Model Output Discussion - Spring 5th March Onwards 6z--->

[IDO]

ECM 12z sticking to the story and you wouldnt expect this model to be wrong normally at T120 so I think we can write off Good Friday now, not looking great with a full suite of 12zs showing unsettled conditions:

 

 

  

 

Just watched Countryfile weather and it is good to see that the experts are also seeing the uncertainty for Friday. Looking at the GEFS and the temp graph the models are clearly struggling with the messy interaction around the UK:

 

 

 

The GEFS clusters have 55% support for the op and 45% support for HP to move in. At this range it seems much more likely the GFS op is right especially as it has support from the Control. The clusters for Sunday and Monday have very strong support for HP to dominate and Saturday should improve if it does start unsettled. From then on the GEFS are promising an extended spell of HP right through to D16. The GFS op is an outlier from D9 so I have binned its FI. 

 

D12 & D14 mean:   

 

ECM looks mainly dry from D6-10 plus.

[damianslaw]

Reliable timeframe is Thursday, thereafter it remains an uncertain outlook for Easter, with a messy feature due to move across the country on Good Friday. This feature will interact with some cold air so northern parts could be in for quite a wintry Good Friday.

 

I'm not confident on calling events for easter at this range.

 

In the reliable timeframe, its an unsettled outlook and a cold one for the northern half of the country.

[Frosty.]

Tonight's Ecm 12z ensemble mean shows high pressure generally centred to the west of the UK from T+168 but it's influence covers all parts through the extended outlook period. I'm hopeful we will have some fine weather this Easter and further into April too. :-)

[Summer Sun]

Another settled ECM ens from Saturday and into April

 

 

Temperatures would be around average if that came off feeling pleasant enough in the sunshine, though until this makes it down to a more reliable timeframe I remain cautious, before that a windy week with temperatures remaining low in the north and around average in the south

Edited March 29, 2015 by Summer Sun

[Cheese Rice]

Reliable timeframe is Thursday, thereafter it remains an uncertain outlook for Easter, with a messy feature due to move across the country on Good Friday. This feature will interact with some cold air so northern parts could be in for quite a wintry Good Friday.

 

I'm not confident on calling events for easter at this range.

 

In the reliable timeframe, its an unsettled outlook and a cold one for the northern half of the country.

Looks like a repeat perfomance of March 22 2013 too far out to know the exact track but northern parts could see some snow, 18z shows potential for quite alot.

[Penrith Snow]

MetO fax chart is out for Friday and it is not good, cold and wet with the chance of snow in the north even on low ground.

A classic winter chart really, shame it isn't January!

Those betting on a fine settled Easter would be wise to hold onto their cash although conditions should improve latter in the weekend. Gibby,s call this morning now seems spot on but still room for change better or worse.

Scottish ski resorts however looking at a great Easter with loads of snow that has barely began to reduce since the winter.

Andy

[IDO]

Mon-Thur has been showing continuity for a few days and Friday synoptically now showing more certainty with a feature moving SE in a cold pool. There are timing, intensity and track variations cross and inter models so surface conditions re wintry mix/rain may change. Looking at the temp graph still lots of scatter as to how cold the pool is:

 

 

Again the op is an extreme example from its suite so again it looks a worse case scenario. The same applies to precipitation. Improvement from Saturday and the GEFS confident of the south having some decent settled weather Sat-Mon:

 

 

Saturday is an improving picture but Sunday and Monday look to warm up and the ECM agrees with that:

 

 

 

With the differences at D5 the GEFS showing little continuity from D10 and the two hi-res runs highlight this:

 

op:   Control:

 

I would have low confidence for after D8.

Edited March 30, 2015 by IDO

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 08:00 ON MONDAY MARCH 30TH 2015.

 

THE CURRENT GENERAL SITUATION Troughs of Low pressure will cross East over the UK today and at first tonight in a strong Westerly flow.

 

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

 

MODELS-2 WEEK HEADLINE The changeable and sometimes windy spell will be replaced by drier and more settled conditions from the Easter weekend.

