Model output discussion - 16th Nov onwards

[solarcycle]

The French high res output still brings the precip in as snow and shows a few cms for East Anglia and SE.

 

AROME    ARPEGE                      

 

42 hour accumulated total - probably not going to lie with ground temps and dew points.  

 

 

BBC weather forecast just now seemed to follow above from French high res.

Edited November 19, 2015 by solarcycle

[Dr. Astro]

GEM, is a Gem tonight for festive weather lovers....

 

 

I think it's worth keeping an eye on the Siberian High...

[blizzard81]

Now I have heard of rapid cyclogenesis but the deepening of the atlantic low on the ECM from 1005mb at 168hr to 955mb at 192hr - Really ECM? Doesn't look right to me!

[Mucka]

Well ECM doesn't go the UKMO/GFS route this evening but there are some improvements on the 00z run with better trough alignemnt into Europe and more robust high pressure to the East.

JMA is somewhere between so I would say ECM is a little out on its own from the mid range but then it is the best performing model so we will see better by tomorrow no doubt.

[Cloud 10]

Now I have heard of rapid cyclogenesis but the deepening of the atlantic low on the ECM from 1005mb at 168hr to 955mb at 192hr - Really ECM? Doesn't look right to me!

 

Huge temperature contrast where that LP spawns causing the explosive development.

 

 

 

A cold and stormy start to winter if the ECM verifies.

[blizzard81]

Not sure what to make of ECM tonight to be honest. If it is correct at 144hrs then both GFS and UKMO are way off the mark at the same timeframe.

Edited November 19, 2015 by blizzard81

[Liam J]

Now I have heard of rapid cyclogenesis but the deepening of the atlantic low on the ECM from 1005mb at 168hr to 955mb at 192hr - Really ECM? Doesn't look right to me!

Yep, extreme explosive cyclogenesis on the ECM this evening, quite plausible if all parameters fall into place, doubt it could pick that out at such a range though, but the ECM has been showing a significant windstorm (with variations) on the last few runs now. 

[nick sussex]

A pretty chaotic scene this evening with some big differences especially over Europe, in terms of pattern the GFS/UKMO are closer. The ECM makes little of pressure rising over central Europe and is much more progressive, it finally dives low pressure se at T168hrs in response to the Siberian high influence.

 

Putting aside those differences there is a strong signal to drive the PV further south towards the UK. The issue at the moment is whether high pressure to the east/ne forces low pressure further se into Europe and how much if any trough disruption occurs.

 

In terms of the GEM I'd be dubious of yet another of its over amplified specials, something that was mentioned in tonights NCEP extended discussion.

 

NOTE THAT THE CANADIAN ENSEMBLES, WHICH ARE TYPICALLY A FAN OF
AMPLIFIED FLOW, WERE MUCH WEAKER WITH THE HEIGHT FALLS INTO THE
WEST AND DID NOT SHOW A CLOSED LOW IN THE MEAN BUT DID SO IN A FEW
MEMBERS.

 

Likely outcome looking at the overall trends then is PV and associated lobes near the UK, Azores high likely to remain displaced to the west/sw. Siberian high forcing some trough disruption into Europe.

 

 

[Polar Maritime]

Both GFS & ECMWF showing a similar story, With a stormy cool/cold start to Winter from a N/W Pm flow.

Edited November 19, 2015 by Polar Maritime

[A.J]

just a gentle reminder that 'Will it snow on/at....' type posts are not model discussion......best advice is to ask in the regional threads, or the current 'cold snap' thread, which can be found here........... https://forum.netweather.tv/topic/84455-weekend-cold-snap-20th-23rd-nov-2015/ ......or if the 'will it snow' post is aimed at a specific member, then the most direct way to ask them is to pm them.....thanks

[Bristawl Si]

Standard output for start of UK Winter, esp for The North

[Polar Maritime]

Standard output for start of UK Winter, esp for The North

 

Absolutely BB, What we would expect 'traditionally'. Perfect set-up for Blizzards in the North with continuation of cold/stormy tracks from the N/W into Winter.

Edited November 19, 2015 by Polar Maritime

[Frosty.]

It's great to see the forum buzzing again and the Ecm 12z shows a wintry weekend coming up and the southeast stays cold into early next week but it's this weekend which all the coldies richly deserve following a very mild autumn. There will be snow around, especially on hills and icy patches with widespread frosts. Looking further ahead, I can see there being further cold shots from north of west in the form of polar maritime incursions within a generally very unsettled pattern...Enjoy this weekend guys.

