Model output discussion - 1st December onwards

[gottolovethisweather]

11 minutes ago, nick sussex said:

I always become more melodramatic when faced with these types of outputs! lol The death low is circled red! The mothership is in black. As soon as the death low gets attached to the mothership its game over.

Even without the phasing its a hard slog to keep any colder conditions but with it is akin to climbing Mount Everest without crampons.

Its doubly frustrating because the jet does dig quite far south and amplifies the mothership trough later but once that phases with the death low the energy spills all ne.

 

Ok cheers, Thanks for that, intriguingly this is pretty much where FI begins, to my mind, as can be seen by the divergence in the ensembles member clusters. We also have a split Jet out in the Atlantic during those timeframes too, which is usually helpful. Beyond these troublesome wave depressions who knows what might occur.

 

I wouldn't bank on any chart being correct beyond the early part of next week right now, so in that fact alone, there is still hope for some watered-down kind of pattern change in my opinion into the middle of next week.

Edited December 9, 2015 by gottolovethisweather

[Cheese Rice]

Even the ECM, a model that downplays any snow potential is picking up on the snow.

[Nick F]

With an upper trough looking to be stuck over the north Atlantic for quite a while ... with long fetch SWly flow beneath a succession of surface lows heading NE towards northern Britain on the forward side of the upper trough - the dreaded 'atmospheric river' keeps visiting the UK sourced all the way from the Caribbean like last weekend:

This Sunday's PWAT over the Atlantic (Weatherbell)

... and again the following weekend:

GFS Rainfall accumulation in high res out to t+192 is rather alarming for Wales in particular. Cumbria right on the edge of the high values, wouldn't take much for the emphasis to shift north. Please don't come off 12z GFS operational medium range, not good!

 

 

Edited December 9, 2015 by Nick F

[Ali1977]

2 minutes ago, Greenland1080 said:

You know it's bad when your looking at the FIM, CMA, CPTEC etc

Anyway can the ECM give us an89th minute penalty today

Can't see it, no support of any cold signals from the METO this side of New Year....think we need to Focus on signals for something different early Jan unless this could be a long few weeks for coldies.

[cheshire snow]

4 minutes ago, Cheese Rice said:

Even the ECM, a model that downplays any snow potential is picking up on the snow.

Indeed

some surprise snowfall is a possibility

 

C.S

[Nouska]

3 minutes ago, Cheese Rice said:

Even the ECM, a model that downplays any snow potential is picking up on the snow.

ARPEGE is also bullish with accumulated snowfall over Scotland and the northern hills in England.

Rainfall totals continue to mount up the further south you go.

[Cloud 10]

6 minutes ago, Cheese Rice said:

Even the ECM, a model that downplays any snow potential is picking up on the snow.

 

GFS 12z going for nearly 10 inches over the Pennines by the end of Sunday.

 

 

Love the Christmas skin for the forum btw.

Edited December 9, 2015 by Cloud 10

[Kentish Snowman in Yorks]

It is looking marginal but I will take a punt that somewhere in Northern England could take a hammering snow wise this weekend.  Obviously the more elevation the better.

The latest runs forecast that front coming up from the South to grind to a halt and wherever it does could be very very wet or very very white!

[Tom Jarvis]

Is the ECM going to give us a Scandinavia high!!

[Mucka]

1 hour ago, Captain Shortwave said:

The GEFs keep the slug entrenched until around the 23rd, then there seems to be signs of a pattern change with low heights forming over the eastern Seaboard which may entice something cooler to develop for the UK.

Perhaps seeing an Atlantic ridge/Scandi trough form just in time for Christmas. It is very far away though.

December so far is trying its hardest to go into the hall of infamy with the likes of the winter of 88/89 and 2013/14.

 

I like it, breaks the gloom,  but that is quite an optimistic interpretation of those charts IMO CS. We really need to see negative anomalies showing in Europe and much stronger positive anomalies showing to either NW or NE before anything other than zonal is favoured but yeah any signal that does away with positive height anomalies to our South is welcome as it would at least likely allow for some PM incursions further South  in the flow.

