Model Output Discussion 19th January 2014-18z onwards.

[chris55]

Ukmo certainly hits the sweet spot this morning!!! Some proper cold uppers in the mix. Good consistency from this model, but overall an uncertain outlook. Often the way when a block to the east is being modelled.

[IDO]

Long way out and a bit IMBY but the GFS op not good for snow on the two potential days, late Thursday and Saturday next week. On the latter occasion the dewpoint only goes negative pre the front, when we are in a short wave ridge. eg Saturday:

 

 

 

The subsequent warm front clears the low DPs and though there could be some snow to rain on the leading edge on higher ground in the south it looks very transitory.

 

A better chance on the Thursday/Friday cold front from the NW for the south, though the track of the N Sea low currently suggests the south are borderline with regard to a warm sector:

 

 

 

So again higher ground for the south based on these very early charts.

 

 

[Liam J]

JMA not looking too shabby this morning either, shame it only goes out to T84 on the 00z run. It would certainly feel like winter under this...

 

 

 

 

[Cecil Hogmanay Melchett]

GEM is sublime this morning

UKMO is very very nice.

ecm/gfs not so nice.

The models are clueless-so am i...

[Mucka]

Broadly they do seem fairly consistent - except for the area over the UK.

 

They can only be so different just 8 days out.

UK) Yesterdays deep trough from UK right down to Souther Europe, today low pressure NE of Scotland.

Atlantic) Yesterdays LP running NW/SE down displaced Azores high, today LP running W/NW over Atlantic ridge.

 

I honestly wouldn't call the ECM output consistent but it's all academic and just opinion, no right or wrong. 

[Frosty.]

It's always been about the track of sunday's stormy low and how it engages with that lovely huge cold block to the ne,, sunday looks severe, I said that low is a game changer in terms of breaking the shackles on the persistent mildish and stormy autumnal pattern of the last few months. I firmly believe we are on the cusp of a proper wintry spell.

[Long haul to mild]

Every morning I get up,look at the models thinking "this will be sorted out by now" and it still isn't!

 

The UKMO is incredibly consistent though, and it's evolution simply cannot be ignored or dismissed.

 

GFS tends to thrash about like a fish on dry land in these setups, and I don't buy into a return to milder Atlantic driven weather any time soon. During our cold spell last year, it keep trying to bring back the Atlantic far too soon, it was wrong on so many occasions. Therefore I don't trust it's output, even more so its comedic precipitation charts which I mistakenly took far too seriously during the summer. They're awful at anything beyond about 48 hours, don't go there folks!

 

ECM however seems to be joining the GFS in not really knowing what to do with the current setup, which is unusual, because it usually copes with blocks better.

 

So I'm sticking with the UKMO for now as if it's the short term that dictates the longer pattern, then its consistency has to be taken seriously.

 

I hope people don't hang too much on the 06z GFS today either; it is not reliable and we should wait for the 12z suite today to find out any real developments.

[TEITS]

Damn just deleted my post by accident and cannot be bothered to type it again.

 

Gist of what I was saying is in my opinion we shall see a blend of the current output being correct. What I mean by this is the ECM/GFS moving the block further W but just maybe the UKMO has it too far W.

 

Not convinced we shall see the type of E,ly the UKMO is projecting i.e classic snow shower due to very cold uppers. I believe a cold outlook with snowfall is possible but this is due to slider LPs rather than convective snowfall like the UKMO is suggesting.

 

The latest +72 fax chart is an exact copy of the UKMO model but then again they always are 99.9% of the time.

[Snowman.]

Remember back to last winter folks, UKMO took both the GFS/ECM and won.

 

This morning has been better slight shifts towards a dryer cold pattern as the NAGEM has joined forces with UKMO, JMA and GEM.

Edited January 25, 2014 by SN0WM4N

[Weather-history]

Interestingly Blue Tits have started checking out the nest boxes in my garden. I ponder which models they follow.

They don't, nature is reactive not presumptive. If nature were presumptive then we would never have spring frost damage because nature would have anticipated it.

[weather eater]

As others have said a mixed bag this morning, never mind dear old Shannon Entropy it looks more of a case of the Clint Eastwood’s this morning, The Good, The Bad and The Ugly, The UKMO keeps its theme and its consistency with a much more robust easterly. The GFS in many ways also consistent, just a different theme, a brief easterly before the return of the Atlantic in the form of some very cold PM air. Then there’s the ECM, a dog’s breakfast of a run, a brief easterly before becoming a right Jackson Pollock, more ammunition that maybe the ECM’s reputation for modelling blocking on our side of the pond is not that great.

