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

[West is Best]

It's faaaaaaar tooooooo early to be talking about whether it will snow in Cardiff, Castle Cary or Cambridge.

Details such as sleet vs snowfall as well as surface temps are secondary, or even tertiary, engagements. As has been said on here many a time, get the macro synoptics right first, worry about the finer detail later. There will be ups and downs on the micro level: there always are. What matters at this range of T120 are the right synoptic patterns being in place. Compared with a few days ago there's cause for much cold lovers' cheer this morning.

Edited January 7, 2016 by West is Best

[snowking]

11 minutes ago, *Sub*Zero* said:

2m temps on the 00z ECM not as cold as yesterdays 12z but you've probably guessed that looking at the 850 temps which aren't as low, different story over Scotland though with some very low minimums into minus double figures. 

That deep low introduces some less cold air with temps around 6 to 9c in the far south with a strong onshore flow, temps do drop as the low moves east and the wind switches back to north as the depression exits east, minus 15c in parts of Scotland! 

Snow chart probably quite optimistic looking at the above temp charts especially in the south but certainly looking better Wales & Midlands northwards, if it did happen I don't think snow would be as widespread as shown below away from high ground with many seeing cold rain, looking at the dew points they are around 3 to 5c from the Midlands southwards... Anyway probably a different set of charts on the 12z later. 

Just to follow on from WiB's post, always worth bearing in mind the stated ratios on these charts too - it's highly unlikely in a setup such as this that we would end up with a 10:1 ratio. Theseare of course more aligned to North American climatology.

And of course it's all conjecture at this stage!

SK

[JoeShmoe]

4 minutes ago, January Snowstorm said:

I've said before the ensembles chop and change just like the op runs.

You need only look at last night where practically full agreement and 12 hours later it's 50/50!!

As ever more runs needed and the met are correct in holding off for now.

Absolutely - any cold getting in is still at T+96 with different routes where less cold air is entrench or that air not being cold enough , especially in the south

can see full well while the MetO don't start ringing alarm bells until this is modelled at much shorter range

The full 12zs later and their ENS suites will hopefully push more members back to cold - let's see 

 

 

 

[phil nw.]

Good morning all.

Unfortunately we are still having to remove some off topic posts which clog up the thread.

Just a reminder to use the other threads if discussing the MO outlooks or where it may snow etc.

We have different threads open for these including the new thread for the upcoming cold spell.

Thanks all.

[mulzy]

Solid day 8 ECM ensemble mean.

[blizzard81]

The ecm ensemble means look quite a bit colder than last night's 12z

[mountain shadow]

4 hours ago, January Snowstorm said:

I've said before the ensembles chop and change just like the op runs.

You need only look at last night where practically full agreement and 12 hours later it's 50/50!!

As ever more runs needed and the met are correct in holding off for now.

My memory from 09/10 was that the models were always trying to break the cold down and failed.

That day 8 ECM mean is pretty incredible. 

[Frosty.]

Let the good times roll, stellar 00z output has strengthened my belief we are heading for a prolonged cold spell, these charts from the Ecm 00z...winter is coming with a vengeance, I have been itching to say that for the last 5 weeks..

[Shuga ice]

1 hour ago, BM4PM said:

Sorry to put a imby type post up, but for myself its not looking that great. Current temp forcast for next week in my area is around 5 degrees.

The uppers are there but im guessing the sst must be still quite warm which inturn must be modifying the air. 

I really dont understand as i dont think these charts could get any better. 

 

 

They could get a lot better for your area, I am looking for an easterly feed which would be great for Plymouth.  At the moment though I am only seeing a dry bright interlude for most of the U.K for 3 to 4 days before a return to wet & windy weather with hill snow in the north.

[Tony Beets]

10 minutes ago, mulzy said:

Solid day 8 ECM ensemble mean.

It is a very nice mean chart mulzy! Love how the arctic high is 1040 as a mean , if we can keep that up there pushing the cold air out to lower latitudes then we should have plenty of chances of cold and snow.

its like that feeling you get when your team is in a penalty shootout, it's 4-4 and the other team miss! All we are waiting for is our last player to score and boom we win.

keep up the great work everyone.

