Model Output Discussion - 05/01/2016 18z onwards

[Badgers01]

4 minutes ago, Earnest Easterly* said:

Who missed the significant snowfall for London & Home Counties on the pub run!

the fax charts look the best for snow since March 2013 ...

[Cheshire Freeze]

1 minute ago, ukpaul said:

18z Short Ensembles

12z Short Ensembles

And people wonder why I distrust ensemble forecasts. They can change just as much as the Op at times! 

[bradymk]

Quite a shift in the Ensembles too but wouldn't read much into it quite yet. Still think though that we do have a decent chance of staying cold for quite a while longer than has been showing on some runs but we do need the high modelled in a favourable place (further north) like on tonight's GFS. Let's see what tomorrow brings, seen some pretty big inter run changes last few days

[Allseasons-Si]

4 minutes ago, ukpaul said:

18z Short Ensembles

12z Short Ensembles

And what do i think of that!!!

[feb1991blizzard]

Just now, CreweCold said:

And people wonder why I distrust ensemble forecasts. They can change just as much as the Op at times! 

Its only the spread that's different, the higher 850s probably depict an anticyclonic spell, just a slight difference (which you expect at 180) of positioning of high, there are a similar number of frigid runs, but it is an upgrade but not a whole sea change.

[Jason M]

The control run looks fairly similar to the opp. By day 10 the rest of the GEFS are a mess tbh.

If the models push the heights any further north tomorrow things will get interesting. As we know though, its the last hurdle the always proves the hardest to clear!

[swilliam]

2 minutes ago, KasimWeatherQuarnford said:

Anything at night time with light winds would bring snow down to sea level given fairly moderate intensity and -6 uppers in mid January.

I can see a definite risk of some snow even across Southern areas later in the period generally agreed on my most runs, it would make sense given the 2 snowless winters of late for some in general in the South.

This being hinted at by ECM & UKM. One operational GFS run can not be singled out as a trend setter, we will have to wait for the morning for that, it is possible.

After this period, it is looking like turning quite cold with the high pressure, with lows in double digits possible over some snow fields given adiabatic & reflective cooling. 

 

 

No way will it be singled out as trendsetter  - quite the opposite in fact. Still not decided though but the ensembles are very encouraging. If we get cross model agreement for next weekend with a  cold highnear or to the W of us I will begin to believe it - no doubt the UKMO will now show a sunken high next weekend though.

[pages]

9 minutes ago, swilliam said:

P5 shows what can happen if we do not phase the PV with the lows in the W Atlantic and these then merge and then we get trough disruption - builds the high much further N

 

 18ZNavgem at 144hrs even better than GFS. would be bit chilly under that high with -10 uppers

 

[Man With Beard]

20 minutes ago, nick sussex said:

Tonights UKMO fax charts:

T96hrs:

T120hrs:

 

T96 looks a bit messy in terms of snow, the T120hrs looks less messy and I like that pool of sub 510 dam to the nw.

These are superb FAX charts for southern England - a succession of fronts well inside 528 dam air, winds north of west - pretty unusual. Surely an excellent snow chance for the end of the week.

ECM ens for London: the op was slightly more progressive than the main cluster but the cluster is also on the slow road to milder conditions by the 20th. That's still a way off of course.

 

[Woollymummy]

"Nearly half of U.S. stocks are in a bear market"

by Matt Egan   @mattmegan5January 8, 2016: 1:54 PM ET

 

"There hasn't been a bear market in the U.S. since the Great Recession. And even after the atrocious start to 2016, Wall Street isn't close to a bear market. The major indexes have to plunge 20% below their previous high to be in one."

(From CNN Money)

The bears are welcome to come and live here for a little bit if they like....

I know we are not meant to get over-excited every time we log on to this thread and we should be looking for the bigger picture, but I am looking forward to seeing if the possibly low temperatures turn out the way they just seemed to have on GFS, even if we have no snow, a frost can be just as memorable and can lead to ice-skating possibilities in unusual places. 

