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

[Cloud 10]

Not much agreement between the ECM ensembles and NAEFS at day 10,with the ECM looking quite blocked compared to the more unsettled NAEFS.

 

ecm..  naefs..

 

 

A snippet from the NOAA forecast discussion.

 

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, REASONABLY
GOOD AGREEMENT AMONG THE TEMPERATURE/PRECIPITATION TOOLS, OFFSET BY THE
INCONSISTENT OF TEMPERATURES FORECAST BETWEEN THE NAEFS AND ECMWF ENSEMBLES

 

Full discussion here:

 

 http://www.cpc.ncep.noaa.gov/products/predictions/610day/fxus06.html

[johnholmes]

All these high pressure charts seem to be stuck out at 200 hours. We were supposed to be seeing high pressure for the start of March....this weekend....it's been postponed!. For days the GFS has been playing around with HLB at the end of the runs .....it's not moving forward in time!

 

If the pattern over the US doesn't shift, what's the betting that the weather will still be westerly and unsettled two weeks from now?

that is the form horse for sure

[knocker]

that is the form horse for sure

 

Maybe just a suspicion John? The ext eps is looking ar heights building to the NE as well as the SW.

Edited February 24, 2015 by knocker

[nick sussex]

In mid winter the ECM would be a lot more interesting as you'd have a better chance of developing a cold pool which is less likely now with the strengthening sun,  the issue for those hoping for a Spring taste of winter is how you'd get some deeper cold into the circulation, for an easterly to deliver in March you need some injection of Arctic air.

 

Looking at the extended ECM ensembles the wind directions do show a cluster ne to east but no real sign of any deeper cold:

 

http://www.weerplaza.nl/15daagseverwachting/?r=midden&type=eps_pluim

 

Theres still disagreement even to get to the ECM set up with the GFS less interested. Personally I'd be happy to see any high pressure set up as this zonal dross has outstayed its welcome!

[Frosty.]

Great to see winter cold and polar maritime flying the cold flag and I will join them. Tonight's Ecm 12z shows some very potent Pm outbreaks, especially early to mid next week. Looking further ahead, I've not given up hope on a very cold spell during march, looking through the GEFS 12z perturbations there is so much volatility in the further outlook that we can't rule out something more wintry further into march and I won't give up the chase, glad to see some others on here won't either.

[Nick F]

My latest Synoptic Analysis - which has a look at the last few days of February and the prospects of a stormy start to March:

 

http://www.netweather.tv/index.cgi?action=news;storyid=6476;sess=

 

Like the 12z, 18z GFS has the deep low too on Monday, though a little further north, but still with damaging wind gusts for Scotland, especially the north:

 

 

Looks like calming down towards the end of next week though ... as we see start to see troughing dig SE over the NW Atlantic - forcing ridging NE across the UK. This also marks a pattern change ( that's been showing for a while now upstream over N America) for early March, as we see the cold ease over eastern USA while the cold troughing begins to drop over the Rockies and the western ridge eases back west:

 

Edited February 24, 2015 by Nick F

[bluearmy]

i can understand the lack of trust in the predicted upper ridge with associated high slp as we head through the first half march but this time looks different re the predicted behaviour of the vortex. perhaps the location of the high is open to plenty of question but i do believe we will see a decent spell of blocking.

[knocker]

The 00z GFS has the usual mix up to T240 and thereafter HP to the end of the run.

[Ali1977]

Nice ECM from day 8, especially for the South . Cold enough for snow showers and northerly reload poss a day 10

[bluearmy]

Nice ECM from day 8, especially for the South . Cold enough for snow showers and northerly reload poss a day 10

Outrageously amplified by day 8, given the three months that preceded it. A toned down version more likely although as I already stated the vortex profile will allow a big nw Atlantic storm to drive some WAA more north than east. Also note the dig of split jet se into the mid Atlantic to support the pattern. perhaps progressive but perhaps along the right lines for a little later in march.

