Model output discussion - 20th Feb onwards

[northwestsnow]

1 minute ago, terrier said:

I would be very wary of any snow accumulation maps the gfs churns out. We know the gfs tends to blow these out of all proportion. If the gfs had been anywhere close this winter my area would have seen at least 2 good snow events. Think apart from some wintry showers I can't really see anything apart from a dusting over many areas. Certainly no March 2013 event as Ian f has alluded too many times already. 

Agreed

Even a dusting would be nice, im sure many across the south would appreciate even that. I wouldnt have thought any lying snow would last that long in march but me and yourself and others in our vicinity may wake up to a snowy suprise friday morning.

[Weather-history]

7 minutes ago, terrier said:

Certainly no March 2013 event as Ian f has alluded too many times already. 

Why does it have to? 

As I mention before the snowiest March of the 90s here was 1995 and that was overall average, temperature wise. Infact I saw more days of lying snow in that March than I did with 2013.

 

[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 TUESDAY MAR 1ST 2016

THE CURRENT GENERAL SITUATION Troughs of Low pressure will move East and SE across the UK today followed by an increasingly cold and unstable Westerly flow with Wintry showery troughs moving SE across the UK tonight and tomorrow.

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

CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across the UK near 6000ft this morning will fall steadily across the UK later today and tonight to be nearer to 2000ft by tomorrow with plenty of snow showers over all high ground tomorrow settling in places above 1500ft asl.

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

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

MODELS-2 WEEK HEADLINE  Rather cold and breezy with rain or showers at times with snow on hills. Perhaps drier later. Temperatures mostly rather below average with frosts at night in places.

THE GFS JET STREAM FORECAST  The Jet Stream is predicted to blow SE across the Atlantic and France over the coming week with a deep trough across the UK by next weekend with this pattern only slowly being replaced by a more undulating pattern on a more West to East axis and further North than currently later next week.

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

GFS OPERATIONAL The GFS Operational Run today shows Low pressure to the North and East of the UK over the coming week with winds from between West and North for much of the time with spells of rain, sleet and snow plus some drier and brighter intervals. From about a week's time the axis of flow of depressions changes to a more to West to East axis close to the North of the UK so still plenty of rain or showers. It still looks rather cold at times but wintriness will become more confined to Northern hills, this theme enhancing further towards the end of the run as High pressure edges closer to the South and SE of the UK at times with milder air moving NE across the UK with rain in places more especially focused towards the North and West.

GFS CONTROL RUN The Control Run's theme follows a similar course as the Operational through the first week with a lot of chilly West or NW winds and wintry showers with snow on fairly modest hills nationwide at times. Then in Week 2 the pattern differs showing High pressure setting up shop over Europe with Low pressure over the Atlantic. In theory this could bring milder South or SW winds with rain at times for all but with High pressure over Europe engaging cold air on it's Southern flank implications from this or adjustments North of the pattern could change the overall theme to a colder one for the UK especially in the East.

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 offer no real clues in the weather likely across the UK in two weeks time with an even split between High pressure or Low pressure based weather patterns a possibility for all parts of the UK.

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 remains a chilly outlook as Low pressure sinks SE across the UK towards the end of the week and then edges only slowly away East from the UK through the weekend with a cold showery Northerly flow in it's wake giving way only slowly early next week to a ridge of cold High pressure moving into the UK from the NW. 

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

THE FAX CHARTS The Fax Charts today show a similar sequence of events as the raw data with complex Low pressure slipping SE across the UK over the next 3-4 days culminating in a cold and unstable Northerly flow over the weekend with wintry showers a risk for all.

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

GEM GEM today shows Low pressure areas slipping SE across the UK over the next 33-4 days with a complex mix of rain and showers falling as sleet or snow over the hills. Then unlike some of the other output release from this pattern is slow and arduous with cold Low pressure remaining close to the East or indeed over the UK before a slow push of High pressure down from the NW settles things down across the UK later next week last to reach the South.

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

NAVGEM NAVGEM is slow to clear the trough out of the UK too next week with it showing approaching midweek next week before the ridge of High pressure to the West and NW edges in sufficiently to settle the weather down across Britain to any large degree.

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

ECM ECM this morning follows the general theme too of cold and unsettled conditions under Low pressure to the East of the UK through the next 5-7 days with High pressure trying desperately to displace Low pressure as it moves slowly in from the West. So a messy mix of showers, wintry on hills and the increasing likelihood of frost at night as winds fall lighter the main theme as we move into next week with the run ending with High pressure over much of the UK with frosty nights alternating with dry, crisp and OK sort of days.