[Shuga ice]

No real change in the output from last night, a lot of dry and bright weather next week for 3 to 4 days before wet and windy weather with hill snow spreads to northern areas.  The south holding on to dry weather a little longer.

[Singularity]

Alright then... we seem to have the U.S. amplifying + anchored trough sorted out now (fingers crossed), but we've now been presented with a new source of uncertainty; how that Azores Low behaves.

To me it looks like the behaviour will be strongly influenced by the extent to which shortwave features develop on the western flank of the UK/Sceuro low and nibble away at the ridge to our west. 

Worst case scenario sees such a disturbance move southwest under the ridge to meet the Azores Low as it comes the other way, resulting in the feature intensifying substantially while still SW of the UK. This is a very particular scenario requiring all manner of things to be just-so, much like the event at other end of the scale, which sees the low from the Azores moving east as a fairly shallow feature, but then engaging with the UK trough and developing right as it hits the UK. This is likely to bring the feature south of Scotland but perhaps as far south as N. France based on past experience with such things. To name a recent example, I'm fairly sure the March 2013 Channel Islands storm was originally shown to slam England and Wales.

Something in between is also possible - such as the low developing just SW of the UK, introducing a notable warm sector but with a good chance of pulling the cold back in for back-edge frontal snow. OR we might see the low not make the trek for a long time; we can't assume anything about those disturbances trying to develop on the western flank of our trough complex.

 

Much room for thought then. I'm aware that some of the very biggest snowstorms have occurred via lows from the Azores engaging with a cold pool over the UK - the moisture levels can be high enough for snow to fall in measures of feet as some have already noted on here this morning - but also that the cold pool in place is usually a bit more impressive ahead of it. A cleaner initial import of cold would be very beneficial I expect. As it is, what shows this morning looks sufficient for the northern half of the UK to get a good dumping.

Given the complications now showing their hand, of which one or two are likely to be realised to some extent or other, it looks likely to be that the (far) south will have to put up with some very bleak with cold rain and a raw, damp wind ahead of any snowy weather achieved. This is common enough in a UK winter, but I figure it's worth giving the heads-up just in case any southerners are imagining snowy weather arriving quickly and cleanly by the middle of next week, say.

Yes, I'm playing the level-headed card this morning, I wouldn't be much use at forecasting if I couldn't 

[i luv snow]

3 minutes ago, Shuga ice said:

No real change in the output from last night, a lot of dry and bright weather next week for 3 to 4 days before wet and windy weather with hill snow spreads to northern areas.  The south holding on to dry weather a little longer.

I know I shouldn't bite the bait, but this is not true, this isn't what the models are showing.

[johnholmes]

10 minutes ago, Shuga ice said:

No real change in the output from last night, a lot of dry and bright weather next week for 3 to 4 days before wet and windy weather with hill snow spreads to northern areas.  The south holding on to dry weather a little longer.

Your post is not a true reflection on what any model is showing in the broad scale pattern of things.

Please pm me if you wish to discuss my post further.

John

Edited January 7, 2016 by Nick L

[BLAST FROM THE PAST]

1 hour ago, West is Best said:

Good morning my old friend. Well well well ... just when January was being written off by soothsayers these runs come through. Actually the models have been indicating developments for some time, it's just that we're in the unusual position of having huge upgrades at less than T168.

That ECM is an awesome set up, entirely backed by the other two. The GH of 1058 in yellow heights is a thing of great beauty

Hi Richard

I noted you were back in, good to have you around.  Yep agree with these huge upgrades, fascinating stuff.  