 

Talking of optimism, snow for Northern England?

Unlikely based on current output but the heavy nature of the PPN will have evaporative cooling going for it I guess.

High ground will obviously catch some snow as likely will even low ground in Scotland but unless the output pushes the colder air further South any snow to low lying areas of England seems like a long shot.

Very happy to be proved wrong on this of course.

 

Edited December 9, 2015 by Mucka

[nick sussex]

The ECM eventually clears the death low into the continent, no phasing although it was perilously close to doing so. It might just be a stay of execution as a lot of energy is still running over the top.

You can clearly see how marginal this phase scenario is because upto T120hrs it looked like it was going to.  Regardless of what the ECM goes on to show this is a small victory in an otherwise miserable evening for coldies.

Not saying that we'll suddenly see something interesting but not to overplay this phasing situation but all our hopes rest on that issue. Because I can't see anyway of holding back the Atlantic train unless some energy gets diverted into the continent to help support the high.

 

 

 

[Mucka]

GFS 12z predicted rainfall totals almost biblical

 

 

That is  in excess of average rainfall for the entire month in places which would actually fall in around a 72h period as most of it falls after 78h in.

Edited December 9, 2015 by Mucka

[phil nw.]

Just another look at the stalling front across the middle of the UK over the weekend.

Fax T72hrs(Sat 12z)

we can see the kink forming around the Irish sea which is giving some forecasting headaches this would pep up the percipitation as it runs along the boundary layers between the cold air to the north and the balmy tm air further south.

The problem at this stage is forecasting where the wave will actually form along the front and how much it deepens.

GFS 12z at T72hrs 850hPa chart

upland areas on the cold side could well see snowfall,freezing levels based on the GFS look to be around 3-500mtrs,but of course this could change as we get closer.

We keep saying it but the rain associated with this is the main concern and ideally we would rather the front head through without these complications stalling the rain band for many hours.

 

[Gavin Hannah]

Ok, come on Pub Run!! Lets get this weather sorted for crimbo!

On more somber note, I'm starting to feel the cold death grip of 13/14 creeping up on us again...

[nick sussex]

2 minutes ago, Greenland1080 said:

Well we missed the penalty had 2 men sent off by referee slug...time to give it couple days off

 

The ECM actually scored the last minute penalty to bring the game back to 1-1, but then the scores remained level until the penalty shoot out where the ECM hoofed the ball into the stands!  The fact it managed to clear that low into the continent is a minor miracle given both the GFS and UKMO outputs phase that with the upstream trough.

[Redwood]

Its depressing reading guys and gals.  Im having a break for a bit.  Maybe come back in a week or so and see if anything seasonal will pop out of the proverbial bag for Christmas, but I doubt it.  Thanks to all your efforts, especially Nick Sussex, John, Chinio, BFTP and Tamara (where is Tamara?).  I've learnt loads over the years following this forum, just never had the confidence to post.

[Methuselah]

Set phasers to stun, and fire at will!

Edited December 9, 2015 by Ed Stone
I was thinking about a pathetic joke!

[mulzy]

7 minutes ago, nick sussex said:

The ECM actually scored the last minute penalty to bring the game back to 1-1, but then the scores remained level until the penalty shoot out where the ECM hoofed the ball into the stands!  The fact it managed to clear that low into the continent is a minor miracle given both the GFS and UKMO outputs phase that with the upstream trough.

JMA also fails to phase the lows and we end up here.

[gottolovethisweather]

Well the ECM 12z runs continue to be fascinating NH wise of late, in a similar fashion to this post from the other day in fact.

On the above I stated, that we should be looking at what is forecast to go on across the nearby continent, well changes are a-foot over there for sure but they are just NOT in our favour yet.

 

Again this maybe only one run in isolation but there are two features I want to highlight to you which are bringing about much of the model suite confusion in my opinion. Firstly look at this very late in the season tropical depression development over in the Pacific as early as D3 (my much lauded 12th December). Notice how deep in terms of mb it is modelled to be and also where the feature wants to track to, this in turn has three potential impacts for us beyond the reliable timeframe, ramifications of which could possibly make or break our overall impression December as a whole.

