Model Output Discussion - Autumn 2018

[blizzard81]

1 hour ago, nick sussex said:

After the recent stormy and wet weather it’s looking a lot better for the UK.

High pressure looks like taking over. 

The GFS 12 hrs looks a bit more like the ECM 00hrs, quicker to remove those lower heights to the nw .

It throws in a mini tease around day 9 and 10, although the main cold looks a bit too far east . It could though bring some much colder nights .

For coldies something to look out for if upstream develops a bit more amplitude in future runs . A bit too early to see anything of note but interesting to see whether the ECM might add a bit more amplitude into the mix .

Indeed Nick. The models over the last 48 hours or so have converged on a much more settled medium term outlook when compared to the previous few day's runs. Can somebody then please tell the meto. Even today's 6 - 15 day outlook sticks with the predominantly unsettled theme. They really can be way behind the game at times :) 

[Frosty.]

Looking through the GEFS 12z there is good support for a cold start to November with some arctic / polar maritime shots but equally there are some very mild runs too..not that it really matters at this stage with the meteorological winter still six weeks away but there is potential for some wintry weather end of oct / start of nov.☺

 

[SMU]

ECM 168> 192 says hello to a new pattern for the end if October

- AO heading south

- Huge PNA + Pattern 

- Deep Scandi Trough

- Retrograding Atlantic high...

[feb1991blizzard]

2 minutes ago, Steve Murr said:

ECM 168> 192 says hello to a new pattern for the end if October

- AO heading south

- Huge PNA + Pattern 

- Deep Scandi Trough

- Retrograding Atlantic high...

TBH the deep scandi trough and not dissimilar pattern was advertised on a few GEFS not so long ago Steve.

[blizzard81]

Just now, Steve Murr said:

ECM 168> 192 says hello to a new pattern for the end if October

- AO heading south

- Huge PNA + Pattern 

- Deep Scandi Trough

- Retrograding Atlantic high...

Was just going to comment on the ecm but you beat me to it. Incredible northern hemisphere shenanigans going on to say the least. Just look at that WAA up into the western Canadian Arctic by day 7. Even more epic by day 8. Great synoptics going forward enhancing UK cold winter prospects. 

[feb1991blizzard]

Anyhow the net impact of the pattern could be huge scandi early snow cover building up, given relatively early falls occurring already.

Edited October 16, 2018 by feb1991blizzard

[SMU]

1 minute ago, feb1991blizzard said:

TBH the deep scandi trough and not dissimilar pattern was advertised on a few GEFS not so long ago Steve.

Of course 

Whats very unusual is the depth of the high pressure into the pole for October in the PNA which then drives the trough further south - & the cold along with it- something I alluded to in the NH pattern thread yesterday-

[blizzard81]

Late October fog = cold snowy winter. Simple as!

[feb1991blizzard]

Just now, Steve Murr said:

Of course 

Whats very unusual is the depth of the high pressure into the pole for October in the PNA which then drives the trough further south - & the cold along with it- something I alluded to in the NH pattern thread yesterday-

Yes, was thinking we could do with a -AO to end October, don't want to bring that swearword October something index up again at he risk of derailing thread but not many stunning winters had a +AO all the way through October and what better part of Oct to have a buckled meridional NH pattern than the end of it.

[Frosty.]

What a day 10 tease from the Ecm 12z just about to pull the trigger with all that bottled up arctic air poised to surge south...would love to see days 11,12,13 etc!

[blizzard81]

The ecm gets a little carried away with itself from days 9 to 10. Days 4 through to 8 all good though. It's all about the building blocks at this time of year. The fun and games can start when they are supposed to. 

[bluearmy]

In the land of repeating patterns, the modelling over the past few days continues to promise much for coldies ..............

 

 

[blizzard81]

Just now, bluearmy said:

In the land of repeating patterns, the modelling over the past few days continues to promise much for coldies ..............

 

 

A BA ramp is a rare beast indeed. Must crack open a beer and raise to that.

[bluearmy]

20 minutes ago, blizzard81 said:

A BA ramp is a rare beast indeed. Must crack open a beer and raise to that.