Edited January 25, 2014 by weather eater

[Gibby]

Good morning everyone. Here is the report of the midnight outputs of the NWP for this morning Saturday January 25th 2014 and updated and raised twice daily from my website at http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm 

 

All models show Low pressure moving across the Atlantic towards NW Beitain later today with attendant fronts crossing the Atlantic too and approaching Western Britain by midnight tonight. This follows a brief ridge of High pressure which keeps many Southern areas dry today with some showers in the North, heavy and wintry for a time. Tomorrow sees the fronts cross East over all areas with a spell of heavy rain then showers sweeping East with further flooding issues in places. Through Sunday night and Monday the weather will be very windy and showery as well as become colder with wintry showers over hills, even in the South with hail and thunder too in places. Through this time Low pressure will be slipping South over the UK to be across Southern Britain on Tuesday with rain and showers continuing with sleet or snow over the hills, chiefly in the North. Then by midweek the Low exits the South with a period of cold Easterly winds carrying wintry showers West over the UK with snow most likely over the hills and in the East.

 

GFS then has the second half of the week with the cold East flow dissolving away with Atlantic low pressure areas returning rather cold and changeable weather from the NW with further rain at times expected with snow over Northern hills. Later in the run Low pressure becomes even more pronounced up to the NW with bands of rain then showers sweeping East over the UK with strong winds too in places with temperatures returning to average values.

 

The GFS Ensembles show a spell of colder weather this week as winds swing to a NE or East quadrant briefly. This isn't shown to last long though as milder Atlantic air returns across all areas with rain and wind at times and temperatures returning to average.

 

UKMO today closes it's morning output with next Friday being very cold and breezy with Easterly winds carrying some wintry showers of sleet and snow across Eastern and Southern areas while Northern areas become dry and chilly with frosty nights but sunshine by day.

 

GEM today shows a cold and unsettled spell developing next week as Low pressure takes a much more Southerly aspect with Easterly winds the trend over the UK with rain, sleet and snow at times with some substantial falls possible in places almost anywhere but chiefly over the hills.

 

NAVGEM this morning also shows cold Easterly winds holding their own this morning for later this coming week with some snow and sleet showers or even longer spells of precipitation likely in the West and South at times towards next weekend.

 

ECM today is disappointing for those looking for cold and snowy weather as it quickly removes the Easterly feed soon after midweek in the place of a depression moving ESE into the North Sea with more rain followed by chilly and showery weather feeding down from the NW by next weekend. However, it does somewhat redress the cold balance later by suggesting cold and unstable air developing over the UK late in the run with the chance of rain, sleet and snow in the West as a front bumps up against the cold block still just about holding on to the East.

 

The ECM 9 and 10 Day Mean Charts shows a trend towards a UK rough the most likely in 9 and 10 days time on an axis which runs off Southern Greenland the UK to Italy. Whilst this trend is not bad for incursions from the cold continental air the pattern could do to be further west still to enable us to stand a better chance of tapping into something more meaningful.

 

http://www.wetterzentrale.de/pics/Reem2161.gif

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

 

The Jet Stream Forecast sees the strong flow crossing the Atlantic continuing to be diverted South across or to the West of Britain before turning East over southern Europe. This trend remains for a time with even the flow eventually taking a more direct route East to the South of the UK in the second half of the run.

 

In Summary today the weather remains very unstable and often wet as Low pressure continues to dominate proceedings over the next 4-6 days at least. Through this period it's position will change as it migrates South of the UK to bring a spell of cold East winds and possible snow in places later this week. How long will it last is hard to determine from today's output with the ECM and GFS throwing a spanner in the works as both shows progressive conditions late next week which cut off any Continental influence for a time as new Low pressure slips into the North Sea with NW winds carrying rain then wintry showers across the UK later. This pattern is also backed up quite strongly by the GFS Ensembles. However, other output is rather more compelling with UKMO, GEM and NAVGEM all looking much more sustained with regard to longevity in it's cold output. So we have a stand off between these giants of the model field and which one is right? I'm afraid more runs are needed before this one becomes any clearer so we must expect more changes good and bad in the operational outputs of all models over the coming days. My best advice will be to watch the ensembles as they may give a better idea of where we are going than any individual operational run from any model alone.

[IDO]

Looks like another ECM op over amplification of the Atlantic Ridge if the T192 mean says anything:

 

OP:   MEAN: 

 

MEAN T216:   T240: 

 

Mixed signal from the D10 mean suggesting SE diving lows not the clear majority cluster and a more westerly regime also showing in the ens.