[nick sussex]

You've got to love tonights NAVGEM 18hrs run to T144hrs. It was okay on its 12hrs but has upped the ante on its later run:

 

[Allseasons-Si]

2 minutes ago, pages said:

 18ZNavgem at 144hrs even better than GFS. would be bit chilly under that high with -10 uppers

 

That is an easterly in the making

[Dancerwithwings]

12 minutes ago, ukpaul said:

18z Short Ensembles

12z Short Ensembles

It's certainly going to be a roller coaster ride is that

[Severe Siberian icy blast]

13 minutes ago, Mucka said:

Well it is only one set of ensembles but big flip tonight from GFS with ensembles much improved and any Westerly incursion delayed if not postponed indefinitely 

I say that because some are finding way to have the Azores low and Atlantic trough undercut and that is the first time that has been modeled to the best of my knowledge.

Given GFS knack for picking up new trends let's hope it is sniffing a new signal.

This has been a crazy roller coaster ride but we may not yet have hit the really wild part!

Tomorrow could be a day of massive upgrades

or

Not 

Absolutely agree my old Mucka , feeling optimistic now for a massive turn around tomorrow, I expect the ECM to fall in line with the other two , but it's the ramifications this has longer term also , if we can get the Azores low to keep a separate entity then it good open the door for the beast . But I'm getting ahead of myself there !

[northwestsnow]

WOW - stunning change in the ens !!!

ECM maybe the one backing down tomorrow!!

Amazing roller coaster and some headscratching going on all round .

[feb1991blizzard]

ECM London Ens aren't special though, these are different to the GFS on meteociel remember - these are surface temps and a decent clustering go fairly high.

[Rinse The Raindrops]

2 minutes ago, feb1991blizzard said:

ECM London Ens aren't special though, these are different to the GFS on meteociel remember - these are surface temps and a decent clustering go fairly high.

Do you have the chart from Feb 1991?

[Mucka]

Nice to see the strat warming still there too

Here are the full ensembles for the SE - the cold has been deepened a degree C or two and prolonged 24-48h from the 12z set which is quite a lot for a mean average.

[VillagePlank]

10 minutes ago, northwestsnow said:

...and some headscratching going on all round .

Not really. Fine edge, really, particularly with that Atlantic high - and how far, and how quickly east it's going to go in the reliable forecasting future - if it does at all. It looks to me as if 100 miles (or even less) either way is the key here. We're going to get cold (and colder) through to Sunday, I think, and bitterly so for some according to GFS18z. Main thing to remember is that it's going to be West a bit, then East a bit, then West a bit etc etc almost up to the day. Tri-model agreement over a number of runs is key for (accurate) predictions, I feel, and we're running out of time for that, now.

Edited January 10, 2016 by VillagePlank

[VillagePlank]

2 minutes ago, Mucka said:

Curious 'blip' on the 16th, there; it's like FI should start, and then it just doesn't. Probably something to with the exact placement of these boys:

A minor position here and there etc.

[Chris1986]

3 minutes ago, Mucka said:

Nice to see the strat warming still there too

I expect the warming trend to continue. Past 4 GFS runs shows an upgrade.

[Daniel*]

My stomach is not the only thing which is doing somersaults. 

 

[Allseasons-Si]

10 minutes ago, Mucka said:

Nice to see the strat warming still there too

Here are the full ensembles for the SE - the cold has been deepened a degree C or two and prolonged 24-48h from the 12z set which is quite a lot for a mean average.

Chino's just posted this on the strat thead

Both EPS and GEFS showing another "nudging" period of the stratospheric polar vortex on day 15 pic.twitter.com/JDJsqY2D64

— Michael Ventrice (@MJVentrice)

January 10, 2016

 

Edited January 10, 2016 by Allseasons-si

[bryan629]

Meanwhile back at the wood shed.....

The heat seeking missile is beginning to home in on its target >>> 

[Ice Day]

OK, time to pause for breath.  There have been a plethora of posts over the last week promising a roller-coaster ride which is exactly what we've got.  The models are wobbling all over the place.  None have this upcoming spell nailed, however momentum is going the way of cold.  I'm a glass half full type of chap,  but I really do think there could be some massive charts coming up in the next 36 hours.  We shall see, but if nothing else, this weekends models have stopped me painting the downstairs toilet, so that's a positive.

Until tomorrow gang.