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

[johnholmes]

I see we have the same pie in the sky forecasts being produced.

Yesterday being a prime example.

Frosty gave run down of the 00hrs and showed a chart for 10th may, large heap of pretty pink snow based mainly over north east and rain else where.

Then on the 12 hrs he showed some lovely temps charts with temps topping 22c over south/south east, oh and the snow fields had now 18c.

With huge numbers in the winter on here that would have been mayhem, however it just goes to show the models just dont produce eye candy in the heart of dec to feb.......

 

You will always, well for a good many years to come in my view, get these marked variations in synoptic model outputs. At beyond T+144 try using the same time model run rather than each run. It does cut some of the variability out. Watch the 500mb anomaly charts, they again, over several days meaning out, will give a more reliable idea of the upper air flow. With practice one can get a decent idea of just what type of weather, what airmass etc.

[ANYWEATHER]

Evening folks. So the much protracted cold and unsettled spell is upon us!  An unusually cold spell tonight, then a run of convective days both Monday/Tuesday with thunder ,lightning  gusty winds hail etc, frost still likely, Then later in the week perhaps some frontal rain during late Tuesday early Wednesday then again colder air. Pointless looking at the Bank Holiday Precip  this will change....

[knocker]

Looking at the anomalies for next weekend still leaves some doubt on the outcome with ridging or not being the question.

 

The GEFS has it bringing a quite strong influence and thus HP over the UK with the trough mid Atlantic. The ECM on  the other hand is perhaps a fraction not quite so keen although all in all at this stage I would think a good chance of settled weather, certainly for England.

 

The HP is transient though as the upper trough edges eastward bringing cyclonic influence over the UK with a SW flow

Charts weatherbell

Edited April 26, 2015 by knocker

[summer blizzard]

Euro not looking to get rid of northern heights anytime soon..

 

[knocker]

A quick run through of this mornings GFS

 

Once the low currently swinging into Scotland by 18z is out of the way it has a secondary low swinging SE over Wales by 12z Thursday, wet but above average temps. Then some brief ridging before the large area of low pressure out west nudges in Saturday morning. The GFS being the GFS of course complicates this by forming two lows with one running up the channel. Temps slightly above average. I'm inclined to wait awhile before placing any bets.

Charts courtesy weatherbell

EDIT

And to quote Matt Hugo, " text book northern blocking on Thursday with lows held well south over the Azores and approaching the UK from the SW".

Edited April 27, 2015 by knocker

[Frosty.]

The Gfs 00z looks generally unsettled with sunshine and showers being the main weather type for the next few weeks but at least temperatures recover from the BH weekend onwards, closer to where they should be at this time of year and favoured spots which have the most sunshine and fewest showers could reach the high teens celsius at times next week according to this run.

[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 APRIL 27TH 2015.

 

THE CURRENT GENERAL SITUATION A cold and unstable Westerly flow will blow across the UK tonight and tomorrow with a trough of Low pressure moving East later tonight and clearing East tonight..

 

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

 

MODELS-2 WEEK HEADLINE Unsettled and changeable with bright spells and showers or rain, heavy and wintry on hills in the North. Local night frosts still possible.

 

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream is focused to blow on a much more Southerly track than usual for the entire period not ideal for conditions over the UK all in association with Low pressure near or over the UK through the period.

 

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

 

GFS OPERATIONAL The GFS Operational this morning shows rather chilly and showery conditions in rather cold uppers across the British Isles in the coming week. A few longer spells of rain are likely too especially on Wednesday as a trough spills East. Then through Week 2 although some moderation of the chill in the SE fis likely for a time conditions remain very changeable with rain and showers at times as further Low pressure moves NE or East across the UK from the Atlantic.

 

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

 

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

 

THE GFS CONTROL The GFS Control run is very similar to the operational in substance through the period though it does suggest somewhat less cold weather in the second week with more of a Southerly aspect to the airflow at times though it is equally changeable in pattern with rain at times for all.

