Model Output Discussion 01/09/17

[knocker]

Looking at the ecm this evening Scotland and the north not looking to clever the beginning of next week, in fact in general.. The next Atlantic low is centred over Iceland by Tuesday 00 with a small disturbance in it's southern quadrant impacting Scotland with some heavy rain and also quite windy. This clears but is quickly followed by another 12 hours later.

This also quickly clears but by 12 Wednesday the main frontal system associated with low arrives bringing more heavy rain and strong winds to N.Ireland, Scotland and the north of England.

The rest of the run is much of the same with the  Azores HP ensuring a very marked NW/SE split.

Temps trending a little above average in the general south west flow

Edited October 6, 2017 by knocker

[ANYWEATHER]

Evening! The gfs and ecm show the Atlantic in full control in one shape or another , but caution needed as to the detail as we proceed into next week, there will be a few weak ridges developing across the nation thanks to the jet stream but yet again the strong jet stream will give Britain some proper Autumn weather , model viewing at the moment is a little bit like viewing Boats on a Stormy Sea!

[ANYWEATHER]

On ‎05‎/‎10‎/‎2017 at 20:34, LightningLover said:

nooooooooo, I want cold, wintry, crisp weather!

Its Changing!

Edited October 6, 2017 by ANYWEATHER

[Newberryone]

According to the professionals only 10mm of rain is expected over many parts of Ireland between now and next Friday, 13th Oct, with the exception of higher ground over parts of the southwest, west and northwest. To be fair, this is very evident in the 12z Ecm, as one can see the majority of any Atlantic activity is being diverted to the very far off northwest with only Scotland and the northern tip of Ireland being affected to any degree. If anything, the huge swathe of high pressure to the south looks like taking an even firmer hold in the latter stages of this run. So what looked like becoming a more entrenched unsettled period from next Wed according to the models only a couple of days ago has been watered down considerably tonight. 

[knocker]

The anomalies this evening still seem to be playing around with the pattern they have been hinting at recently and that is the retrogression and orientation change to the Greenland/Iceland trough into the western Atlantic. This should allow the upper flow to back a tad to south of west and allow the high pressure to push north in the vicinity of the UK. The problem there is no agreement on the precise nature and timing of this as seen with difference between the GEFS and EPS ( with as it happens the usual role reversed) so at the moment no great confidence on how the det  will resolve this with percentage play remaining a NW/SE split vis the UK.

 

 

 

Edited October 6, 2017 by knocker

[blizzard81]

Very interesting that the GFS 18Z follows a very similar path to the ECM 12Z. Warmth for us and cold western Russia. I like that trend going forward into Winter. 

[blizzard81]

If you ever wanted to put the SAI to the test, you would pray for the GFS 18Z to be somewhere near the mark. 

[LRD]

On 9/29/2017 at 21:33, LRD said:

I've recently read a theory that, in the last 30 years, global warming has bloated the Azores High and other sub-tropical high pressure systems (the Hadley Cell) way beyond it's usual, historic autumn and winter latitudes. Looking at the models the last week I'd say that it's ready to form in it's autumn/winter/interesting-weather killing position once again. Even in poor summers the SE benefits from the over-inflation of the Azores high and its ridging into France and it is now pretty rare to get truly awful summers in the SE quarter of the UK these days. This is something I'm going to be looking out for this winter. The funny thing is, if the high becomes ridiculously bloated it could end up in and around Greenland, accidentally plunging us into the freezer!

Well, looking at the models this evening, it looks like my fears are already being realised - a big, bloated Azores high ridging into Europe = no interesting weather for the UK. I realise it might not have a lot of bearing into late November onwards but it is never nice to see at this time of year

[Ice Man 85]

38 minutes ago, blizzard81 said:

If you ever wanted to put the SAI to the test, you would pray for the GFS 18Z to be somewhere near the mark. 

SAI?

[Ice Man 85]

7 minutes ago, LRD said:

Well, looking at the models this evening, it looks like my fears are already being realised - a big, bloated Azores high ridging into Europe = no interesting weather for the UK. I realise it might not have a lot of bearing into late November onwards but it is never nice to see at this time of year

Never nice to see at any time of year. Getting sick of that sodding thing now.

[Hairy Celt]

16 minutes ago, Ice Man 85 said:

SAI?

Sardines (followed by) anal irrigation. Perhaps.

[JeffC]

6 hours ago, Ice Man 85 said:

SAI?

Snow Advance Index

[knocker]

Today will be cloudy and wet fairly windy in many areas as a cold front tracks south across England and Wales clearing the south coast by afternoon apart from this neck of the woods where it may well linger. Heavy showers in N.Ireland and particularly NW Scotland but the good news is eastern Scotland will probably have the best of the weather today with plenty of sunshine.

Things improving and quietening down overnight and into tomorrow apart from northern Scotland where more persistent rain will move in and quite windy as well.

So on to this morning's gfs. After some transient ridging tomorrow and Monday the next Atlantic low tracks north east to be over Iceland 983mb with the associated fronts already impacting N. Ireland and north west Scotland. These track south east across Britain, along with a little wave that has developed, to be over Denmark by 18 so the rain soon clears.

The usual story then continues to unfold with the next deep low 964mb arriving Iceland in the early hours of Wednesday bringing more rain to the north but probably light showery stuff further south in the quite strong westerly wind. At this point the upper trough to the NW is still dominant, suppressing the Azores HP resulting in a strong westerly gradient.

