Model Output Discussions 18z 31/01/2016

[Lukesluckybunch]

24 minutes ago, Alexis said:

Big story this morning is how the UKMO is doing its own thing and disagrees with all the rest 

 

 

So what's the big story here then,it's just a weak ridge not  strong enough high.no doubt it wil only get flattened again!

[Captain Shortwave]

Two things to focus on in the coming days, first off is the cold snap at the start of next week.

   

Arctic maritme air sweeps southwards with showers, most favoured across coastal parts of Scotland and Irish sea coasts, there could be other areas which could get some, especially with tweaks in the orientation of the Atlantic ridge/Scandi trough. Pretty standard fare though, the UKMO does offer a different outlier solution at the moment though.

 

The second is the development of above normal heights over the Arctic in general as we move into week 2 and beyond.

GEFs

At day 10 we see below normal heights over Europe with a ridge in the Atlantic and to our north/north east. This would support the idea of the ECM, though an extended easterly looks unlikely.

We do get another attempt at this though.

     

 

This looks quite promising in the extended range with the hint of heights to our north west with another Euro trough developing, also note upstream the clear indication drain the low heights south east into the Atlantic as opposed to riding over the Atlantic ridge as shown on the day 10 anomaly.

So a sign that the we will see a waning of the zonal westerly pattern that has dominated this winter with something more blocked developing. The question would be whether we can develop a cold enough pattern to give a showery/snowy outcome as opposed to dry and cloudy one. That said heights to the north west is often more favourable to the former solution than say a Scandi high.

I would also say at this point that if we do see a pattern change that this has been well signposted by the longer range models. 

 

[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 FEB 18TH 2016

THE CURRENT GENERAL SITUATION  The remains of yesterday's frontal trough will clear SE England this morning leaving all areas under a rather cold and somewhat showery Westerly flow.

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

CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across much of the UK is close to the 2000ft mark. Snowfall will be restricted to hills above 600ft or so in the form of well scattered showers though perhaps a little lower under the frontal boundary over the SE at first.

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

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

MODELS-2 WEEK HEADLINE  Some rain or showers at times with snow over hills. Temperatures mostly near or somewhat below average though with a few short milder interludes in the South.

THE GFS JET STREAM FORECAST  The Jet Stream will surge West to East across the UK over the next few days and remain in a fairly similar position for some considerable while undulating 400-500mls North and South at times. Towards the end of the period there are signs that the flow could move well NW of the UK to lie in a NE flow near the Iceland region.

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

GFS OPERATIONAL The GFS Operational Run today still shows a generally rather chilly and changeable pattern across the UK through the next few weeks. Low pressure areas are shown to continue to pass to the North or down across the UK at times alternating with some drier and colder periods as ridges of High pressure pass over. The trend towards the end of the period appears to be for High pressure to become more influential from the South or SW for longer periods with cold frosty nights developing for many but with some compensatory almost spring-like sunny days in average temperatures between less active rain and shower bands. 

GFS CONTROL RUN The Control Run today shows a trend towards very changeable conditions with some short cold spells with some snow for some alternating with equally short milder and rainier periods as several areas of Low pressure areas sink down across the UK at times and give bursts of occasional very cold NE winds on their rear side before milder winds from the West return for a spell again thereafter with an almost rinse and repeat pattern ending the UK cold and potentially wintry under a Northerly flow at the end of the forecast period with High pressure out to the West in the Atlantic.

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

GFS ENSEMBLE DAY 14 DATA  The GFS Clusters today have shown a marked increase in pushing High pressure previously well to the SW much closer in to South or SW Britain in 14 days time with rain bearing fronts and the Jet stream returning to more Northern latitudes. Only a 25% cluster indicate a colder Northerly theme down across the UK with Low pressure over Scandinavia with the other 75% showing variations upon the High pressure to the South and SW theme.

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

UKMO The UKMO model this morning shows an interesting set-up in that A) it delays the NW flow early next week as another Low that only NAVGEM replicates moves into the UK and keeps unsettled and wet conditions longer with colder air filtering down from the North across the UK early next week with snowfall gradually feeding further and further South towards midweek. and B) this delays the onset of the transitory ridge midweek that other outputs show.

