Model Output Discussion - 26th December - 1st January

[shedhead]

This pattern wont last. Signals are a foot for a pattern change to cooler conditions mid Jan.

NAO heading into neautral and slightly negative. The mean AO is heading to negative.

Ridging in the Atlantic bring N, NW air flow, with troughing across eastern europe.

Can you try posting some charts to back up the above bullet points?

[johnholmes]

I think if you look at the NOAA site 'shed' for AO and NAO our poster is being rather enthusiastic about them doing what he suggests for both the AO and NAO. Certainly they have a trend downwards but its towards the end of each prediction period and their reliability at these distances is no more than any other prediction. No idea where the final one comes from.

Edited December 30, 2011 by johnholmes

[Grimsby Snow Lover]

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

The NOA is now confidently heading negative towards the middle of January, not very negative like last December but negative non the less. As for the AO, this is less clear some runs suggest negative, others suggest positive. My take on this would be a more neutral forecast as mid January arrives.

[shedhead]

I think if you look at the NOAA site 'shed' for AO and NAO our poster is being rather enthusiastic about them doing what he suggests for both the AO and NAO. Certainly they have a trend downwards but its towards the end of each prediction period and their reliability at these distances is no more than any other prediction. No idea where the final one comes from.

Yes I know John, hopefully our poster will think twice in future before making such bold statements that simply mislead less experienced members.

Edited December 30, 2011 by shedhead

[nick sussex]

http://www.cpc.ncep....a/nao.sprd2.gif

http://www.cpc.ncep....ex/ao.sprd2.gif

The NOA is now confidently heading negative towards the middle of January, not very negative like last December but negative non the less. As for the AO, this is less clear some runs suggest negative, others suggest positive. My take on this would be a more neutral forecast as mid January arrives.

I'd be a bit wary of reading too much into those forecasts as they are just a representation of the ensemble members, unfortunately i've never managed to find a totally independent AO and NAO forecast.

Just a side note regarding the upstream pattern, NOAA mentioned yesterday evening that they expected some de-amplification of the pattern in the USA past ten days which isn't great news, however even though this is the medium term discussions of this morning this seems to suggest otherwise today, that any flattening will only be temporary:

THIS LEANS TOWARD A

MODERATELY PROGRESSIVE SOLN OVER THE WEST/PLAINS BY LATE IN THE

FCST GIVEN A BRIEF RETURN TO LOWER AMPLIFIED MEAN FLOW UPSTREAM.

We certainly need the upstream pattern to hold on to some amplification.

Edited December 30, 2011 by nick sussex

[Derp Patrol]

Well the GFS is still showing atlantic dominated weather throughout. The reliable time frame shows a continuation of average-mild weather which really does not look like changing any time soon. All in all a pretty average winter outlook for the UK

[Buzz]

Well the GFS is still showing atlantic dominated weather throughout. The reliable time frame shows a continuation of average-mild weather which really does not look like changing any time soon. All in all a pretty average winter outlook for the UK

If you're just looking at the reliable, short-term GFS charts, yes ............

[weathe20]

Yes I know John, hopefully our poster will think twice in future before making such bold statements that simply mislead less experienced members.

It is not a bold statement, I dont draw the charts, I can only comment on what they show.

Thanks Grimsby for attaching the charts.

Nice to be shot down for trying to add to this thread...thanks shedhead

What am i supposed to do? Comment on the exact oppostite to what a chart is showing shedhead? For example... the NAO is heading massively positive...when it very obvious heading towards neutral / negative???

Wont bother again.

Edit:

If it was the end of June and I said summer is over from current poor charts, I would get shot down totally. Whats the date? What time of year is it?

Edited December 30, 2011 by phil n.warks.
I agree but can`t allow sniping

[Osbourne One-Nil]

Yes I know John, hopefully our poster will think twice in future before making such bold statements that simply mislead less experienced members.

Shed, they don't have to meet with your approval you know. If you've a problem with a post, PM the team, as you have done in the past. That's what we're here for. Thanks.

[weathe20]

Shed, they don't have to meet with your approval you know. If you've a problem with a post, PM the team, as you have done in the past. That's what we're here for. Thanks.

My post was not misleading. I just commented on what the NAO, AO charts ACTUALLY SHOW.

[Derp Patrol]

If you're just looking at the reliable, short-term GFS charts, yes ............

Which is really the only part that should be looked at to make sense of the weather

[wolvesfan]

Personally i can't see whats wrong with the post from weatha20,the three statements are all correct,the NAO,AO are forecast to trend negative this will decrease westerly airflow for the uk,and increase easterly airflow to the polar region bringing about a northen hemisphere pattern change.Ridging is also being shown from a mid atlantic high and troughing to eastern europe on most of the mods at the moment.I'm a less experienced model watcher and it wasn't missleading to me.

Edited December 30, 2011 by phil n.warks.
Removed copy of deleted post

[dixonoid]

Looking at the Ao and Nao at the moment, they do look like they are heading neutral to negative, but this also showed during November and December, and they both ended up positive, the only difference I can see now is that they are heading into the negative with possible strat warming, which is a more positive sign than November and December. So my conclusion is that we maybe heading into the negative at the moment by the graphs, but will they stay like that?

[phil nw.]

Some posts have been edited/deleted,because of unfriendly comments.

If you can`t respond to posts you disagree with by discussing the output constructively-then press the report button or go onto the moaning thread.

