Model Output Discussion

[mcweather]

Excellent upgrade this morning from the ECM in two respects. Firstly a much more potent northerly with features coming south

and secondly the 216 and 240 charts want to send the scandi low down into central europe and with a much weaker northern jet arm , That suggestsI to me that Mr High from Siberia may want to head westwards. I think if the ECM went to 16 days it would be showing a screaming east or northeasterly. The Scandi low diving south is classic precursor to easterly outbreaks.

Lots to be upbeat about for cold and snow lovers this morning from this winters most reliable medium term model.

[Frosty.]

Very good Northerly on this mornings ECM. More potent and longer lasting than previous runs.

Indeed, the ECM 00z is a bitterly cold run once the Northerly kicks in, the initial southward plunge is too far east but we don't have to wait long for the main event and it shows a prolonged Arctic outbreak developing, the ukmo is also very promising @ T+144 with the N'ly on the way. The GFS keeps the atlantic high too close really and we just get a more modified NW'ly and another desperately poor FI from the gfs 00z with high pressure ridging north from france and the jet going further north, GEM 00z looks pretty wintry too with a 2-3 day N'ly toppler, hope the ecm is right this time.

[Ben_Cambs]

Excellent ECM run this morning, a Northerly followed by a Easterly in FI due to the postioning of the displaced PV

Edited January 23, 2010 by Snowman0697

[Duane S.]

Aha! The ECM Operational finally gives us a run that its ensembles have been hinting at for a while. I'm surprised there isn't more interest in it this morning.

The energy has moved out of Greenland allowing a pressure rise in the area vacated which in turn sets us up for a nice Northerly blast. There would then likely be an attempt at a potent Easterly as our pressure cell tries to link in with the Siberian one. As long as the Northern arm has reduced energy at this stage, it's quite plausable that that would occur on the ECM after +240

Edited January 23, 2010 by s4lancia

[cooling climate]

Excellent upgrade this morning from the ECM in two respects. Firstly a much more potent northerly with features coming south

and secondly the 216 and 240 charts want to send the scandi low down into central europe and with a much weaker northern jet arm , That suggestsI to me that Mr High from Siberia may want to head westwards. I think if the ECM went to 16 days it would be showing a screaming east or northeasterly. The Scandi low diving south is classic precursor to easterly outbreaks.

Lots to be upbeat about for cold and snow lovers this morning from this winters most reliable medium term model.

This time next week we may very well be entering into a very long, very cold and wintry spell of weather.

The signs to the north are certainly there and if as many of us have said this morning already that a

potent easterly does develop then it could be a very protracted and bitterly cold spell of weather to come.

1947 anyone,lol.

[Lewis]

Excellent ECM run this morning, a Northerly followed by a Easterly in FI due to the postioning of the displaced PV

That chart shows 31st of jan which is my birthday, i would love that on my birthday

lewis

[Nick B]

Aha! The ECM Operational finally gives us a run that its ensembles have been hinting at for a while. I'm surprised there isn't more interest in it this morning.

I am sure it will be a case of watching with interest but waiting for a few consecutive runs, support from other models and less scatter in the ensembles before anyone allows themselves to get too excited. The key will be whether the high that reaches up into S. Greenland will stay there and extend north if we want cold spell rather than cold snap. No doubt that were the 192-240 ECM synoptic to appear it would not just be cold and dry, but it's very FI at the moment and lack of postings apart from it still being early-ish weekend is due to caution, I would have thought.

[KTtom]

http://www.wetterzentrale.de/pics/Rtavn6617.png

A touch of frost comming up for eastern Europe

[bluearmy]

NAEFS upgrade to T180 with ecm looking more plausible than GFS ..............

we are slap bang in the middle of the dam spread at T180. still 50/50 then. (or maybe close enough to cold/less cold to get the most s__w)

beyond T180 the anomolies are quite weak but the the trend is for the ecm op run to be correct with the siberian high to ridge west again. strength in the northern arm at a similar timescale could mean another no mans land outcome for us. too far out for over analysis though

[billy]

I think this mornings ECM run ties in pretty well with yesterdays meto 6-15 day update. It will be interesting to see if todays update from the meto continues along the same lines . If it does and tonights 12z runs start to show a similar scenario to this mornings ECM then it could be game on for a very good cold spell.