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

THE FAX CHARTS The Fax Charts today show the rather chilly Westerly flow currently across the UK chased away by advancing Atlantic milder westerly winds behind warm fronts moving East tomorrow. The weekend is then characterized by a frontal trough trailing across England and Wales with further rain and drizzle in mild air while Scotland becomes colder and more showery again, this extending quickly SE to all areas on Monday.

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

GEM GEM today shows a Westerly component to the winds across the UK throughout the next 10 days. Whereas nothing distinctly cold is likely some colder periods with wintry showers such as is shown for early next week will occur at times under a general theme of rain or showers at times in average or fractionally below average temperatures for most of the time.

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

NAVGEM NAVGEM shows a variation on a theme of Low pressure over Scandinavia early next week but in it's run absorbs a new Low moving in off the Atlantic to form a complex Low pressure over the UK midweek with rain and showers, falling as sleet or snow over the hills as temperatures fall after a mild weekend for many to levels near or somewhat below average at the end of the week long period covered by this model.

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

ECM ECM this morning is potentially the most wintry of the set this morning showing the theme of a mild and in places wet weekend yet again quickly replaced by windy and cold NW winds and wintry showers early next week. This in itself is then shown to be displaced by further Atlantic Low pressure feeding in from the WNW setting up a Low complex across the UK by next weekend. Pressure at this time is shown to be trying to build well to the North of the UK and if this develops could greatly increase the risks of more widespread cold weather and potential snow for many towards the end of the period if the Low pressure complex near the UK orientates itself favourably.

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

ECM 10 DAY MEAN The 10 day mean chart today shows the Jet stream a long way South in 10 days with Low pressure close to northern Scotland and High pressure well away to the SW. The UK looks likely to lie in a NW flow with rain or showers at times in temperatures near to or a little below average with snow a risk on hills of the North at least at times.

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

NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS There are many differences in evolution shown this morning of a broad Westerly based weather pattern between the outputs this morning with little specific cohesion between outcomes felt across the UK at the surface.

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 at 99.5 pts and GFS at 99.4 pts.  At 3 days ECM is leading with 97.7 pts to UKMO's 97.2 pts while GFS lags behind at 96.6 pts. At 5 days ECM leads with 92.0 pts to UKMO at 89.9 pts and GFS at 88.8 pts. Then at 8 Days ECM has the leading spot from GFS with 69.7 pts to 65.4 pts. Finally at Day 10 GFS leads today at 51.6 pts to ECM's 51.2 pts.

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   Quite an interesting set of output this morning with no clear direction shown between different models as to where we might end up in two weeks time. The main message is still one of Atlantic domination but the disagreements are in the eventual positioning of both the Jet Stream and whether High pressure is allowed to build somewhat later in the period to the North of the UK similar to what this morning's ECM Operational run shows. These two factors will determine whether we remain relatively changeable with mild rainy periods alternating with colder showery ones whereas the ECM route could lead us into something rather more wintry for many towards he turn of the month. The Jury is well and truly out at the moment as the GFS Clusters in particular this morning has shown a marked shift in pushing the Jet Stream further North longer term and bringing less wet and relatively mild weather to the UK when compared to ECM who in their 10 day mean chart shows Low pressure stretching down across the UK from Iceland with a Jet Stream well South of the UK meaning wet and probably cold weather more likely from this model a pattern that looks unlikely to move towards the GFS Solution at day 14. So with such diversities shown between outputs longer term I can only be speculative in my predictions this morning but given the next weeks hemispheric profile I think ECM may have a better handle on the outcome and I would edge towards the fact that GFS may well edge towards a more ECM like outcome for later next week over the next few days. As is often the case and never a truer word said 'more runs are needed' before a better confidence in any one outcome beyond a week from now can be interpreted.         

Next Update Friday February 19th 2016 from 09:00

Edited February 18, 2016 by Gibby

[Alexis]

11 minutes ago, Lukesluckybunch said:

So what's the big story here then,it's just a weak ridge not  strong enough high.no doubt it wil only get flattened again!