Edited February 25, 2015 by bluearmy

[IDO]

As I pondered yesterday "is ECM up to its old tricks?". The 0z from D8 -10:

 

 

 

These types of charts usually herald a change, just ECM tends to over do the signal when it spots a new pattern. The GEFS mean continues to support the change, a move away from the westerly zonal draff:

 

D10:   D16: 

 

GEM moving towards the GEFS mean: 

 

Looking at the spread at D10 I am not convinced the GFS has found a route for D8 plus and its a case of waiting till it finally has that Eureka moment:

 

 

No surprise that only 2 (maybe 3) of the members match the ECM D10 chart, and you could expect that amount of background noise.

 

Closer to home still some disagreement on the Sunday/Monday storm:

 

  

 

The GEFS are also just as spread. Temps for the next 8 days remaining run of the mill for the south:

 

[Severe Siberian icy blast]

Outrageously amplified by day 8, given the three months that preceded it. A toned down version more likely although as I already stated the vortex profile will allow a big nw Atlantic storm to drive some WAA more north than east. Also note the dig of split jet se into the mid Atlantic to support the pattern. perhaps progressive but perhaps along the right lines for a little later in march.

One would think with a pump of warm air into the pole the natural progression from that would be for rapid high pressure to build over northern regions ? Maybe Iceland over to Scandi a good bet ? Ironically it's about the only way to receive deep cold and snow in March ! If we could get some deep cold in place it would be fun and games not only with showers ,given the strength of the sun it would really help fuel some potent showers during daylight , but for significant snow we would like a good old southerly tracking low bumping into -10 850's !

Certainly not saying this will happen but there's certainly the opportunity for some type of Northern blocking as we head into March !

Edited February 25, 2015 by Severe Siberian icy blast

[Captain Shortwave]

The ECM this morning does seem to be out on it's own with respect to the other output which continues to support the Azores high building into southern England. I would also add that even if the ECM did come off, it might not necessarily be as snowy as some would think, dry and cloudy weather could easily occur under that set up as the 850s and 500mb heights combined cannot achieve the amount of convection required to develop showers and instead we end up with a sheet of low level stratus.

Following on a Scandi high would seem to be a reasonable solution, even if the models are giving it outside odds, given that the upstream pattern is likely to shift eastwards somewhat resulting in a moderation of the cold weather over the Eastern states and the resulting Atlantic troughing, this would offer the chance of a split jet occurring to the west of the UK, which would support some form of block over or just east/north east of the UK. It really depends on the strength of the jet to whether we get this or end up with high pressure further south and a milder solution, though a drying theme looks likely either way.

[Frosty.]

Ecm 00z shows plenty of Pm outbreaks and a dash extra next thursday, with an increasing risk of snow showers for the east / southeast as winds veer Northerly before pressure rises sharply at the end of the run when it becomes anticyclonic although perhaps some wintry showers clipping the SE. In the meantime, rain gradually spreading north and east today, a heavy band of rain sweeping south and east tomorrow morning followed by colder, brighter weather from the NW with blustery wintry showers piling into the northwest, wet and milder for a time during the weekend and then becoming progressively colder with frequent wintry showers from early next week with snow down to lower levels with night frosts and icy patches.

Edited February 25, 2015 by Frosty.

[Captain Shortwave]

ECM ens

 

GFS

 

GEM

 

The ECM looking by far the most keen to build heights further north across the UK and potentially into Scandinavia, the GEM and GFS wanting to hold the high further south with a generally westerly flow.

[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 mild SW flow will develop across the UK today followed by a cold front moving SE across all areas tonight and tomorrow

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

MODELS-2 WEEK HEADLINE Changeable and windy at first with rain at times and hill snow across the North. Becoming brighter and drier everywhere later.

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream Ensemble Forecast shows a strong West to East flow across the Atlantic through this week before it disrupts and splits over Europe with the main flow dragged South over Europe with a weaker northern arm across Scandinavia. Later the flow becomes more diffuse and weaker as High pressure develops close to the UK and remains over Europe.