[Grimsby Snow Lover]

Looking at the Ao and Nao at the moment, they do look like they are heading neutral to negative, but this also showed during November and December, and they both ended up positive, the only difference I can see now is that they are heading into the negative with possible strat warming, which is a more positive sign than November and December. So my conclusion is that we maybe heading into the negative at the moment by the graphs, but will they stay like that?

Just to add to your post D, during November and December the NAO/AO charts only showed a brief dip to neutral before quickly returning positive again. The difference with the forecasts graphs this time is that the dip to neutral/negaive looks more prolonged. How long is anyones guess at the minute. As Nick S mentioned earlier on these charts are only as reliable as the others on here so nothing is guarenteed yet.

[weathe20]

Personally i can't see whats wrong with the post from weatha20,the three statements are all correct,the NAO,AO are forecast to trend negative this will decrease westerly airflow for the uk,and increase easterly airflow to the polar region bringing about a northen hemisphere pattern change.Ridging is also being shown from a mid atlantic high and troughing to eastern europe on most of the mods at the moment.I'm a less experienced model watcher and it wasn't missleading to me.

Thank you wolvesfan, I was just trying to positively add to this thread.Im very interested how our current may change, and what things to look at to indicate a change. The NAO and AO was just something I saw and thought it was worth commenting on. But as for now the models look zonal. When we get stuck in such a pattern, severe cold, or mild, or hot, I always find it interesting see what occurs to change a current weather pattern.

Edited December 30, 2011 by phil n.warks.
We agree but OT comments removed

[Jason T]

Bit of an interesting read this, However could explain certain issues relating to the GFS. Hope the MODS will allow, If it means nothing then sincere apologise's.

If you look at the verification charts you see we have a projected dip to negative in the NAO on the last few runs of the GFS. The AO, while not going negative makes a drop towards neutral. These drops all happen in the 26th-29th date range. It offers some hope along with a PNA that should be positive in this timeframe.

I used these charts, however, to illustrate how we should proceed with caution with the GFS projections here, even from only 8 days out. The blue line is the actual verification, and the gray area is a single model run (4X daily). You can see the recent projected dips have not nearly verified over the last month.

We'll keep watching.

Edited December 30, 2011 by silver line

[syed2878]

I do agree the met makes a blonder now and then so far this autumn-winter they have done well and the model shows that too. Happy newyear every1.

[tcc]

Seeing the Op on the ensembles graph takes me back a few years (07 or 08 maybe?) when the GFS Op went off on one showing cold (beast from the east) run after run after run, yet the rest of the ensembles refused to follow it's lead.

There was even one run from the ECM which supported it, however within T120 or T96, the Op fell in line with the rest of the ensembles. I think it didn't take into consideration a shortwave off Norway.

Anyway my point being is that this is what we could be seeing with the warm Op against the rest, it'll be interesting to see what will be correct.

[Cecil Hogmanay Melchett]

Well 12z gfs is an improvement on recent days but nothing to get excited about,the meto update posibly reflects that run with a UK high perhaps giving some colder conditons esp at night if skies clear.

If the best we can hope for at the moment is a mid lat high(And given the state of the NH patterns) it probably is,then i'll take it over the last couple of wet and miserable days here!!

[The PIT]

I think we should forget about lala land and concrentrate on next week. If the GFS comes off a widespread windy spell for most of England which could be a problem if the earlier storm comes off for Tuesday as it will tricky to get any repairs done. 80 - 90 possible on Tuesday across Wales north Midlands and Nortehrn England followed gusts up to sixty during wednesday. Far from boring folks. No warnings yet on Met office site so time for it to go the way of the pear. Some near time model watching coming up.

[Tim Bland]

Well 12z gfs is an improvement on recent days but nothing to get excited about,the meto update posibly reflects that run with a UK high perhaps giving some colder conditons esp at night if skies clear.

If the best we can hope for at the moment is a mid lat high(And given the state of the NH patterns) it probably is,then i'll take it over the last couple of wet and miserable days here!!

Doesn't look like much of an improvement to me! Above 0c uppers north of Shetland, snow melting in scotish ski resorts, a long way from what many were predicting for mid Jan.

[Cecil Hogmanay Melchett]

Doesn't look like much of an improvement to me! Above 0c uppers north of Shetland, snow melting in scotish ski resorts, a long way from what many were predicting for mid Jan.

Sorry tim i should have been less IMBY in my post,its been very wet and horrible here for the last 2 or 3 days and i'd welcome any sort of high pressure spell if we cant get high latitude blocking in the outlook,and lets face it,taking the models at face value there is going to be no high latitude blocking for the forseeable future!!

<_<

[snowingman]

the 12 GFS is dire !! utterly consistent with models over the past 4 weeks - the Bartlett high is as SOLID as a ROCK, and not going anywhere fast . We are stuck in probably the most stable situation I have seen in many a year. The polar vortex is tight and concentrated - with our Bartlett under no influence to fade or be displaced. What this means for almost all of us is a continuation of depressing damp and mild/very mild weather for the next 2 weeks , but more than likely the next 8 weeks.

Could this be the least snowy winter ever?? I reckon that the majority of the UK will see no snow this winter, remarkable in any winter period.

I would imagine we will be breaking the warmest January on record based on these charts

[Backtrack]

What's this Barlett high I keep hearing?

There is no Barlett high on the GFS....