 

THE GFS CLUSTERS The GFS Clusters today show a 65%/35% split in favour of Low pressure expected to lie to the West and SW of Britain in two weeks time with the wettest and most unsettled conditions likely over the South and West while the other 35% reverse the theme with Low pressure to the NE and High over the Atlantic with the most unsettled weather in the North.

 

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 this morning shows Low pressure sitting out to the West of the UK by the weekend following a chilly and showery week for many as Low pressure moves East over the North. With time and by the end of the run the resultant Southerly winds though still disturbed will deliver slightly less chilly air to the South and East.

 

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

 

THE FAX CHARTS The theme of the Fax charts this week shows a widening of isobars as we move into next weekend following the cool and unsettled week with showers and more prolonged rain on Wednesday in strong winds. By the weekend the flow across Britain will be slack and still rather cold with troughs threatening the South and SW while the North stays drier with scattered showers.

 

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

 

GEM GEM this morning looks very changeable and often rather cold over the next 10 days when apart from a brief drier slot towards the weekend all areas are at risk of cold showery weather with occasional longer spells of rain too as new Low pressure trundles across the UK on occasion from the West.

 

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

 

NAVGEM NAVGEM too shows Low pressure migrating slowly to the NE of the UK this week with continued chilly and showery weather with the caveat of a longer spell of windy and wet weather likely on Wednesday. Then at the weekend while Northern and Eastern areas become dry but still chilly the South and West look like becoming cloudy and rainy again as troughs move up from the SW in a strengthening SE breeze.

 

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

 

ECM ECM this morning looks unseasonably chilly in it's 00z run as Low pressure remains positioned such that cold polar air remains the dominant feature across the UK and with pressure generally quite Low the message remains one of sunshine and showers and occasional longer spells of rain over the 10 days with some snow on northern hills and frost where skies clear at night and winds fall light.

 

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

 

ECM 10 DAY MEAN(12z) The ECM 10 Day Mean Chart  from last night shows Low pressure likely to be lying across the UK at the 10 day point stretching from the Eastern Atlantic to much of Northern Europe with a heady mix of rain at times, some bright intervals and temperatures average at the very best.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trends this morning show a common theme of rather cold uppers lying across much of Britain through the vast majority of the runs today.

 

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 97.4 pts followed by UKM at 96.8 pts and GFS at 96.1. At 5 days ECM  leads UKMO with 88.4 over UKMO's 88.3 pts with GFS at 85.5. At 8 days ECM remains the leader with 61.8 pts over GFS's 59.3 pts. Then at Day 10 ECM retains superiority at 46.1 pts over GFS at 42.6. 

 

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 Not much sign of Summer in this morning's set of output with the most dominating feature being the chilly uppers aloft and then translating down to the surface for many areas away from the SE at times being the most notable feature in the next two weeks. In addition with the air unstable and pressure relatively low at times rain or showers are also shown across the board with only limited periods of rather drier and brighter conditions most likely towards the early part of the Bank Holiday Weekend. The air will continue cold enough at times to see some wintry conditions over the higher ground of the North and anywhere where skies clear at night and winds fall light the risk of quite sharp frosts locally is a real possibility at anytime through the period but of course most likely in the North. With regard to rainfall amounts in general I don't thing there will be any noteworthy amounts of rain with the weather more showery in nature rather than sustained trough related. Nevertheless where and when it falls it will accentuate the cold feel and hold temperatures generally short of average for much of the time. So why has this happened and how long will it last? Well our warm anticyclone of last week with it's warm uppers has been replaced by Low pressure positioned such that it is dragging cold polar air South across the UK from the West and North and as long as pressure remains higher than lately over the Arctic and the Jet Stream remains positioned South of the UK which it is forecast to do for the forseeable future then cool conditions look like persisting with rain or showers for all at times as Low pressure areas come in on more Southerly latitudes than usual. Of course being May when the sun comes out it will compensate for the cold air and make things very pleasant but on the cloudier days it will feel distinctly chilly. The Bank Holiday Weekend looks like it could be best towards the North and East as troughs of Low pressure to the SW could run into the South and West of England and Wales with some rain but it doesn't look likely to be particularly warm anywhere but useable for many in the North and East. So all in all and as I see it chilly and changeable are the best terms to use for the UK weather in the coming few weeks with still some frost at night on occasion. 

