Model Output Discussion 01/09/17

[snowray]

Looks like its going to be two bad 18z runs on the trot. I'm not that worried after the fab 12z runs, particularlyECM, this is probably 18z up the boozer again like it was last night, but none the less I may just have to get up early this morning for the 00z runs.

[ICE COLD]

The GFS 18z is completely different to GFS 12z , ECM , UKMO and GEM . So don't get to hung up on this run . Yet again we are still none the wiser to where we  are going ? 

[Nick F]

If it was bad enough that Monday morning is looming, the 18z GFS is dishing up the horrors of wet and windy fair from the west to send us to bed on a low! Doesn’t look like it can redeem itself either, hopefully the EC will stick to its guns in the morning.

Edited November 12, 2017 by Nick F

[Allseasons-Si]

Isn't it a good thing that the 18z pun run isn't showing stella runs for a change

[Man With Beard]

17 minutes ago, Allseasons-si said:

 

 

Thanks guys

just didn't know what the green line represented

We've all been there mate with the NOAA charts!! At first the anomalies look like pressure lines but it's just the lines that contain the detail! Keep posting though, this forum is not just for the experts (which I am certainly not one of).

TBH I am still scratching my head over what the colours on the EC clusters mean - instinctively they seem as if they should be anomalies but doesn't seem to add up...

[snowray]

7 minutes ago, Allseasons-si said:

Isn't it a good thing that the 18z pun run isn't showing stella runs for a change

Yes its doing the opposite now, wants to catch us out I guess.

[BlackburnChris]

28 minutes ago, northwestsnow said:

LOL 18z is a horror show-  and wet, very wet.

All that blocking to our North west and we get soaked.

 

 

Cant seem to get access to my old account on here but from previous years since 2003 . Ive never been a fan off weekend model runs or the 18z pub run , whatever it shows good or bad ...sticking with ECM version of events for now ... But do remember GFS did very well in 2010 and quite a long way out.  

[nick sussex]

 Some good news there for us downstream in Europe from US forecasters at NOAA.

This is from New York state for next Friday to Sunday, I've picked out the bits more pertinent to us in terms of the downstream pattern:

"Before we get to the day to day specifics...its worth pointing out
that the preferred guidance for this time frame is the ECMWF. The
GFS has been notably faster than other packages for several runs
now...and this fact has not been lost with the modeling experts at
the Weather Prediction Center...who also favor a blend of ECMWF
solutions for this period.

As we open this period on Friday...the aforementioned energy
crossing the Intermountain west will encourage a broad downstream
ridge to amplify somewhat over the Lower Great Lakes."

So at least some positives that the ECM is preferred upstream, the amplification of that ridge should help to sharpen up the troughing ahead of it which does help us. The differences upstream start appearing quite early with the ECM and UKMO disagreeing at T96hrs, this has a huge impact moving forward.

To put some detail on this take a look at the different views of shortwave energy off the eastern seaboard of the USA.

ECM                                                            UKMO

 

 

 

Edited November 12, 2017 by nick sussex

[snowray]

Well at least the 18z control run is showing some consistency and is very close to the 12z run.

[ICE COLD]

14 minutes ago, snowray said:

Well at least the 18z control run is showing some consistency and is very close to the 12z run.

I'll take purb 4 .  

[Geordiesnow]

Details wise, the 18Z is not the best but at that range we know the details will change and the fact its hinting at colder air coming down from the North is encouraging as the is the signal that the Arctic high is much nearer Svalbard which eventually starts to bring its colder uppers into Scandinavia also. Of course the west based NAO is a concern and it has been hinted by all the models this may happen but there is still time for this to change.

It does seem we can be confident that it will turn colder again by the end of the week but just how much colder and how strong the NW'ly will be is up for debate, the ECM is pretty good in this aspect if albeit on a convective point of view rather than a wintry one.

On the other hand as hinted by the UKMO/GEM and nearly in the case of the 18Z run, a much milder SW'ly is actually not that far away from verifying either which knowing our luck will probably be what will occur.

 

[The Eagle]

1 hour ago, A Frayed Knot said:

That's it in a Nutshell then ' Back to Normal Mush after next weekends Cold snap ' Oh the Joys of living in a Polluted world of today ' i remember when we had Blizzards and very Cold Winters ' 2010 had nothing on the winters we had in the 1960s -70s and early 1980s . There again Winter is approaching in just under 3 weeks time ' Lots of ups and down's ' we will get a brutal cold snap before Christmas as this seems to be like a De JA VUE - To me ' Cold in November with early frosts ' cold end of November with snow showers and a very cold December .

You are in Wales? 2010 was very severe for locations exposed to the east wind with frequent snow showers and constant daily ice. Extraordinary by any definition. That is both cold spells - start of the year and end of the year. Nobody exposed to it will ever forget those winters.

Edited November 13, 2017 by The Eagle

[knocker]

I was going to start with a brief run down on the latest anomalies but after looking at them i couln't think of anything meaningful to say so i'll leave that to later.

