Model Output Discussion - 1st February Onwards 12z--->

[Frosty.]

The GEFS 06z mean has a more benign look to it during early march with high pressure building across the south but central and especially northern parts of the UK remain in a more unsettled zone to the north of the high pressure.

[Mucka]

-Some interesting changes in the output this morning with the wet and windy weather being somewhat curtailed by high pressure rising from the South toward end of Feb.

Indeed we could see some lovely Spring like weather to enjoy next weekend if current output is anything to go by.

However it looks like it may be fairly short-lived as trough potentially pushes down from the North and may perhaps allow a chilly Northerly blast early March.

This means there could be some fairly big contrasts in the weather we experience end of Feb early March - from Springlike to Winter-like.

Before all that some unsettled chilly weather around probably peaking early next weak but remaining unsettled and on the cool side right through the week, especially further North and West.

Edited February 21, 2015 by Mucka

[Winter Cold]

Well, differences this afternoon on the GFS 12z and UKMO 12z at T144. The former wants a high building over us but the latter wants to continue the cool Nwerly with wintry showers:

 

 

Maybe its just timing issues, but there are lots of variations on how next week will play out. Some indications of a settling down perhaps, but then there are also signs that it might not be a strong build of pressure affecting us all...

[Eugene]

GFS has got HP builds over us hopelessly wrong this month, no reason to doubt it hasn't again.

 

GEM which has been much more reliable shows a deep low for next Sunday on it's 12Z run.

Edited February 21, 2015 by Eugene

[IDO]

The models are no nearer to resolving D6 plus. Both GEM and GFS hold their nerve and keep to their stories from the 0z:

 

 

 

Neither had support from their mean on the 0z and in fact both have similar means; zonal. However it is not as simple as that and various outcomes remain viable.

 

GFS op is resolutely consistent with HP from D6 to D10 plus. However as others have pointed out they were wrong before and this may be the default outcome from the new GFS op. Time will tell, but potential for a very warm few days:

 

 

 

[Eugene]

The models are no nearer to resolving D6 plus. Both GEM and GFS hold their nerve and keep to their stories from the 0z:

 

gfsnh-0-192.png  gemnh-0-192.png

 

Neither had support from their mean on the 0z and in fact both have similar means; zonal. However it is not as simple as that and various outcomes remain viable.

 

GFS op is resolutely consistent with HP from D6 to D10 plus. However as others have pointed out they were wrong before and this may be the default outcome from the new GFS op. Time will tell, but potential for a very warm few days:

 

gfs-15-186.png

 

 

 

11C/12C isn't very warm, even GFS quickly cools it down.

 

When is early March very warm, you need something exceptional for this early in the year, sorry but you are really misleading people.

[Summer Sun]

Similar to last nights 12z the high could be one which has a fair bit of cool air in it after a mild start

 

 

Edited February 21, 2015 by Summer Sun

[Polar Maritime]

An interesting pattern showing with blocking trying to take hold, I would expect some large swings over the next few days into week 2.

 

 

Edited February 21, 2015 by Polar Maritime

[IDO]

11C/12C isn't very warm, even GFS quickly cools it down.

 

When is early March very warm, you need something exceptional for this early in the year, sorry but you are really misleading people.

 

Yes apologies. "Warm" is not really useful in the Winter. According to the meteorological terminology the temps will be very mild (+4 to +5c above average) to exceptionally mild:

 

 

 

Pedantics aside, in the sun that will feel very nice.

 

All probably academic as the GEFS mean still shows very little inclination to follow its op: 

 

Op   mean: 

[Winter Cold]

ECM 12z tonight doesnt build pressure over us like the GFS wants to. As has been mentioned, were possibly seeing the new bias of that model with that regard, but as ever, more runs needed to prove it!

 

In fact the ECM is quite a chilly run, with frequent invasions of polar maritime air. The runs ends on a very 'un-spring-like' note with a big swathe of -6 to -8 T850s pushing in. Nice to see of course

 

Edited February 21, 2015 by Winter Cold

[Frosty.]

I think beyond T+240 hours, the Ecm 12z op would go on to show high pressure really taking control of our weather, once that low to the NE clears off, I think the further outlook would become fine for all areas, Similar to today's Gfs 12z in low res

[Frosty.]

This evenings GEFS 12z mean is trending towards an anticyclonic further outlook with the south becoming fine during early march and gradually improving across central and northern uk a few days later. I would think most if not all parts of the BI should become settled before mid march.

[Eugene]

JMA quite cold tonight with PM northwesterlies, most likely scenario is somewhere in the middle, short mild SW'ly next weekend before cooler westerlies and a flat atlantic pattern.

[Winter Cold]

Most of the 12z GEFS are no where near as settled at T144 as the GFS op was. Most are more inline with the UKMO infact! I do suspect that once again we're seeing the op love in with high pressure....

 

 

EDIT: sorry the pics a bit small, when I saved it I thought it was looking huge lol

Edited February 21, 2015 by Winter Cold

[Frosty.]