[bluearmy]

a long cold spell may not be possible through teb - from todays NOAA discussion

THEREAFTER...THE MOVEMENT OF THE POLAR VORTEX BACK TO

THE NORTH POLE COULD LEAD TO AN ACCELERATION OF THE WESTERLIES IN

THE MID-LATITUDES WHICH WOULD FLATTEN THE AMPLIFIED FLOW PATTERN

AROUND GROUNDHOG DAY.

[damianslaw]

a long cold spell may not be possible through teb - from todays NOAA discussion

THEREAFTER...THE MOVEMENT OF THE POLAR VORTEX BACK TO

THE NORTH POLE COULD LEAD TO AN ACCELERATION OF THE WESTERLIES IN

THE MID-LATITUDES WHICH WOULD FLATTEN THE AMPLIFIED FLOW PATTERN

AROUND GROUNDHOG DAY.

This backs up what the GFS is showing, however, the ECM is showing the opposite happening and the UKMO is trending more to the ECM.

I am predicting the ECM has this one right with the PV maintaining its displacement out of Greenland, I don't foresee the atlantic firing into gear anytime soon, upstream signals do not support this with most of the energy of the jet being pumped into the southern arm.

Watch that low to the north of Scandanavia transfer south Europe - classic scandi trough territory, meaning once again as we head into Feb we will be looking east for our weather again, that cold high pressure cell over west Russia is not going anywhere and as is often the case during Feb such heights do have a tendency to advect west more so than in Dec and Jan.

Cold outlook becoming very cold.

Edited January 23, 2010 by damianslaw

[stewfox]

Aha! The ECM Operational finally gives us a run that its ensembles have been hinting at for a while. I'm surprised there isn't more interest in it this morning.

The energy has moved out of Greenland allowing a pressure rise in the area vacated which in turn sets us up for a nice Northerly blast. There would then likely be an attempt at a potent Easterly as our pressure cell tries to link in with the Siberian one. As long as the Northern arm has reduced energy at this stage, it's quite plausable that that would occur on the ECM after +240

Why ?

Last few days T72 and maybe T48 was FI, now charts at T168 and T240 are generating 'excitement' by a few because there showing what people want to see. If it was mild mush people would be saying ignore it and suggest T96+ is FI

Talk about what could occur on the ECM after T240 today is fine but Im not having a party yet. (Although its nice to see this morning an improving trend (if you like cold/snow etc)

Edited January 23, 2010 by stewfox

[snowspotter]

Well if the latter stages of the GFS verify then I think its normal service has resumed. PV to our northwest , flattened jet and no northern blocking. To be honest we had a great cold spell followed by a slowly declining high pressure to our east. In the overall scheme of things I suspect the cold start to January will be balenced out from now on.

A lot of straw clutching going on but sometimes I think you have to be realistic and accept we have had a good winter for cold but that its now likley to return to average. Maybe a few frosts though.

The overall trend is there to see in my opinion. No raging atlantic in FI but a pretty average looking set of charts ( if you like cold) .

My money is NOT on the ECM solution but I would love to be proved wrong, we need height rises over greenland to show again.

Also the high pressure to our east has been a bit irritating recently not moving anywhere and keeping us in no mans land

8 days and counting now without temp dipping below 0c. 15 consecutive nights prior to that below zero!

[Guest North Sea Snow Convection]

Lots of ramping this morning about the ECM in FI and a long historic cold spell etc, but first things first. A northerly does seem to have good agreement from the models for the end of next week, which is step no 1 first and foremost.

It should be noted that the northerly is arising through an amplified atlantic ridge moving north towards Greenland rather than any arctic ridge causing a true cold blocking high such as we saw Dec/early to mid Jan.