 

BFTP

[SMU]

ECM extended superb -

also those keen eyed spot that the op was a mild outlier at day 8 & 9 indicating that low was probably to deep over the UK day 7-

s

[BLAST FROM THE PAST]

2 minutes ago, Steve Murr said:

ECM extended superb -

also those keen eyed spot that the op was a mild outlier at day 8 & 9 indicating that low was probably to deep over the UK day 7-

s

What does that control look like Steve!!?  I mean its colder still,

 

BFTP

Edited January 7, 2016 by BLAST FROM THE PAST

[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 THURSDAY JAN 7TH 2016

THE CURRENT GENERAL SITUATION   A trough will move NE across remaining Northern and Eastern parts becoming slow moving across NE Scotland again with strong SE winds. Behind the front a somewhat showery Westerly flow will replace the front before a new showery trough crosses East over England and Wales tomorrow.

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

CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across the British Isles lies between 1500ft asl over NE Scotland to nearer 4000ft across Southern England. Snow is expected across higher Scottish hills later today, tonight and tomorrow and extending to higher Northern English hills as well by then.

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

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

MODELS-2 WEEK HEADLINE  Becoming colder and still rather unsettled with some rain, sleet or snow at times and frost at night.

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 next 4-5 days as the flow stalls across the Atlantic and ridges North. It then returns SE across Ireland later and then back east across or to the South of the UK late in the period.

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

GFS OPERATIONAL The theme of the GFS operational run today shows a slow change to much colder conditions across the UK with rain at times turning to snow for all higher ground at times next week and lower ground too at times. The axis of the cold moving South is shown to be slow and quite laboured as milder air from Low pressure close to the South could hold up its progress over the extreme South especially later when alternating less cold and cold periods are more likely across the UK as Low pressure tracks West to East across the UK renewing cold NW or North winds behind them.

GFS CONTROL RUN The theme of the Control Run is very similar to the Operational run today with solid support for colder conditions for all of the UK next week. Low pressure remains largely in control too with Greenland High pressure too far away to exert total influence enabling some milder conditions to filter into the South at times later with a messy mix of rain, sleet and snow across the UK throughout the latter stages of the output.

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 today shows Low pressure still in control of the weather next week and looks less supportive of widespread cold this morning as it dd yesterday. the problem here is the inclusion of higher pressure over Iberia which keeps a Westerly flow across Southern Britain with the coldest weather held to the NW. Nevertheless colder weather will affect the UK with rain or showers continuing and increasing amounts of snow in the North and on the highest ground of the South too at times.

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

THE FAX CHARTS The Fax Charts show fronts and Low pressure across the UK gradually transferring to the East of the UK early next week opening the door to a slow change to colder weather with rain at times turning to snow especially in the North but more slowly in the South.

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

GEM GEM this morning brings colder conditions across the UK more cleanly next week as Low pressure transfers away east from the UK to Northern Europe and pressure builds across the Atlantic. The resultant Northerly flow would bring wintry showers of sleet and snow and widespread frosts at night with High pressure close by to the west by Day 10. 

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

NAVGEM NAVGEM shows colder air too slipping down across the UK next week but not as a result of a Greenland High but slow moving cold pools of Low pressure which remain in situ across the UK next week maintaining unsettled conditions with rain and snow at times, with the snow at times in the hills almost everywhere.

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

ECM ECM today shows a very messy journey towards cold weather too next week as Low pressure transfers some of it's energy away to the East but maintains a lot of troughing across the UK keeping unsettled conditions going with rain, sleet and snow almost anywhere at times next week and into next weekend.

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

ECM 10 DAY MEAN The 10 day mean chart is a good one for cold lovers today as it looks favoured for Northerly winds across the UK with High pressure to the West and NW. With a Jet stream averaging at a point between members to the South and SW of the UK the most likely weather type has to be cold weather with wintry showers especially in the North and East..

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

NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The theme of the output continues to favour cold weather developing from next week with a more realistic approach to how things are likely to turn out next week than was shown last night.

