Model Output Discussion - Into Autumn 2020.

[Methuselah]

And here's the end result... the possibility of a mid-November Atlantic storm. Though one hardly needs to be a genius to suspect that one of those might happen:

    

[Frosty.]

For high pressure lovers there’s some peachy charts to sink your teeth into once we reach later next week onwards according to the ECM 0z op / ens mean & GEFS 6z!...If high pressure sets up favourably there will be plenty of foggy nights / mornings and overnight frosts. ? 

 

[sundog]

32 minutes ago, Jon Snow said:

a nice alternative to high pressure stagnating over or close to the u k for 2 weeks plus of nothingness!!!!   

 

Have you not being bigging up plenty of hp charts the last number of weeks?? Lol

[Kirkcaldy Weather]

On 20/10/2020 at 11:50, Kirkcaldy Weather said:

Fair few of the GEFS keen on the idea of trying to get the higher pressure developing in or around Scandi as I mentioned in a previous post linking with phase 5 of the MJO perhaps just a slight bit of patience required, before that worth keeping an eye on tropical storm Epsilon it could interact with lows developing around Greenland as it (possibly) heads towards the UK.

Lots of the latest GEFS interestingly trying for a split in the tpv whether that happens we will see but I still think scandi is the area to watch for the higher pressure, fair few weren’t a million miles off a similar pattern to that of the BFTE not saying anything of that severity just focusing on the pattern also again to highlight that the pv over Greenland isn’t always a game ender for cold conditions. 
the ridging through scandi and the cold pool to the E/NE is what I’m looking out for. Akin to the BFTE setup as mentioned.

[Frosty.]

Just looking through the latest output, I’m thinking this upcoming anticyclonic spell won’t necessarily be the idyllic peaches and cream extended outlook some are dreaming of, it could be an occasionally cloudy high, there could be a nagging breeze off the North Sea, there could even be some weak fronts drifting down into the high at times with drizzly rain...all I’m saying is, don’t expect unbroken sunshine and crisp frosty nights with freezing fog unless the high sets up favourably. 

[snowking]

7 hours ago, bluearmy said:

two days on and the features  A and B advertised by the ec spreads are firming up - the Siberian side lost its shape on the spreads day 9 so it’s no surprise to see that area less certain, run to run 
 

     

I'm a big fan of an Azores high in this position, not only because it offers the possibility of my favourite type of autumnal weather - morning frosts/fog, sunshine by afternoon (though this is always very uncertain with warmer SST's around our island), but because particularly when it is propped up by LP through the med, it leads to all sorts of interesting shorter and longer term possibilities, particularly if we can combine it with an Aleutian trough as the overall longwave pattern rotates eastwards around the northern hemisphere...

Edited October 28, 2020 by snowking

[NApplewhite]

5 hours ago, Jon Snow said:

The GEFS 18z / 0z wasn’t without interest for coldies towards mid nov with some wintry potential...a nice alternative to high pressure stagnating over or close to the u k for 2 weeks plus of nothingness!!!!   

 

A fair start to the day in eastern parts of Scotland and eastern England with some bright or sunny spells here. Rain and cloud through Ireland, Wales and southwest England early in the morning, this then spreading east and north during the day. Wet in Scotland in the afternoon, heavy in the southwest. Damp in eastern England, although heavier rain in northwest England. Drizzle for southern England and Wales and staying rather cloudy. Staying wet in western Ireland. Staying breezy for all. Highs at 10 to 14C.

Friday
Another unsettled day on a Friday as a shallow area of low pressure crosses Ireland and the UK. This brings rain into Ireland and western parts of England and Wales through the morning, spreading eastwards through the afternoon although turning lighter and more patchy. East Anglia and southeast England may stay dry although always some drizzle along southern coasts. Scotland will have some rain in the south but most other parts will be drier with sunny spells, apart from a few showers on western coasts. Highs at 16C in much of southern and eastern England, 14C in northwest England and Wales, 10 to 12C in Scotland and Ireland.

Saturday

A deep area of low pressure over Ireland on Saturday will be bringing a windy day to all. There will be rain, most of it in the north and west and some of it could be heavy. Eastern parts will see more patchy rain although it is going to be staying windy here as well. Heavy showers across Ireland, some of them could be thundery. A risk of severe gales in the west. Highs at 10 to 16C.