The Gfs 12z @ T+144 does look the odd one out, especially compared to Ukmo with the Ecm somewhere in the middle. I want to make clear I would love a big turnaround to wintry weather but I'm just going with the flow, and if that flow ends up being mild and anticyclonic then so be it, at least I will keep posting as I'm a regular throughout the year who doesn't quit just because the models don't show what I want.

[Cloud 10]

Quite deceiving looking at the day 10 ECM ensemble mean anomaly as looks fairly mild at first glance but is actually pretty cold.

 

  850's..

 

 

Anti-freeze salesman in North America/Canada must be doing pretty well this winter.

[damianslaw]

Quite a divergence between ECM and GFS at the edge of the reliable timeframe - no surprise...

 

Mean outputs across the models suggests the ECM solution is more likely, a continuation of the zonal disturbed patter, a rinse and repeat affair with only a temporary quiet interlude later next week before we see another deep low to the NW swing towards us. I'll not be surprised to see GFS tomorrow back away from its high pressure scenario.

 

Longer term though the models do appear similar with the azores high set to nose itself across the country setting us up to a possible settled spell as we move into March proper.

 

In the meantime its a wintry outlook rather than spring outlook.

[IDO]

 

 

In the meantime its a wintry outlook rather than spring outlook.

 

 

As the London graph indicates, pretty average fare for the remaining days of Winter. A cool westerly flow after the warm front passes through in the next 18 hours, so for the east, south, NE and SE from Mon-Wed as the trough passes through, followed by a brief ridge under a cool upper flow we should get below average temps in a relatively cloudy setup with showers and sunny spells.

 

ECM repeats this pattern to D10. GEM continues with it's Siberian High disrupting the NW flow and the UK bound within the disrupting trough. The GFS continues to vary its HP scenario, though more a N/S split this morning:

 

  

 

After D10 the GEFS mean is now buying into the slow pressure build from the south:

 

D9 mean:  D16: 

 

That is a general consensus amongst the members for pressure to rise close to the UK more than to fall, a definite trend away from previous runs. Need to see that backed up with further runs though, and it is borderline on some of the runs, including the control, so just as easy could be a continuation of a quasi zonal flow. The op still does it FI blowing up of high pressure cells so I am ignoring these runs at the moment as clearly there is a ghost in the machine:

 

 

Today some snow on high ground Birmingham north from the hi-res model: 

[mushymanrob]

a suggestion that pressure might rise to our south as the azores high drifts closer?

 

yesterdays

 

todays

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS.

THE CURRENT GENERAL SITUATION A deep Low pressure area will move East to the NW of Scotland and send active fronts quickly East today and tonight followed by a very strong and cold showery Westerly flow tomorrow.

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

MODELS-2 WEEK HEADLINE Changeable and windy with rain at times and hill snow across the North at first. Milder generally later and maybe drier in the South.

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream Ensemble Forecast shows a strong West to East flow across the Atlantic through this week and down across the UK ahead of fronts and retreating back North in their wake. Longer term the flow appears to weaken and becomes more diffuse as multiple options are shown.

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

GFS OPERATIONAL The GFS operational today shows a very changeable week ahead with spell of wind and rain later today and again midweek book ended with cold and showery weather with gales in the North. The cold period late in the week will be much less pronounced over the South and replaced quite quickly everywhere with mild SW winds with occasional rain almost anywhere at times but chiefly towards the North and West. High pressure develops near the UK late in the run migrating NE and threatening the quiet weather with bright days and frosty night with a cold East wind over the South to end the period with the threat of wintry showers in the SE.

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

http://www.wetterzentrale.de/pics/Rtavn3841.gif
 
THE GFS CONTROL The GFS control run differs only in as much as it keeps the UK windier and more unsettled for longer into the second week as the strong Westerly flow persists. It's not until late in the run that High pressure becomes most influential just to the South with temperatures throughout the run gradually returning to average values after the variability of those in the first week.

THE GFS CLUSTERS The GFS Clusters support a 60/40 split in favour of Atlantic westerly winds driving the weather across the UK in two weeks time. The 60% show High pressure to the SW with Low pressure to the North driving rain bearing fronts east across the UK periodically. The 40% show a mix of high pressure just to the SE or North-West with fine weather for many with frosts by night.

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 looks distinctly changeable under Westerly or NW winds. There will be spells of rain alternating with showers all week with temperatures fluctuating between mild on Wednesday and Saturday and rather cold on Tuesday, Thursday and Friday.

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

THE FAX CHARTS The Fax Charts this morning support the operational well with an active Westerly flow across the Atlantic maintaining changeable conditions across the UK alternating between wet and windy weather and sunshine and showers, wintry on hills especially in the North all in association with active troughs crossing West to east across the UK all week.

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

GEM GEM this morning shows a very changeable pattern too with a lot of rather cold and showery weather between occasional bands of milder SW winds with rain. It's not until the last few frames of the run that High pressure noses more meaningfully towards the West of the UK in the wake of a cold Northerly.

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

NAVGEM NAVGEM also shows a breezy and changeable week with some sunshine but occasional rain at times in the form of showers in cold West or NW winds and a band of wet and windy weather midweek in a brief milder interlude. Then late in the week a milder SW flow takes hold more substantially with rain at times especially in the North and West.

