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

[Troubleatmill]

32 minutes ago, mb018538 said:

I quite like the look of how things are lining up. Looks as if we're going to get a cold shot, followed by a cold high.....eventually everything swinging back to a more W-E flow, though by that time there could be an inversion under the high and it stays cold anyway. Looks like more eastern half of the UK may even fare best for a change!

Not sure how you could say that after the December floods? For snow the east is more often for not the best place  

Edited January 11, 2016 by Nicholas B

[i luv snow]

2 minutes ago, Nicholas B said:

Not sure how you could say that after the December floods? For snow the east is more often for not the best place  

I was going to post the same. I grew up and lived in East Anglia until 2011, and have now lived in Manchester since 2013, and so far (and this may just be timing with the 2 pathetic Winters we have had since), the East usually manages to fare best for snow. Much to my dismay and disappointment of course!

[Nick F]

00z GEFS show over half members (12+) still blocked with high pressure over the UK by Thurs next week, not many, far less, show a return to Atlantic mobility. A few interesting solutions with northerly reload too.

GFS op has been against its ensemble consensus until last few runs and funnily 12z EC high res yesterday appeared to be against the EPS mean of ridging over the UK next week, so be interesting to see if it's on it's own again.

From a purely IMBY POV, nice to see the -10C T850 line on EC high res into SE an Anglia

 

[mb018538]

I meant W-E in the orientation of the general flow pattern, though with a HP bias rather than low pressure dominant. Here in Cambridge we're often too far inland for anything substantial snow wise unless it's a major low pressure truckload of snow!

[Day 10]

Upgrades this morning, a few tweaks here and there to pull the high a little further north would be good. A decent start to the week, the cold keeps getting prolonged and on the latest GFS run the high throughout the low res part of the run just keeps moving around and doesn't really want to sink which is a good sign going forward.

[beng]

2 hours ago, TEITS said:

On a more negative note I feel some in S areas are expecting too much from the potential snow this week. I am of the opinion that the S is more likely to see snow falling rather than snowfall and this to occur on the backedge as fronts clear.

Bah - pains me to say it (given I live down S), but I agree.  The depth of cold isn't there IMO for snow 'here' from the initial blast on Thursday.  If the -5 air had been established for a few days and had a chance to mix down to lower levels then it would be more likely.  I expect some further North will do quite well - more especially if you have a bit of altitude.

Our best chance may be the little feature project to run across Friday night - which I'd prefer anyway since if it did amount to anything I won't be stuck in the morning commute as it'll be the weekend.

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=114&mode=2

http://www.meteociel.fr/modeles/ukmo2.php?ech=84&carte=2000  (wave just west of Ireland) - it may track too far west though.

 

 

 

 

Edited January 11, 2016 by beng

[Frosty.]

I will gladly take what the Gfs 00z shows, gradually turning colder this week with an increasing chance of snow, especially on higher ground but the risk also applies to lower ground..increasingly widespread frosts which become sharp or severe over the snow fields and more snow early next week too with cold air persisting...poor daffs!

[Connor Bailey Degnan]

Great news this morning, all models trending towards very cold air until at least Monday. Highest risk of snow certainly across the east, where even to lower levels a few cm+ is likely. Wishbone becomes active on Saturday so any snow at the eastern coast. In summery, the further west you are, you're much drier but very cold. The further east you are the more snow and very cold also. Time to start getting excited!

[Paul_1978]

On another note, Ryan Maue on Twitter has posted a graphic suggesting the AO is to go positive, which unless I'm mistaken suggests a reformation of the Polar Vortex? :-(

https://twitter.com/ryanmaue/status/686309114692136960

[nick sussex]

Morning all

Well at last a bit more convergence in the outputs for the earlier timeframe so it does look like the ridge will topple towards Scandi before the Atlantic flattens this or tries to.

That's what the operationals suggest, though looking at the ECM spreads particularly the 850's theres still a cluster within the ensembles which keep the high further north.

For any more prolonged easterly the trigger and key pointer is this shortwave circled red:

This responds to the cut  back or not in terms of the jet. The ECM takes the shortwave se at T168hrs, for the block to hold further north you need that shortwave cutting back towards the UK as this would correlate with a more favourable upstream pattern.

