Model Output Discussion; into 2015

[pdiddy]

 

In summary, no issue with you disagreeing with Crewe. Nor is there any issue with people pointing out they will be happy with a temporary PM flow (whatever floats your boat really), but maybe reflect next time on how you might be more respectful in doing so.

 

 With respect, I think the point is the chart posted was selective and 2 days later, a good part of the UK is under -6 uppers.

[Long haul to mild]

Although still nothing of note within the GEFS in terms of anything cold, a trend today has been for a few of them to run the jet further south and lose the heights over Iberia. This won't do any harm at all for second half of Jan if it comes to pass. Before that, IMO we might struggle a bit for cold enough uppers to our east, but stranger things have happened.

Would be good to see that happen; the persistence of those heights to our South has often been a significant stumbling block thus far with respect to getting any colder air drawn far enough down across the country.

[swilliam]

I am aware that I am doubting ECM again (was chastised for doing it this morning)  but a 1055hpa High over Alaska is quite rare, I thought 1050hpa were uncommon (more common in Siberia):

 

ECH1-240 (4).gif

 

So I would be very wary of taking that seriously and looking at the height bias for D7 for the Alaskan Region you can see that even at that early stage it has massively over done heights on the last 5 12z runs:

 

NOAA_NWS_NCEP_WPC_MODEL_DIAGNOSTIC_-_INTERACTIVE_MODEL_BIAS_PAGE 7.png Mean: EDH1-240 (2).gif

 

Just something to take into account.

They cannot be that uncommon - the NH chart I posted for Jan 18th 2013 had one of 1050 hPa and in fact this grew to 1060 hPa by Jan 20th.

 

 

Point taken about ECM overdoing heights in the later charts though.

[leemondo]

Hi everyone, I don't think I have ever posted in this thread before, more of a regional bod, but I do follow the MOD thread with great interest.

I do not have a great amount of free time to learn how to read the charts, so I value everyone's insights and views, however I have found the last 48 hours almost unbearable, almost to the point where I wanted to throw in the towel, the level of personal attacks and disharmony shocked me.

Everyone has a personal preference for the weather, that's what makes this forum so amazing, I just hope that the waters have calmed and you guys with the knowledge can co-exist now!

 

So thanks once again everyone, have a fantastic new year!

[Jason M]

 

 With respect, I think the point is the chart posted was selective and 2 days later, a good part of the UK is under -6 uppers.

 

 

Usually when people say 'with respect' they mean the polar (pardon the pun )opposite :smiliz19: . Anyway, yes, I'd imagine it was selective, but I could as easily say the same about the chart above on the basis that two days before there was a mild chart (to be fair I haven't checked the uppers on Crewe's chart as not really relevant). The point is that he was saying the overall pattern was very poor and I think if we start requiring people to post charts that show the opposite of the point they are making life is going to get very confusing indeed (might be quite fun though!!).

 

The thread is usually pretty friendly but over Christmas its got a bit nasty at times, with people getting slated for making fair points. I want to see all views in here and would like the posters such as Knocker and Ian Brown to be back posting.  

 

FWIW I agree with what Crewe said but this is a dynamic thread and even this evening people such as BA are starting to latch onto new trends.  Would be good to get some cold charts in the GEFS, even if just to whet peoples appetite again.

Edited December 27, 2014 by Jason M

[Winter Cold]

Well to say its at T144, there is decent agreement between all models tonight for a cold ~2nd January, or somewhere around that period. UKMO, ECM, both GFS brothers and GEM all have cold uppers again approaching from the west. Could it just be coincidence or have they picked up on a strong signal??

 

Id love two snowy Fridays in a row! :w00t:

[whiskers]

Well to say its at T144, there is decent agreement between all models tonight for a cold ~2nd January, or somewhere around that period. UKMO, ECM, both GFS brothers and GEM all have cold uppers again approaching from the west. Could it just be coincidence or have they picked up on a strong signal??

 

Id love two snowy Fridays in a row! :w00t:

I would love one snowy Friday!

[mulzy]

With respect, I think the point is the chart posted was selective and 2 days later, a good part of the UK is under -6 uppers.

-6 uppers in an Atlantic flow - can't wait for my cold rain!

PS Crewe Cold is absolutely spot on. Polar Maritime or returning Polar Maritime is great for upland parts of Northern Britain but for most low lying areas of the South, it is in all honesty pretty useless as far as significant snow is concerned.

Edited December 27, 2014 by mulzy

[Frosty.]

Tonight's Ecm 12z ensemble mean is not without interest, once the current cold spell expires by midweek or soon after, the mean at T+144 / 168 hours hints at a brief Arctic blast with a bit more amplification, some signs of ridging to the west and a trough to the NE, perhaps with a bit more westward adjustment we could see a blast from the north with snow showers and sharp frosts. Looking further on, the polar front jet is to the south of the BI with the uk in a zone of strong chilly westerly winds of arctic origins so I think there is scope going forward for further wintry spells but with short milder blips too.

Edited December 27, 2014 by Frosty.

[sorepaw1]

I used to look at the coldswell GFS charts what happened to them or does anyone know a link where I can view the same runs .I'm using various chart models at the moment including weather online. I think we need a lot more high pressure north of the uk to give us a decent cold spell.there seems to be a lot of low pressure activity around Greenland and to the east of the uk. I can't remember seeing this much low activity in recent years of computer model watching. I stand to be corrected of course.

[johnholmes]

A question for those who really are able to answer this?