 

Sunday 1/11/20
Another unsettled day with more wind and rain for most areas. The heaviest of the rain will be across western parts of England, Wales and western Scotland as well as Ireland. Eastern parts of England and Scotland seeing light rain overall. Highs at 9 to 16C.

 
 
 

 

Monday 2/11/20
Rain may linger across southern counties of England through Monday as a front become slow moving. Elsewhere it should be brighter with some sunny spells, but also showers affecting western areas. The heaviest of the showers in western Scotland and western Ireland. Cooler for all. Highs at 8 to 12C.

Tuesday 3/11/20
Day of sunshine and more widespread showers on Tuesday. The showers may be heavy I will pass from west to east. Longer spells of showers could affect western Scotland and the west of Ireland. A breezy day. Highs at 8 to 12C.

Wednesday 4/11/20
A ridge of high pressure builds across the UK and Ireland on Wednesday. There may be some morning mist and fog patches in more sheltered areas as well as a touch of ground frost. For most the day will be bright and dry with some decent sunny intervals. Highs at 8 to 12C.

Thursday 5/11/20
No pressure remains across the country on Thursday. They may again be some morning mist and fog patches and these could be slow to clear. Where they do the day should be dry and bright. Breezier in northern Scotland where they could be a few spots of rain. Tempertaures around 7 to 11C.

[summer blizzard]

Euro0z built pressure from days 6-10 albeit uppers above 0C are a recipe for cloud and fog at this time of year under the center of a high. 

GFS12z is a bit more progressive (as is the UKMO at day 6) in suggesting that this particular high may get shunted east (albeit the GFS builds a second high in FI) although the GEM12z does agree with the Euro. 

[Tim Bland]

Can someone at the Met office please put a penny in the meter...No sign of  the 12z ECM on Meteociel

[I remember Atlantic 252]

3 minutes ago, Tim Bland said:

Can someone at the Met office please put a penny in the meter...No sign of  the 12z ECM on Meteociel

Ay, noticed it wasn't trickling out

[Frosty.]

I noticed the GFS 12z operational makes a bit of a dogs breakfast / dinner of trying to settle our weather down properly and only really succeeds at T+384 hours, on the other hand, I think I’m right in saying the GEFS 12z has a few arctic shots still popping up towards mid nov...as I mentioned earlier, if we want the perfect high with sunny days / frosty & foggy nights it’s not looking so easy judging by what I’ve seen so far today..

[Zak M]

The 12z ECM shows this at day 9... pretty decent chart.

[Frosty.]

9 minutes ago, Zak M said:

The 12z ECM shows this at day 9... pretty decent chart.

Indeed Zak, much better from the ECM 12z op than the pig’s ear attempt by the GFS 12z op!

Edited October 28, 2020 by Jon Snow

[stodge]

Evening all

Interesting contrasts between the 12Z models on the Northern Hemisphere profile. GFS OP keeps the PV in its usual place while GEM moves the PV over to Siberia and ECM significantly weakens it in situ. 

GEM and ECM look similar while GFS OP is very different - take your pick or if you play ice hockey, take your puck.

[bluearmy]

Extended eps takes the NAO slightly negative with lowish Azores anomaly and higher sitting above .... it’s an interesting set up approaching middle period of November 

[Daniel*]

33 minutes ago, bluearmy said:

Extended eps takes the NAO slightly negative with lowish Azores anomaly and higher sitting above .... it’s an interesting set up approaching middle period of November 

If I get on the naughty step so be it definitely much improved on October. An end to the most wretched, unsettled month I’ve ever known in London... 163mm not know anything like it.

[Allseasons-Si]

Is anyone having trouble with the 18z gfs (stuck at 120)?,the NOAA/cpc site isn't working either. 

Edited October 28, 2020 by Allseasons-si

[mb018538]

Models starting to firm up on a bit of detail through next week now. The building high looks to be a short lived affair as it builds from the west, before sliding off to the east:



GFS ensembles look similar, and thankfully a fair bit drier into November:

[Jeremy Shockey]

UKMO 0Z @ t144

 

 

UKMO 850 hPa ( C )

 

First decent frost for many waking up on Wed morning ( 4th Nov ) i suspect.