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

ECM 10 DAY MEAN The 10 day mean chart shows a gradual shift East of the trough previously shown across the UK suggesting a gradual trend towards High pressure becoming more influential from the West at that time with temperatures still rather chilly.

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

NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The pattern between the models is well documented for this week as rather cold and unsettled conditions are projected by all models. The theme beyond that continues to suggest some influence of High pressure moving into the UK from the Atlantic next week.

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 97.6 pts to UKMO's 96.9 pts while GFS lags behind at 96.3 pts. At 5 days ECM leads with 90.9 pts to UKMO at 89.0 pts and GFS at 87.2 pts. Then at 8 Days ECM has the leading spot from GFS with 67.6 pts to 64.6 pts. Finally at Day 10 GFS has taken over the lead from ECM again with a score of 50.6 pts to 49.6 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  Not much change in the theme from the models this morning from that shown yesterday with the main story being the late Winter synoptic pattern promoting what could be the first snowfall of Winter over the coming days for some parts of the South of the UK. The amounts of snowfall should not be alarmist though and could well be restricted to the night hours and over the hills for many. The pattern bringing this messy wintry mix of weather is Low pressure moving SE across the UK in two bands between now and the weekend each one bringing progressively colder air into the mix across the UK. Much of the precipitation will be showery in nature although Friday looks a day when something more interesting may develop across the UK as the second Low moves South over the UK with a wraparound of cold North or NE winds develop in it's wake. Then as we move into next week the main story evolves around how quickly and how much High pressure to the West of the UK displaces the cold Northerly flow over the UK at that time as it edges further East. It does look a slow and arduous process and it maybe towards the second half of next week before the general theme of dry and settled conditions look likely to replace the showery feed of early in the week. Frosts at night remain likely and daytime temperatures remain close to or a little below normal by then. I am using the ECM theory in these projections as I feel this is the most likely outcome of what's on offer this morning endorsed by the ECM Mean Chart of late which has remained fairly constant in this general theme in recent days. Alternatively GFS offers something a little less settled as High pressure slips further South with a milder Westerly flow across the UK in Week 2 but the model remains very fluid in it's projections longer term as does it's Clusters. So in a nutshell the 1st of March does not indicate too much in the way of early Spring conditions across the UK in the models today although what's on offer is a typical mix of conditions for March across the UK in the next few weeks.          

Next Update Wednesday March 2nd 2016 from 09:00

[KTtom]

There does seem to be a continued obsession with getting a deep freeze in place in order to get some snow, 2013 was a rare exception, you just don't get those sort of temperatures when low pressure is in charge, these fax charts for Wednesday and Friday really are as good as you can get for March.

 

 

[karlos1983]

What is interesting is how the Eastern US is due to warm up quite considerably next week, getting into the teens, I'm sure I read an article that said if the eastern US is warm then our chances of cold increase, I'm guessing due to the Jet  not getting the umph from deep cold/warmth devide.

 

 

Edit: yes a weak Jet

 

Edited March 1, 2016 by karlos1983

[Purga]

The GFS FI anticyclonic mild fest again this morning seems to be on its own amongs the GEFS

Although ECM seems to be trending that way

Not desperately mild though

Let's either have a decent last blast of winter with snow for all or bring on some nice warm spring weather and let's forget this endless mediocre crud!

[winterof79]

51 minutes ago, terrier said:

I would be very wary of any snow accumulation maps the gfs churns out. We know the gfs tends to blow these out of all proportion. If the gfs had been anywhere close this winter my area would have seen at least 2 good snow events. Think apart from some wintry showers I can't really see anything apart from a dusting over many areas. Certainly no March 2013 event as Ian f has alluded too many times already. 

There would be more than a dusting from this wintry shower.Bit more reliable than GFS snow charts too

[moffatross]

1 hour ago, northwestsnow said:

Maybe one last hurrah on thur night into friday across the north ,,,

Aye, but your 'north' is barely the south midlands relative to the UK

[mushymanrob]

11 hours ago, fergieweather said:

Tonight's EC Monthly retains the colder than average, effectively northerly-dominated regime all the way through March. So, continuity with the last run.

i can live with 'colder than average' , id struggle with 'cold'.  and theres the difference.

[frosty ground]

On 25/02/2016 at 9:09 AM, knocker said:

Yes I suppose I'm guilty of brown nosing and pandering to the tastes of the majority.