More the uncertainty than the actual synoptics. When the UKMO diverges at 96h it's worth paying attention and casts doubts over what the others are showing. 

[Lukesluckybunch]

18 minutes ago, Alexis said:

More the uncertainty than the actual synoptics. When the UKMO diverges at 96h it's worth paying attention and casts doubts over what the others are showing. 

Oh I see then,is the ecm similar at 96hrs?

[nick sussex]

Some bizarre goings on with the UKMO which continues to throw out different solutions to the ECM/GFS. I thought after last nights output it would move to the others as the UKMO weren't convinced and modified their fax charts to the ECM.

Todays solution is different to last nights so its not as if its sticking with one theme. Unless the GFS 06hrs run makes a big move towards it then I think its very unlikely.

After this divergence we're left with an underwhelming GFS or on the face of it a much better ECM synoptically but lacking any deep cold to tap into. The latter is still the one you'd want to verify because its building a block ne.

[Lukesluckybunch]

The crucial timeframe here is between 96 and 120 hrs,with that ridge.can it build more strongly and give us a good shot at a cold northerly,or will it flatten out and leave us with milder westerlies!

[Nick F]

The extended EPS continue to look interesting, have done a rough sketch of the anomalies for day 15 below from the 00z EPS mean rather than describe it.

Really need to work on getting a decent enough deep cold pool to tap into if such an upper pattern evolves longer term as we head into early March. The downfall this winter has been getting decent enough synoptics in the 'colder' spells we've had that have delivered in the past, but have only delivered average day time temperatures and lack of settling snow at lower elevations

[feb1991blizzard]

1 hour ago, IDO said:

UKMO D6 charts should have a health warning like the ECM D10 charts IMO.

There are no signs of any pattern change to March 5 on the GFS 0z run. The Azores every 5 days will try to build north but gets flattened by the PV lobe off Canada, so the potential for toppler after toppler, but as this "cold spell?" testifies to, much ado about nothing! Poor synoptics for most of the country as you need a lot to go right to get anything worthwhile.

The CFS w3 and w4 are showing this theme maintained: 

Looking at the GEFS for the next 16 days for London and overall pretty average fare:

 

Not sure the strat PV will be killed off by a Major SSW; its demise has been much exaggerated this Winter, and probably too late for us the way its going. After the last few winters it was hard to think this could be any worse, but its up there with the worst of them for cold. What we don't want now is a Spring dominated by a cool flow with cold rain, though I suspect that is what is upcoming. 

IF UKMO D6 charts and ECM D10 charts should have a health warning then shouldn't GFS D16 charts as well???

The CFS is run very often considering its a LR model, yesterday it was showing a cold blocked March.

 

 

[IDO]

7 minutes ago, feb1991blizzard said:

IF UKMO D6 charts and ECM D10 charts should have a health warning then shouldn't GFS D16 charts as well???

The CFS is run very often considering its a LR model, yesterday it was showing a cold blocked March.

 

 

Just my opinion from this winter that the UKMO is dire at handling rises of pressure in the Atlantic, wrong every time. It can get undercuts right, but Health Warnings for when it predicts rises and others counter. Not saying its right or wrong but I would be very surprised if it is correct based on past efforts.

CFS does four runs a day so yes the odd one or two in a few days may show something different but the overall trend has not been for those heights.

GFS at D16 should be treated with caution but my consensus is that the great D16 charts come and go as quickly and we end up back with the ENSO pattern that has dominated this Winter. That applies to Major SSW charts.

Edited February 18, 2016 by IDO

[Froze were the Days]

2 hours ago, Timmytour said:

Yes some good FI outlook again, but that's been a constant theme of this winter, a winter of promises but precious few deliveries.

tbh I think fewer and  fewer people can get themselves excited about such charts popping up in FI now. Not even the Daily Express can be bothered with them any more!!!!

True to a point but have to say even the models were showing sweet nothing right out to FI through the majority of December until towards the end...probably the worst winter month ever as regards to 'hunting' for cold. Agree it takes now some fairly exceptonal charts once you get into March to catch my interest and as other posters have mentioned northerlies won't do much for more southern and central areas due to the Arctic being some warm and the drasted mild sectors in such 'Am' flows which seem to be occuring more often.