 

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream is shown to blow strongly across the UK in a West to East direction for the next three to four days. The flow then is shown to veer more towards a Northerly drift down across the UK as a ridge builds to the West. Then after a few quieter days the flow resurges in strength over the Atlantic and crossing the UK again later in a West to East direction.

 

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

 

GFS OPERATIONAL The GFS Operational this morning shows a strong Westerly flow across the UK through the coming few days with further rain and showers before the flow eases as pressure rises towards and over the Easter weekend. Then as we move through next week High pressure is squeezed away to the SE as Low pressure over the Atlantic regains some control with wind and rain once more moving West to East across the UK later especially over the North and West. 

 

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

 

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

 

THE GFS CONTROL The GFS Control Run shows similar easing in the Westerly flow later this week as High pressure builds across the UK. Unlike the operational it holds on to High pressure across the UK for much of next week too with plenty of fine and dry weather with some sunshine, light winds but frosty nights. It's not until the end stages of this run that the threat of an Atlantic breakthrough develops towards the North and West.

 

THE GFS CLUSTERS  The GFS clusters continue to show a High pressure based bias across the UK in two weeks time, most likely positioned just to the SW. Whether or not it is influential enough to keep the Northernmost areeas of the UK dry and settled is less clear but a light NW or west flow across the UK looks the most likely.

 

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 UKMO today shows a stalling cold front crossing slowly East on Thursday as pressure builds across the UK from Scandinavia over the start of the Easter weekend. Rain on Thursday and perhaps Good Friday looks like dying out leaving the UK rather chilly and cloudy but dry by Easter Sunday.

 

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

 

THE FAX CHARTS The Fax Charts continue to show complex arrangements of troughs periodically crossing West to East across the UK over the next 96 hours or so delivering rain and showers at times in fresh to strong winds from a Westerly quadrant.

 

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

 

GEM GEM today makes very little of any meaningful High pressure restricting improvements to just a few days fortunately over the weekend Easter break. Then as we move through next week the return of Atlantic West or NW winds with some rain or showers at times for most especially the North.

 

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

 

NAVGEM NAVGEM looks a little like UKMO this morning developing a chilly ridge SW across the UK from High pressure over Scandinavia which in itself slips South late in the period but ensuring a dry and bright second half to the Easter Holiday though definateley not warm.

 

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

 

ECM ECM shows improvements taking shape at the weekend as the Atlantic Jet flow and bandwagon weakens. High pressure is shown to build through the UK forming a centre across the UK before it drifts further out to the west or even NW later maintaining fine and dry conditions next week too but never overly warm with frost at night and variable amounts of sunshine day to day.

 

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

 

ECM 10 DAY MEAN(12z) The ECM 10 Day Mean Chart shows High pressure well in control of the UK weather in 10 days with a centre close to or over the West of the UK

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models continue to show a trend towards High pressure based conditions from around Easter lasting through most if not all of Week 2.  

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKM & ECM The current verification statistics for the past 31 days shows ECM leading the way at 3 days with 97.8 pts followed by UKM at 97.4 pts and GFS at 96.6. At 5 days ECM  continues to lead the field at 91.4 pts over UKMO at 90.5 pts and GFS at 88.3. At 8 days ECM remains the leader with 67.5 pts over GFS's 63.3 pts. Then at Day 10 ECM retains superiority at 47.5 pts over GFS at 46.1. 

 

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.prig

 

 

MY THOUGHTS All models show the current very strong Westerly flow across the UK giving way to something much quieter from the Easter weekend. Such a change is never straightforward and the transitional period is fraught with complications in the shape of a stalling front moving into higher pressure setting up to the NE of the UK. The front having brought rain slowly East across the UK through Thursday looks like decaying in situ over Good Friday leading to a disappointing and cool start to the 4 day break. However, all models support High pressure building across the UK by the second half of the weekend with fine if rather chilly weather developing with the chance of some sunshine developing but with clearer night skies frost becomes a risk too. Then as we stretch our thoughts into conditions post Easter it does look like High pressure could hang around near or close to the West or NW of the UK for some considerable time supported by a weaker Jet flow over the Atlantic. The exact positioning of the High will dictate the airflow source across the UK but in any long spells of April sunshine temperatures will approach average values but in any clear skies by night some very unwelcome and possibly quite sharp frosts could continue. Then as we look at the extreme timelines of this morning's output principally from GFS we see the risk of the Atlantic Westerlies returning at least to the North and West of Britain but at two weeks away this may change in subsequent runs.  