Ah yes ... the land of repeating patterns ........ i’m late, i’m late for a very important date .........there’s another land of make believe ......fwiw, the theme that has been catching my eye is the diving troughing from the northwest ...... the high lat blocking we are also seeing is as likely to end up in the right place for cold nw Europe  as wrong .........the diving troughs in the east Atlantic would be a more reliable indicator of potential nw European cold imo .........

 

Edited October 16, 2018 by bluearmy

[Mike Poole]

Hmmm, I also would have liked to see the next few frames of the ECM 12z, a sudden flip to cold around the change of the month is increasingly the form horse, how well it would tie in with this year as a whole!

FV3, aka GFS parallel, shows a potent northerly blast here at T276:

Edited October 16, 2018 by Mike Poole

[Man With Beard]

30 minutes ago, Frosty. said:

What a day 10 tease from the Ecm 12z just about to pull the trigger with all that bottled up arctic air poised to surge south...would love to see days 11,12,13 etc!

T240... commonly known as a "trigger low"... and on cue for perhaps the first date of the autumn when lowland snow would be possible

It's not as if it's out of sync with the ensembles - but we need many more runs like this to get truly interested. 

[Cheshire Freeze]

What a pretty picture...

A tri-pronged attack on the trop vortex and a tanking AO

[Dancerwithwings]

43 minutes ago, bluearmy said:

In the land of repeating patterns, the modelling over the past few days continues to promise much for coldies ..............

 

 

A considered new name for FI.....fits well

suppose not, we'll stick with the 'dangling a carrot' metaphor 

Edited October 16, 2018 by Dancerwithwings

[Rayth]

40 minutes ago, Frosty. said:

would love to see days 11,12,13 etc!

 

As we change our clocks , we change our seasons

[tight isobar]

p-stamps...out @months end....

some really intresting mixes there.

meanwhile the designs are firmly in place for a monster pacific/western seaboard-bite....or formation into large mass USA.

bossing' any gain of the pv into usual territory....and ainding squeeze of smaller...yet significant arms of waa in and around the mid/upper latts...

just a case of trough and cell segment exactions.....winter in the northern hem has kicked off....and ...and is eyecatching on many levels.....

Edited October 16, 2018 by tight isobar

[damianslaw]

A generally pleasant spell ahead, with a rather ineffectual atlantic, thanks to significant ridge development over the UK, edging west as we move through the weekend, allowing frontal/trough to move down from the NW, bringing a spell of moderate rain for the NW, petering out as it moves into the ridge. Into next week both ECM and GFS consistent in showing the ridge holding firm to our west, and building which should maintain the generally calm conditions, risk of frost and fog and night, and a change in airstream will pull in some cooler air from off the atlantic as well, so maxima won't be far off average.

As we approach latter stages of next week, indications the ridge may shift sufficiently west to bring down a much chillier airstream from the north, with some form of trough/frontal feature - it might slip to our east which would prevent a full on northerly, conversely we might see developments to our NW which would send the ridge towards Greenland and leave us exposed to a cold polar outbreak as we end the month.

Late October can be a very stormy period full of wind and rain - this year it looks like being relatively quieter, with fog and frost probably the most notable feature. 

[Scandinavian High.]

This is what I’ve been waiting for if all falls in to place we could have frosty bonfire night.

[Snowy Hibbo]

4 hours ago, Steve Murr said:

The September pattern with the huge blocking high west of Alaska ( -EPO ) & the downstream trough over the central plains does not equate to a trough in the East- it encourages the opposite - A warm ridge in the East ( -PNA )

With all due respect, you are wrong. A -EPO's downstream effects often create a Eastern trough. That is what it is known for doing, disturbing the polar jetstream up to Alaska, and bringing cold down to the Eastern Half of the United States. A -EPO if it stretches down towards the West Coast of America often gets called a joint +PNA and -EPO. So the assertion that a -EPO must go with a -PNA or vice versa is entirely misleading.

[Summer Sun]

A cooler end to the month has support from the ens whether it'll be fairly settled or not remains to be seen

ens

op

Edited October 16, 2018 by Summer Sun

[feb1991blizzard]

1 minute ago, Summer Sun said:

A cooler end to the month has support from the ECM whether it'll be fairly settled or not remains to be seen

ens

 

op

 

TBH i think a FAIRLY settled end to the Month is a good bet based on the models (particularly further West), cant see huge amounts of precipitation anywhere barring a huge model flip.