Model Output Discussion:

[johnholmes]

Could we all put our toys back in the pram and start discussing the models like adults please? "That's it, it's over, I'm leaving" style posts are just a waste of space.

oh so very true NR but I doubt it will stop the said comments

[Guest North Sea Snow Convection]

The UKMO is not as good as this morning at 96hrs but still holds the upper trough energy much further west.

Obviously the output from t120 and beyond is not good so far this evening. But this energy question still looks very suspect to me. The sequence up to t96 on the UKMO looks promising and suggests going the same way as this mornings UKMO output with an expansion of the ridging from the east as the shortwave over the UK fills up and pressure rises across the north, Iceland and into Greenland from the east. (I don't buy that this shortwave near Norway is that much of an issue tbh)

The next sequence though, seems to be discontinuous at t120 with a sudden drop in pressure in all the areas it was rising and from an evolution of dissipating energy, it is suddenly igniting again. And then at t144 the heights are completely gone across the north and including Greenland. Even this mornings ECM showed pressure high over Greenland at the same time. It all looks very ultra progressive and implausible to me with the jet to far north

Yes, I could be wrong, but it looks overdone and (still) against the background trend to me. I see pressure rising near the east and north of the UK rather than falling from the weekend onwards.

Obviously if the ECM agrees and then another round of modelling tomorrow morning shows the same, then it is time to accept it might not be going to happen - but dare I say it, this isn't yet conclusive, even though the face value modelling so far this evening is not the best.

I think the models continue to be a mess!

Edited February 2, 2010 by North Sea Snow Convection

[karyo]

It's possible that the models have reacted to the westward move of the MJO. Maybe the MJO forecasts will verify for once and it will move east again in the coming days. GPs input here would be useful!

Karyo

[Bobby]

The GFS ensembles continue the trend, they're a fair bit worse than the 06z.

Mean at +174 for 12z

http://91.121.94.83/modeles/gens/run/gens-21-1-174.png?12

Mean at +180 for 06z (p)

http://91.121.94.83/modeles/gensp/run/gens-21-1-180.png?6

Edited February 2, 2010 by Barb-

[The PIT]

Ah well the milder outlook seems to be the chosen root as most models now seem to be in agreement. Low pressure pushing from the south west it's just a question of how long will it take for the milder air to push through.

Interesting that the block is being pushed away fairly easily.

[Geordiesnow]

Maybe a little lesson for us all too learn is to take every output the models shows seriously and not just dismiss it because its not showing what you want. I'm on about last nights 18Z where one member got critisized for saying the 18Z could be start of a milder trend and thus far this does appear to be the case. Although the UKMO and this morning's ECM show an easterly albeit very brief.

I think its premature to write off the output yet though but i can't see any cold that will be long lasting however we all know how things can change in a flick of a switch.

[Guest North Sea Snow Convection]

Now that it is out on wetterzentrale the UKMO looks even more questionable imo between t96 and t144.

Time will tell if this is the case or not

Note - I haven't commented on the GFS because I simply don't believe anything it suggests these days!!

Edited February 2, 2010 by North Sea Snow Convection

[SP1986]

Now that it is out on wetterzentrale the UKMO looks even more questionable imo between t96 and t144.

Time will tell if this is the case or not

Note - I haven't commented on the GFS because I simply don't believe anything it suggests these days!!

I don't blame anyone for taking this approach, I mean given that most models were agreeing on an easterly, and I admittedly perhaps was a little sceptical of the easterly at the time, it would still be hypocritical of me to suggest that just because the models are showing a southwesterly that this is the outcome.. the truth it isn't necessarily, however this is really interesting model watching no matter which way it ends up going.

[cooling climate]

With the way the models have behaved the last few days I think it would be rather

prudent to wait another 24 hours or so to see if the models offer some consistency

to what they are showing this evening.

I'm still of the belief this is not over yet. T96 still looks like FI and maybe confusing

signals from the MJO, SSW and downward propagating easterly winds are playing

there part.

[Bobby]

I don't blame anyone for taking this approach, I mean given that most models were agreeing on an easterly, and I admittedly perhaps was a little sceptical of the easterly at the time, it would still be hypocritical of me to suggest that just because the models are showing a southwesterly that this is the outcome.. the truth it isn't necessarily, however this is really interesting model watching no matter which way it ends up going.

It's easy to dismiss one operational but the whole GFS ensembles have taken a sizeable turn for the worse. It doesn't seal a mild outcome no, but with UKMO and ECM saying the same thing confidence in an easterly is at rock bottom right now.

Even the smaller models are awful.

[Guest North Sea Snow Convection]

I don't blame anyone for taking this approach, I mean given that most models were agreeing on an easterly, and I admittedly perhaps was a little sceptical of the easterly at the time, it would still be hypocritical of me to suggest that just because the models are showing a southwesterly that this is the outcome.. the truth it isn't necessarily, however this is really interesting model watching no matter which way it ends up going.

In essence I am questioning both the eastward extent and depth of the low pressure in the atlantic by t144. Is it really going to be as such by then? I am not convinced by the suggested orientation of the lows and jet patterns and paths.

I was more sceptical of the suggested easterly last week than I have been of the suggestions mooted by the models in the last day or so!

[Bobby]

Here's the 12z GEM at +144

Nuff said.

[Guest North Sea Snow Convection]

With the way the models have behaved the last few days I think it would be rather

prudent to wait another 24 hours or so to see if the models offer some consistency

to what they are showing this evening.

I'm still of the belief this is not over yet. T96 still looks like FI and maybe confusing

signals from the MJO, SSW and downward propagating easterly winds are playing

there part.