 

Next update from 08:00 Tuesday April 28th 2015

[Frosty.]

The GEFS 00z mean shows the PFJ heading north through the extended outlook with milder T850 hPa replacing the chilly polar air so at least temperatures would return to normal with some rather warm days in any prolonged sunshine, however, the outlook continues generally unsettled with sunshine and showers, some heavy and thundery being the main theme but there will also be fine spells with more in the way of sunshine.

[Captain Shortwave]

The ECM again blows up that Scandi low past day 5 and keeps it in situ resulting in the blocking pattern for week 2, again this doesn't have support from the rest of the model suite including the ensembles. It still looks unsettled but less cold after this week with temperatures generally back in the teens (mid/high teens in the south and low teens in the north).

 

Convection wise - looks good for northern and western areas today and tomorrow, the south looks mainly dry due to a weak ridge restricting convection somewhat, so isolated showers.

 

Wednesday will see a band of rain pushing through the country before the showers return for Thursday, this time more promising for the south.

 

Beyond this we see another very weak ridge push in, how things go beyond here is uncertain as to whether this ridge can hold on through the bank holiday weekend or another weather scenario will crop up as low pressure in the Atlantic moves towards the UK.

Edited April 27, 2015 by Captain shortwave

[Summer Sun]

@WSI_EuroEnergy

 

Risk of warmer temperatures across NW/mainland Europe early next week as per GFS op, ECM op cold outlier

 

[Gael_Force]

@WSI_EuroEnergy

 

Risk of warmer temperatures across NW/mainland Europe early next week as per GFS op, ECM op cold outlier

 

 

WTF is "risky" about some warmer temps for the first week in May?

 

I do wonder where some of these folk get their weather dialogue from.

[Frosty.]

There is a chance some of us will have respectable temperatures (pleasantly warm) during the BH weekend according to the Gfs 12z with sunny spells but there is also a continuing risk of showers.

Edited April 27, 2015 by Frosty.

[Milhouse]

Yes it looks like the approaching low pressure will come with a sector of very mild air. So despite the BH weekend becoming increasingly unsettled there may be some drier brighter and warmer interludes to enjoy as well.

[Summer Sun]

GFS giving hints again of something warmer and more settled developing around the 10th

 

 

Northern Scotland looks prone to some unsettled weather still at times before the high covers all of the UK later on

[Frosty.]

Really hope the Gfs is on to something here, much better charts in low res from the 12z with summery temps returning as high pressure builds from the s/sw.

[Stuie]

ECM ditches the cold uppers by Sunday. That`s good for me and my chillies.

 

Edit: And into FI

Edited April 27, 2015 by SaffW

[mushymanrob]

Personally i dont think its good news for summer IF we get another dry settled spell next week. It wont stop dry sunny settled and warm until september and many recent dry springs have resulted in washout summers.

So id prefer unsettled weather now for a while.

[Rocheydub]

Personally i dont think its good news for summer IF we get another dry settled spell next week. It wont stop dry sunny settled and warm until september and many recent dry springs have resulted in washout summers.

So id prefer unsettled weather now for a while.

Now! We all know weather pattern matching doesn't work!!!

[ANYWEATHER]

Evening folks the cold and unsettled weather is with us for some time to come . Interesting weather this coming week ,I said a few days ago about news headlines....and minus 8 c is a some sort of record for N .Ireland. for this time of year  ! I think convective weather and frost will mark the news headlines this coming week....

Edited April 27, 2015 by ANYWEATHER

[Timmytour]

The bit of chilly weather we're experiencing remnds me of May Day bank holiday in 1997. I was in Italy on holiday at the time but heard about it snowing on the bank holiday. I hope recent runs about warmer weather coming are on the button because I seem to recall that cold blast in 97 hanging around for a while

[Frosty.]

Both the Ecm & Gfs 12z show more of a tropical maritime influence in just over a weeks time so daytime temperatures would be more in the 16-19c range, much more pleasant. Even though I'm a coldie I don't want an unseasonably cold May.