Can the effects in the Stratosphere affect down to sea level within 168hours?

If not at what time scale can such effects perhaps be noticed?

 

thanks

[mulzy]

It is the Model output discussion thread - pdiddy has posted exactly that.

What does London not getting any snow have to do with it?

Some folk on here really have to log off this now and then and venture outdoors - I cringe reading this thread at times - the people who cause all the angst and bickering in here are the folk who are depressed about not seeing any snowfall and so they come into this thread to have a whinge about any sort of chart that does not show snow for them.

Please keep that for the moans thread or have a whinge about it in the regional along with other folk who are depressed about it.

This thread is UK wide - current charts show PM incursions and that brings snow for some.

Now let's all get along, get back to discussing what the charts show and stop this constant bed wetting schoolboy outlook on anything that is not showing the favoured weather type for your own postcode.

Cheers.

Calm down dear! Think you need to re-read my post...

[Paul_1978]

I want to see all views in here and would like the posters such as Knocker and Ian Brown to be back posting.  

 

Woah! ;-)

[Methuselah]

Calm down dear! Think you need to re-read my post...

It rather seems as if quite a few of you need to calm down. So please keep things polite - and friendly! :smiliz64:

[johnholmes]

Not to worry frosty, I have a thick skin, and I missed the 'fun' anyway as I was out at the time.

 

But, at the risk of setting of WW111 I really would love to come in here at any time of the 24 hours and see folk discussing amicably their version of a particular model.

To add a little science, okay in the name of anomaly charts, and they, not totally in agreement but seem to be suggesting, say in the 8 day + period that the Atlantic, at least at 500mb, if that does not sound too odd, is going to be the main player for most of the country, some influence in the south due to a possible ridge effect at 500mb, but for many a quite mobile and disturbed westerly 500mb flow. Expect at least one spell of very windy weather with them, although the pattern does not suggest the type of development we got a few weeks back. Relatively cold air at height as well, with NOAA charts continuing to suggest somewhat lower 500mb heights than they did a few days ago. This of course does allow for temporary incursions of TM air, chiefly for the south, as a deep surface feature comes across the Atlantic but also some rather colder slots and a temporary calmer spell as the ridge, mentioned above at 500mb, takes over for a short time. A quick description being fairly unsettled the further N/W you live and the more settled the further S/and SE you live.

We will have to see how far out this is in 8-15 days time when we can compare the 500mb actual chart over several days with the current prediction.

Edited December 27, 2014 by johnholmes

[bluearmy]

A question for those who really are able to answer this?

Can the effects in the Stratosphere affect down to sea level within 168hours?

If not at what time scale can such effects perhaps be noticed?

 

thanks

Actually john, I was thinking that over the next 6/10 days, I see the strat and trop in very close agreement. As close to one dynamic as I recall on a change in pattern as the split occurs.

And the 18z gfsp is another step towards what I posted earlier this evening. Also, yes, that is a chunk of discarded Canadian vortex at our latitude in the Atlantic T186!

[Timmytour]

JH.....it's been obvious since the September CET came within 0.2C of August's that we'd have to wait until the end of Jan for a taste of real winter that extends througout most of February.....people should look at statistics not the models!!! <tongue firmly in cheek>

[Snowman.]

Para looking tasty.

 

[Frosty.]

No problem John :-)

Anyway, compared to last Christmas the models are much more seasonal and the current cold will dig deeper in the next few days with severe frosts and freezing fog as high pressure becomes centred across southern areas before slowly drifting away SE. Then we are likely to see a number of polar maritime shots of variable potency.

[DAVID SNOW]

A question for those who really are able to answer this?

Can the effects in the Stratosphere affect down to sea level within 168hours?

If not at what time scale can such effects perhaps be noticed?

 

thanks

 

Thanks John, not usually within 172 hours unless the B+Q is coupled with the GLAMM rock ( sometimes INXS) this would then lead onto a slippy sliddeos( stanly unwin) resulting in widespread outbreaks of profanities( if Stanley) got it wrong.

[Polar Maritime]

The Arctic Hight much stronger on this run, And a bigger lobe of PV dropping S/E over the UK, Some interesting synoptic's starting to show as we move into January.

 

Edited December 27, 2014 by Polar Maritime

[snowy weather]

The Arctic Hight much stronger on this run, And a bigger lobe of PV dropping S/E over the UK, Some interesting synoptic's starting to show as we move into January.

 

what does the polar vortex dropping south mean please?

Thanks

[bobbydog]

A question for those who really are able to answer this?

Can the effects in the Stratosphere affect down to sea level within 168hours?

If not at what time scale can such effects perhaps be noticed?

 

thanks

hi john, as no-one has directly answered your question yet, having taken on board the info provided by those more qualified, i believe the effects of a warming in the strat take about 2 weeks to have an effect on the ground. therefore only the GFS would attempt to model any trop responses to the strat if these were shown at the beginning of the runs (as it is the only one to go out to that range)

hope that helps

Rob.

[Polar Maritime]

what does the polar vortex dropping south mean please?

Thanks

 

It means a stronger signal for this to happen than on the last run, And a much better chance of colder air being pushed South like this, Giving heavy Snowfall for Southern UK.

 

Edited December 27, 2014 by Polar Maritime

[snowy weather]

It means a stronger signal for this to happen than on the last run, And a much better chance of colder air being pushed South like this.

 

thanks mate (I have learnt so much in the last couple of weeks  )