Model Output Discussion 13/11/13 >

[Ian Brown]

GFS and UKMO are quite similar at T144 with placement of the High not as far as NW as on some of last nights output, hence any easterly is more short lived. ECM is very messy, looking like it is going to go one way then pulling something out of the fire later on. As they say, more runs needed.

[radiohead]

Some stunning charts in the GFS ensembles. Some nice eye candy to lift spirits?

 

[That ECM]

The detail is really not important yet. All three give a variation on a cold theme. What has to be the most pleasing output has to be the UKMO by virtue of the fact it sends the energy coming out of the nw south east and not e/ne as it did last night. To be honest I was expecting to see this again from UKMO this morning and other output following. Very pleased to say that it is not the case. Let's hope it now firms up on this idea and doesn't flip back in future runs.

Until we are sure that this is going to happen the rest of any run is really just for fun.

[Captain Shortwave]

Oh boy as I said yesterday that low is going to be a right pain as the models are notoriously bad at resolving these. Some models take it south east, some over the top and some make it do the Irish jig and fart on my cornflakes 

Buckle up, it's going to be a bumpy ride. UKMO is better than it's previous outputs this morning.

If only the NAVGEM was a good model......

Edited November 15, 2013 by Captain shortwave

[bluearmy]

ECM could be 'overdoing' it with that w Atlantic depression. On the other hand.............

This lack of ECM op consistency should tell us everything about the current situation post the initial plunge of colder air.

staying cold but how cold ????

[Paul]

Reposting this as we've had one or two problems this morning that have resulted in at least one member falling foul of the zero tolerance policy, which is a shame..

 

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Thanks

 

Paul

[Man With Beard]

Seems to be a difference between ECM 12Zs and 00Zs at the moment, the former with much stronger pressure builds to the north ... even so, the latest ECM is actually the coldest yet

[SMU]

Morning All-

Not a huge amount to add to the discussion

Minimal model continuity this morning-

The only green light is they are all cold-

S

[Frosty.]

Here are a few snapshots of the GEFS 00z mean, the overall synoptical set up is very impressive from a cold perspective, there is scope for reloads from the northeast which is hinted at later in the output. The T+144 is particularly impressive and remember that the mean output just provides the broad brush strokes, within the 00z perturbations there are much more severe outcomes so we have a very cold shot next week with ice, frost and snow dominating the forecasts from day to day next week and the potential for a prolonged cold spell is there, or at the very least, reloads of wintry weather in the weeks ahead. 

[BLAST FROM THE PAST]

Morning All-Not a huge amount to add to the discussionMinimal model continuity this morning-The only green light is they are all cold-S

 

It seems a quite unusual period ahead Steve and model variability is probably a plus rather than minus.  There is no apparent supportive 'connect' for this development and thus it seems difficult for models to get full handle on it. 

Like you say cold is the theme, and thinking of last year for me getting the UKMO model on board is one I look for...and it looks the best this morning.

What does seem to be clearing is that the cold is more likely to be prolonged for the south as the HP doesn't look like ridging as far north into the arctic as many would want.  That to me is the stumbling block.

 

BFTP

 

 

BFTP

[swfc]

Seems a more realistic set of runs so far after last nights drama ete be it great to look at.

 

.As a poster already said ecm seems a lttle confused to where it takes the small low hence the ridging is flattened before reloading.The latest outlook for next week"tv ete"is trending colder but mainly dry which may indicate pressure slightly further south"in metos thinking"via a mlb.Still looking interesting tho and many a twist to come as fi seems to be around the 162 hr mark imo.

Edited November 15, 2013 by swfc

[Average Joe]

Morning All-Not a huge amount to add to the discussionMinimal model continuity this morning-The only green light is they are all cold-S

Surely for the time of year that's not a bad thing.

 

Positives from negatives, glasses half full, patience being a virtue etc etc.... 

[nick sussex]

Jeez what happened to the ECM? no cut off high, then a complicated series of outcomes, even though it develops some interest after the initial climbdown it looks all too fanciful and manages to get to some decent looking charts but the route there rings my emergency likely to go wrong red warning!

The UKMO now looks the best of the big 3 after being a bit lukewarm, the GFS is a bit underwhelming this morning as we see the high not as far enough north.

I think its crucial we at least see the cut off high near Iceland otherwise the ECM trend looks to end in tears, sadly it gets filed in my SSO Suspicious Synoptic Outcome category and hence IMO any cold it shows at 192hrs onwards is unlikely to verify.

Edited November 15, 2013 by nick sussex

[Frosty.]

These are nice charts for late autumn 

[swfc]

These are nice charts for late autumn 

Indeed frosty and ten days ago you would have snatched someones hand off for that.It does seem after last nights dramatic session that things are trending drier tho than were shown but still cant complain.The pv via the nh profile does look just to strong to allow a real push north imo but things are very fluid in the mo atm so who knows!!!

[SomeLikeItHot]

The ECM ensemble mean at 240 hours looks pretty good for ongoing cold.

 

[Frosty.]

Nice upgrade from the ukmo 00z with a cold flow locking in next week with widespread sharp frosts and snow showers, especially around the coasts and far north but could be troughs swinging south in the arctic flow with bands of snow showers, bottom line is, it will feel like winter has come early this year.

[Summer Sun]

Latest from Gibby

 

All models to continue to agree on the course of events of the next 5 days with a spell of quiet and benign weather today, tomorrow and much of Saturday too in the South as pressure is very high to the SW. There will be some chilly and frosty conditions overnight across England and Wales while skies stay cloudier in the far West and North. Later tomorrow a band of rain on a front moves South through Scotland and on South to England through Sunday. Following behind is a more active front on Monday which heralds the arrival of a cold NW flow with showers turning wintry across Northern and Western areas in particular during Tuesday while many Eastern and SE areas become largely dry, bright, breezy and cold.