[knocker]

A brief look at the latest EC32 update

 

By the 5th May the anomaly still showing trough orientated SE over Scandinavia and the main trough south in the eastern Atlantic. Thus the UK still in the cyclonic regime with lows popping along from the SW bringing periods of unsettled weather with temps about average.

 

But the next couple of days marks a pattern change with the trough to the NE dissipating and the Atlantic trough edging west with a build up of heights over Scandinavia and to the SW.  So by the 12th we have the LP banished off of NE Canada and HP influencing the eastern Atlantic with temps still around average.

 

This evolution continues and by the 20th the anomaly has ridging eastern Atlantic to Iceland but there is a weak trough Scandinavia so although in general the HP is in control on the surface the HP is centred just to the west so cooler northerlies with temps below average.

 

By the 29th the weak upper trough to NE is no more but the HP is too far to the SW to indicate significant height build up UK and the east. Temps still around average.

 

Summary.

 

The UK should see the pattern change around the 8th from unsettled south westerlies to a much more stable regime with ridging from the Azores, interrupted briefly with weak troughing to the NE and the endof the run is a bit vague with the HP sliding SW but no obvious sign of cyclonic activity. The temps are generally around average for the run and perhaps a bit below for a time.

 

So no obvious sign of any great heat but could well be quite a pleasant May.

Edited April 28, 2015 by knocker

[Captain Shortwave]

Long way off but the second week of May is starting to show hints of some kind of southerly plume developing.

This reflected in the GFS and GEM outputs this morning.

GEM

 

Ens giving the hint too.

 

Still plenty of near normal and unsettled members still.

 

Last nights ECM was showing something quite similar in its attempt to build a ridge just east of the UK to introduce a much warmer flow.

 

As I said at the start, a long way to go to have any hope of this coming off with the likelihood that the unsettled regime will come off over this.

 

In the nearer term, it still looks cool and unsettled until Friday, then Friday and Saturday look fairly dry but still cool. A front will run north east Saturday night (it could be earlier or later at this point) which will see a warm up during the second half of the bank holiday weekend.

Edited April 28, 2015 by Captain shortwave

[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 APRIL 28TH 2015.

 

THE CURRENT GENERAL SITUATION A cold and unstable Westerly flow will blow across the UK today. Tonight and tomorrow will see a trough of Low pressure crossing East across Britain tonight and at first tomorrow.

 

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

 

MODELS-2 WEEK HEADLINE Unsettled and changeable with bright spells and showers or rain, heavy and wintry on hills in the North at first. Becoming less cold and possibly drier later especially towards the South and East.

 

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream is focused to blow on a much more Southerly track than usual for the vast majority of the run before slowly returning North across the UK at the end of the period

 

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

 

GFS OPERATIONAL The GFS Operational this morning shows the rather cold conditions remaining in place this week with a mix of sunshine and showers. A ridge crossing East towards the weekend could give rise to a sharp frost on Friday night before troughs moving slowly up from the SW over the Bank Holiday weekend should introduce milder air into the South which through the remainder of the run gradually extends to many other areas with time. The changeable conditions will likely continue with a slow inprovement in conditions from the South as pressure builds and the end of the period looks fine and settled on this morning's run with sunny spells and temperatures above average.

 

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

 

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

 

THE GFS CONTROL The GFS Control run ends up in the same place with regard to fine and settled weather two weeks from now with the passage of time getting there showing a mix of changeable conditions with rain at times for all gradually being replaced by less unsettled and less cool conditions towards the end of the second week though the time this run takes to get to the High pressure area is rather more traumatic and hindered..

 

THE GFS CLUSTERS The GFS Clusters today show a 60%/40% split in favour of High pressure lying somewhere over or close to the UK in two weeks time with fine and dry conditions dominant. This is a turnaround from yesterday morning and with only 40% of members showing the chance of Low pressure over the UK in two weeks time.