Whether we can achieve this well you'd think currently the operationals are pretty resolute about flattening the high but still enough time for that to change. The odds would favour the flattening but its been a strange week so we'll just see how things develop.

Earlier at least chances of snow and some frosts so all in all not a bad start to the week.

PS for some reason the image won't enlarge, can't work out what happened here!

 

 

 

 

 

Edited January 11, 2016 by nick sussex

[Snowman.]

2 minutes ago, Paul_1978 said:

On another note, Ryan Maue on Twitter has posted a graphic suggesting the AO is to go positive, which unless I'm mistaken suggests a reformation of the Polar Vortex? :-(

https://twitter.com/ryanmaue/status/686309114692136960

Way too far away but the general trend is for the AO to go back to neutral.

[mb018538]

I'd say quite possibly looking at this chart:

Most of the consensus at around day to is for low pressure to start filling the polar region again, with a big trough over Iceland and Greenland, and high pressure back to it's usual position over the south. High pressure locked away over Siberia for the time being again perhaps.

 

[nick sussex]

Well I'm pleasantly surprised, that cluster I mentioned in my previous post seems larger than I thought:

You can see by those ensembles theres a strong cluster keeping much colder conditions for De Bilt which suggests the high further north.

Even if the UK doesn't get a straight easterly any surface flow off the continent would produce much colder conditions.

Lets hope that the ECM operational run has over reacted to events upstream. A chance I think to extend the cold by a few days. After that the ECM ensembles are much more resolute in bringing in the Atlantic but that's a long way off if we go by the ensembles.

 

Edited January 11, 2016 by nick sussex

[Nick F]

26 minutes ago, Paul_1978 said:

On another note, Ryan Maue on Twitter has posted a graphic suggesting the AO is to go positive, which unless I'm mistaken suggests a reformation of the Polar Vortex? :-(

https://twitter.com/ryanmaue/status/686309114692136960

Well the stratosphere PV remains strong, though forecasts show it getting torpedoed later in Jan, maybe signs of a SSW. The troposphere PV, which has been disconnected from the strat, has of course, been blown apart, as signified by the current -AO, though GEFS suggest a return to more neutral indices.

on another note, 00z EPS mean shows a 500mb +height anomaly centred over UK even at day 13 . Control more akin to high res up to day 10.

Edited January 11, 2016 by Nick F

[mushymanrob]

im not so sure the high is going anywhere fast, despite what the ops are suggesting.

the noaa anomaly chart is pretty consistent in keeping the high to our near west, so the uk looks like being calm and cold with sharp overnight frosts and fog issues for much longer then the current ops predict.

 

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 09:00 ON MONDAY JAN 11TH 2016

THE CURRENT GENERAL SITUATION   Low pressure across the UK will ease East out into the North Sea later today with a slowly increasing NW flow across the South and West of the UK bringing showers and sunny spells late today and tomorrow.

http://www.wetterzentrale.de/pics/Rtavn001.gif 

CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across the British Isles will lie around 1000m or 4000ft across the UK today and tomorrow with some snowfall in the form of showers on hills and mountains above around 2000-2500ft

http://www.snow-forecast.com/maps/dynamic/uk

http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow.gif

MODELS-2 WEEK HEADLINE  Rain or wintry showers at first. Becoming colder and drier with frost and fog patches likely next week.

THE GFS JET STREAM FORECAST  The main theme of the Jet Stream today shows the Jet Stream continuing to stream East across France over the first week before becoming more variable and harder to interpret in both strength and location in the second week as the synoptic pattern becomes uncertain.

http://www.netweather.tv/index.cgi?action=jetstream

GFS OPERATIONAL The GFS Operational Run today shows a rather cold and wintry showery week to come as winds turn NW with Low pressure meandering around over the North and East of the UK later this week at the same time as pressure gently rises from the West over the weekend. Next week then sees High pressure occasionally give way to Low pressure with some rain at times for a while in slightly less cold air before High pressure gains total control of the UK weather late in the run with frost and fog patches widely night and morning but with some dry, bright and sunny days.