[heccygabber]

here's the ecm storm, it looks sweet.

[tinybill]

It's great to see the forum buzzing again and the Ecm 12z shows a wintry weekend coming up and the southeast stays cold into early next week but it's this weekend which all the coldies richly deserve following a very mild autumn. There will be snow around, especially on hills and icy patches with widespread frosts. Looking further ahead, I can see there being further cold shots from north of west in the form of polar maritime incursions within a generally very unsettled pattern...Enjoy this weekend guys.

ps  i love  to how knockers  daffs  going to say its  looking very cold this weekend  and even fantasy world looking tasty  to say the least

[mb018538]

Back to more of a normal looking set up after all the high pressure and mild air of Autumn so far. Trough set up right around the UK, with HP surrounding it. LP spins and regenerates in the trough, it'll need a big boot from somewhere to move it along....or we could be with this set up a while!

[solarcycle]

Back to more of a normal looking set up after all the high pressure and mild air of Autumn so far. Trough set up right around the UK, with HP surrounding it. LP spins and regenerates in the trough, it'll need a big boot from somewhere to move it along....or we could be with this set up a while!

Care to post any charts to back that statement up?

Edited November 19, 2015 by solarcycle

[Cloud 10]

12z ECM day 10 ensemble mean looking very unsettled,much like the op. run.

 

 

850 hpa winds (about 5000ft up) showing high levels just to our West so could be  going through quite a few letters of the storm alphabet towards the end of the month.

 

Must be some wild individual members amongst them.

 

[bluearmy]

End of the gefsp shows an impressive mean upper ridge to our ne

Edited November 19, 2015 by bluearmy

[knocker]

First I would like to allay any fears vis the well being of the dafs. A little nip in the air this weekend should bring them on a treat.

 

But to tonight's anomalies. Essentially although differing a little in detail the GEFS, ecm (including the ext) and NOAA are all singing from the same hymn sheet. HP NW North America, LP northern Canada/Greenland with negatively tilted trough SE towards the UK with a varying influence from the HP to the SW. The one that does break ranks a tad is the ext ecm which introduces an Alaskan trough and pushes the HP east. Plus the ext ecm and GEFS 11-15 tend to increase the ridging over Russia

 

So essentially after this weekends little interruption we are looking at and airflow from the NW/SW quadrant with a good dollop of Pm although the south could fair a little better with warmer air pushing up from time to time. All in all temps around average but colder with the Pm incursions up north.

Edited November 19, 2015 by knocker

[DAVID SNOW]

Care to post any charts to back that statement up?

 

Its not a forum rule to do so you understand?

[damianslaw]

Significant change in synoptics for all from tomorrow onwards and for the foreseeable, gone is the euro high and instead we see the atlantic trough once again having a love in with the UK - a pattern we have seen much this year, the outcome a predominantly polar maritime airflow, which will bring disturbed conditions especially in the NW with lively bouts of rain, snow on higher ground next week, but also some bright showery outbursts in temps overall not far from the late Nov mean (perhaps trending below in the north).

 

Looking at the overall northern hemispheric pattern, the Siberian high is exerting its influence early this year looking to put pressure on the polar vortex and if we do see it building northwards this may result in the trough coming unstuck somewhat and who knows forced to dive SE under building heights to the NE.. its a possibility.

[Newberryone]

here's the ecm storm, it looks sweet.

The centre of that potential storm does seem far enough away to the northwest to have little or no impact on Southern Ireland as well as England and Wales. Besides, that huge swathe of high pressure to the southwest, which is very pronounced throughout most of next week's output will possibly deflect it even further away nearer that timeframe. All very average indeed.

[Costa Del Fal]

Some light snowfall running down the western/central slice of the country again on Saturday night on the GFS 18z which had gone walkies on the 12z. Thus this clearly needs further model runs to firm up on details although if we see this event transpire into reality, the favoured areas for this currently seem Central Scotland, NW England/Pennines and down into the Midlands (Mainly Central parts) and perhaps CS England but possibly losing intensity by then. 

 

Attached are the latest GFS charts from the 18z.

 

Certainly nothing too disruptive, especially as it weakens travelling south. Minimal impacts on a saturday night/sunday morning anyway for most.

 

[pip22]

Next weekend could be interesting:

 

 

 

 

 

 

 

Maybe some snow in places when the -5 uppers are in place.