Today will start quite calm and chilly for apart from a few showers lingering along the east coast as the ridge edges east over the UK and will remain that way for England and Wales for the rest of the day. In N. Ireland and Scotland Cloud and later patchy rain will soon star encroaching as fronts track in from the west and the wind will also start to pick up. These will gradually push SE during the night across Scotland and into northern England and eventually further south tomorrow introducing more cloud and higher temps generally.

Once the fronts have cleared the ridge has shifted to the south east leaving the UK in a SW drift but the interest really lies to the west because this isreally going to dictate our weather over the rest of the week and the weekend  By Wednesday 18 we have an upper trough to the north west linking to the one over the Azores with a surface front orientated from west of Ireland to the Azores with a low that has developed on it WNW of the Hebrides 994mb. Over the next12 hours this low rapidly intensifies to be 968mb east of Iceland with the front over western Britain with rain and strong winds in the north

The fronts quickly track SE on Thursday and by Friday midday the intense low is filling slowly and moving south east as the high pressure to the south west once more amplifies and ridges NW giving some very strong WNW winds over N. Ireland and Scotland with squally wintry showers and maybe a fair amount of snow on the high ground  By Saturday 00 the low has continued on it's track and is NE of Thurso with the surface wind veering north westerly and still possibly gale force in the north particularly on exposed coasts.

The low continues down into eastern Europe setting up a large low pressure area to our east and the ridge and slack gradient over the UK comes under pressure from the next trough pushing in from the west  and in fact becomes the battle zone. This skirmish does introduce a southerly drift and warmer air over the UK but I think it's best left here.

It's tricky what to make of all this but to some extent it is supported by this morning's GEFS anomaly

 

Edited November 13, 2017 by knocker

[swfc]

It would seem the gulf between this mornings gfs and ecm which is currently running is massive. Ecm steady as she goes tho!!!

[Duane S.]

Yep this morning's GFS is pretty dire but the ECM is trying to keep the spirits up at least.

Surprised D8 not better than it is after the D7 chart. Definitely trying to bring in a Scandinavian high though.

Or rather, sniffing at it. No chance of it with the tracking of the low to our east.

Edited November 13, 2017 by s4lancia

[bluearmy]

5 minutes ago, s4lancia said:

Yep this morning's GFS is pretty dire but the ECM is trying to keep the spirits up at least.

Surprised D8 not better than it is after the D7 chart. Definitely trying to bring in a Scandinavian high though.

 

I wònder if this solution would be better a few weeks later as the wavelengths change that bit further. without much upstream to keep it going the northern arm is still modelled stronger and the subsequent ridging from the  sw prevents the next system from going se. Without that we would get the blocking able to link up to the Arctic. 

Btw, can anyone conform that nothing unexpected  is going on re sunspot activity. 

[terrier]

Well the gfs follows on from last nights pub run. Pretty dire to be honest. The ecm try’s and keeps the sprit up but I think eventually it will fall into line with the gfs like it seems to do at this time of year. So after things looking good over the past few days. It seems we are back down to earth with a bump. But at least we are still 3 weeks away from official winter 

[cyclonic happiness]

Here we go again! The GFS has swapped our northerlies for southerlies, and you can bet it'll be right too. Just as we were supposed to be going into the freezer, we jump into the oven instead lol!!   

1st big letdown of the silly season ticked off.

[snowking]

5 minutes ago, bluearmy said:

 

Btw, can anyone conform that nothing unexpected  is going on re sunspot activity. 

Not as far as I'm aware Nick, we're running at 12 spotless days and flux at similar levels to the last pre-minimum

[Chesil View]

Worth remembering before the toy throwing and writing off of winter in mid November begins that both the Met office and our  american friends prefer the ECM prognosis going forward.

Edited November 13, 2017 by Broadmayne blizzard

[knocker]

The key difference between the ecm and gfs would appear to start over the weekend, The gfs allows the ridge to be dissected by the energy/trough and thus opens the door to the west whereas the ecm does not and in fact the ridge is reinforced by more ridging to the west of the trough which creates a cut off low to the south west out of harms way so to speak. This allows the high pressure to build in the vicinity of the UK and to my mind this is the much more likely solution. It was this that was causing me a problem vis the anomalies so it will be interesting to see the EPS this morning

.

Edited November 13, 2017 by knocker

[bluearmy]

Incidentally, the gfs suite takes the AO more negative than recently (op -5 and ens -4) before a fast recovery back to positive. Perhaps that elastic band is tugged a bit too much for the model to cope with, especially the op. 

[Frosty.]

Early December daffodils anyone? If the Gfs 00z verifies..that's what we will get thanks to blowtorch sw'ly zephyrs.this model watching could drive you crazy!!.

[blizzard81]

Well, most of us know the propensity of the ecm to over amplify but let's keep the faith for now. Remember it is still the best performer in terms of verification. 

[markw2680]

How about they just don’t no yet what the outcome will be, if it was showing a big freeze everyone will be saying Stella etc if it was the other way it’s panic stations, it’s a week away so loads of time for things to change! Just enjoy the ups and downs it’s never a smooth ride unfortunately