Model Output Discussion 19th January 2014-18z onwards.

[weather eater]

@GibbyPeople look for wintry weather in winter. The rain has been mentioned by others but we have had so much of the stuff many choose to ignore the latest prognosis for obvious reasons.

Mostly in vain downpour it has to be said, meanwhile we continue to have one of the most extreme winters outside of cold and snow that I can remember, I’ve said it before but during the winter we may as well rename this thread the hunt for cold thread. Most of us and I include myself in that are indeed looking for something of a cold snowy variety, however, sometimes when confronted with what’s really happening weather wise it seems a little one dimensional.

[Frosty.]

I agree although on nearly all the model runs today the "parts of the uk to have settling snow" are the parts above 300m and mainly north and east of the midlands. Low levels of England / wales may see a sleety mix at time. Let's hope for more upgrades over the next few days!

I think this is by far our best chance of a wintry spell since last spring, due entirely to the track of that vigorous low on sunday, there is wintry weather even before then, we have 528 dam thicknesses across the uk tomorrow with a lot of sharp showers, wintry to low levels in the heavier ones, then a risk of leading edge snow across the central spine of the uk with elevation on friday, wintry showers into the north and west on saturday, then sundays storm which could bring more heavy snow across northern hills / mountains but then I think we will have accumulations of snow in places next week with 528 to 522 dam making inroads, especially between tues / thurs..Fingers and toes crossed we get our long awaited snow fix next week. It's even worth a BOOM 

[bluearmy]

the ecm ens mean is just about a carbon copy for the op run out to day 8. 

[UV-RAY]

Assuming the JMA solution doesn't happen I think coldies will be best looking to the NW for cold air and potential snow

Indeed, forget looking East anything cold and wintry appears to my eyes to be heading from the NW.

[Joe Levy]

It remains the overriding concern and focus for UKMO. Yes, there are folk at Exeter equally beguiled by snowy set-ups (who isn't) but the real meteorological interest this winter is, and remains, the rain. It's been utterly fascinating for those of us not risking cardiac failure over snowflake failure. However next week could indeed offer snow based on low track, entrainment of colder air from E; diurnal phasing and evaporative cooling effect. All those beyond current model scope and likes of GFS PPN type at that range are just a toy. Ignore.

I love snow as much as any coldie on here, but living in Exeter, where travel in and out of the city depends on several main riverside routes being accessible, my primary immediate concern is rain totals! It is deeply troubling the totals that are being forecast and I think many on here greatly appreciate the updates you give us on such matters Ian. There have been numerous times when the main reason I was able to warn relatives of flooding long in advance was because of your updates here.

Edited January 22, 2014 by Joe Levy

[shaky]

the ecm ens mean is just about a carbon copy for the op run out to day 8.

good thing or a bad thing bluearmy??

[Summer Sun]

Pretty good agreement between the ECM ensemble and Op out to t216

 

couple of exmaples

 

Op

 

 

Ensemble

 

 

Op

 

 

Enesmble

 

 

Op

 

 

Ensemble

 

[Jimmy0127]

It remains the overriding concern and focus for UKMO. Yes, there are folk at Exeter equally beguiled by snowy set-ups (who isn't) but the real meteorological interest this winter is, and remains, the rain. It's been utterly fascinating for those of us not risking cardiac failure over snowflake failure. However next week could indeed offer snow based on low track, entrainment of colder air from E; diurnal phasing and evaporative cooling effect. All those beyond current model scope and likes of GFS PPN type at that range are just a toy. Ignore.

 

Hi Ian, any further thoughts from you or your colleagues on the track of that low? Looks potentially troublesome regardless of PPN type?

[Ali1977]

Ensemble mean looks better than the Op going on the charts SS has just put up.

Maybe there will be a minus 30c scale on the ens charts , gone up in fives from 15 over the last 2 evenings ....

[Jason H]

Models still teasing us mid term. I've a feeling that the High Pressure is just too far East to effect this part of Europe, which has been the story so far this winter. We're probably due a snowless winter by the laws of average. Rain does look the immediate concern. Friday & Sunday look like rub outs.

Edited January 22, 2014 by Jason H

[bluearmy]

that russian high is a bit of a monster. i wonder how long it can just sit there ?

[Gibby]

Unable to post my regular report over to you tonight but for those who wish to read it you can find it on my website at this link

 

http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm

[Frosty.]

I Think the Ecm 12z op run shows a lot of wintry potential, it's similar to the ukmo run and check out these thicknesses, 528 dam making regular inroads, especially next week, even a risk of sub 522 dam in places. There is a huge mass of bitterly cold air to the east/north east which will be heading towards the uk, cold enough for snow next week, especially further north but even the south has a risk of snow as cold air digs south. And then a potentially very cold west / north westerly flow by the end of the run with 522 dam sweeping into the northwest of the BI later with snow showers, so we could be attacked by cold from the north east and then the north west during the next 10 days. 

[Biggin]

I think raising the concern of rain here Ian is falling on deaf ears as most just look for one thing I'm afraid. i have relatives who live in Moorland Nr Bridgwater and I am quite concerned for their welfare if your weekend predictions come to fruition.

I am sure there is a thread on here somewhere bout the approaching rain / poss deep low pressure.

[Frosty.]

I am sure there is a thread on here somewhere bout the approaching rain / poss deep low pressure.

One thing is certain Biggin, a big stormy low will definately hit the uk on sunday, no question about it..batten down the hatches again and get the sand bags ready in flood prone areas.

[chionomaniac]

There seems to be a lot of general winter chat getting into this thread. Please stick to the models, not winter weather preferences, thanks. 

Will be moving posts over to the winter thread shortly.

