Model Output Discussion - Autumn arrives

[Frosty.]

Wowzers, it’s like the Mary Celeste in here!  

…anyhoo, at least the Gfs 12z operational shows some occasionally settled spells, as shown here!   ️  

[Jordan S]

A very active frontal system tomorrow ofcourse, giving very wet conditions for northwestern areas, quite wet further south too with a good 5-15mm for many places here, more in the north and west.

Very windy for many, though nothing unusual about this ofcourse with gusts no higher than 40-45mph in the more exposed locations over central and southern areas of England and more generally 30-40mph, windier in the north with values a bit higher in places particularly in exposure, quite stormy for the western isles though, winds gusting upto 65mph here through the morning. 

Worth noting this small area of low pressure on the charts below crossing the atlantic, although development is a bit uncertain, the development is likely to be modest, not really far enough north to really engage with the Jetstream, it's probably going to bring further rain into the southwest on Saturday night into Sunday, rain perhaps spreading over other parts of southern England/south Wales briefly, breezy here, possibly quite strong winds from a west/northwest direction developing around the southwest coast of England and possibly southwest Wales too, Drier further north. 

Then that drier theme for the south for the rest of the first week of October, though perhaps more interrupting wetter interludes here compared with what I thought a couple weeks ago, nevertheless the emphasis is on a drier few days for the southern half of the UK.

As have said previously before, the unsettled conditions in the north continuing, though also the potential for gales over the northern isles from this deep low pressure just to our west/ northwest for Tuesday.

Although the strongest winds probably going to remain away slightly to the northwest, it will still be very windy here along with wet conditions at times on Tuesday. High pressure remains to our south and particularly southwest extending into southern parts of UK, and this will be the case into week 2.

As for week 2, It probably won't be a low pressure dominated pattern over the whole of the UK throughout which I thought would be the case, but low pressure probably continuing to effect Scotland, northern Ireland and possibly northern England as we go through the second week of October at times, with high pressure over the south most of the time period, quite likely turning very unsettled over northern areas once again though towards mid month, with gales/severe gales possible, large rainfall accumulations too here by then, especially northwest Scotland.

By the end of the second week so days 12th/14th October high pressure looks to retreat slightly more to our southwest bringing those more persistent unsettled conditions further south over southern areas too, so to be honest the low pressure pattern becoming established over the whole of the UK I mentioned previously, is just being delayed by a few days, winds will probably be westerly for most of the time, but ofcourse there will be the odd drier and sunnier day for many, bringing just a few showers in-between each system from the west northwest and these could be wintry over Scottish hills/mountains as temperatures lower slightly.

Anyway have a good rest of the day guys and will update again at some point next week.

[Frosty.]

For the most part, the GEFS 12z mean indicates a broadly north / south to northwest / southeast split with the Azores high / ridge largely holding sway across the s / se whereas there’s a stronger Atlantic influence across the n / nw where it looks largely unsettled although with some quieter interludes too!…so…it’s a mixed picture but the general rule of thumb is the further s / se you are, the drier it looks….which is pretty normal really!    ️ 🌫 🌧 

Edited September 29, 2022 by jon snow

[Methuselah]

4 minutes ago, jon snow said:

For the most part, the GEFS 12z mean indicates a broadly north / south to northwest / southeast split with the Azores high / ridge largely holding sway across the s / se whereas there’s a stronger Atlantic influence across the n / nw where it looks largely unsettled although with some quieter interludes too!…so…it’s a mixed picture but the general rule of thumb is the further s / se you are, the drier it looks….which is pretty normal really!  ️ 🌫 🌧 

That'll do nicely! 

[Cambrian]

Ah, the last day of September already. I know it’s a bit slow but I actually really don’t mind this quiet equinoxial time of the year - the days slowly shorten, shadows slowly lengthen, and as the sun slowly heads to more southern latitudes, the position where the mad summer rush would like us to be located slowly migrates north to the position where the mad winter rush would like us to be located.

  

Aaah, fleetingly for a few weeks around each September, things feel just about right! 

  

Plenty of rain today for real for the UK and Ireland - 24 hour accumulations from 0z ECM op. Stay dry and have a great day. 

