Model output discussion - 20th Feb onwards

[Cloud 10]

Various troughs/disturbances moving down from the North this week on an increasingly cold Northerly airflow.

 

[January Snowstorm]

Indeed let's get the cold in first and see what happens.

It will be mostly dry but on the upside any ppn that does fall could well be wintry.

We've learnt one thing this Winter

Nobody can predict the weather beyond about 7 days!

[Man With Beard]

1 hour ago, fergieweather said:

In contrast to GFS, the 00z EC manages to keep any meaningful precip away from the south of the UK all through this week (and thus offers no snow at all), but it's clearly a fickle situation with low confidence in many aspects. What joy....

Yes disappointment for snow lovers if the precipitation charts are to be believed - I just find it hard to believe that we could go through 7 days without snow with so much Atlantic activity to our north/south/east/west - this is the UK, after all!

Still, maybe these charts will find a way not to verify at all!

[Ravelin]

Taking about the ECM, the last few frames are about the 'messiest' I think I've ever seen. At T240 for example... 

 

[West is Best]

23 minutes ago, January Snowstorm said:

We've learnt one thing this Winter

Nobody can predict the weather beyond about 7 days!

I'm not so sure about that. I fear we've learnt one thing which is that every time there are cold prospects they downgrade. The jet stream has been irrepressible.  I was tempted to post yesterday that this looked like another example coming up and now the 0z runs appear to be showing just that. In place of a potent easterly southern Britain may just have a day or two of slack cold air.

The Scottish ski industry looks to keep its good form though.

[karlos1983]

6 minutes ago, Lukesluckybunch said:

So does this upcoming cold spell look the best thing we have seen this winter?also is it likely to happen,or will we be let down again ?

I think anyone that says yes to that is setting themselves up for failure Luke. It's looking good, but we really do need more runs. We've been bitten to many times this winter. 

 

[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 SUNDAY FEB 21ST 2016

THE CURRENT GENERAL SITUATION   A mild Westerly flow covers the South of the UK while a cold westerly flow covers Scotland and Northern Ireland. Separating the two is a slow moving frontal trough oscillating North and South over Central Britain.

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

 CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across the UK currently sees the level at 10000ft over Southernmost England and 2000ft across Scotland where some snowfall is likely across the higher ground in the form of showers.

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.

THE GFS JET STREAM FORECAST  The Jet Stream is shown to trough strongly to lie well to the South of the UK by the end of the coming week in association with Low pressure there. Later in the period there is some suggestion of the flow migrating back North towards crossing West to East across the UK in Week 2.

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

GFS OPERATIONAL The GFS Operational Run today shows the UK heading for a shift to generally rather cold conditions as the current Westerly flow weakens in the days ahead at the same time as rather colder air seeps slowly South to all areas from Scotland over the next 48hrs. Thereafter winds will strengthen from the east or NE for the first time this season and bring cold and raw conditions with rain and sleet at times with snow over the hills especially towards the South and East, Then in the second week a slow return of West or NW winds and changeable conditions is shown with rain at times and snow at times on hills of the North.

GFS CONTROL RUN The Control Run today shows a similar theme to the Operational Run with this weeks colder conditions gradually returning back to less cold and changeable conditions with Atlantic westerlies through Week 2.

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 show a lot of marginality between them ranging from a slight bias in favour of High pressure lying to the South in two weeks time but with many other options too none of which look particularly troublesome in terms of cold or any other severe weather type.

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 quite a quiet week to come on the while as pressure becomes quite slack over the UK as it gently falls in response to Low pressure slipping SE to the West of the UK by next weekend. Colder air will slowly become established across the UK through the week with some frosts and rain or sleet later following the wintry showers across the North and East beforehand.

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

THE FAX CHARTS The Fax Charts today supports the theme of the raw data with the UK lying in nomansland weather-wise this week as no real pressure system has overall control of the UK weather. The main theme though supports colder and fair conditions with just coastal wintry showers through the middle section of the week before approaching fronts from the Low pressure to the West threaten the SW by next weekend..

