Model Output Discussion - Into Autumn 2020.

[Paul_1978]

23 minutes ago, LRD said:

Ah the folly of chasing GFS FI charts

The 0Z run gave us something like Jan 1987

The 6Z run gives us something like Jan 1989

From winter cold affluence to winter cold effluence in 6 hours!

Ah well, it's only November

Thankfully most people on here know that looking for consistency at T+384 is a futile exercise

[LRD]

2 minutes ago, Paul_1978 said:

Thankfully most people on here know that looking for consistency at T+384 is a futile exercise

Most of the time, yes. But Nov/Dec 2010 was an exception. Models, inc GFS, picked that cold up from way out and I don't recall them ever wavering from what then transpired. So, rare of course, but unheard of? No

[mushymanrob]

I dont think ill ever understand the pointless excitement generated by a deep fi outlier chart... hey-ho

The gfs 00z in fi suggests a cold easterly, the GFS 06z suggests a bartlett heatwave... 

The NOAA 8-14 day mean suggests something in between - ish. High pressure to our East, a mean upper southwesterly courtesy of a mean upper trough in the mid Atlantic.

To me that looks mild, somewhat unsettled,  NW/SE split , but not overly wet as we still have a positive pressure anomaly.  there could well be cold pooling to our East, and IF shortwave lows circulation on the southern flank of the mean trough, erode pressure over Iberia then Southern Europe , then the cold option is viable.

Of course if they dont then its entirely feasible that the milder 06z gfs becomes close to reality.

 

Edited November 3, 2020 by mushymanrob

[LRD]

2 minutes ago, mushymanrob said:

I dont think ill ever understand the pointless excitement generated by a deep fi outlier chart... hey-ho

The gfs 00z in fi suggests a cold easterly, the GFS 06z suggests a bartlett heatwave... 

The NOAA 8-14 day mean suggests something in between - ish. High pressure to our East, a mean upper southwesterly courtesy of a mean upper trough in the mid Atlantic.

To me that looks mild, somewhat unsettled,  NW/SE split , but not overly wet as we still have a positive pressure anomaly.  there could well be cold pooling to our East, and IF shortwave lows ciruculation on the southern flank of the mean trough, erode pressure over Iberia then Southern Europe , then the cold option is viable.

Of course if they dont then its entirely feasible that the milder 06z gfs becomes close to reality.

 

A quick question over those charts. Everytime I look at them those green contour lines seem, to me anyway, showing the exact same thing whether in summer or winter. Probably the mind playing tricks but what will it take for them to show a NE'ly

What I don't understand about them is that they show a high anomaly which, in that chart you've posted, would suggest a Southerly or Se'ly rather than a SW'ly and that contradicts the green contour lines which are in a seemingly permanent SW'ly

Honest question - I'm not trying to dismiss that model just trying to understand them more

[bluearmy]

A  lack of continuity in the week 2 nwp in respect of the nuances 

the single eps cluster yesterdays 12z reflective of the likely wide spread of solutions

[mushymanrob]

1 hour ago, LRD said:

A quick question over those charts. Everytime I look at them those green contour lines seem, to me anyway, showing the exact same thing whether in summer or winter. Probably the mind playing tricks but what will it take for them to show a NE'ly

What I don't understand about them is that they show a high anomaly which, in that chart you've posted, would suggest a Southerly or Se'ly rather than a SW'ly and that contradicts the green contour lines which are in a seemingly permanent SW'ly

Honest question - I'm not trying to dismiss that model just trying to understand them more

Yes they are similar because our weather is basically westerly. So the green lines will be very similar as we usually have troughing in the mid north atlantic. It is very unusual in the northern hemisphere for the mean upper flow over the time period concerned to become easterly, so seeing an easterly or northeasterly on these charts are very rare. 

The chart i posted does show a gentle southwesterly mean upper flow, and hight anomaly to our east. from that over the days covered there will be a southwesterly mean over that time. but within that time there could well be briefer surface winds from the south or southeast, but not sustained. 

Im sure @johnholmes will be able to correct me or explain further.

[Tim Bland]

GFS goes from a cold outlier (00z) to a warm outlier (06z) looks like everything is still on the table for week 2...

[johnholmes]

19 minutes ago, mushymanrob said:

Yes they are similar because our weather is basically westerly. So the green lines will be very similar as we usually have troughing in the mid north atlantic. It is very unusual in the northern hemisphere for the mean upper flow over the time period concerned to become easterly, so seeing an easterly or northeasterly on these charts are very rare. 

The chart i posted does show a gentle southwesterly mean upper flow, and hight anomaly to our east. from that over the days covered there will be a southwesterly mean over that time. but within that time there could well be briefer surface winds from the south or southeast, but not sustained. 