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 96.5 pts respectively.  At 3 days ECM is leading with 97.6 pts to UKMO's 96.9 pts while GFS lags behind at 96.4 pts. At 5 days ECM leads with 89.8 pts to UKMO at 87.9 pts then GFS at 87.5 pts. Then at 8 Days ECM still leads at 66.1 pts over GFS's 62.8 pts. Finally at Day 10 ECM is ahead of GFS at 47.8 pts to 45.3 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   The models continue to point towards a much colder regime across the UK from what we have endured of late although I'm sure folks reading this and having seen last nights output will be unsatisfied with what's on offer this morning. Nevertheless, there is solid support for colder air to replace the average temperatures across the UK currently and the general pattern in the next few weeks is thousands of miles from the pattern we had in December. We still have another 4-5 days of deep Low pressure in control of the weather over the UK with the continued mix of rain and strong winds at times for all. The air is already cold enough over the hills and high ground of Scotland for some snow and this theme will extend to the hills of Northern England and Wales too over the weekend. Then as we move into the new working week things get far more interesting for Southerners too. The likely outcome is that part of the complex Low pressure areas across the UK will shift to the East and allow colder NW or North sourced winds to  move down across the UK. The problem lies with High pressure areas. The one which develops over Greenland is almost too strong and sets up a strong North flow down the Atlantic and helps maintain Low pressure closer to the East of the UK and with some evidence of higher pressure over Spain it takes a long tome for any true cold to reach the South. All these complexities mean the UK doesn't get a clean clearance of Low pressure to the East that's needed and instead we maintain a complex trough across the UK in a lot of model output this morning. The positioning of this trough is paramount to what happens weather-wise across the UK in terms of whether it's rain or snowfall we receive but what is quite concerning to me more than anything is that we might not lose the high levels of precipitation across the UK that we so desperately need to at least offer the flood stricken parts of the UK a break in the wet conditions. So despite this negativity I'm sure the message today is still one of colder weather with rather cold or cold conditions likely for all from early next week for the foreseeable future. Some snowfall is inevitable probably for most at some point but whether it will be enough to satisfy the needs of snow lovers remains to be solved by the models in the coming days. However, the synoptics are right to bring cold to the UK for the next few weeks and although we may have to be patient down here in the South I still feel with time we remain in the best synoptic set-up for cold in the UK next week and I expect a lot more changes in the output up and down in the coming days and in the lead up to next week. I'll be back tomorrow to report on how things have developed and transpired by then.

Next Update on Friday January 7th 2016 at 09:00 approx

[Shuga ice]

6 minutes ago, johnholmes said:

Your post is not a true reflection on what any model is showing in the broad scale pattern of things.

Please pm me if you wish to discuss my post further.

John

I understand your point but I see the outputs playing with different scenarios.   The outputs do look stunning but I really can't see the Atlantic playing ball to the extent shown.  Remember, last week there was no sign of anything but mild, wet weather showing with a lot of despondency in here.  I am just taking the middle ground view.  It's pointless having a forum where you are only safe to post snow and cold possibilities and be berated when your view is the opposite.

tonights outputs may show a great outlook for cold but there is also a chance that they may start to get watered down.

I hope for cold snowy weather but it isn't in the bag yet!

[Paul_1978]

21 minutes ago, Shuga ice said:

No real change in the output from last night, a lot of dry and bright weather next week for 3 to 4 days before wet and windy weather with hill snow spreads to northern areas.  The south holding on to dry weather a little longer.

So how are you seeing this when most of the forum isn't? What's the logic behind your assessment?

[Geordiesnow]

Got too admit, I finding  the model output this morning with a little bit of mixed feeling, just looking at the details on the ECM/UKMO run for the trigger low, quite a backtrack in respect on how far eastwards they want to send the low initially, it follows the GFS runs of it faffing on over the UK before finally pulling away so its the usual of the cold air being delayed(and past experience will tell you that isnt always a good thing). Also the potency of cold has dropped somewhat, still feeling cold but uppers are marginally warmer than they were yesterday. 

Now the bit I am more happy with is that all 3 models have a successful Greenland ridge and none followed last nights 18Z run which i'm relieved about although I would not want the ECM idea of a deep low coming from the Azores to interact with the cold air because for me, the cold air over us is not all that cold to deliver a decent battleground/frontal snow set up, you really need a more pronounce firmer cold batch of air over us to really deliver the goods on that one. 

