Model Output Discussions 12z 01/09/2016

[Johnp]

Erm..is it me or has there been a massive swing overnight? And at quite an early stage too?

Where did all the blocking go?

[northwestsnow]

15 minutes ago, Johnp said:

Erm..is it me or has there been a massive swing overnight? And at quite an early stage too?

Where did all the blocking go?

Gfs still looks very seasonal with some sub zero nights as we move through next week, ukmo looks very different at 144 and im not entirely sure what to make of it, ecm will be interesting, have to say gfs suits me fine, plenty of frost and possibly fog to boot..:) hear what your saying about the blocking though, thats why i never get carried away by greeny highs until they are within 78 hours...

Edited October 28, 2016 by northwestsnow

[knocker]

Today

A weak front lies across the north of England so essentially a split north and south of this although the weather is fairly benign. To the south mainly cloudy with some bright intervals and rather mild as winds remain in the anticyclonic flow from the SW. North of the front a bit cooler but more in the way of sunshine and some blustery showers initially in the north west of Scotland

In the reasonable time frame the GFS this morning is not dissimilar to yesterday evening although there are some small but significant differences.

By now we are all familiar with the disrupting Atlantic trough scenario and by Tuesday 00z we have the cut off upper low to the south west, HP to the NW and the upper low that is part of the Canada energy conduit just north of the Shetlands. Thus the start of the breakdown of the HP that has been influencing the UK weather over the weekend

The Shetland upper low tracks SE into the Baltic states and introduces a cold northerly to the UK but unlike last evening it is slightly further east and doesn't forge a meaningful relationship with the cut off low to the SW.

This allows HP to ridge once more into the UK and set everything up for a rerun next weekend although possible things are about to change with the advent of a s deep upper low in the Newfoundland area.courtesy of the phasing of troughs running SW from Canada and NE along the eastern seaboard.

Edited October 28, 2016 by knocker

[winterof79]

The big finger of heights across the pole nearly splitting it,how refreshing to see these synoptics remaining.Only a matter of time before the cold entrenches somewhere in Europe I feel

[northwestsnow]

http://old.wetterzentrale.de/pics/Recm1441.html

Is that icelandic low going to swoop SE and spoil Bonfire night? Or will it dive to our east?

Either way its not looking much like UKMO at 144 so i guess uncertainty reigns for now...:)

[winterof79]

Another scenario from ECM in line with METO update

 

Winds from a cold source too

 

Edited October 28, 2016 by winterof79

[bluearmy]

Quick resume on the eps 46

we know where we are first week or so November. By mid month, the low sceuro heights relax and higher ones become prevalent. nothing dramatic.  Beyond that period, around the 24th, they return and become marked to our south. This run indicates a likely cold last week of nov and beginning December.  Unless mogreps (and probably glosea) Is on the same page, Exeter will not take too much from one run although the overall background trend for the sceuro low anomoly is unavoidable. the parallel eps 46 will update tomorrow so we have another run to look at rather than having to wait until Tuesday for some further support. 

I think that based on that run November returns a neg AO. Ian may be able to put a number on the mean return if ECM allow? 

Parallel eps 46 is out and shows slightly less of a relaxation of any chill mid November but then fails to build a euro low anomoly late November and we look quite blocked last week Nov/first week Dec. uppers are not as anomalously low as the current model throughout November.  This model only shows me 7 day averages so a bit less informative re any potential detail. 

Edited October 28, 2016 by bluearmy

[northwestsnow]

Atlantic looks pretty blocked on the ECM operational.

But there are differences between all the big 3 this morning so who knows, i think i would least prefer the UKMO solution if i were being honest.

[Paul_1978]

1 hour ago, Johnp said:

Erm..is it me or has there been a massive swing overnight? And at quite an early stage too?

Where did all the blocking go?

I was expecting a horror show when I read that. But in summary (GFS): 

- high pressure over the UK for pretty much the whole run. 

- Atlantic never gets going. 

- Polar Vortex never forms. 

So not sure what you saw?

Edited October 28, 2016 by Paul_1978

[knocker]

Overall the ecm is quite similar to the GFS. The differences will arise on the timing and orientation of the troughs running east from the Canadian vortex and then south east into eastern Europe  Obviously any slight variation in the track will impact on the weather for UK anyway the ECM has two bites of the cherry this morning, the first at T120 and the second at T192 and overall the last half of the run is a bit nippy with temps a fair bit below average.