Edited January 25, 2014 by i'm dreaming of...

[karlos1983]

Any thoughts on the ECM ENS? Looks like it supports the op to me?

[bluearmy]

the ens are not supportive of the op.

 

they are a watered down version of the last few runs wrt the troughing backing sw. the mean has settled very close to the gefs post T144, though more bullish re the trough extending se into europe. this keeps us in the battleground but whereas the last three runs have indicated a strong likelihood of snowfall over much of the uk, this says much more 50/50 and likely incursions of less cold uppers from the sw at times. becomes more n/s as opposed to sw/ne if you get my drift.

 

the ens always seem to be skewed somewhat towards the op so i guess it means we have to see the trend on the 12z's. certainly a case of the vortex and azores ridge fighting back somewhat.

[jvenge]

Hum. I wonder how the MetO see it. Yesterday they didnt back their own model 100%, but did give a large nod to the change. Cautious and considering how far out, rightly so.

I'm surprised to see the MetO and ECM so far away from each other. Saying that, the ECM isn't mild either. People seem hung up on the westerly and zonal, but it still looks to be below average temperature wise.

[ZONE 51]

It's always been about the track of sunday's stormy low and how it engages with that lovely huge cold block to the ne,, sunday looks severe, I said that low is a game changer in terms of breaking the shackles on the persistent mildish and stormy autumnal pattern of the last few months. I firmly believe we are on the cusp of a proper wintry spell.

Yes we need to arrive at Sunday night first, then the models/data would likely have a better idea of next week. My personal view point on this is only mild flirts, I cannot imagine the Scandi high losing grip not the characteristic of such a situation that we have now. From experience with set ups unfolding like the oncoming there is great uncertainty, therefore no one I expect can say for certain what the late next week would bring...

Edited January 25, 2014 by ElectricSnowStorm

[ZONE 51]

Cool, is that a new info bar above my post!??

[Purga]

Good output this morning from UKMO in particular and so - so, from the others.

 

 

 

The ECM ENS for Reading still show a cold trend

The Op on the mild side of the suite and considerable spread after day 6 so confirming the uncertainty.

 

On the UKMO it's nice to see METO for the first time suggesting some wintry showers for the SE

 

Outlook for Monday to Wednesday:

Strong winds and blustery heavy showers on Monday, these perhaps wintry. Further showers on Tuesday, sometimes heavy, with strong winds. Colder later on Wednesday with wintry showers.

Updated: 0518 on Sat 25 Jan 2014

 

 

Suggesting they are going with their GM model.

Edited January 25, 2014 by Purga

[Polar Maritime]

Hum. I wonder how the MetO see it. Yesterday they didnt back their own model 100%, but did give a large nod to the change. Cautious and considering how far out, rightly so.I'm surprised to see the MetO and ECM so far away from each other. Saying that, the ECM isn't mild either. People seem hung up on the westerly and zonal, but it still looks to be below average temperature wise.

 

Yes agree, As Fergie said yesterday regarding back to Westerly/Zonal, it's not going to be back to mild Westerly in fact far from it. A N/W flow in Jan/Feb is not mild by any means. Ice/snow/bitter winds i would expect.

Edited January 25, 2014 by Polar Maritime

[Jason M]

I'm sure I've read somewhere that the METO has the highest resolution upto 72 hours. Given that the divergence is before this timeframe that might be important on this occasion.

[Jason H]

I'm pretty sure it's going to be cold in 5-6 days time, but is it from the East or the North West? Tough one. I know which outcome I'd be rooting for

[bluearmy]

I'm sure I've read somewhere that the METO has the highest resolution upto 72 hours. Given that the divergence is before this timeframe that might be important on this occasion.

ECM op is a higher resolution throughout, inc the first 72 hours where ukmo is indeed running at a higher res than thereafter.

[Summer Sun]

Big differences between ECM, GFS and UKMO at t144 again this morning, its UKMO v GFS and ECM

 

ECM shows the cold air out east but never makes it here

 

 

UKMO on the other hand brings in the cold air big style

 

 

GFS not massively cold either like ECM

 

 

Away from the big 3 GEM is the closest to UKMO

 

 

NAVGEM is chilly in the north but no where near as cold as what UKMO would be

 

Edited January 25, 2014 by Summer Sun

[TSNWK]

ECM op is a higher resolution throughout, inc the first 72 hours where ukmo is indeed running at a higher res than thereafter.

But is it possible to tell of the 2 which runs at the higher res for the 1st 72 hours. Edited January 25, 2014 by TSNWK