Im sure @johnholmes will be able to correct me or explain further.

Bit occupied at the minute mushy but will take a look at the relevant posts when I can, probably during this evening

cheers  John

[swfc]

I still think there is enough scope over the next 10-14 days for a decent pressure rise to the ene which could bring a drop in temps over the UK. Nothing scientific just a hunch looking at the nhp. Looking at the background signals hasn't always delivered so maybe I could be correct

[mushymanrob]

2 minutes ago, swfc said:

I still think there is enough scope over the next 10-14 days for a decent pressure rise to the ene which could bring a drop in temps over the UK. Nothing scientific just a hunch looking at the nhp. Looking at the background signals hasn't always delivered so maybe I could be correct

You may well be right, from experience if theres high pressure to our east as expected, then it may well migrate to a more northern latitude and bring about cold. The problem is that that GFS cold chart is outside the NOAA chart i use so if that cold chart, or any subsequent cold chart is to appear on the Anomaly charts it wont be for a few days yet.
 

[Relativistic]

4 hours ago, Paul_1978 said:

Thankfully most people on here know that looking for consistency at T+384 is a futile exercise

That's questionable 

[Anthony Burden]

Met office blowing cold and hot gfs the same charts struggling at the moment 

with what happens in the next 10 days,best stay only with fax 120 hrs.

[SMU]

UKMO 144 looks very encouraging for scandi blocking forming

GFS - I love the shape of that HP over Scandi-

[BLAST FROM THE PAST]

12 z looking chilly and heading towards a very cold end with Easterly looking likely on this run post day 10.  

LP to west won’t allow it to develop 

BFTP

Edited November 3, 2020 by BLAST FROM THE PAST

[Tim Bland]

Scandi High...lots of possibilities from there...the term ‘slider’ could be coming out the bag...

[swfc]

Go on baby!!! Easterly still trying to unload on the UK. Still in the mix on the gfs 12z

[East_England_Stormchaser91]

Evening all. Been quite a while since I’ve wrote in here! Hope everyone is ok on what has been a challenging and exhausting year for all of us. 

To start off with, I’m quite liking the continuous hinting of that massive ice slice to advect into Europe, potentially giving an early entry into the freezer! A long way off yet, but the trend is certainly there. 

In the meantime, it’ll be nice to enjoy some nice, still, foggy and maybe frosty mornings, which will be quite a treat, given how wet and windy it has been. 

Take care all. I’ll hopefully be posting more often on the run into winter proper. 

[Allseasons-Si]

That is one impressive block to the NE with a very cold pool of -20-22 uppers and 500 dam

trough disrupting SE under the block,lots of possibilities on the table

p.s,i love you Scandi hp

 

 

 

Edited November 3, 2020 by Allseasons-si

[Ali1977]

Thats a mighty cold pool to the East on this run, they keep cropping up don’t they

Edited November 3, 2020 by Ali1977

[Zak M]

Impressive from the 12z GFS. Look at that blocking near Scandinavia..

Edited November 3, 2020 by Zak M

[SLEETY]

Nice to see such a cold pool develop so early in the season, compared to recent years. Let's hope this trend continues. 

[BLAST FROM THE PAST]

Looks like eventually getting there, not likely to pan out like this but good to see sone serious cold developing to the east....with chilly enough air coming from the west.  Nice run to look at

 

BFTP

[Kirkcaldy Weather]

On 01/11/2020 at 12:28, Kirkcaldy Weather said:

Slowly we are starting to get towards that pattern it’s around the 192 hour mark which is 9th November (to start looking for the pressure building across scandi) still a bit of wiggle room on the timing and still too far off to be looking for exact details but all very positive and if we can get a cold pool waiting in the wings ️ 

Models firming up that the 9th will be when the ridge begins to develop and pressure starts to increase across Scandi, something that’s also caught my eye is just how cold the air to the east is being shown on some of the runs between -16 and -20 hpa has been re appearing, for this stage in November that’s quite impressive and again akin to the Beast From The East 850s. Also just worth remembering for those that tend to get panicky with the less impressive looking runs is that we have seen it over the years the models often over do the strength of the low pressure to the west and underestimate the higher pressure / block. 

Edited November 3, 2020 by DiagonalRedLine
Post was displaying funny on my phone

[booferking]

19 minutes ago, BLAST FROM THE PAST said:

12 z looking chilly and heading towards a very cold end with Easterly looking likely on this run post day 10.  

LP to west won’t allow it to develop 

BFTP

Years of watching will tell you gfs 9/10 over progressive with Atlantic .

Its all there to see Yesterday 12v v todays 12z and todays 06z Atlantic getting pushed run by run.

[damianslaw]

Interesting to note Met Office going for cold end of November, so we may eventually get there..