Edited October 28, 2016 by knocker

[summer blizzard]

Inversion on the GFS (sun and frost).

[weirpig]

Just now, summer blizzard said:

Inversion on the GFS (sun and frost).

Are    Some very nice Autumn charts  frost and possibly fog  going by those charts.  Lovely weather and as of yet still no sign of the Atlantic.

[January Snowstorm]

I suppose it all depends what your weather preference is. I have a bit of a hatred for high cells in winter as I think it's v non descript....

Enough has changed to our North to worry if normal service can resume in a week or ten days time. Of course it's all very early days but things are not as postive looking as 48hours ago.

I do take the point that long term prospects could still be v good 

[mb018538]

9 minutes ago, January Snowstorm said:

I suppose it all depends what your weather preference is. I have a bit of a hatred for high cells in winter as I think it's v non descript....

Enough has changed to our North to worry if normal service can resume in a week or ten days time. Of course it's all very early days but things are not as postive looking as 48hours ago.

I do take the point that long term prospects could still be v good 

I don't buy this really...



Zero vortex there, still split into pieces

[Frosty.]

2 minutes ago, mb018538 said:

I don't buy this really...



Zero vortex there, still split into pieces

If you like benign, the models look fine.

[Day 10]

1 hour ago, Paul_1978 said:

I was expecting a horror show when I read that. But in summary (GFS): 

- high pressure over the UK for pretty much the whole run. 

- Atlantic never gets going. 

- Polar Vortex never forms. 

So not sure what you saw?

Me too. As you say everything still looks fine. I think people are forgetting it's STILL ONLY OCTOBER.

If charts like this show up then we can moan

But charts like this heading into winter we must be extremely happy with, if we are looking/hoping for a cold winter which equals snow

 

[Ravelin]

Spot the odd one out at day 6...

ECM & GFS in the same ballpark with UKMO out on it's own. Given the constant chopping and changing at the moment I'd not bother looking beyond t120, in fact, I'd not rule out changes withing t120 either. I suspect the 'unusual' synoptics and the predicted split (temporary) in the strat vortex is playing havoc with the models. Far from boring watching though.

Edit: Actually, looking at them side by side like that and they ain't a million miles apart. Just the position of the low around Iceland that's making the difference.

Edited October 28, 2016 by Ravelin

[karlos1983]

I will say one thing, it isn't the most inspiring set of GEFS ENS. Yes they trend cooler, but I think cooler being the key word here, not Cold by winter standards.

But it is only the beginning of November, so expectations of deep cold reaching our shores at this time of year is not high for me anyway. 

No complaints, we are as many have posted in a much better position than this time last year. Just would really like to see similar charts showing for December for obvious reasons.

 

[Ali1977]

This run looks much better , block developing over Greenland again and much better over the NH with regards heights. Could bring back a cold Easterly by day 9 again.

[weirpig]

2 minutes ago, Ali1977 said:

This run looks much better , block developing over Greenland again and much better over the NH with regards heights. Could bring back a cold Easterly by day 9 again.

Yes  much more robust block on the 6z  am i really looking for wintry charts in October?

[feb1991blizzard]

 

2 minutes ago, Ali1977 said:

This run looks much better , block developing over Greenland again and much better over the NH with regards heights. Could bring back a cold Easterly by day 9 again.

Yes, this is going to be a stonker.

[SMU]

Any newish members looking in & wanting to see a chart to save to images for WAA up the western half of greenland.

Pick this one. & save it for reference as it doent get any better than that.

S

[knocker]

As mentioned earlier

[weirpig]

Day 10  chart.   Wet and Windy anybody?,   A very stubborn block  and cold uppers making there way to the UK 

[andymusic]

lovely model charts with blocking this year I grant you and the set up is definitely different to other years - and it's very early in the season yet for "true" cold - but one thing that does seem to be repeating itself is the way the "colder/cooler" charts keep getting pushed back around the change to low res - from Halloween - mid-way between halloween and bonfire night - bonfire night - and now after onto the 7th Nov and beyond - looks like - in past years - we may be chasing ghosts again - I hope that's not the case though!