[jamesthemonkeh]

Interesting range of opinions on the development of a small low on Sunday:

GFS:

ECM:

UKV:

I'm slightly more tempted by the GFS's soaking for the southern third of the UK on Sunday, it has been pretty consistent with it, but quite a wide range of possibilities for Sunday for those of us in the southern third.

[richie3846]

25 minutes ago, jamesthemonkeh said:

Interesting range of opinions on the development of a small low on Sunday:

GFS:

ECM:

UKV:

I'm slightly more tempted by the GFS's soaking for the southern third of the UK on Sunday, it has been pretty consistent with it, but quite a wide range of possibilities for Sunday for those of us in the southern third.

I've noticed in the past, that models don't seem to handle the details particularly well when rain moves in from the south in setups like this. I've probably noticed it more because of my location, and what often happens is that there is a nowcast situation whereby the rain may travel much further north than anticipated, or remain further south. 

The disparity in the models you have pictured here is a perfect example of this, literally hundreds of miles disagreement just 2 days out.

[Downburst]

The warm anomaly in the north Atlantic is I think evident in the EC 46 day released yesterday, all the way out we are ~1 C above normal 2m temps into mid-November. 

The 500 anomaly charts well into October and into November do show what I expect will be surface highs near or around us and troughing to the east into central Europe. 

 

I think the temp anomaly shows this at the same period end of October.

[damianslaw]

1 hour ago, Downburst said:

The warm anomaly in the north Atlantic is I think evident in the EC 46 day released yesterday, all the way out we are ~1 C above normal 2m temps into mid-November. 

The 500 anomaly charts well into October and into November do show what I expect will be surface highs near or around us and troughing to the east into central Europe. 

 

I think the temp anomaly shows this at the same period end of October.

Nearing on two years we've had heights strong near or over UK. Seems entrenched.

[MATTWOLVES 3]

Well folks its Friday and it's hammering it down outside here. 

What do we have in store over the next week or so? I would say after today's washout the Weekend looks to be drier for many with an ongoing shower risk in places. At quick glance of todays ECM run it looks like next week could remain quite volatile towards the North with Low pressure anchored in that vicinity,areas further South do look drier on the whole and there are some signs of High pressure gradually extending from the W/SW later in the run. Quite the spread on the ensemble members but nothing that appears to dramatic either way!

It's very quite in here just lately which I suppose is to be expected as we go through that transition period....but folks I want you singing from the rooftops very shortly in anticipation for several months of rollercoaster riding winter chasing!

And just a quick little mention from the mets Marco P.. the mjo appears to be on the move which as we know can influence High latitudes blocking....heres hoping folks for something to remember this coming Winter....Let the chase begin

Have a cracking Weekend whatever your doing and the best of luck and health to you all.

[sheikhy]

2 hours ago, jamesthemonkeh said:

Interesting range of opinions on the development of a small low on Sunday:

GFS:

ECM:

UKV:

I'm slightly more tempted by the GFS's soaking for the southern third of the UK on Sunday, it has been pretty consistent with it, but quite a wide range of possibilities for Sunday for those of us in the southern third.

Latest gfs 06z moves to ukv and ecm fully with rain staying way further south and a drier sunday more widely now!!!

[Don]

1 hour ago, MATTWOLVES said:

And just a quick little mention from the mets Marco P.. the mjo appears to be on the move which as we know can influence High latitudes blocking....heres hoping folks for something to remember this coming Winter....Let the chase begin

I just hope this 'potential' is not going to be two months early and we will be back to dross come early winter!

[Frosty.]

Just perused the GEFS 6z mean and I honestly can’t see any change since yesterday, ergo, it’s a predominantly n / s to nw / se split for the majority of the run!…personally, I find autumn boring weather wise but I love the changes in tree colours from green to yellow / brown   but I wish we could just fast forward to winter already.. pffffffft !!!!  

Edited September 30, 2022 by jon snow

[Dorsetbred]

3 hours ago, sheikhy said:

Latest gfs 06z moves to ukv and ecm fully with rain staying way further south and a drier sunday more widely now!!!

Interesting how the models in this case are widely dispersed, in this instance I'm hoping for ECM, although the track of this is still very uncertain across all the models. Let's see who's correct over the next 24 hrs, although the fax chart suggests the following for Monday:

[Frosty.]

