Jump to content

Model Output Discussion - cold spell to end Autumn


Message added by Paul

Please only post model discussion in this thread. 

For more general chat and banter, or moans and ramps loosely around the models, please head to the banter thread:
https://www.netweather.tv/forum/topic/86721-model-moans-ramps-and-banter/

For general weather chat including about the snow/cold chances around the country, please go to the regional threads:
https://www.netweather.tv/forum/forum/142-regional-discussions/

Thank you!

Recommended Posts

I think people need to remain very calm with the daily ups and downs from the charts of the last week.

The charts don't seem as good as last night but I have a real feeling, from years of weather charts watching, that something very special is brewing. In fact I think we may need to take a little bit of disappointment tonight and maybe for a few days, to get a much improved bigger picture for the weeks ahead.

These have been very special charts and I have not seen such, except Nov/Dec 2010.

Just a feeling, but who know I may be proved wrong

  • Like 5
Link to post
Share on other sites
  • Replies 5.7k
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

You know what - I havent seen 1 hopecast on here. People have put all their points of view across in a pretty good mannor- infact its been pretty good debate. The only post that sticks out a mile

Still coming slowly off a cautious fence Long term total global atmospheric angular momentum trends can tell you a lot about pattern changes due to the effects the rises and falls in global wind-

Afternoon All - A frantic few days on here with pages & pages of posts flying through in a matter of hours- I think we have 2 main discussion points at the moment-  1) The short to

Posted Images

I reckon we'll land that northerly by 384.....like pulling teeth this run!  This is the rollercoaster of model watching, oh the highs and lows.  Sack this one off, back again in the morning for another go!

gfsnh-0-234.png?18

Link to post
Share on other sites
1 minute ago, karlos1983 said:

Well to me this just looks very similar to the ECM. So I’m not concerned. Evolving pattern.

You're in denial! :D Its currently evolving in a very complicated tiresome way.

Someone might get lucky if the pattern gets edged south as the shortwaves decide what they want to do.

Lots of cold to the north ready to engage and deliver a snow event if by some miracle the weather Gods play nice!

  • Haha 2
Link to post
Share on other sites
23 minutes ago, Daniel* said:

Well, that is what this run suggests. I am very baffled by that the parameters on offer there should allow snowfall even for at least the high ground. Dew points are below freezing.

A5077C2D-C1D1-4E77-AF97-D101367556F9.thumb.gif.26c4c50d06693f4edb9db3d796c27b34.gif

I would take a wild stab at poor isotherm heights / poor wet-bulb temps instead.. Even at 90 hours, it's a blind call. 

  • Like 2
Link to post
Share on other sites
16 minutes ago, MattStoke said:

That model was complete trash last winter. Like most medium to long term models. Hope its the same this winter!

My mistake - was mondays run! Latest week 3 looks a bit more blocked than it did last run

Link to post
Share on other sites
2 minutes ago, karlos1983 said:

@cyclonic happiness yes, it’s been like pulling teeth last past few days. I think I need a break, been a long autumn chasing winter charts :vava: :lazy:

That's it, karlos. I've had enough. I'm going to go and stick red-hot wires down my root canals!:crazy:

  • Like 2
  • Haha 4
Link to post
Share on other sites

Met Office did mention the cold returning next week but with the south milder/less cold initially. The 18z looks to be along those lines, with perhaps the GFS doing its usual of overblowing the low from the Atlantic (I hope).

  • Like 1
Link to post
Share on other sites

To be fair - If the low was weaker and ejected South-Eastwards faster instead of just sitting there waiting for god knows what, this would have been a fantastic run. It would have allowed the cold uppers to the North to move across the UK and would probably bring a snowfall event to some.

It's not that far off being a Carlsberg run.

  • Like 1
Link to post
Share on other sites
8 minutes ago, nick sussex said:

You're in denial! :D Its currently evolving in a very complicated tiresome way.

Someone might get lucky if the pattern gets edged south as the shortwaves decide what they want to do.

Lots of cold to the north ready to engage and deliver a snow event if by some miracle the weather Gods play nice!

I hear you Nick, but somehow we still keep managing to pull it out of the modelling bag. 

EF38794D-9276-410A-A77A-690E9AA907CC.thumb.png.14f1f68368df1a3fbf84049c7cffa02e.png

Im sure I saw someone point out the 9th as optimal timing for blocking recently..

Edited by karlos1983
  • Like 1
Link to post
Share on other sites
Just now, Ryerson said:

It's remarkable that 6 hours ago the GEFS never really offered this.

It's not remarkable-

I've never rated the ensembles nor ensemble forecasting, as I've said many times over the years. I especially don't have time for the GEFS! They're about as useful as a solar powered torch IMO.

  • Like 2
  • Thanks 1
  • Confused 1
Link to post
Share on other sites
1 minute ago, Ryerson said:

The JMA is also on board with this theme.