From this point a shift of the upper pattern takes place with amplification resulting in the trough realigning in the western Atlantic and the high pressure to ridge in the vicinity of the UK. Thus the fronts from the next deep low that is pushed west of Iceland grind to a halt just west of the UK. One result of this scenario would be some WAA into the UK on the southerly drift and temps in the low 20sC in the south of England.  But the surface high cell is not anchored in the east and after a passage of a weak front the high pressure realigns from the south west.

So essentially a changeable picture but very much a NW/SE split next week but although probably generally fairly cloudy not much rain around (apart from the NW) and quite warm at times. Having said that I certainly wouldn't bet the farm on any development after midweek.

Edited October 7, 2017 by knocker

[knocker]

The ecm disagreeing with the gfs as early as Weds where it tracks the main low further to the north east and has it south east of Iceland by 06 Weds with the associated fronts impacting the north bringing heavy rain and gales, They clear quickly into Scandinavia but Weds is a wet and windy day for all with heavy showers post frontal passage. The general theme from here is not dissimilar to the gfs (and the anomalies) of amplification of the trough in the western Atlantic and the HP in the vicinity of the UK which indicates a quiet and dry spell for all apart from, as usual, the north on occasion. Temps generally not too bad

.

Sidney spotted a couple of chionophiles yesterday

[mb018538]

8 hours ago, Ice Man 85 said:

Never nice to see at any time of year. Getting sick of that sodding thing now.

Would that be the same Azores high that we have barely seen for about 3 and a half months??  A nice settled spell would be more than welcome! I think this will get watered down again and not amount to much when it verifies.

[booferking]

I know i know but i have to post it been a few of these charts showing up on the ensembles. The chase begins

Edited October 7, 2017 by booferking

[blizzard81]

2 hours ago, mb018538 said:

Would that be the same Azores high that we have barely seen for about 3 and a half months??  A nice settled spell would be more than welcome! I think this will get watered down again and not amount to much when it verifies.

I agree. Might as well get some nice sunny weather whilst there is still a little strength in the sun. It is way too early to be thinking about blizzards lol. If we don't get the azores high at this time of year all we will get is wind and rain. Who wants that? Especially after the summer we have had. 

Edited October 7, 2017 by blizzard81

[sundog]

21 minutes ago, blizzard81 said:

I agree. Might as well get some nice sunny weather whilst there is still a little strength in the sun. It is way too early to be thinking about blizzards lol. If we don't get the azores high at this time of year all we will get is wind and rain. Who wants that? Especially after the summer we have had. 

The great autumn and winter killer itself has ruined enough autumn's and winters in the past so i would rather it stayed as far away from us as possible.  When we are forecast to get the Azores high i instantly lose interest in the weather until it leaves. People who complain about our weather being monotonous well that can often be the fault of the Azores high. So no thanks!!

[Summer Sun]

Warming up quite nicely for a time next week and not much rain may be the low 20's in parts of the south which would be very pleasant and maybe even be feeling warm locally before a noticeable dip in the 2nd half of the month

[blizzard81]

41 minutes ago, sundog said:

The great autumn and winter killer itself has ruined enough autumn's and winters in the past so i would rather it stayed as far away from us as possible.  When we are forecast to get the Azores high i instantly lose interest in the weather until it leaves. People who complain about our weather being monotonous well that can often be the fault of the Azores high. So no thanks!!

If you don't get the high building in at this time of year all you will experience is weeks of wind and rain. That is my definition of monotonous. As winter approaches then the Azores can do one as then and only then do we stand a chance of something more exciting than wind and rain. 

Edited October 7, 2017 by blizzard81

[Summer Sun]

Some very pleasant temperatures on show from the 06z for later next week

[sundog]

35 minutes ago, blizzard81 said:

 As winter approaches then the Azores can do one 

But what if it doesn't?

I don't want rain everyday myself but I certainly don't want the Azores high hanging around either.

[sunnijim]

2 hours ago, sundog said:

The great autumn and winter killer itself has ruined enough autumn's and winters in the past so i would rather it stayed as far away from us as possible.  When we are forecast to get the Azores high i instantly lose interest in the weather until it leaves. People who complain about our weather being monotonous well that can often be the fault of the Azores high. So no thanks!!

I agree to an extent.

However the Azores high can produce some decent late summer weather in October so it is still a welcome sight for me if it is placed right...

 

And that is the rub.

I pray we don't end up with the sort of rinse and repeat pattern of winter 2016/17 when the Azores high was placed in a position that really pleased nobody.

The sort of half baked position we see it in now in fact.

All meaningful weather is thrown toward Iceland with decaying fronts over the UK:Lovers of extreme weather peeved.

You might get some half baked North westerly from it in the Winter if the Azores H.p 'balloons' North in the Atlantic.: = coldies peeved.

Always on the periphery of any weather type, even the lovers of mild and dry winter weather never really get the BBQ  Christmas they desire as the HP remains just to shy to really build strongly.

[blizzard81]

1 hour ago, sundog said:

But what if it doesn't?

I don't want rain everyday myself but I certainly don't want the Azores high hanging around either.

Well, we are overdue some decent winter cold so fingers crossed! 

[blizzard81]

1 hour ago, Summer Sun said:

Some very pleasant temperatures on show from the 06z for later next week

Next Saturday may be the ideal day for the final cut of the lawn for this season, phew!