 

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 this morning shows Low pressure sitting out to the West of the UK by the end of the Bank Holiday weekend with a marked trough across Central Britain. Southern areas could become somewhat less cold as winds switch SW while the North stays cold and raw at times in an East wind with all areas seeing outbreaks of rain and showers.

 

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

 

THE FAX CHARTS The theme of the Fax charts this week shows a widening of isobars as we move towards the weekend with the cold and showery Westerly breeze dying down as a weak ridge crosses East on Friday. The Weekend is shown to be more unsettled from the SW as milder Atlantic winds behind active troughs move slowly NE across Southern and Western parts by Sunday.

 

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

 

GEM GEM this morning looks mostly quite changeable through the 10 day spell quite closely following the UKMO theme of events. So a cold and showery period for the next few days dies away in preference to steadily less chilly conditions and Southerly winds moving North across the UK early next week but with the weather remaining quite changeable with rain at times in association with Low pressure close by to the West or over the UK towards the end of next week.

 

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

 

NAVGEM NAVGEM shows a similar theme as the majority of the rest of the ouput with a change from cool and showery West or NW winds to milder South or SE winds by early next week, the milder air following a trough North across the UK at the weekend with next week continuing to see some unsettled weather at times with rain in places at times and temperatures nearer to average.

 

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

 

ECM ECM this morning shows the main theme of the period as becoming less cold next week and though still rather unsettled with Low pressure to the West and NW for much of the time some dry and brighter intervals will increasingly develop as pressue gently rises from the South later with temperatures closer to average. Having said all that Low pressure is shown to deepen to the SE at Day 10 thwarting any lengthy improvent here.

 

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

 

ECM 10 DAY MEAN(12z) The ECM 10 Day Mean Chart  from last night loosely follows it's operational route in gradually shifting the emhasis of Low pressure out into the Atlantic with pressure rising gently to the SE bringing milder winds up from the South later in the period.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trends this morning show a slow transition towards less chilly conditions as winds source from a point SW or South of the UK rather than from a polar or Arctic source with this Bank Holiday weekend the pivotal point.

 

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 97.4 pts followed by UKM at 96.8 pts and GFS at 96.1. At 5 days ECM  leads UKMO with 88.4 over UKMO's 88.1 pts with GFS at 85.5. At 8 days ECM remains the leader with 61.8 pts over GFS's 59.1 pts. Then at Day 10 ECM retains superiority at 44.9 pts over GFS at 43.6. 

 

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 chilly and unsettled weather introduced at the weekend has some time to run before something rather less chilly but still changeable arrives by the start of next week. The showery theme currently upheld for most will be aggravated by a trough of Low pressure sinking SE across the UK tonight with rain and squally winds followed by a further few days of chilly and potentially showery conditions especially on Thursday. A ridge of High pressure could give rise to another unwanted frost over Friday night but the SW may escape as thick cloud and rain moves gently NE across these areas at the weekend, gradually extending North. Ahead of the troughs the weather will still be chilly but milder air will be introduced across the South and this looks like extending North to all areas next week. With Low pressure the driving force most likely positioned to the West or NW of Britain all areas remain at risk from rain at times next week before a gentle rise of pressure from the South or SE looks like drying things up and warming things up further in the second week. There are some variations between outputs on how this pattern evolves but there is some common ground that the UK will lie under much drier and warmer weather in two weeks time with a strong chance that High pressure will being a period of fine and bright weather with temperatures near to or above average and we may finally then lose the chance of any damaging night frosts. So all in all not all bad news this morning as the current chilly and still in places wintry feeling air mass we have experienced this week and in the next few days will be hopefully this Winter seasons last hurrah and we can settle into something much more May like with time. 

 

Next update from 08:00 Wednesday April 29th 2015

[Summer Sun]

Nice to see pressure starting to lower up north later on in ECM's run the low to the SE at d10 would bring the risk of rain here but the high is edging up closer from the SW

 

GFS has hinted at an improving picture around the 9th on and off for a few days now and its got it again ECM looks better as well

 

 

 

GFS has the high coming in as early as d9 on this run and that takes us through to mid may at least

 

 

Temperatures much more seasonal with it