 

Issued at 08:00 Monday March 30th 2015

[Summer Sun]

No change from ECM ens with pressure gradually rising through the Easter weekend and this lasts out to d10

 

 

Temperatures should be around average feeling warmer in any sunshine and light winds though cold and possibly frosty overnight where skies clear

Edited March 30, 2015 by Summer Sun

[Frosty.]

The Gfs 06z shows a marked improvement in our weather during the second half of the Easter period and much of next week with high pressure intensifying across the UK with dry and increasingly warm and sunny conditions for many areas. Looking further ahead, the south looks best for further settled pleasant spells.

[mushymanrob]

The Gfs 06z shows a marked improvement in our weather during the second half of the Easter period and much of next week with high pressure intensifying across the UK with dry and increasingly warm and sunny conditions for many areas. Looking further ahead, the south looks best for further settled pleasant spells.

 

indeed, lets hope something like this verifies, but the easter highs behaviour, its orientation, position and even shape is going to make a huge difference to what we get. fingers crossed!

[Frosty.]

The GEFS 06z mean is showing a generally benign, pleasant settled outlook from the Easter weekend onwards, especially by sun/mon which is very encouraging. I'm hoping we will see an increase in sunshine and warmth during next week :-)

As you say mushy, fingers crossed.

Edited March 30, 2015 by Frosty.

[legritter]

afternoon all ,well looking at charts this coming week looks not so good for outdoor activities but further outlook shows signs of something more settled .

just a case of getting the forecasted high in a good position hopefully further east the better .

 not many posters about but i enjoy popping in on the best weather forum around .  

[Summer Sun]

UKMO and GFS both maintain the trend towards high pressure building in for Easter Saturday and through the rest of the weekend

 

 

GFS

 

 

GFS shows temperatures starting to recover with light winds and some sunshine it will slowly turn much warmer than of late with Easter Monday possibly the pick of the 4 day weekend but beyond this the temperature continues to rise just short of 20c next Tuesday in some southern spots

 

Edited March 30, 2015 by Summer Sun

[Frosty.]

The Gfs 12z brings a gradual improvement through next weekend but it's really from Easter Monday onwards when we see the fine spell take off with much more in the way of sunshine and increasing warmth, the anticyclone intensifies next week, really superb charts for fine and warm weather and there is no Atlantic breakdown, indeed the pattern becomes blocked with mainly dry and settled conditions, I would gladly take what this run shows next week.

[Winter Cold]

Evening all

 

Just the ECM to add to the analysis then. Pretty much confirms a poor Good Friday im afraid, but thats the bad news out of the way as this model then agrees with the others of an improving weekend:

 

  

 

 

All eyes now to the positioning and orientation of the building high to see what surface conditions we get. Could be anything from cloudy and cool to sunny and warm:

 

     

Also a hint there of NE Scotland having a poor Easter Monday but the other models dont support that.

Edited March 30, 2015 by Winter Cold

[Frosty.]

Tonight's GEFS 12z mean becomes very settled with high pressure building over the top of the UK, I think there is currently a very good chance that next week will be dry with plenty of sunshine and light winds with temperatures into the 60's F but with chilly nights under clearing / clear skies.

[Milhouse]

At the moment we are looking at high pressure more likely to be sat to the west of the UK than the east. In such a situation its a very fine line between whether we get fine and warm or unsettled and cool. You can get a warm airmass coming round the top of the high, but you can also get cooler air coming into the mix too. Obviously the further east the high is the warmer it will be. ECM still supporting the cooler outcome, but still with milder air circulating round the high at times.