GFS CONTROL RUN The theme of the Control Run is very similar to the Operational run though with High pressure developing near the UK at the end of the coming week with frosty and cold conditions looking likely for all. Then after a short unsettled and possibly still rather cold period with some snow over the hills especially in the North High pressure builds again very strongly late in the period, over the UK with fine and sunny weather with frost and fog at times overnight. perhaps a little less cold in a SW flow over the NW of the UK for a time later on.

http://www.wetterzentrale.de/pics/Rtavn1441.gif

http://www.wetterzentrale.de/pics/Rtavn3841.gif

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=144&mode=0&carte=0

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=384&mode=0&carte=0

UKMO The UKMO model today shows rather cold Low pressure drifting slowly East away into Europe through the end of the week and the weekend with the associated unsettled conditions with rain and hill snow at times gradually reducing in quantity as we move into the weekend as a large and blocking High pressure area edges close to Western Ireland by Sunday ensuring dry and fine but cold and very frosty weather across all areas and just the chance of a wintry shower or two still close to the East and SE coasts. 

http://www.wetterzentrale.de/pics/Rukm1441.gif

THE FAX CHARTS The Fax Charts show complex Low pressure clearing away slowly East late in the week but leaving a legacy of weakish troughs moving South and East down across the UK in NW or North winds and rising pressure but still with instability great enough to give rise to further wintry showers at times especially near Northern facing coasts and hills.

http://www.weathercharts.org/ukmomslp.htm#t120

GEM GEM this morning shows increasingly settled but cold weather developing after this weeks rather cold and unsettled conditions with rain and snow in places clearing away East and SE at the weekend. Next week looks fine and dry but cold with very sharp frosts at night before it becomes a little less cold across the North later as a westerly drift from off the Atlantic moves in with the coldest and frostiest weather then likely towards the South of the UK.

http://www.wetterzentrale.de/pics/Rgem2401.gif

NAVGEM NAVGEM is broadly similar in theme to the other output with rising pressure the main theme leading to High pressure centred across the UK by the start of next week displacing the rather cold and unsettled weather with wintry showers that most places will continue to see through this week before sharp night frosts but dry sunny days develop late in the weekend.

http://www.wetterzentrale.de/pics/Rnvg1681.gif

ECM ECM today also shows a variation of a similar theme of rising pressure leading to a much awaited change towards fine and settled conditions next week. Before we get there there is plenty of showery and rather cold weather to come this week with showers wintry at times with a little snow in places before things dry out and some sharp night frosts develop with some compensatory bright and sunny days take hold. then later in the run into the middle of next week the High pressure area responsible slips South with milder SW winds affecting the Northern half of the UK late in the period and then probably extending slowly South. 

http://www.wetterzentrale.de/pics/Recm2401.gif

ECM 10 DAY MEAN The 10 day mean chart shows High pressure likely to lie close to Southern Britain in 10 days time with fine and settled weather the most likely outcome across the UK through next week with any milder weather restricted to the NW of the UK at that time.

http://www.wetterzentrale.de/pics/Reem2401.gif

NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The models have all trended together this morning towards a prospect of High pressure based rather cold weather to develop after this weeks rather cold and unsettled conditions.

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECM show at 24 hours ECM ahead at 99.6 pts with UKMO and GFS at 99.4 pts respectively.  At 3 days ECM is leading with 97.5 pts to UKMO's 96.7 pts while GFS lags behind at 96.2 pts. At 5 days ECM leads with 89.8 pts to UKMO at 87.8 pts then GFS at 87.3 pts. Then at 8 Days ECM still leads at 66.8 pts over GFS's 63.5 pts. Finally at Day 10 ECM is ahead of GFS at 49.0 pts to 47.7 pts respectively. 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day1_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.png

MY THOUGHTS   We finally have a coming together of the models this morning to the extent that I can predict with more confidence and hopefully more accuracy than for a good while on what weather the UK can expect to see over the next few weeks. Starting with this week we have a complex area of Low pressure still lying across the UK giving a mix of rain and showers falling as sleet and snow over the hills today and this mix will continue off and on for another 4-5 days as the whole set-up slips slowly East into Europe as we reach the weekend. With regard to snowfall the hills at least will see some though disruption is likely to be limited to higher ground and in the North with some places seeing none. However, frosts will be much more prevalent with time especially tomorrow night and then more widely from the weekend as pressure builds into the UK from the West slowly displacing the cold Northerly flow and wintry showers out of the East and SE by Sunday. By the start of next week most output shows High pressure well in control, something we haven't seen for months with light winds, sunny days and very sharp night frosts the order of the days. Then as we move into the latter parts of the output this morning it's all about how quickly and in what way we slowly lose the influence of the High pressure towards a more traditional Atlantic based pattern or any other weather type. This is of course well in the future and is pointless dwelling on detail but in summary today and with some confidence I can say that cold or rather cold weather is here to stay for the next 10 days at least with increasingly sharp frosts and eventually dry weather the main ingredients to enjoy finally displacing the endless mild and wet weather we have all had to endure for what seems an eternity of late and while I can't offer a snowy picture this morning's output does at least endorse something more normal for the time of Winter we are in. Lets hope that the coming together of the models with the pattern now settled can be maintained within the output over this week. 