 

GFS then shows low pressure developing over the North of the UK which sinks South through Southern England and away further South by the end of the week. A spell of cold rain will slide South over Southern britain with some wintriness over the hills. The north will brighten following sleet and wet snow with sunshine and wintry showers in a keen and strong East flow for a time. By next weekend High pressure has developed South over Scotland with clear, cold and very frosty weather here while the South stays cold, cloudy and windy with occasional light rain. Through the latter stages of the run this morning the fine and cold weather over the North extends to all areas with fog developing too, dense and freezing in places. Temperatures by day begin to rise and later milder air reaches the North with cloudier skies but mostly dry weather while the South clings on to quiet and settled weather with night frost and fog.

 

UKMO this morning shows very cold weather through the middle of next week with a Northerly flow having swung NE midweek with wintry showers giving way to the threat of more prolonged rain, sleet or wet snow for a time across the South while the NW become drier, cold and more settled with time.

 

GEM this morning is less interested in a Northerly as such as it brings an innitial push of cold air South prior to midweek with wintry showers in the North and West Tuesday with drier weather for all for a time midweek. Late in the week more deeply unsettled conditions turn up from the North and with chilly air around widespread rain and strong winds will fall as sleet or snow at times, especially on northern hills. The depression responsible ambles around over Southern Britain while filling slowly before a new Low approaches from the SW by the end of the run with wet and windy weather spreading NE with sleet and wet snow possible over hills on its leading edge.

 

NAVGEM today shows probably the best synoptics long term if it's sustained cold weather your after with Low pressure sinking South across England later next week and away to the South by the weekend when a strong Easterly flow brings raw cold and windy weather with rain, sleet or snow in places, especially over the hills. The North would slowly be turning drier by next weekend but still cold as a High pressure belt lies to the North.

 

ECM today has broke away from the pack with the innitial cold surge dissolving away to just a day or two of wintry showers, chiefly over the North and West before a ridge dries things out with a frosty interlude midweek. After a brief lull though cold weather does re-intensify later in the week as High pressure is finally allowed to build to the NW with a deep Low close to SE Britain brnging rain, sleet or snow at times across the UK late next week and the weekend with the NW likely to stay the driest then with overnight frosts.

 

The GFS Ensembles show a marked lowering of uppers for a time next week before the coldness dissolves to levels closer to average later in the run. Rainfall is commonplace throughout the period once the cold weather arrives indicating the close proximity of Low pressure. Some of the precipitation could fall as snow on the hills at times lessening in it's extent with time.

 

The Jet Stream shows the flow way North of the UK currently turning South over the UK to set up a new arm across Southern Europe next week while the Northern arm detaches and weakens. The Southern arm then becomes the dominant Jet flow remaining South of the UK later in the run.

 

In Summary there are a few wobbles in the output this morning especially from ECM which just highlights the fragility of the setup needed to bring guaranteed cold to the UK. The main problem is the models failure currently to handle energy moving out of canada preventing an otherwise straightforward passage Northward to the Atlantic High. This morning it is not until that Low has passed that finally ECM plays catch up with the remainder of the output. Nevertheless, despite this the emphasis on this morning's output is a cold one and there is a fairly good chance that some areas will see some snow next week.

 

The extent of such as always is open for controversial debate but I would urge caution for those looking for a white wonderland next week there seems little evidence to excite me that anywhere other than the highest moors of the South will see much with lower ground in the North too just seeing transient temporary slushy falls. However, we are only in mid to late November and such conditions are relatively marked for this time of the season so a surprise or two could be in store for some folk almost anywhere if some of this mornings more extreme charts verify.

 

http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm

[Purga]

 

So looking like a cool / cold snap this morning with GFS wanting to turn on the zonal train in FI again.

 

 

 

Ending up with pressure rising over Europe

 

Let's hope ECM is closer to the mark

 

 

Although it looks cold and dank rather than cold and crisp

So no 2010 at the moment but at least it won't be too mild.

[radiohead]

06Z GFS is rolling. Let's see what happens this time...

[Summer Sun]

Latest 8 day temperature outlook shows little change all of the UK below normal some parts of the UK are well below normal others are slightly below normal, also unchanged is eastern Europe where they remain 2 to 4c above normal

 

[Cecil Hogmanay Melchett]

Latest 8 day temperature outlook shows little change all of the UK below normal some parts of the UK are well below normal others are slightly below normal, also unchanged is eastern Europe where they remain 2 to 4c above normal

 

Central Europe had an incredibley mild Autumn thus far.Certainly the result of a vast Euro high.

Models today look nice and seasonal,i would imagine this thread in tandem with the strat thread will be interesting.

[mountain shadow]

Summer Sun.

When you show them charts, can you also the predicted temp chart as showing the temp difference from normal does not show the full picture.

For example, two degrees above normal in Northern Russia at this time of year would still be below freezing.

Thanks.

[Summer Sun]

Summer Sun.

When you show them charts, can you also the predicted temp chart as showing the temp difference from normal does not show the full picture.

For example, two degrees above normal in Northern Russia at this time of year would still be below freezing.

Thanks.

 

Hi here are the other 2 temperature charts

 

[Captain Shortwave]

Well the GFS still has the low cutting through the ridge instead of going over the top

This set up upstream looks very very complicated though

Edited November 15, 2013 by Captain shortwave