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

GEM GEM too shows the UK slowly slipping into colder conditions overall as the current pressure pattern is reversed by the end of this week with the current westerly flow becoming slack over the coming days and then reverses to an Easterly flow by next weekend with some rain or sleet at times across the South from next weekend with a raw wind and cloudy skies.

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

NAVGEM NAVGEM is quite gentle on conditions across the UK over the next week with slack pressure over us and major pressure systems staying off shore from the UK. The current mildness over the South will be replaced by colder air over the coming days but largely dry and bright weather will prevail through the week though a few coastal wintry showers and cloudier spells in the South with a little rain or perhaps sleet seem possible at times.

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

ECM ECM this morning follows the theme of slack pressure developing across the UK through the coming week and continuing on this run well into the second week too. In weather terms although details are elusive the theme would suggest rather chilly and benign weather on most days with temperatures certainly declining away from current levels in the South. With no major Low pressure systems making landfall across the UK rainfall will be patchy and unevenly distributed and with temperatures lower than of late some snow or sleet is likely over hills but unlikely to be disruptive or bothersome for most away from the highest ground.

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

ECM 10 DAY MEAN The 10 day mean chart today is made up from a lot of different options most of which show rather cold air across the UK with some showing a chilly Easterly flow while others hold the majority of members in a NW flow with some showers and Low pressure to the East or NE and higher pressure towards the SW. The confidence on the viewpoint shown by the Mean chart this morning is low.

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

NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The theme is for a rather quiet and benign period of weather to develop across the UK this week lasting for some time.

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 92.1 pts to UKMO at 90.0 pts and GFS at 88.6 pts. Then at 8 Days ECM has the leading spot from GFS with 71.9 pts to 66.3 pts. Finally at Day 10 GFS leads today at 53.7 pts to ECM's 53.6 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   In the couple days since my last report the models seem to have developed some clarification in what is quite a complex pattern synoptically over the next week or two. In sequential terms what we have currently is a sharp contrast North to South across the UK separated by a wavering front across Northern England. To the North of it the Westerly flow brings wintry showers and cold conditions while to the South of it dull and drizzly but very mild weather continues for another day or so. Then the front moves gently South clearing the South on Tuesday with quiet and rather cold conditions developing countrywide for many areas for the middle section of the week with some coastal wintry showers confined to the North and East while frosts at night could become widespread. Things complicate later in the week and through the second week as Low pressure is progged to move South of the UK by next weekend and while this would normally suggest a very cold period across the UK at this time of year no seriously cold air is available to tap into so instead it looks likely that the weather will just stay rather cold and in places dull and raw with rain or sleet at times and perhaps snow over the hills. It may equally prove that the North stays bright and cold with night frosts through this period before the general theme of a slow return to Atlantic West or NW winds seem probable through the second week with rain at times especially in the North with snow on hills still likely and temperatures back to average or slightly below. So there it is nothing too dramatic to report on the weather over the UK in the coming couple of weeks and while very mild weather is unlikely no desperately cold weather looks probable either though with better synoptics than recently that support cold I suppose there is always the chance of a surprise wintry event for someone.            

Next Update Monday February 22nd 2016 from 09:00

[karlos1983]

Enter trough disruption, should be another good run this

 

[Banbury]

Cold for all

[SMU]

For those that want snow rather than rain from the SW then the advent of high pressure in this location is great news ....

s

[IDO]

GFS 06z on Tuesday now backtracking towards the hi-res models and this morning's ECM, with the shortwave just a glancing blow in the SW of rain:

I think we can bank the cold uppers now, 4-5 days of around 4c colder than seasonal averages from Tuesday. Mainly dry next week but disturbances can pop up, one on GFS at T69 over the NW is an example:

The HP wedge over the UK around D4 is more robust again on this run (trend) so the pattern is pushed further west.