Next Update on Tuesday January 12th 2016 at 09:00 approx

Edited January 11, 2016 by Gibby

[Chris1986]

34 minutes ago, Paul_1978 said:

On another note, Ryan Maue on Twitter has posted a graphic suggesting the AO is to go positive, which unless I'm mistaken suggests a reformation of the Polar Vortex? :-(

https://twitter.com/ryanmaue/status/686309114692136960

Looking at the latest gfs polar vortex is definately being displaced.

Ozone signals are strong to swing the heating further north and west. 

[carinthian]

Morning all. I think most on here would welcome this chart for next Sunday. A big dry up for the North and West and all with a lot of ice. Some  cold air entrenched over the UK, not only surface cold but lower uppers, particularly over SE Britain next weekend. Note the drop in heights moving westwards in Southern Europe, this should help hold back any fast sinking of the strong developing  high to the west of The British Isles. There is also evidence of a upper trough forming in the Euroland cold flow and maybe the best chance for next weekend for the SE to see snow showers.  For the rest of this week, showers or spells of sleet and snow could crop up almost anywhere, just nay impossible to pin point today, but maybe even the SW of England could have the deepest of cold flow tomorrow afternoon before the 528 dam line cover much of the Kingdom and Eire. Will try and update SE potential for next weekend after getting latest snow portal results later today. Mild here in the Eastern Alps his morning with wet snow conditions and thaw, however the boundary between mild and cold is narrow, so snow could return in a matter of hours.

 C

[Geordiesnow]

Hopefully the cold for nearer the weekend will be a bit more sustained because the cold air for this week is really looking sorry for itself with mild sectors galore unfortunately on the 06Z run in particular, keep harping about it but if the current trough that is over us cleared quicker like some model runs did suggest then we would be in the colder air quicker and by the time things got messy, it would of been less marginal than I think it will be now. 

Hopefully this 06Z run is wrong tbh because it does make more of the milder sectors and again, its not as amplified as the Euro runs in the shorter to medium term. 

[That ECM]

Yet more heights to NW 

[Ali1977]

Greeny high showing on this run at 126

[mountain shadow]

I'm confused.  Geordiesnow says this run is less amplified yet Ali1977 says we have a Greenland High? ??

[radiohead]

If only everything was a bit further west. Frustrating.

[Iceberg]

Interesting take from the gfs 06z particularly n.hemisphere speaking.

it takes directly from what I said this morning, their are hints that the models don't want to destroy the gh and indeed patterns suggest it might well stay in place. 

Many more twists and turns yet in the happenings over the next 15 days.

 

[coldcomfort]

14 minutes ago, Geordiesnow said:

Hopefully the cold for nearer the weekend will be a bit more sustained because the cold air for this week is really looking sorry for itself with mild sectors galore unfortunately on the 06Z run in particular, keep harping about it but if the current trough that is over us cleared quicker like some model runs did suggest then we would be in the colder air quicker and by the time things got messy, it would of been less marginal than I think it will be now. 

Hopefully this 06Z run is wrong tbh because it does make more of the milder sectors and again, its not as amplified as the Euro runs in the shorter to medium term. 

Reluctantly I have to agree GS, even calling the upcoming spell a cold one looks to be on increasingly shaky ground imo, colder yes, but average to rather cold pretty much covers what I can see. Once again the 06 GFS is like a dog with a bone regarded a quick return to milder Atlantic air this weekend, no doubt it will probably be something of an outlier but you can't help thinking that eventually it will come up with a run like this that attracts an unwanted level of support from it's ensembles.