[SMU]

Steering back onto topic for Ed-

 

The ECM clustering at day 7 show perhaps for debilt at least, the prospect of lower surface temps progged by the operational, however at this range the spreads will not translate all of that for the UK - the signal of whether that deep upper cold ( sub -8c) can get across the north sea wont become clear until Friday PM

 

Until then its the fine tuning & adjustements as usual within the models-

 

What to look for- The JMA solution goes for a very sharp gradient across a short lattitude - almost a sandwich of pressure- the more squashed the low looks ( as oppossed to more circular ) is a good thing as when the cold arrives there will be less entrenched mild air-

 

S

[damianslaw]

Models are suggesting a chilly unsettled outlook, with low pressure and trough action aligned more on a WNW-ESE path as opposed to the WSW/ENE path we have seen for most of the winter. This is an important shift as it allows colder polar maritime air to get into the mix and with the strong building block to our NE there are indications of a more 'cyclonic' pattern with low thicknesses and dewpoints wrapped within the low heights and trough action increasing the chances of any precipation being quite wintry down to relatively modest levels. 

 

Tomorrow is a good example, we will see colder uppers move across the country from the NW and in any hefty showers there could be snow falling down to quite low levels in the north around the 250m.

 

The key player remains the Polar vortex, which remains very strong and looks to be going nowhere fast from its NE Canadian home, the Russian high is both a blessing and a curse for those wanting a quick shift to something substantially colder, in terms of a blessing it will have the effect of driving low pressure/troughs on a more SE path opening us up to blasts of polar maritime air and as I said due to slow movement, low thicknesses and dewpoints will begin to settle across the country increasing the chance of at least some temporary wintry bursts of precipitation with significant snow on higher ground in the north, however, at the same time its position looks like being just a bit too far east to enable undercutting scenario and thus looks like preventing a clean build of heights to our west - and because troughs and low pressure look like stalling just to our east this allows time for the next bout of energy off the vortex to quickly move in from the NW. Until we see an amplified flow develop across the NE USA seaboard, we will remain locked under the influence of the trough which means unfortunately more significant rain - adding to the saturated ground.

 

This winter so far has reminded me strongly of the likes of 94/95 and 04/05, which were 2 very wet stormy winters but both became much more settled and colder by mid February with wintry stings at the tail end - notably so in 2005. There are many similiarities with this winter and 2004/2005 in particular - remember the storms and exceptional rainfall of early January..

[winterof79]

Agreement on heights dropping s/e next week.A good sign in any winter

http://www.meteociel.fr/modeles/jma/runs/2014012212/J144-21.GIF?22-12

http:/http://modeles.meteociel.fr/modeles/gfs/runs/2014012212/gfs-0-162.png?12

http://modeles.meteociel.fr/modeles/gfs/runs/2014012212/gfs-0-162.png?12

http://www.meteociel.fr/modeles/ecmwf/runs/2014012212/ECM1-168.GIF?22-0

 

Cracking charts coupled with a cold continent.

http://www.meteociel.fr/ukmo/runs/2014012212/UN144-7.GIF?22-18

 

But i have still scrolled through page after page of unwillingness to accept them as being superb.

Even 144z is pushing the reliable limit i admit.

 

Some colder options showing for the middle of next week on De bilt

http://www.knmi.nl/exp/pluim/Data/pluim_06260_0_12_60.png?1390426804636

Edited January 22, 2014 by winterof79

[Cloud 10]

that russian high is a bit of a monster. i wonder how long it can just sit there ?

 

It may pay us a visit,although i'm not sure i have the necessary stamina to watch it back west. 

 

http://modeles.meteociel.fr/modeles/cfs/runs/2014012206/run1m/cfsnh-0-936.png?06

[bluearmy]

It may pay us a visit,although i'm not sure i have the necessary stamina to watch it back west. 

 

http://modeles.meteociel.fr/modeles/cfs/runs/2014012206/run1m/cfsnh-0-936.png?06

 

my guess would be not before day 16 and possibly by day 21.  i think by mid feb, that will be the major player for europe. whether it makes it quite this far will depend on how far south and west that bloody azores high can shift, allowing the jet to undercut on a more shallow axis and driving the euro trough further se into the med and beyond.

[Purga]

18z pub run off to an atrocious start

 

[Pembroke Dangler]

So yet another winter storm brewing in the nw Atlantic with our name on it for Sunday into Monday, although not coinciding with spring tides like the storms of a few weeks ago it will still produce a lot of unwanted rain for money, thermal gradients behind the initial front seem very marked dropping from +5 to -5 850s in a very short space of time could cause very heavy rain followed by a spell of sleet and snow in heavier bursts almost anywhere settling above 300 metres then Monday into Tuesday? Anyone's guess.

[weirpig]

18z pub run off to an atrocious start

 

yep some severe damage if that came off.

[Blake]

A few still stating "only x days until end of winter..." blah blah.

 

 

March 7th 1976 - Scandi high - low to SE with -4 to -12 uppers

 

http://www.meteociel.fr/modeles/archives/archives.php?day=7&month=3&year=1976&hour=12&map=0&mode=0

 

March 19th 1987 - Greenland high - low to NE - -6 uppers covering all of the UK

 

http://www.meteociel.fr/modeles/archives/archives.php?day=19&month=3&year=1987&hour=0&map=0&mode=0

 

 

In my eyes, having seen snow in April in 1998 and 1999, winter has good 11 weeks remaining at least. Use the archive in the links above.

 

 

GFS updating currently, subtle changes. Bringing the low across slightly faster than the previous run and slightly more to the north for the more NW part of the main low? Seems the scandi high is pushed slightly SE with everything marginally further east?

 

 

GFS 18z - the southern most part of the low out west is 100 miles or so lower. Anything of concern or for discussion?

 

12z

 

 

18z

 

Edited January 22, 2014 by GUWeather