Oh well always next winter and as 2 out of the last 3 have been so bad surely we won't have another poor winter next?...he said.

[karlos1983]

not far apart as I think it was BA alluded to, forgetting the detail, agreement of the overall pattern is remarkably similar again ECM & GFS. 

 

 

 

Is that a spring smile in that strat 

 

Edited February 18, 2016 by karlos1983

[frosty ground]

1 hour ago, IDO said:

Just my opinion from this winter that the UKMO is dire at handling rises of pressure in the Atlantic, wrong every time. It can get undercuts right, but Health Warnings for when it predicts rises and others counter. Not saying its right or wrong but I would be very surprised if it is correct based on past efforts.

CFS does four runs a day so yes the odd one or two in a few days may show something different but the overall trend has not been for those heights.

GFS at D16 should be treated with caution but my consensus is that the great D16 charts come and go as quickly and we end up back with the ENSO pattern that has dominated this Winter. That applies to Major SSW charts.

So the GFS Day 16 chart changes often but shows what you expect to show but the ECM and UKM charts also changes often but is not to be trusted. 

Hint of contradiction? 

[Summer Sun]

For the weekend its look colder for Scotland with the chance of some significant snow further south it will be spring like with temps pushing towards the mid teens

Not much change from the 00z

Early warnings are also out for some heavy rain in the north west one to keep a close eye on given how saturated the ground is still

Edited February 18, 2016 by Summer Sun

[Lukesluckybunch]

Hmm in my oppinion its quite obvious what wil happen in the next week or so,pressure making attempts to rise in the mid Atlantic before Atlantic lows spoil the party,u can see this in the latest gfs run it has 2 or 3 attempts at giving us what we want but in reality never makes it!we shouldn't be expecting much more really it's typical of this winter just being teased my models it seems!

[karlos1983]

1 minute ago, Lukesluckybunch said:

Hmm in my oppinion its quite obvious what wil happen in the next week or so,pressure making attempts to rise in the mid Atlantic before Atlantic lows spoil the party,u can see this in the latest gfs run it has 2 or 3 attempts at giving us what we want but in reality never makes it!we shouldn't be expecting much more really it's typical of this winter just being teased my models it seems!

shall we give up then on that note?  Because I must be honest I'd quite happily right now 

[Derbyshire Snow]

Good Morning,

I have not posted for 3 weeks, hols but also  nothing to get excited at in the models, but at last i see some light, all being a bit  late but better than never. Late February and the first three weeks of March can still provide real winter and persistent snow on the ground, obviously some heights help and that 4 week period, if we are lucky, could provide some tasty synoptics and patterns to drool over.

Well whats changed

1. Time of the year ...traditionally one of the best periods for heavier snow showers and heights developing over Scandinavia or to the north

2. The raging jet stream over the Northern Hemisphere which has been our  problem all winter has recently  become more meridional over the Atlantic providing some colder polar maritime  interludes, even though not providing the goods as yet. We just require some real heights to develop to our north and push the jet stream permanently  further south. At present they are temporary ridges but my feeling is we are due a stronger block

3. AO is predicted a lot more negativity, unfortunately NAO isnt on board as yet

 

I have being looking at charts for over 40 years and my gut feeling is that we will get our strong Scandinavian High and push the Atlantic  depressions further to the south  giving UK the cold side of the jetstream,  and if we are really lucky these heights may  link west and join  forces with a substantial Greenland high and bingo!!! Jet stream knocked out!! Battleground scenarios.

 

Heads up, i know its frustrating but the let downs dont last for ever and i feel our turn is coming. Hang on another week guys.

We might all see some snow falling Sunday, Monday anyway but the model runs  later in the week could be even  more interesting to  view, and they are not really boring as in December and January

Edited February 18, 2016 by Derbyshire Snow

[Lukesluckybunch]

13 minutes ago, karlos1983 said:

shall we give up then on that note?  Because I must be honest I'd quite happily right now 

Well even a couple days ago there was some encouraging signs for next week, they have all but disappeared. It's looking very average!