[Summer Sun]

ECM ens maintains its trend towards higher pressure moving in during the weekend and into next week

 

 

What it feels like is going to be very dependent and cloud cover where we do see some breaks it will be feeling warmer than of late but where it stays cloudy it will still be feeling cool

[damianslaw]

Still a lot of uncertainty as we move towards the weekend, much hinges on the position of heights set to advance their way across the country through the weekend. Thankfully it does look like an improving easter period after what is increasingly looking like a preety miserable Good Friday for many, disappointingly cloudy, damp, wet and in the north cold.

 

GFS is playing around with significant northern heights building as the high retrogresses, aided by an ineffectual weak jet, ECM not too far off such a scenario. Any warm up could be fleeting in nature with some jolly cold nights for the time of year.. Northerlies and easterlies become much more likely now than any other time of year, peaking in May, odds on the atlantic having the upper hand markedly drop now.

[Frosty.]

Tonight's Ecm 12z ensemble mean shows high pressure centred to the west of the UK at the beginning of next week but the good news is it slowly migrates further east to become centred directly over the BI, the further east it gets, the better. The latest ecm and gefs mean indicate an anticyclonic outlook beyond T+168 hours with increasing amounts of sunshine and warming up by day but with chilly nights.

Edited March 30, 2015 by Frosty.

[Milhouse]

Looking good for the SW on those mean charts. Light winds, upper temps above zero translating into some pleasant springlike conditions. Cooler in the east but still looking mostly settled.

[bluearmy]

I suggest the likelihood is we stay on the cooler side of the ridging though to discount it being further east would be foolish. There would be some warm sectors coming around the high but in general we would sit behind the cold fronts.

.

Edited March 31, 2015 by bluearmy

[IDO]

^^^ ECM at the moment places the core high over the UK from Easter and then a slight trend towards the east:

 

D5:  D8:  D10: 

 

Temp wise it is difficult to guage at this range, however the uppers are around average to the west and slightly below to the east. GEM has the high UK based as well:

 

 

 

Looks to me a case the surface temps start below average at Easter but build up and potential in the S/SE by D10 to reach 16c plus. The GFS op is unreliable at the moment and it builds a HLB after D10 so I prefer the GEFS mean:

 

D8:   D10: 

 

Good agreement for a HP dominated period from Saturday for six days plus.

 

In the nearer term the uncertainty re Friday looks like it has now resolved and what the Met thought the most likely solution, that is a stalling front and a cold upper flow was in fact the wrong solution and in fact the front clears most of the country by midday Friday. The GEFS certainly never gave that solution up despite the ops consistency. The FAX highlights that, with the SW probably having a good day all Friday and clearing the far east by about 2pm:

 

 

So Easter looks like a settled four days for many. Looking at the GEFS 13 day mean and it suggests that HP remains the driver:

 

 

All good stuff.

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 08:00 ON TUESDAY MARCH 31ST 2015.

 

THE CURRENT GENERAL SITUATION A strong WNW flow will blow across the UK today before weakening slowly tonight ahead of a warm front approaching from the SW tomorrow.

 

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

 

MODELS-2 WEEK HEADLINE The changeable and sometimes windy spell will be replaced by drier and more settled conditions from the Easter weekend.

 

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream forecast indiciates the current West to East flow across the UK will turn more NW to SE or even North to South as the flow buckles north over the Eastern North Atlantic. thereafter there is some indication that the flow will rejuvenate to the South of the UK but there is a lot of uncertainty surrounding where the flow will lie the further out into the outlook we go this morning.

 

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

 

GFS OPERATIONAL The GFS Operational this morning shows a strong Westerly flow across the UK through the next 24 hours or so before the winds decrease as High pressure edges closer from the SW. However, a further trough moves across from the West on Thursday with the decay of that indicating a change to High pressure based weather from then on. In this run after a few days of the High based very near or over the UK the High looks like migrating to somewhere North and NE of the UK with some unsettled and cold weather encroaching across the Southlooking possible from this run later. 