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

GFS OPERATIONAL The GFS operational today shows a very changeable period under a broad Westerly flow between Low pressure crossing East to the North of the UK and High well to the South but edging North later. The result of this will be less potent polar maritime colder air interventions with milder SW winds at times as a result with rain most likely over the North and West. Then later still High pressure deveops across the UK with fine and settled weather for all with bright sunny spells by day but some night frosts and patchy fog.

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

http://www.wetterzentrale.de/pics/Rtavn3841.gif
 
THE GFS CONTROL The GFS control run is broadly singing from the same hymn sheet with strong Westerly and occasionally cold NW winds with rain and wintry showers steadily giving way later to anticyclonic conditions with fine and dry weather far more dominant for all areas of the UK late in the period

THE GFS CLUSTERS The GFS Clusters this morning are very determined to bring High pressure close to the South or over the UK in 14 days time with fine weather for many as a result but a SW flow over the North with a little rain too. A 15% cluster though show a Scandinavian High with a strong Southerly flow over 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 UKMO this morning still shows a strong and changeable spell this morning within it's time span of 6 days with spells of rain alternating with colder and brighter periods with showers, wintry in the North.

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

THE FAX CHARTS The Fax Charts this morning show a series of troughs crossing the UK over the next 48-96hrs. This turns the weather repeatedly milder then colder with some rain and showers at times for all right out to the start of next week.

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

GEM GEM this morning shows a spell of strong and for a time cold West to North-west winds and showers, wintry on hills following the alternating mild and chilly pattern of the rest of this week and the weekend. towards the end of the run it too shows milder air returning around High pressure having built close to the South by then.

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

NAVGEM NAVGEM maintains it's theme from yesterday showing a strong Westerly flow across the UK through the next week with some milder weather at times but with colder interludes too with rain then showers turning wintry over the hills of the North at times.

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

ECM ECM this morning shows the unsettled westerly period of weather coming to an end about a week from now as a large High pressure bases itself over the Uk towards the second half of next week with dry and fine weather developing for all with sunny days in average temperatures and frosty cold nights.

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

ECM 10 DAY MEAN The 10 Day Mean Chart shows High pressure well in control across the UK and western Europe at the 0 day mark with fine and dry weather for most in light winds and temperatures held to at least reasonable levels by day.

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

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend towards drier and more anticyclonic weather later in the period has increased to almost all output this morning from the 7-10 days range.

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 96.4. At 5 days ECM  continues to lead the field at 90.0 pts over UKMO at 88.3 pts and GFS at 86.4. At 8 days ECM remains the leader with 65.7 pts over GFS's 59.3 pts. Then at Day 10 ECM retains superiority at 46.4 pts over GFS at 42.5.

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 biggest thing of note from today's output is the increased momentum of securing High pressure developing or moving close to or over the UK in a week or so. Before we get there it looks like the same unsettled and windy weather that we have become accustomed to of late has a little while to run yet with rain and showers for all on occasions in fluctuating temperatures from day to day. It's then left to the strong and chilly West or NW flow of early next week to be the last in the series as pressure builds from the South and SW. There is still some uncertainty regarding the timing and extent of influence this takes over Northern Britain but Southern areas at least look like becoming dry and fine by soon after midweek and probably the North too soon after as High pressure looks like settling across the South or all of the UK. While day-times will be dry, bright and possibly sunny in light winds temperatures will probably be held to average levels in the strong march sunshine while the nights could be cold and frosty under clear skies. If of course the High ends up further South then northern areas could stay rather cloudy and mild in a SW Atlantic feed. There is still the hint of the UK High becoming part of the European version which will be present at the time too but the chances of anything of note on a cold Easterly feed across Southern Britain looks unlikely at this stage with any part of this being shunted down over the Southern European nations rather than the UK. So in Summary a change in the weather is on the way. After a further period of changeable weather over the next week it looks like dry and almost springlike weather may arrive later this week but although days will resemble Spring no record breaking high temperatures look likely and night's could still be jolly cold and frosty where skies stay clear.  

Issued at 09:00 Wednesday February 25th 2015

[mushymanrob]

interestingly, the noaa 8-14 day anomaly chart appears to be building high in more over us. all part of the sequence its been showing for several days now.