[Vince Coombes]

Want snow thesedays one must relocate to the middle east ,i note the gfs 240 has most of Spain  under the snow hatchings......something odd is going on.....

Edited February 18, 2016 by Vince Coombes
Typo

[Nouska]

58 minutes ago, karlos1983 said:

Is that a spring smile in that strat 

 The nose is looking a bit blue .... scarf and gloves needed.

[Ripeberry]

In days gone by, the fact that the South of England is missing out on snow would be seen as a blessing! Maybe it's all the old folk praying very hard for a mild winter?

 

Or more likely, we are very, very lucky.

 

Luck doesn't last...

[karlos1983]

28 minutes ago, Lukesluckybunch said:

Well even a couple days ago there was some encouraging signs for next week, they have all but disappeared. It's looking very average!

Well I think we will have to agree to disagree there.

The last thing I want is cold in Spring, but I think it is a distinct possibility

[PolarWarsaw]

25 minutes ago, karlos1983 said:

Well I think we will have to agree to disagree there.

The last thing I want is cold in Spring, but I think it is a distinct possibility

 

See previously I'd agree, but it's becoming more and more apparent that November and December are just extended periods of Autumn, whilst late February and March have offered us the best cold synoptics in the last few years. As far as I'm concerned, the first half of March is now spent searching for a last shot of cold and snow (ironically, this year, perhaps a first shot)..there is plenty of time for yet more of the 'averageness' this climate provides from...April until December. Searching for something out of the ordinary (IE cold and snow) is worth it IMO. After this winter, I just hope the spring/summer provides some entertainment in the extreme weather department..(april squalls, huge summer thunderstorms).

What a shame we can't 'build' on the atlantic, it would perhaps help slow the jet stream down. But i'm going way off topic here. 

Apologies. 

[Singularity]

For me, the interest is more about the unusual nature of the weather that may occur.

Let's just take a moment to consider the extreme state to the global temperatures at this point in time in terms of the next 5 days going by GFS and then the 6-10 and 8-12 day periods:

  

It's an unbelievably dire situation in the Arctic at the moment, particularly on the Asian side. Cold air has been displaced along an axis about 90 degrees to the UK, and is expected exhibit this behaviour again in the near future, hence the focal points again being across the central/eastern U.S. and the eastern half of Asia.

So no wonder sea ice extent is tracking lower than any other year for mid-Feb. Only 2014 comes close. I can't see much hope for that to recover in the near future, either. The persistence of the temperature pattern is just insane.

So who fancies trying to nab a decent cold airmass via HLB in the next fortnight?  

 

Well, the best approach I can see is to have a large, strong Arctic High which sets in motion a large scale shift of the cold air from eastern Asia toward Scandi and beyond.

The GFS 00z was tragic in this sense, with HLB mysteriously absent from the high Arctic as early as day 7 when compared to other model runs. The 06z has since recovered, but the low heights out of Canada still push toward the pole too strongly in the 10-16 day period. Hopefully just model bias.

ECM's 00z is encouraging, with a strong Arctic High by day 10 and having its origins around day 8. Compare that to the GFS 06z and you can also see a better retained cold pool over East Asia which helps the Arctic High to become anchored in place, ready to fend off the advances of the polar vortex from Canada. 

 

 

Need to watch the MJO update today; 

Yesterday's observation was at higher amplitude than any of the ensemble means. A similar disparity today would see the MJO knocking on the door of phase 7 at considerably higher amplitude than the models have been expecting. 

Going forward, ECM's quicker move into phase 8 may be helping with getting the right manner of amplification to the hemispheric pattern for building an Arctic High in a favourable location for having a positive influence on the UK with respect to bringing some properly cold air our way. It's just a shame that it has such a long way to travel first and so much anomalously warm air to displace!

[Man With Beard]

On the face of it, some charts around that seem to scream wintry possibilities:

But going by the ECM ensemble members, chances of a day where snow falls south of, say, Manchester = less than 10%. Chances of an ice day = less than 1%.

(Obviously areas further north looking rather better, especially with a bit of elevation)

It's just getting too late in the day, and there's not enough cold already in place.

A long-fetch NEly lasting several days or a massive Greenland High is the only way to deliver a substantial snowfall now.