

Interesting comparison of outputs between 06z and 12z.

Here's T+72 06z first, 12z second:

And T+96 again 06z first, 12z second.

I'd suggest this illustrates GFS current limit of reliability is around T+80-ish and then we are into FI.

[bluearmy]

the parallel is also not overly plausible with the trough sitting over us like a limpet. i think its the general inconsitency below T144 which is concerming on the GFS at present.

on all the output, we're not that far from something wintry. its just that to get there we would need to sink the overall pattern around 500 miles (and a bit more sw than s if poss). the events in the arctic are far from certain over the next week - it always used to be the case that we would say : 'northern blocking - dont expect the models to get that right'. 500 miles isnt much of a distance in the NH context. however, those who have done this for the past decade (well it feels like its been that long)expect the 500 miles to go northeast, not southwest.

i guess we just have to keep watching with an open mind and a bit less cynicism and be prepared for let downs.

Edited November 30, 2009 by bluearmy

[Cloud 10]

Slight uncertainty in the 12z air pressure ensembles for aberdeen.

[Frosty.]

Forget the GFS run, the model is really struggling. I would expect the ECM to show a progressive pattern from T144 onwards.

Forget everything unless it shows mild you mean

I'm looking forward to seeing a cold spell like most on here but we will probably have to wait until nearer the end of the year as GP said earlier. I expect the weather to remain unsettled, never terribly mild but near average seems likely although a bit cooler up north with the jet generally remaining southerly tracking.