 

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

 

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

 

THE GFS CONTROL The GFS Control Run shows similar easing in the Westerly flow through the rest of this week as the next trough on Thursday looks like the last for the time being before High pressure develops across the UK over the second half of the Easter Weekend. thereafter the run indicates High pressure very much in control of the weather over the UK through the second half of the run with fine and dry weather with sunny spells but temperatures probably little better than average with some frosts at night.

 

THE GFS CLUSTERS The GFS clusters show little indication of certainty as to where we will lie synoptically two weeks from today with an equal share of several evolutions ranging from a chilly showery Northerly or a more quiet and anticyclonic based pattern with the centre of High in one of several different options.

 

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 UKMO today shows a stalling cold front crossing slowly East on Thursday as pressure builds across the UK from Scandinavia over the start of the Easter weekend. Rain on Thursday and perhaps Good Friday looks like dying out leaving the UK rather chilly and cloudy but dry by Easter Sunday.

 

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

 

THE FAX CHARTS The Fax Charts follow the course of the raw data with the troughs of Low pressure moving into the UK from the west towards Easter weakening and decaying as High pressure builds through them over the Easter weekend.

 

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

 

GEM GEM today becomes very High pressure driven over the UK from Easter with the current unsettled, windy and changeable weather being replaced by fine and dry weather with slowly increasing amounts of sunshine and probably temperatures too as we move through next week.

 

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

 

NAVGEM NAVGEM is quite tentative in it's build of High pressure across the UK, taking until early next week to completely eliminate the risk of a few showers from the South of the UK with the close of the run joining forces with the other models in settling the weather down with sunny spells developing.

 

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

 

ECM ECM continues to show improvements taking shape at the weekend as the Atlantic Jet flow and bandwagon weakens. High pressure is shown to build through the UK by Easter Sunday with the start of next week then largely dry with variable cloud cover but unspectacular temperatures.

 

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

 

ECM 10 DAY MEAN(12z) The ECM 10 Day Mean Chart shows High pressure well in control of the UK weather in 10 days with a centre close to or over the UK.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models continue to show a trend towards High pressure based conditions from around Easter lasting through most if not all of Week 2.  

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKM & ECM The current verification statistics for the past 31 days shows ECM leading the way at 3 days with 97.8 pts followed by UKM at 97.4 pts and GFS at 96.7. At 5 days ECM  continues to lead the field at 91.2 pts over UKMO at 90.6 pts and GFS at 88.3. At 8 days ECM remains the leader with 68.5 pts over GFS's 63.6 pts. Then at Day 10 ECM retains superiority at 48.9 pts over GFS at 46.6. 

 

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.prig

 

MY THOUGHTS The pattern shown within all the models this morning closely resemble the pattern shown by yesterdays output with just small but subtle differences in positioning of High pressure determining small scale weather differences in any one place across the UK from early next week. The basic pattern is that the current strong and blustery West or NW winds die away by the middle of the Easter holiday along with the attendant rain and showers. High pressure then looks like forming over the top of the UK by the end of Easter but with a lot of residual cloud left across the UK from decayed troughs there may not be much sunshine and temperatures are likely to be suppressed as a result. Then next week we have to try to pin down where the High pressure area sits or migrates too with a whole array of options shown this morning which could have subtle differences to the way things feel at the surface and confidence on any one option occurring is unusually low this morning. A fair amount of options most notably from GFS shows it migrating North which is not good as it could set up a cold feed from Europe and allow fronts to encroach from the SW- a mouth watering pattern for snow lovers in a mid Winter month but pretty unwelcome in April from the point of view of cold rain and temperatures becoming possible. However, other output shows the High slipping South, West or just revolving around the vicinity of the UK with much more benign conditions if the latter happens with increasing amounts of sunshine and moderate warmth but frosts by night. Wherever the High ends up the vast majority of output is stating that we can look forward to a cessation of the current strong winds and spells of rain and showers to a much more useable weather pattern in which we may not be breaking any records temperatures wise but be able to pursue outside activities in the knowledge that conditions are unlikely to be rained off.  

 

Issued at 08:00 Tuesday March 31st 2015