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

ECM ECM this morning shows  a much more unsettled period throughout the duration of the run today with a strong west to east flow over the Atlantic maintained and delivering the UK spells of wet and windy weather in somewhat milder weather and colder more showery spells especially over the North where snow could fall at times particularly over the coming week. The run ends with a small but vigorous Low near to NW Ireland with rain and gales for all.

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

ECM 10 DAY MEAN The 10 Day Mean Chart shows a familiar pattern of High to the South and Low to the North in a broad Westerly flow. With less of a cyclonic NW direction to the flow and more of a SW to West then the incidence of tropical maritime air influences across the UK especially the South is likely to be greater than of late.

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

NOTABLE TREND CHANGES FROM PREVIOUS RUNS There are still mixed messages from the output today of how much and what impact High pressure has across the UK in Week 2 with a variety of options shown not all for fine weather.

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 97.5 pts followed by UKM at 97.1 pts and GFS at 96.3. At 5 days ECM just continues to lead the field at 90.0 pts over UKMO at 88.0 pts and GFS at 85.6. At 8 days ECM remains the leader with 62.7 pts over GFS's 60.2 pts. Then at Day 10 ECM retains superiority at 44.6 pts over GFS at 40.6.

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 Improvements in the current changeable, unsettled pattern of weather across the UK look quite slow again from this morning's output. Both UKMO and ECM continue to paint a very changeable pattern as we move into March but probably less of polar maritime rather cold weather than of late but still with wind and rain prominent at times. There are variations on a changeable theme from GEM longer term and NAVGEM looks broadly similar.. The main culprit of the slow build of pressure lies with a Jet flow which refuses to lie down and repeatedly flattens any ridging from the Azores High. As this High extends more influence towards Iberia and the Med later winds will back off somewhat towards the SW or West which should see temperatures recover somewhat across the UK with less influence of any cold pools behind cold fronts to the NW. Nevertheless if it's sustained fine and sunny Spring weather your looking for as we enter March you may have to wait a little longer yet. GFS is worth a mention as it shows a cold High to the North and NE and the threat of something cold from the East late in the operational's run but it is poorly supported and will likely be removed in the upcoming 6Z and 12z runs. So in Summary typical early March weather seems likely over the next few weeks with a Westerly flow most likely delivering some rain for all, especially across the North and West with some brighter and chillier phases when patchy frost is likely by night otherwise temperatures look broadly close to average for much of the time after this coming week.  

Issued at 08:30 Sunday February 22nd 2015

[bluearmy]

As I mused yesterday morning, the Azores ridge could finally make it across the uk and establish a broad block in tandem with the Russian ridge - the gfs op may be broadly in the right area though whether we advect cold air across from the east or southeast is questionable.

[Frosty.]

Ecm 00z ensemble mean continuing to look unsettled with polar maritime outbreaks out to T+240 and beyond.

[phil nw.]

The main theme of latest models seems a continuation of the rather cold and unsettled weather into March.

Certainly this coming week sees Winter proper out on this note.

A look at a couple of charts from the 06z GFS for mid-week are typical of what we can expect.

 

bands of wind and rain as frontal systems move through bringing alterate cold and milder days.Northern elevations should continue to see quite a few snowfalls through the period as freezing levels drop quickly behind the cold fronts.

 

At this time of year the Arctic is around it's coldest with the resident cold pool at it's furthest point south around the hemisphere so anywhere could see some flakes in the heaver showers.

 

Looking into week 2 some GFS op runs want to build a UK high but this seems unsupported by the ens. means 

Day 10 images

 

we can see the high still to the south with a weaker jet running across the Uk so still looking rather changeable.Still a hint that the south will see something drier as pressure tries to rise from the Azores later but no strong sign yet of anything more than that.

A quick look at the 2m temp graph for Warks.

 

temperatures still rather depressed with no sign yet of a real warm up so remaining rather chilly and unsettled seems to be the message as we go into the first week of Spring. 

[damianslaw]

A mixed bag best way to describe what the models are showing on offer today. No sign of a settling down in conditions anytime soon, nor any suggestion of anything particularly mild or cold for the time of year.

 

GFS keen on building heights over the country and towards scandi longer term ushering in a more settled but chilly continental feed. ECM showing continuation of current pattern with further frontal attacks from the west under alternating returning polar maritime and polar maritime air, but not quite as cold as the current situation.

 

Conflicting signals but I suspect the unsettled weather we stay through at least the first week of March with the azores high unable to ridge sufficiently northeastwards to kill off the atlantic, however, longer term we may see a more settled spell before middle of March, but not sure whether it will be courtesy of heights building over the country and towards the east, or courtesy of a mid atlantic high.

[Frosty.]

GEFS 06z mean is looking a lot more settled by 10th March across most of the UK, this ties in with the latest met office outlook for most of March. However, the next 10 days widely (longer further north) are still looking very unsettled with bouts of wet and windy weather and further outbreaks of polar maritime air with wintry showers and night frosts, tomorrow is looking cold, showery and windy with high wind chill factor making 5 or 6 Celsius feel like freezing point.