06z:  0z: 

Little chance now of any frontal snow later this week now. Next weekend's low for the south now looking doubtful. This beginning to look like mainly a dry cool period.

D6: 

Edited February 21, 2016 by IDO

[Banbury]

LP much further South , less of an Easterly

[BarnetBlizzard]

If you are looking for settled, chilly weather then the GFS 6z is great news. Anyone that wants anything remotely exciting will be disappointed. 

Big let down for me after yesterdays great output.  Hope its wrong but the GFS has been the trend-setter this winter. 

Lets see what the rest of the day brings but a back track from the GFS is pretty unlikely. 

 

[MR EXTREMES]

1 minute ago, Banbury said:

LP much further South , less of an Easterly

Less on an easterly on this chart for this actual timeframe but moving on a lot better.

the colder air to our ne could well trickle west southwest so much chopping and changing be very surprised if there's nothing wintry moving further on even in the south.

[Banbury]

6 minutes ago, emotional rollercoaster said:

Less on an easterly on this chart for this actual timeframe but moving on a lot better.

the colder air to our ne could well trickle west southwest so much chopping and changing be very surprised if there's nothing wintry moving further on even in the south.

Not too sure about that , the distribution of cold air isnt as good.........................one run one model and all that

[BarnetBlizzard]

6 minutes ago, emotional rollercoaster said:

Less on an easterly on this chart for this actual timeframe but moving on a lot better.

the colder air to our ne could well trickle west southwest so much chopping and changing be very surprised if there's nothing wintry moving further on even in the south.

How is it moving a lot better?  The 6z shows less of everything -cold, snow and prospects for a reload. 

[Banbury]

2 minutes ago, BarnetBlizzard said:

How is it moving a lot better?  The 6z shows less of everything -cold, snow and prospects for a reload. 

Agreed

[Banbury]

Yep quite a let down from the 6z .....................next please

[snowray]

Well its only one run but everything way further west again,  goes to show that if anything can go wrong for snow it will.

We end up cold and dry, probably won't even feel all that cold in the sunshine, Spain and North West Africa get snow on the 06z. 

Edited February 21, 2016 by snowray

[Banbury]

Wonder if this will sit on the high side of the ENS

[mulzy]

Poor run from the 6z run if it's snow you want.  Night time frosts and cool (but pleasant in the sun) days ahead this week after the clearance of rain from the South on Monday.  Let's see where this sits within the ensembles...

Edited February 21, 2016 by mulzy

[PolarWarsaw]

One thing seems notable this morning - the strength and consistency of a proper Greenland high as been watered down, quite significantly. It's no surprise to see that the longevity/distribution of cold has diminished somewhat this morning. Cold and dry at the moment next week, however, as they say - get the cold in first and then see what happens. Wouldn't it just sum the life of a snow fan up, to finally get a cold week supportive of snow and for the first time in about 6 months...an entire full week go by being dry. 

[snowray]

Personally I think that the 06z has gone off on one again this morning, 06z being the 06z, a trend Westwards seems likely, GEM is similar after all, but I bet we get a correction back east and something more interesting later on.

[andy_leics22]

While I am very disappointed at this mornings 06z run, we have to remember that shortwaves sometimes don't show up on the models until within T48-72. I have lost count of the amount of times that we've seen the models show a cold but dry week and as the week has progressed, shortwaves and troughs have developed and brought about a nice surprise of snow for some people. 

 

Most important thing, get the cold in place first and then see what unfolds. We are still 5-6 days away from what could be a good snow event if things were to shift in our favour. The models never handle this type of scenario too well until 2-3 days before. There will be some chopping and changing between now and next weekend and we could yet see an upgrade over the next few days, so lets just wait and see.

[IDO]

Looking at the GEFS and although the Control supports the op, far more members have next weekend's low further north. Though to be honest they are all over the place. Not a good trend from the 06z but more runs needed to see if it maintains this theme and if it drags members on board.

T144: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=144