As I said yesterday, I much prefer the cold air to come in quicker and I am a little shocked at the backtrack of both Euro models regarding the trigger low which does affect the output somewhat but when you get a Greenland high, you always got a chance. 

[Polar Maritime]

Post are having to be hidden again, Just sensible/friendly 'Model Discussion' please in here otherwise your post will go missing, There are banter/winter threads open. Please back up post's with charts/evidence as 100's come on here for valuable information. .

Thanks. 

Edited January 7, 2016 by Polar Maritime

[karlos1983]

3 minutes ago, Geordiesnow said:

Got too admit, I finding  the model output this morning with a little bit of mixed feeling, just looking at the details on the ECM/UKMO run for the trigger low, quite a backtrack in respect on how far eastwards they want to send the low initially, it follows the GFS runs of it faffing on over the UK before finally pulling away so its the usual of the cold air being delayed(and past experience will tell you that isnt always a good thing). Also the potency of cold has dropped somewhat, still feeling cold but uppers are marginally warmer than they were yesterday. 

Now the bit I am more happy with is that all 3 models have a successful Greenland ridge and none followed last nights 18Z run which i'm relieved about although I would not want the ECM idea of a deep low coming from the Azores to interact with the cold air because for me, the cold air over us is not all that cold to deliver a decent battleground/frontal snow set up, you really need a more pronounce firmer cold batch of air over us to really deliver the goods on that one. 

As I said yesterday, I much prefer the cold air to come in quicker and I am a little shocked at the backtrack of both Euro models regarding the trigger low which does affect the output somewhat but when you get a Greenland high, you always got a chance. 

Hi Geordie

I have to agree with you. Im in a state of unease this morning. After being on cloud 9 after the 12z of yesterday, I found the 18z from the GFS worrying. Although I'm confident a cold outbreak is almost certain, I'm still a little underwhelmed this morning RE longevity, more particularly for those further south. I've been watching the Low that has been key for me to keeping the Atlantic ridge joining the Greenland High for days now and I must admit not for 1 minute did I consider that it might spin off another low and attack the south coast as early as it is being modelled this morning.

I do take some relief in the extended ECM Steve M has recently posted, which does suggest that it may have overdone the intensity of the low and what trajectory it takes, I prefer more E than NE.

Certainly very interesting nonetheless.

 

Overall still good synoptics, but I'm keeping my excitement held back for a bit longer yet, especially for my area. No question areas of the Midlands North could get a pasting from the 168 chart.

[i luv snow]

24 minutes ago, Shuga ice said:

I understand your point but I see the outputs playing with different scenarios.   The outputs do look stunning but I really can't see the Atlantic playing ball to the extent shown.  Remember, last week there was no sign of anything but mild, wet weather showing with a lot of despondency in here.  I am just taking the middle ground view.  It's pointless having a forum where you are only safe to post snow and cold possibilities and be berated when your view is the opposite.

tonights outputs may show a great outlook for cold but there is also a chance that they may start to get watered down.

I hope for cold snowy weather but it isn't in the bag yet!

I'm sorry but you can post this when that is what the models show (IF they ever show it) but you can't make statements like that when the charts aren't showing it. It is unfair to those people who use the forum for information. At the very least, be clear it is speculation based on what you suspect might happen, despite what the models show.

Edited January 7, 2016 by i luv snow

[Geordiesnow]

18 minutes ago, Paul_1978 said:

So how are you seeing this when most of the forum isn't? What's the logic behind your assessment?

To be fair, I think his analysis could well be spot on regarding it will be brighter and quite dry next week but there will be some showers around however I think the emphasis will be more on that it will be dry, chilly and sunny, the PPN charts do reflect this. Regarding the other part of his view on the outputs, Its too early to say what will happen. 

In terms of this mornings output, if the cold air is slightly more modified then I certainly won't be digging any snow shovels out just yet, the air might be barely cold enough for any showers to fall as snow nevermind settling snow.