 

yesterday mornings ( i dont view in the evening)

 

 

this mornings

 

 

id have thought would support a synoptic chart something like this (ecm 00z t240)

 

 

so possibly the hint of high pressure more towards being sat over us then to our south?

but there are tangible signes that high pressure will become more dominant towards mid march (if not slightly sooner) as both the gfs (00z) and ecm suggest this....only the timings amiss.

 

 

 

[Summer Sun]

The ECM ens is certainly becoming consistent with a pressure rise later next week, incidentally the beeb last night were talking about the chance of a  taste of spring for the south later next week but more unsettled for the north so its a case of wait and see what happens it could be that the 10 day ENS from GFS is closer with low pressure to the north and the high keeping the south driest and brightest

 

 

GFS ens at d10

 

Edited February 25, 2015 by Summer Sun

[Harsh Climate]

Where did this come from lol

 

 

Bet my bottom dollar that it's a huge outliar though, as currently has no support what so ever...

Edited February 25, 2015 by Harsh Climate

[Daniel*]

Where did this come from lol

Bet my bottom dollar that it's a huge outliar though, as currently has no support what so ever...

To be fair these colder synoptics have been showing since the past week, with increasing support.

Just variance in how the cold arrives, I say the likelihood of a colder start to March is much greater than a milder start. Looking at the ECM it seems essentially rather dry, more so the further north you are.

But very cold. +240 has -8C 850s tucking in the far SE. I'd expect the forum to be more busy...

Also March sun can start triggering off convection I do think March is not a closed doors month.

Not great model output if you are mildie! Something is definitely bubbling and frothing.

Edited February 25, 2015 by Daniel*

[STORMWATER]

To be fair these colder synoptics have been showing since the past week, with increasing support.

Just variance in how the cold arrives, I say the likelihood of a colder start to March is much greater than a milder start. Looking at the ECM it seems essentially rather dry, more so the further north you are.

But very cold. +240 has -8C 850s tucking in the far SE. I'd expect the forum to be more busy...

Also March sun can start triggering off convection I do think March is not a closed doors month.

Not great model output if you are mildie! Something is definitely bubbling and frothing.

image.jpgimage.jpg

I have to agree, it will be interesting to see if this trend continues and if it does it could get stronger and we could end up with a very cold start to spring.

[nick sussex]

Both the GFS and ECM today deliver drinks at the Last Chance Saloon! Frustrating for coldies as the set ups would lead to a forum meltdown earlier in the year but into March you do need 5 star synoptics to deliver.

 

The ECM given its track record over the winter is hardly one to trust post T168hhrs. Interestingly however the GFS does dig that upstream troughing further south with more amplitude so in effect the GFS has jumped on board but whether the ship capsizes this evening is another question!

 

The issue for the UK in these set ups is getting the high sufficiently north and orientated in a manner to advect any cold further west.

 

I think its best to reserve judgement and any possible excitement to this evening as the ECM and GFS have picked up on a quicker signal re any blocking and we'll have to see whether they've overreacted or are actually going to deliver this time.

[Daniel*]

I have to agree, it will be interesting to see if this trend continues and if it does it could get stronger and we could end up with a very cold start to spring.

Further to the point: “@bbcweather: Some computer models suggest very wintry weather later next wk. Low risk at present. We're keeping an eye on it. Johttp://twitter.com/bbcweather/status/570539746373595136/photo/1†1hr ago.

[knocker]

Despite the morning convolutions the GFS mean anomaly is painting a similar picture as before with ridging over the UK or just to the SE. Surface wise HP just to the SE. This slack area of HP persists into the ext period. Not that I'm taking one run as gospel but it does follow on from last nights anomalies.

Chart courtesy weatherbell

 

[Frosty.]

GEFS 06z mean shows high pressure gradually taking control from around the middle of next week onwards, the pressure pattern becomes very slack / flabby with generally high pressure lasting well beyond mid month. Even though I love wintry weather, to have a spell of benign and hopefully sunny weather for a few weeks would be nice for early spring.