Yes - I think the obvious thing is low pressure. With an initial meridional set up the temperature differential should promote plenty of rain, especially as things will initially become "cut off" before the Atlantic fills the vacuum 

16-day summary; temps returning to near normal for time of year, but much colder not far to the north-east. Rain mostly across Scotland week 1, but large totals everywhere week 2.

GFS: LP intensifying to SW and moving up across the UK Tue/Wed 20/21st 985mb with some hang-back as yesterday; for the following week some deep LPs fairly well to the N giving a W/SW-ly airflow (but no doubt some fronts traversing the UK from time to time) until Sun 1st 960mb over Scotland and a brief N-ly blast before W-ly resumes. Signs of an ex-hurricane off New England Thu 29th which may be adding oomph to that LP on the 1st.

GEFS: a warm day Tue 20th after which not much agreement - mean of runs a little below average throughout (Scotland, an extra dip around the 22nd). Rain starts Tue 20th and persists, with suggestions of heavier stuff by end of month in the S. 

ECM: those Atlantic depressions (in bold above) closer to Scotland esp 955mb Rockall Tue 27th; also again suggestion of some possible ex-hurricanes but earlier (Mon 27th) and less definite.

GEFS 35 day European grid available here:

https://www.theweatheroutlook.com/twoforecasts/gefs-europe.aspx

Include weekly 2m temp anomaly charts for the next 5 weeks.

Er ...all I get is a promise it will open in a new window but all that window contains is a URL, e.g. https://www.theweatheroutlook.com/charts/gefs/gefs850temp_35day63_-18.png

and no chart - what else should I be doing? 

Jetstream currently has a broad loop mid-Atlantic which transfers E-wards and closes up this week as it approaches UK. A strong jet keeps throwing off loops which develop W of UK  and  transfer across the UK, this pattern repeating  Sat/Sun 24th 25th, Wed/Thu 28th/29th, Sat/Sun 31st/1st and Tue 3rd. Looks both unstable and unpredictable.

GFS - LP moves across UK Tue/Wed 20th/21st, after which a generally W-ly pattern with depressions moving E-wards in N Atlantic but perhaps surprisingly in view of jet forecast, only coming S as far as brushing N Scotland, Mon 26th, Thu 28th, Sat 31st; still close enough for frequent gales across UK.  Ex-hurricane off New England Sun 25th swallowed up by general circulation.

GEFS - brief burst of mild air Tue  20th, fair agreement on close to norm to Mon 26th then cooler (In Scotland, cooler throughout) but with uncertainties, rain starting soon and continuing on and off for rest of October and beyond

ECM keeps pressure higher after Sun 25th, less Atlantic activity and indeed ridge of HP across N UK Tue 27th ( & LP to SW) with some very warm air advecting N-wards the following day  as HP settles over Scandi. Also disagreeing with the jetstream forecast! But does also show the ex-hurricane.

Which isn't a bad thing at this stage. Apart from the fact I work outside two days a week I really enjoy late Oct/Nov wind and rain. In fact it seems everytime we've had any cold weather in the mid to late Autumn period in recent years it's always been followed by a mild Winter. 

Sorry, it should be ok now. The charts had only plotted to -10deg lon. I've now increased to -25.

[quote=nsrobins;1266631]Looks like all the talk of robust high lat blocking into November is unravelling with the jet looking to take-up residence in it’s normal late Autumn position, firing lows into the UK for the next few weeks.[/quote  

Yes the pattern looks like its resuming early this year....a pattern change to colder weather end of November beginning  December would be interesting although a very mild November isnt a good sign.Or it could mean a bonus month of dross from 3 to 4.....

From a cold winter perspective there are arguments for and against. I think there is a correlation between milder than average autumns and milder than average winters. Paul Bartlett I believe favoured a "warm" and dry October followed by a cold and cyclonic November. One thing I would add is despite the headline view about an El Nino leading to a greater chance of cold weather in late winter I would favour a La Nina.

I'll add to the site tomorrow (hopefully) but the weeks 2, 3, 4 and 5 GEFS 850hPa anomaly charts are visible on the tweet.

Weekly 850hPa temp anomaly plots using GEFS 35 data will be added to the TWO website tomorrow. Test charts attached. pic.twitter.com/iWnWDWCQll

— TheWeatherOutlook (@TWOweather) October 18, 2020

Yes that used to come up every October! Looking at the stats I'm not sure where he came up with that because I found there was very little corrolation. If anything, an October that was very average in temperature and rainfall was marginally more likely to be prior to a colder winter.

OK now - thanks

Amongst the unsettled zonal charts in mid-term there are hints at some pretty stormy episodes

GFS 18z serves up a cyclogenesis special with a LP with a central pressure below 910mb - fortunately it stays in mid-Atlantic.

FAX gives a good view of the way LP this week first moves up from the S with its associated fronts (and, incidentally, makes Thu look to be wetter than previously forecast, even the BBC wavering on this now) and then on Friday 2 major LPs out in the Atlantic, 970 near Iceland and 986 mid-Atlantic, the latter in prime position to sweep across the UK. Let the gales begin!

GFS shows current LP moving NE-ward this week then on Fri the mid-Atlantic feature (see FAX) weaker but combining with main low off Iceland to give trough mainly affecting Scotland Sun 25th. Very deep low 920 mb Iceland Tue 27th (hasbeen augmented by an ex-hurricane) spinning off a secondary 975mb W Ireland Thu 29th which moves to Scotland on the Fri. but keeps associated trough over UK. By Mon 2nd the trough has split with ridge of HP aligned E-W across Scotland, intensifying and moving S to england 1035mb Wed 4th

GEFS mild to ca Wed 21st then most runs a bit below norm throughout, possibly quite  a bit cooler 1st week Nov. Rain this week, drier for a day or two (not S Scotland / NW England) then rain for rest of October, possibly drier for 1st week Nov

ECM makes less of the LP near Iceland possibly because it isn't augmented by the ex-hurricane which instead moves E-wards to Biscay Thu 29th. UK under influence of SW-ly then W-ly after Fri 24th with no LP or HP particularly close

A comparatively tame sub 920mb on the 00z GFS op run http://modeles.meteociel.fr/modeles/gfs/runs/2020101900/gfs-0-204.png?0 

GEFS 850 and 2m temp weekly anomaly charts and European grid can be selected here:

https://www.theweatheroutlook.com/twoforecasts/gefs-europe.aspx

850s look below par late Oct and early Nov then a little above the 30 year mean.

Two-thirds the way through Nov 10 and the CET was running almost 1c above the 71-00 average. October a smidgen below Ave. 

Nov 09 finished 2c above the same average. October was almost 1c above.

Both Octobers were drier than average, though. 

I'd be delightedly happy with a repeat of either of the subsequent winters. 

I think that option is probably a more realistic scenario than the system shown in the previous runs. Definitely something to keep an eye on.