Lovely HP shown on all 3 main models at t144 with light winds and a gentle North westerly flow.

[carinthian]

On 28/10/2020 at 09:18, carinthian said:

The overview chart from this mornings ECM High Res does offer the prospect of some nice chilly settled conditions with its positioning of the high and a cold front heading down the North Sea. Seems to be on its own at this stage with the mean model runs having the high further to the SE. However, GFS and ECM both showing a cut off low to the SW of The British Isles by day 10 , this should help to disrupt the Atlantic trough and zonal flow for a while.  Looking at the outer time range of the GFS control run, high pressure is dominant to the North of Britain with an Easterly flow developing.

C

The latest lower res control run from GFS still showing strong high pressure over the British Isles as we head towards Mid - November with its centre over the North Sea. I just hope this scenario comes off for you guys  as I think you will all have had a belly full of rain by the end of this week. However, the Ensemble mean of the model seem to have the high centre slipping SE , sort of supported by the ECM run and may allow the Atlantic back in. Anyway ,looks like some dryer weather next week for a while which I think will be most welcome.

C

[Downburst]

Well we should be slightly drier in November, starting mid next week, based on the ECM EPS monthly's, this is run on Monday 26

And the following week

I notice in general the long range pressure anomalies are indicated to be very week in the northern hemisphere for the end of November. So I am expecting a very average end of November based on that.

[Methuselah]

GFS 06Z at T+336... quite a lot of frost & fog methinks?

    

[johnholmes]

24 minutes ago, General Cluster said:

GFS 06Z at T+336... quite a lot of frost & fog methinks?

    

It will depend on cloud cover overnight of course and the isobars are, for many, from a SSW point. Additional to this is the strength of the flow. I would suggest that areas west of the 1035 isobar, other than very sheltered valleys may have too much gradient and subsequently similar with the surface flow?

[johnholmes]

Thursday 29th

A while since I updated this although, as usual, I have been checking each day. I’ll put the charts in first (getting near the end of my page) and the text below them.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

http://www.cpc.ncep.noaa.gov//favicon.ico Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

Certainly some changes on the ec-gfs outputs. Both now have a marked cut off upper low with fairly small –ve heights in it, both have the ridge and +ve heights to the north of this feature, over the uk (with strong S of W 500 mb flow. The rest of the charts are reasonably similar too. This pattern has been developing on these models for a couple of days.

Noaa, has also shown a similar pattern, especially with the prediction of the ridging/+ve heights extending towards the UK from the SW. It was a bit slower to go along with the cut off idea but last evening it agrees pretty well with the other two. Upstream (W of the UK), the chart is also similar to the other two. This normally does indicate that the 500 mb flow, as an average over the 6-10 days, is about 70% likely to validate. The 8-14 is somewhat different in the area of interest for the UK. The ridge is replaced by a rounded trough around 20 W, from the main Arctic trough coming out of NE Canada/western Greenland, with some minor +ve heights over/E of the UK. This perhaps suggests that the build of surface heights over the country may be a shortish term feature.

 So a break from the current disturbed, wet and windy in places to a shortish spell with ridging being the main influence on our surface weather for most areas away from the far NW. Then probably a return to some kind of Atlantic flow again, how active is too far ahead to judge yet. The amount of fog and frost will be dependent on just where the surface high spends most of its time before declining along with cloud cover overnight and the strength of the flow working down to the surface.

 

[Kirkcaldy Weather]

23 hours ago, Kirkcaldy Weather said:

Lots of the latest GEFS interestingly trying for a split in the tpv whether that happens we will see but I still think scandi is the area to watch for the higher pressure, fair few weren’t a million miles off a similar pattern to that of the BFTE not saying anything of that severity just focusing on the pattern also again to highlight that the pv over Greenland isn’t always a game ender for cold conditions. 
the ridging through scandi and the cold pool to the E/NE is what I’m looking out for. Akin to the BFTE setup as mentioned.

Can certainly see interesting charts from a cold POV appearing over the next few weeks