Colder than average is cold..... Silly semantics aside

[knocker]

How the rest of March will pan out is concentrating the minds of many at the moment so a quick look at the anomalies for the next fourteen days.

Next week is continuing with the theme of more settled weather with temps remaining depressed as the HP establishes to the west of the UK with the trough slipping down to southern Europe.

Moving further afield the HP continues to edge east over the UK which would seem to indicate a continuation of the more settled weather, particularly in the south with temps rising to nearer normal.

I suspect this may be subject to change.

[weirpig]

Latest Hirlam has Wednesday as being quite an eventful day.  snow into wales and the north and the midlands   even making it into the south east

[Singularity]

Thickness values look quite decent for a short time tomorrow across the southern half of the UK - but the timing of precipitation features will be crucial and although GFS has moved even more toward a snowy outcome on the 06z, the high-res models are not so keen. HIRLAM is a notable exception across the areas outlined by weirpig thanks to an organised line of heavy precipitation. Further south there are only brief spells of sleet or snow for a time early in the day.

On Friday we see another import to the southern half of the UK of low thickness air from the NW - it's a remix of Wednesday but with the air a bit colder. The main issue is then whether there's any precipitation coinciding with that and early enough in the day; if it affects your area in the afternoon, rain is a more likely outcome away from high ground at least.

On both days, the possibility of isolated particularly large, heavy showers serves as a wildcard that forecasters are not enjoying. A few spots could see a brief slushy accumulation of snow if such a feature arrives overnight or in the morning hours - this most likely for elevated locations of course. 

Further north, heavy frontal snow looks a distinct possibility for areas near and along the Scotland/England border during the night and perhaps into Friday morning - assuming the track of the low doesn't change too much from what the 00z/06z runs show. Conditions don't look very good for preserving snow cover at low levels during the daytime, though (except up on high ground) but hey, it is March after all.

 

Saturday has begun to look more unstable than was looking to be the case and for once the air looks cold enough for widespread wintry showers - but that's as far as we can go with that for now and of course the usual caveats apply, with the risk the air is modified more than currently predicted.

For my part, I am allowing myself to hope to see some large snowflakes at some point as part of a classic late winter/early spring wintry shower, regardless of whether anything settles (which I consider a long shot to say the least). I share this to give a sense of what may be a realistic limit for hopes to be set to for low level locations in the south. The further north you go, the higher the bar can be set, though settling snow looks a tough ask for most low-lying areas away from the frontal snow event early Friday.

[Mucka]

1 hour ago, weirpig said:

Latest Hirlam has Wednesday as being quite an eventful day.  snow into wales and the north and the midlands   even making it into the south east

Yup MetO warnings out for snow for much of N England which is a first this year I believe?

Plenty of people looking far ahead for snow but the set up for early hours Wed is perfect for accumulations even to low levels with a freeze likely followed by heavy and prolonged snow showers.

These may turn more sleety through the day so I wouldn't expect snow to stick around too long at low levels although there could still be some beefy prolonged snow showers to enjoy as well, more especially for NW England I would think.

Could be a damp squib but I feel confident I will at last see some snow falling proper for the first this Winter.

Edited March 1, 2016 by Mucka

[mushymanrob]

1 hour ago, frosty ground said:

Colder than average is cold..... Silly semantics aside

sorry, i dont agree.
 

colder then average suggests a few degrees below the average - cold suggests temps much lower, silly semantics or not theres a difference.

[feb1991blizzard]

1 minute ago, mushymanrob said:

sorry, i dont agree.
 

colder then average suggests a few degrees below the average - cold suggests temps much lower, silly semantics or not theres a difference.

I disagree, VERY COLD means temps MUCH lower, the 2010 and 2009/10 spells  were MUCH lower temps ditto March 13, you could almost categorise Wednesday in my location as Very cold. max's of 2c, don't forget the average for March is about 8c not 6c like January (using my location as the example here obviously higher in the South East)

[Man With Beard]

Apart from the next 5/6 days, are we looking in the wrong direction here? Spring is within touching distance according to some of the ensemble output. Starting with the D10 means:

It's a close call between a slight northerly breeze and a south-westerly drift, I'd say. Uppers still slightly chilly but double figures in sunshine I'd think. And a closer study of the GEFS sees a proper breakthrough of the WSWly winds showing on many, for instance:

I'd guess 15C and sunny spells in the east on this one. And this isn't the warmest ensemble member either

ECM extended ensembles: cold has gone by the 10th, aside a slight frost or two

So it's not a one-way street for cold on the models - just saying...