HEY…!!!!!! I’m a coldie at heart..all hail P21 for mid October!!!    

 

Edited September 30, 2022 by jon snow

[damianslaw]

1 hour ago, jon snow said:

Just perused the GEFS 6z mean and I honestly can’t see any change since yesterday, ergo, it’s a predominantly n / s to nw / se split for the majority of the run!…personally, I find autumn boring weather wise but I love the changes in tree colours from green to yellow / brown   but I wish we could just fast forward to winter already.. pffffffft !!!!  

My interest picks up late October.. we are in that transitional period when odds of 'extremes' temp wise at least are at there lowest, though at the start of the 6 month period of the year when storms and heavy rain most likely. 

[Frosty.]

The GEFS 12z mean indicates a predominantly north / south split which becomes even more prominent in the period between early-ish to mid October!…for sure, the nw / n looks quite unsettled / Atlantic driven for a while but even that tends to fizzle out somewhat further ahead…as far as the s / se is concerned, it’s drier than the n / nw, not settled as such but more settled than the Gfs 12z operational suggests, which I think was an unsettled outlier!..just my opinion..or is it!? .. anyhoo, some of the ensembles further into October look quite settled! ️ 🐿

 

 

[I remember Atlantic 252]

6 hours ago, sheikhy said:

Latest gfs 06z moves to ukv and ecm fully with rain staying way further south and a drier sunday more widely now!!!

Aye, 12Z too, still position not definite though, fax seems to be suggesting wet Monday

[Summer8906]

36 minutes ago, I remember Atlantic 252 said:

Aye, 12Z too, still position not definite though, fax seems to be suggesting wet Monday

Don't you just love how that frontal system prevents perhaps the one chance we have for prolonged sunshine for the next week or so!

[ChannelThunder]

13 hours ago, Summer8906 said:

Don't you just love how that frontal system prevents perhaps the one chance we have for prolonged sunshine for the next week or so!

We still need all of the rain we can get to try and make up the deficit. 90% of fronts this year have decayed before they even get here & the sunny conditions have won out.

[Methuselah]

Judging by the huge number of posts in here, I guess I'm nae the only one who finds autumn weather a tad on the boring side?

[mushymanrob]

The first half of October looks pretty ordinary to me... average unsettled, troughs and ridges, ...

[Summer8906]

11 minutes ago, Ed Stone said:

Judging by the huge number of posts in here, I guess I'm nae the only one who finds autumn weather a tad on the boring side?

Depends on the autumn, I guess. Those of 1985, 2003, 2010 and 2011 were quite seriously interesting at times.

Edited October 1, 2022 by Summer8906

[Cambrian]

Yesterday’s rain left us with 196mm for September, well above average - good news for the western rivers and waters; with an average temperature of 12.7 degrees, bang on the 20 year average. In the context of this year, normal is the new different, so I’m quite liking this, and October seems to be setting off in similar vein. 

The pattern remains resolutely keen on a slow-moving 4-wave hemispheric setup, with occasional extension of the polar trough down into the North Atlantic, which then takes a few days to get nudged east to Northern Europe. The 0z ECM mean charts and their anomalies capture this nicely. 

While the new week kicks off with a pleasant looking day under a useful ridge on Monday, 

 

the low over Greenland at day 2 has drifted east to Iceland by midweek, day 5, re-establishing a more westerly influence.

 

By next weekend, day 8, the trough is transferring east to Scandinavia, with as shown by the day 9 0z ECM op, the chance of a cooler northwesterly for a day or two. It’s off a long northerly track too.

  

Lower heights gathering over the pole are a feature throughout, as is the eventually generous ridging into western Canada, a continuing good setup perhaps for occasional brief northerly spells heading into the new month, in between the more cyclonic periods and the next ridge arriving.

Edited October 1, 2022 by Cambrian

[Frosty.]

The GEFS 6z mean essentially indicates a north / south split, but ultimately, it could be even better than that from just after mid month according to these ensembles!…now, this could be seen as misleading, there are some very unsettled members.. but this is just my take on what will be.. call me an optimist..   .. perhaps I am…  .. yay it’s October..a step nearer winter.. that’s a plus innit.. cheers!   

Edited October 1, 2022 by jon snow