• changes in NH Jet positioning and ferocity come Mid-December
• Prevents the development of Northern Blocking, at least over the poles
• potential for a displaced Polar Vortex

FWIW I have far from given up hope yet from a cold-loving perspective and I've always been a half-glass full type of chap anyhow. Moving on, below are the ECM charts showing said feature (encircled in Magenta) through 12th December to 14th December timeframes (D3-D5)

 

 

The knock-on effect this has downstream/upstream on Central to Eastern parts of Europe from t+120 (D5) through to t+192 (D8) hours is quite dramatic. Just imagine the kinds of Air Temperatures (20c or more below average at the extreme end) some lucky folk might be receiving in those parts. The European Arctic blast highlighted in encircled Blue area, whilst we are forecast to sit within the milder Magenta encircled region.

Having said that it'll only be a temporary blip in the overall scheme of things it seems before milder air once again rushes in. Whilst, I guess the same can be said of the Northern UK weekend's snow potential. A heck of a lot going on in the weather world right now and I suspect more NWP output melodramas will be incoming yet before we are able to reach general consensus for the weather over our little tiny island. 

 

 

 

 

Edited December 9, 2015 by gottolovethisweather

[WillinGlossop]

1 hour ago, Nouska said:

ARPEGE is also bullish with accumulated snowfall over Scotland and the northern hills in England.

Rainfall totals continue to mount up the further south you go.

Are there any forecasting websites that use nmm and arpeg models as their forecasting tool?

just looked at arpege model online and theyve got 30-40cm forecast for peak district.....

Edited December 9, 2015 by WillinGlossop

[tinybill]

well i see  the gfs  is suggesting a white xmas   for scotland  and  the north of  the  uk  at the  moment!!  things  will change

[Nouska]

14 minutes ago, WillinGlossop said:

Are there any forecasting websites that use nmm and arpeg models as their forecasting tool?

just looked at arpege model online and theyve got 30-40cm forecast for peak district.....

The forecasts on Meteo France use their own models (AROME and ARPEGE). Only limited locations for the UK forecast.

http://www.meteofrance.com/previsions-meteo-monde/royaume-uni/pays018

They have the numerical models in animated form for wind, rain, snow and temps - the link is below - just hit play.

http://www.meteofrance.com/simulations-numeriques-meteorologiques/europe-atlantique

[Newberryone]

8 hours ago, Newberryone said:

The only respite from flooding for the foreseeable future, judging by some of the latest output, will be as a result of transient ridging and dare I say not much more. FI models have been offering up many different solutions as of late, many hinting at perhaps the possibility of sustained ridging but as we've seen time and time again, this eventually becomes downgraded. As is often the case with this type of weather pattern, parts of the south and southeast of the UK will be influenced more by any amplification from the south, whereas in broad terms  northwestern areas seem destined for more of the same.

Only one run, but it would appear going by the 12z Ecm op that northwestern parts, not alone areas further south may after all  be spared the worst of the Atlantic onslaught, for on this update things are looking far more amplified from Tues next onwards. Which no doubt to the relief of many kinda makes my earlier post redundant now.

[Cleeve Hill]

With ECM at 144 (where it is pretty accurate) next tues / wed shows something a bit different. No conveyor belt lows but a depression sat pretty central over England and a small high to its west. 

So I reckon temps below ave and something a lot more seasonal. 

[tinybill]

14 minutes ago, Newberryone said:

Only one run, but it would appear going by the 12z Ecm op that northwestern parts, not alone areas further south may after all  be spared the worst of the Atlantic onslaught, for on this update things are looking far more amplified from Tues next onwards. Which no doubt to the relief of many kinda makes my earlier post redundant now.

well i just looked at the gfs  from now to xmas  day all i can can see there no let up for the weather in them parts   from rain to possible snow