I agree with all of that and especially the bolded part

It might well come to nought, but I think the obituary posting may be rather overdone and just perhaps a little premature

The latest lurch tonight by the models is yet another huge swing and could, yet again, be completely over baked and an overreaction to a wrong signal, or one that is not going to occur.

Anyway, enough from me for now. Have a good evening all

Edited February 2, 2010 by North Sea Snow Convection

[MR EXTREMES]

With the way the models have behaved the last few days I think it would be rather

prudent to wait another 24 hours or so to see if the models offer some consistency

to what they are showing this evening.

I'm still of the belief this is not over yet. T96 still looks like FI and maybe confusing

signals from the MJO, SSW and downward propagating easterly winds are playing

there part.

i dont agree we only had 1 evenings output in the last few days hint at easterly and its all a hint nothing else.

i really think we have to except what the models are showing us there is massive agreement on all models of mild sw type.

ssw event still has to take effect and as many have noted the neg nao is west based,

nothing is aiding a good cold setup.

[bluearmy]

With the way the models have behaved the last few days I think it would be rather

prudent to wait another 24 hours or so to see if the models offer some consistency

to what they are showing this evening.

I'm still of the belief this is not over yet. T96 still looks like FI and maybe confusing

signals from the MJO, SSW and downward propagating easterly winds are playing

there part.

your persistance is admirable CC. however, we've been 'dangled' in this way many times over the years and very rarely have we come back to somehting worthwhile. the solution now looking to be offered across the models with reasonable agreement of extensive northern blocking and west based -NAO is, as has been posted earlier, consistent with GP's general teleconnection assesments. it was assumed that if heights transfered from siberia to canada to set up this WB -NAO, we would benefit from a cold spell of some nature. when the models began to flip saturday am, i posted that it is possible for this evolution to occur with us missing any real cold. you are seeing the NWP showing this evolution. i would be astonished if, with such massive blocking to our north for the foreseeable future, we didnt see at least a cold snap before feb is out. however, at this juncture, the first half of feb seems to look unlikely to bring it.

[MKN]

It's easy to dismiss one operational but the whole GFS ensembles have taken a sizeable turn for the worse. It doesn't seal a mild outcome no, but with UKMO and ECM saying the same thing confidence in an easterly is at rock bottom right now.

Even the smaller models are awful.

The ensembles are of little relevance really when one run they can all be in nearly perfect agreement of one outcome only for them to all be completely different from each other the next. However as you say, wet and windy would appear to be the most likely outcome at this stage.

[Frosty.]

All the doom and gloom about the failed Easterly and yet the GFS 12z shows a very cold FI with a chance of Northerly winds with snow in places and widespread frosts, the milder atlantic type spell was always the favourite in the short term and it's looking very unsettled with strong winds and spells of rain and still a chance of snow on northern hills up to and including the weekend.

[High Altitude]

Here's the 12z GEM at +144

Nuff said.

I don't see what's so wrong with that? Plenty of heights to our north and even if that chart verified who's to say that once that low pressure pushes through (and probably on a more southerly track) that those heights don't fall in nicely behind.

[Tom D]

So far this evening there's overwhelming agreement that the Atlantic will break through, but is it still long enough away for it to all change and/or downgrade the temperatures slightly?

Edited February 2, 2010 by Tommyd1258

[Cumulonimbus Tower]

Here's the 12z GEM at +144

Nuff said.

I have seen much worse for cold at this time of year over many of the last 20 years or so. You don't have a long southerly fetch and heights are rising over Greenland instead of the core of the polar vortex centred there driving the weather. I don't see a block as such on todays charts either, just a cold Scandinavian trough which keeps throwing cold air westwards as the shortwaves track across us (weakening every time, from what they start out as on the models) We have a nice covering of snow now and expect more tomorrow so i can live with a week or two of this sort of a pattern

[SP1986]

All the doom and gloom about the failed Easterly and yet the GFS 12z shows a very cold FI

This is part of the problem I suspect, we need this pre 144 hrs.

More runs to follow though.

[MR EXTREMES]

I don't see what's so wrong with that? Plenty of heights to our north and even if that chart verified who's to say that once that low pressure pushes through (and probably on a more southerly track) that those heights don't fall in nicely behind.

pushes through where?

heights to our south and north and east hold low pressure inplace wet windy but id say not blowtourch.

after there is always a chance pressure will hold firm to our east but its a fight on with strong winter storm leading the way.

id also be suprised if the ecm throws another spanner in the works for us coldies i think it to earlier was already giving us hints to where it wants to head up the mild garden path looks like the most likely route:cc_confused:

Edited February 2, 2010 by badboy657

[Weathizard]

It will probably change back to the prediction for Easterlies later, knowing the recent-past it really would not surprise me in the slighest.

[Shunter]

Midday for the 8th Feb is now at T144. The 12z GFS ensemble mean for London now shows +6c at 850hpa ( around 10-11c ) so an increase of 1c in the past 12 hours.

http://85.25.71.112/wz/pics/MT8_London_ens.png

[PubliusEnigma]

I have an idea

Right today its the 2nd of February

Is there anyway to look back 168 hours and see what the GFS and ECM where forecasting

for 7 days time i.e. today, and just see who was the nearest, and if either one missed

todays set up by a mile. Might be useful as a tool to try to understand what happens next.

Whilst the majority scenario over the last 3 or 4 days has been the atlantic to win over

and mild to return, the cold scenario, keeps popping up at times, completely reversing

the flow, Would be interesting to note.