It's remarkable that 6 hours ago the GEFS never really offered this.

Which is why we should all be cautious with watching every run and jumping to a conclusion. 2/3 GFS model runs and 2 ECM runs with different scenarios... We've just had a full day of beautiful charts for cold fans.

The race goes on.

  • Like 1
Link to post
Share on other sites
  13 hours ago, northwestsnow said:

Hmmmm GFS0z was getting towards being a cold outlier in the crucial 7th Dec timeframe.

Its only my two penneth but i think the phrase 'Huston we have a problem' is ringing in my ears this morning

I'm sure UKMO has modelled this shortwave energy ejecting North before and scuppered a previous cold spell- hope history is not repeating itself here!!

On a brighter note some lovely cold weather until the weekend- i'm sure the temps will drop really quite low Tue/wed/thur night..

I think there is a problem I think everything is moving away from cold to just around average. Even if we get the artic air to come south via a block this morning ECM is showing energy getting through the high if that interacts with the artic air it could deepen into a full blown depresion  and cut of the air and send it to the Atlantic 

 

I wouldn' be surprised if this cold spell beyond the weekend is dead by the 12z runs

That's what i posted this morning I got it wrong by 6 hours...... I think we've seen next week' cold spell killed off. 

  • Haha 1
  • Confused 3
Link to post
Share on other sites

Having a had a look at the latest trends being picked up by the ECM 12z and now the GFS 18z, it looks as though a complex pattern is evolving at around the 7 day timeframe.

This is based around two areas of high pressure, a blocking high to the NW centred near Greenland and an area of high pressure to the SE over Europe and two areas of low pressure, one out to the SW in the azores and one to the NE up over Northern Scandinavia

How these interact is crucial, obviously affected by the much maligned Shortwaves! The most favoured outcome for coldies is for more of the Southern high pressure to link up with the Greenie high, maintaining an Atlantic block, and allowing Northerly winds to flow down through the country. Conversely, the worst case scenario is for more of the heights to sink south, thus setting up a West based NAO- with winds coming up from the SW as the azores low is allowed to move towards the UK due to a lack of Atlantic blocking.

Obviously, with these kid of setups, the North and East of the country is in the best position as it is closest to any northerly outbreaks that may occur.

Now there is still lots of time for change with this set up and little alterations East or West will have a great impact on whether the UK see's the cold upper 850hpa's move down across the country or whether we are stuck in a somewhat milder set up.

What will probably happen? An evolution somewhere inbetween. 

However, the coldie in me wants the Northerly winds to win the battle!

Edited by Building Blocks
  • Like 1
Link to post
Share on other sites

The models are struggling due to MJO - Its just moved into phase 4 and very active in Continental Maritime area with possible cyclone forming, You then have an area around Southern India where potential for circulation is possible too. That means all prediction about a moderate phase 4 are up in the air. (Pardon the pun)

This could move the MJO back into Circle of death prematurely

Negative NAO and moderate phase 4 ( 7 -10 days lag) are total contrasts

Until the models get a grip on that area those small margins up with us will matter a lot, The main thing to watch is the possible Cyclone near south of India as i believe thats what makes the difference ( we want some activity around that area to keep our high to the West next week.

  • Like 3
Link to post
Share on other sites

The models can try and take away our cold spell next week but they can't take away our sense of humour!;)

Another great day / night of ups and downs..let's do it all again tomorrow.:drinks:

Next week is far from resolved but I remain positive regarding the cold potential, there is still plenty to be positive about, we have arctic air about to push south.:santa-emoji::cold-emoji:

  • Like 5
Link to post
Share on other sites

I cant buy into that low pressure in the Atlantic resisting the Nly incursion at time +220hrs. on the 18z GFS. I think it s a blip as the models are struggling with the whole evolution past time +144hrs. Lets face it is just classic GFS where it goes along with a pattern, drops it and then comes back with it again in a much more reliable timeframe (like last weeks cold weather).

  • Like 1
Link to post
Share on other sites
4 minutes ago, pyrotech said:

The models are struggling due to MJO - Its just moved into phase 4 and very active in Continental Maritime area with possible cyclone forming, You then have an area around Southern India where potential for circulation is possible too. That means all prediction about a moderate phase 4 are up in the air. (Pardon the pun)

This could move the MJO back into Circle of death prematurely

Negative NAO and moderate phase 4 ( 7 -10 days lag) are total contrasts

Until the models get a grip on that area those small margins up with us will matter a lot, The main thing to watch is the possible Cyclone near south of India as i believe thats what makes the difference ( we want some activity around that area to keep our high to the West next week.

That’s exactly what I said 

but I used the terminology ( flip flop )

thats exactly what I meant

  • Like 2
Link to post
Share on other sites
Guest
This topic is now closed to further replies.
×
×
  • Create New...