[mushymanrob]

35 minutes ago, feb1991blizzard said:

I disagree, VERY COLD means temps MUCH lower, the 2010 and 2009/10 spells  were MUCH lower temps ditto March 13, you could almost categorise Wednesday in my location as Very cold. max's of 2c, don't forget the average for March is about 8c not 6c like January (using my location as the example here obviously higher in the South East)

this is getting daft.... very cold surely means colder then cold, colder then average isnt as cold as cold.

eg march average = 8c , colder then average = 6c, cold = 4c , very cold = 2c . just as a rough example. of course cold and very cold are colder then average - but colder then average doesnt mean very cold.  colder then average means a few degrees below..

[feb1991blizzard]

Just now, mushymanrob said:

this is getting daft.... very cold surely means colder then cold, colder then average isnt as cold as cold.

eg march average = 8c , colder then average = 6c, cold = 4c , very cold = 2c . just as a rough example. of course cold and very cold are colder then average - but colder then average doesnt mean very cold.  colder then average means a few degrees below..

Yes but 1.7c as a mean for January is only a couple of degrees below average but I bet there haven't been any Jans with a CET of around 1.7c that you wouldn't describe as very cold.

[Paul]

Getting way off topic here, but John kindly uploaded a document a few years back with the 'official' met office descriptions of how they describe cold/v.cold etc depending on the season. 

Perhaps beyond this, the best place to continue the discussion would be in the winter chat thread. 

[Bristawl Si]

18 minutes ago, mushymanrob said:

this is getting daft.... very cold surely means colder then cold, colder then average isnt as cold as cold.

eg march average = 8c , colder then average = 6c, cold = 4c , very cold = 2c . just as a rough example. of course cold and very cold are colder then average - but colder then average doesnt mean very cold.  colder then average means a few degrees below..

Agree totally Mushy.

We're talking early March average temps versus actual temps.

IMBY - I'd punt at 8/9c average. So colder than average 5/6c?

If daytime temps were going to get down, to say, 3/4c I'd be happy for someone to describe that as "Much colder than average"(for early March)

[Frank Trough]

2 hours ago, Man With Beard said:

Apart from the next 5/6 days, are we looking in the wrong direction here? Spring is within touching distance according to some of the ensemble output. Starting with the D10 means:

It's a close call between a slight northerly breeze and a south-westerly drift, I'd say. Uppers still slightly chilly but double figures in sunshine I'd think. And a closer study of the GEFS sees a proper breakthrough of the WSWly winds showing on many, for instance:

I'd guess 15C and sunny spells in the east on this one. And this isn't the warmest ensemble member either

ECM extended ensembles: cold has gone by the 10th, aside a slight frost or two

So it's not a one-way street for cold on the models - just saying...

I've been working on the assumption that any pressure build is being over done and that come next week the high will be supressed back more towards the Azores leaving us in a more northwesterly regime.  However, it keeps cropping up. To be honest i'd love to see just some falling snow this week and then for something more spring-like to turn up thereafter but given the METO expectations for things to be generally below average overall out to early April i'm not holding my breath.

[weirpig]

2 hours ago, Mucka said:

Yup MetO warnings out for snow for much of N England which is a first this year I believe?

Plenty of people looking far ahead for snow but the set up for early hours Wed is perfect for accumulations even to low levels with a freeze likely followed by heavy and prolonged snow showers.

These may turn more sleety through the day so I wouldn't expect snow to stick around too long at low levels although there could still be some beefy prolonged snow showers to enjoy as well, more especially for NW England I would think.

Could be a damp squib but I feel confident I will at last see some snow falling proper for the first this Winter.

Just noticed those warnings. Wales and the parts of the Midlands included as well I think I will see some snow but I think the n west  is more in the firing line

Edited March 1, 2016 by weirpig

[Banbury]

Shows the potential quite well for the Midlands and North

[johnholmes]

2 hours ago, feb1991blizzard said:

I disagree, VERY COLD means temps MUCH lower, the 2010 and 2009/10 spells  were MUCH lower temps ditto March 13, you could almost categorise Wednesday in my location as Very cold. max's of 2c, don't forget the average for March is about 8c not 6c like January (using my location as the example here obviously higher in the South East)

sorry that interpretation is wrong, see the post from Paul on what the correct terms are through the year-please?