Model Output Discussion - 8th December Onwards

[Stoxs]

All togeather now...........

Who do you think you are kidding mr GFS if you think old Englands Down!!

da daada dada daaadaddadaadaaaaaa

just reminds me of the starting sequence to dads army

we are being attacked from all angles and we sit in the middle with bugger all!!

DONT PANIC MR MANNERING!!!!!!

[ITSY]

For anyone who read my comments RE the 12ZGFS runs, this is exactly the sort of scenario I was hinting at. The models don't know what way to turn but this is as likely (I would say more likely) than any. (Explanation is further back in these pages). This will be on the cold side, perhaps a cold outlier to some small extent, but it will be interesting to see its level of support. Very plausible and we are back in the game by T+144.

[bluearmy]

The five day faxes have not survived 12 hours recently.

[JP1972]

I can see the mods having a field day with the delete button in the morning!!

[nick sussex]

The five day faxes have not survived 12 hours recently.

Yes lets hope that trend continues!

That fax chart for 120hrs certainly needs to meet an untimely end!

[BARRY]

now we await the 00z with more enthusiasm

[TEITS]

any transistional snow next week though has vanished on this run , the over lying trend has been for the Mider air to creep in Wednesday well ahead of the PPN , Nice to see the blocking putting up a ight as we head towards +180 but looking at the charts its an odd run , as in 9 out of 10 runs that low would go straight through.....

If I was honest the 18Z was always likely early in the run. If we continue to see this trend of the pattern shifting W then an E,ly is a perfectly reasonable outcome. This is why I was surprised the Met O seemed so confident about next week.

Probably get into trouble for saying so but these days forecasters rely too much on computer models to do the job for them. Gone are the days of using forecasting ability and instinct. Remember the fiasco last winter when the radar obviously suggested the NAE was wrong at +0 and yet the forecasters still predicted snowfall in W Midlands when it was pretty obvious the models had got it wrong.

[Panayiotis]

Normally i understand, but could you say this a little clearer please?

Here you go,what he is talking about is very similar to lake effect snow

http://en.wikipedia.org/wiki/Lake-effect_snow

[Cloud 10]

Yes lets hope that trend continues!

That fax chart for 120hrs certainly needs to meet an untimely end!

I'm not overly keen on the +96hrs either!

[Liam J]

Forget snow, Tonight's late faxes show some disturbing weather heading for the SW late in the week.

http://www.meteociel...h=96&carte=2000

http://www.meteociel...=120&carte=2000

Indeed a very worrying set of charts with wind damage on top of the further (serious) flooding misery should these charts verify. Much weather action to talk about this week without being led up the garden path yet again with some phantom easterly. When it's actually happening outside my window thats when I'll believe it

[mulzy]

If I was honest the 18Z was always likely early in the run. If we continue to see this trend of the pattern shifting W then an E,ly is a perfectly reasonable outcome. This is why I was surprised the Met O seemed so confident about next week.

Probably get into trouble for saying so but these days forecasters rely too much on computer models to do the job for them. Gone are the days of using forecasting ability and instinct. Remember the fiasco last winter when the radar obviously suggested the NAE was wrong at +0 and yet the forecasters still predicted snowfall in W Midlands when it was pretty obvious the models had got it wrong.

Oh yes - remember that one, the same NAE predicted next to nothing here in West London - we got over 2/3 inches that day.

[chris55]

The 18z certainly "Trumps" the 12z. Right on Cue as well!!

[gaia rules]

Although this is my 4th post (Horray) I have been watching models for 35 years. I have to say that this is the most confused I have seen them in years. I am now not even convinced that the timing of the breakdown from the Atlantic can be believed at only at T+90.

[Snowman.]

Classic pub run, then drops the entire thing a goes for a full PV, classic GFS.

[TEITS]

Oh yes - remember that one, the same NAE predicted next to nothing here in West London - we got over 2/3 inches that day.

What I don't understand is sometimes the Met O seem to be 24hrs behind the rest of us on here, sometimes even more.

For example the forecast issued today for my region for Tues to Thurs.

"Bright or sunny spells but remaining cold, with hard overnight frosts lasting well into the day. Perhaps some wintry showers in the east on Tuesday, otherwise mostly dry."

That is what I said on Thursday and yet it took the Met O till sunday to downgrade the snow shower threat in my region.

Apologies if im coming across as arrogant but this particular period has not been the Met O's greatest hour and the same can be said for the Fax/models.

[Nick123]

So can someone please tell me : Snow for NE England at the end of this week... on or off? Also, does it look like the Atlantic will be in charge for a long time or just a few days?

[LomondSnowstorm]

If I was honest the 18Z was always likely early in the run. If we continue to see this trend of the pattern shifting W then an E,ly is a perfectly reasonable outcome. This is why I was surprised the Met O seemed so confident about next week.

Probably get into trouble for saying so but these days forecasters rely too much on computer models to do the job for them. Gone are the days of using forecasting ability and instinct. Remember the fiasco last winter when the radar obviously suggested the NAE was wrong at +0 and yet the forecasters still predicted snowfall in W Midlands when it was pretty obvious the models had got it wrong.

Yep, I think given the volatility of the models in the last week putting any outcome as 'high confidence' past day 5 is being very presumptious, even with good model agreement, which there doesn't appear to be anyway. I don't think we're done with the changes by any means, this is a notoriously tough setup to model and I'd urge everyone on here to continue to be extra cautious with the output over the next few days.

I have similar horror stories about failure to adapt to short range changes, including one where a pre-recorded BBC Scotland forecast following a report on heavy snow didn't even mention the possibility of snow. Not that I want to get into Met bashing here, they have a tough job trying to decipher this output as well as balancing the PR side of things so I do have sympathy for them.

Edited December 9, 2012 by LomondSnowstorm

[East_England_Stormchaser91]

Does anyone want to invest in a huge pane of glass we can stick up from france all the way to the faroe islands, so the atlantic can stop spoiling our optimism!! Very interesting times ahead though, we can expect a lot of ups and downs this week I reckon.

[Panayiotis]

The past runs have shown this for around the 20th if you see, there is is low pressure in Southern Europe bringing us easterly winds. Certainly a trend and i will be looking quite closely at this to see how it develops.

Edited December 9, 2012 by panayiotis

[Timmytour]

The models have really teased us recently.

Rather like winning a football game 1-0 with 90 minutes almost up, only for the other side to score twice in the 90th minute to deny Spurs coldies the chance of victory.

Sorry, couldn't resist

I really don't beieve this. Been in London all day with the kids. Was looking forward to watching MotD for once without knowing any off the results, and especially the Spurs game. Back home, kids dropped off back with thier mum, avoided Twitter and facebook to keep in the dark. just model watching along with the thread. Having seen the way 18z panned out I started looking back through the thread to see what people were thinking prior to it. Then I see this one. And I know!!!!

Sorry Mods...way off topic but...well as frustrating as model watching itself!

[Craigers]

If all of the models start with the gfs westward trend tomorrow then could this be the life line for our easterly? hope so

[Dean E]

All weekend, I've been saying the models (especially the GFS) will slow push everything westwards. I've seen its hundreds of times over the years and this setup is no different... Blocks and cold air are incredible difficult to just 'shove' out of the way.

The Met office faxs' for Friday is very concerning indeed, the ground to the SW is still extremely saturated and wouldn't take much rain to cause more serious conditions. From this weeks experience, the Fax charts have only been correct out to 48 hours, with beyond that being changed every day. Let's hope this is the case tomorrow. With cold air and warm air fighting with each other, a strong Low developing is not out of the question

As much as I love the cold snaps being modeled and a possible hold on of the block, I really do feel a worried for the SW, if that Low becomes a more occurring feature.

SM

[gaia rules]

What I don't understand is sometimes the Met O seem to be 24hrs behind the rest of us on here, sometimes even more.

For example the forecast issued today for my region for Tues to Thurs.

"Bright or sunny spells but remaining cold, with hard overnight frosts lasting well into the day. Perhaps some wintry showers in the east on Tuesday, otherwise mostly dry."

That is what I said on Thursday and yet it took the Met O till sunday to downgrade the snow shower threat in my region.

Apologies if im coming across as arrogant but this particular period has not been the Met O's greatest hour and the same can be said for the Fax/models.

That's because there are no windows in the central forecast room!...I have worked there..... it could be a blizzard outside and they wouldn't know...they also have no more regional forecasters who were vital in bringing real weather observations and comment. My opinion is that forecasting still depends on experience + computers+ common sense. Sorry off topic well kind of off topic.

[BARRY]

We do not need anymore rain the fields still have run off which is not normally there so lets hope those faxs are wrong

[damianslaw]

Take what the models are showing 96hrs + with a pinch of salt at the moment - as I said yesterday in these set ups when you have two major dominant forces trying to do battle over the country i.e. high out east, low out west there is a great margin of room for error in the models.

Take the FAX charts which in all honesty have chopped and changed so much in recent days and are struggling with the 'shortwave' developments. GFS continues to chop and change with various scenarios as shown by this evening 18Z and the ECM which tends to be the best performer when it comes to easterly blocking scenarios, had to do a major u-turn within the space of 24 hrs in its 96-120 hr output.

The position and strength of the shortwave attack spilling out of the low pressure on Thursday is noteworthy as it suggests the current super low pressure system setting up shop over the atlantic is going to struggle against the block and will eventually simply squeeze itself to death so to speak with further shortwaves spilling out from it from the SW and it will eventually once it has dropped copious rain over the country be forced on a SE path into Europe thanks to the very strong heights over west russia not budging anywhere fast - remember the air will be exceptionally dense with a well established entrenched cold pool never easy to dislodge. Heights will then be able to build out over the top of the trough- the end result a strong build of heights over Greenland and a northerly/northeasterly airflow.