Often with these atlantic retrogressing highs and northerlies the models in FI will show a block developing to the north, but seldom is it the case that this actually happens and the truth is a much toned down outcome as time approaches. Therefore it is unlikely to be a sustained feature. However, should the trough move far enough south through Scandinavia into central europe/low countries then it is quite possible that a N'rly veering NE'erly is achievable for another day or so before the pattern flattens out.

Atm we have positive zonal winds, courtsey of the lagged cold stratosphere in the atmospheric system and therefore the chances of this leading so soon to northern blocking are not high and the most likely outcome is for the pattern to flatten out again at the start of Feb. Effects of the recent rise in stratosphere temps, if they are to come, will not be apparent till well into Feb and even March.

So I would treat the ECM FI with caution in terms of northerlies becoming freezing easterlies.

Edited January 23, 2010 by North Sea Snow Convection

[swilliam]

Aha! The ECM Operational finally gives us a run that its ensembles have been hinting at for a while. I'm surprised there isn't more interest in it this morning.

The energy has moved out of Greenland allowing a pressure rise in the area vacated which in turn sets us up for a nice Northerly blast. There would then likely be an attempt at a potent Easterly as our pressure cell tries to link in with the Siberian one. As long as the Northern arm has reduced energy at this stage, it's quite plausable that that would occur on the ECM after +240

15 day extended ensemble don't really support the easterly after the northerly - many more go for the NOAA idea of a flattened mild solution

[TEITS]

Splendid ECM this morning. However I still remain rather dubious of a prolonged cold spell via N,lys. At the moment I still think the favourite is a +48/+72 spell of N,lys before the block sinks and we see a spell of mild W,lys. The simple reason for my caution is the continuing signs of a positive AO.

Back to this weekend/early next week and im glad to see the BBC have backed down although I still cannot understand the reasons for their forecasts yesterday. At least this puts an end to the nonsense of the Met O having secret models that we don't see. Still the chance of a few wintry showers on Monday like I said last night but thats about it!

Just seen your post Tamara. A spot on assesment wrt to the N,ly.

Edited January 23, 2010 by THE EYE IN THE SKY

[Guest North Sea Snow Convection]

Splendid ECM this morning. However I still remain rather dubious of a prolonged cold spell via N,lys. At the moment I still think the favourite is a +48/+72 spell of N,lys before the block sinks and we see a spell of mild W,lys. The simple reason for my caution is the continuing signs of a positive AO.

Back to this weekend/early next week and im glad to see the BBC have backed down although I still cannot understand the reasons for their forecasts yesterday. At least this puts an end to the nonsense of the Met O having secret models that we don't see. Still the chance of a few wintry showers on Monday like I said last night but thats about it!

Just seen your post Tamara. A spot on assesment wrt to the N,ly.

Morning Dave - I can increasingly see a milder pattern beginning as we go into Feb as well. It could be that the northerly is a party piece to round off the main part of winter.

To me prospects for a continuing cold pattern through Feb don't look very high. That doesn't mean that we won't see anymore wintry weather before the days get too long for it, but as GP has signalled consistently for eg, the signals for Feb look rather different to the winter pattern we have seen so far.

However, we shall see!

Whatever happens, we can't complain, it has been a remarkable winter so far.

[PB22]

ECM 00Z London ensembles:

http://www.meteogroup.co.uk/uk/home/weather/services/ensemble_forecast.html

Looks like the northerly progged on this morning's run was one of the coldest runs on offer, so I really wouldn't get my hopes up too high. :unsure:

[huntso]

I can increasingly see a milder pattern beginning as we go into Feb as well. It could be that the northerly is a party piece to round off the main part of winter

having cast my less than expert eyes over the models reckon you could be spot on with that assessment

Like a good gig with a short but exciting encore before the lights go down on this winter

Couldn't grumble about that and then look forward to spring

[Snowly does it]

Conversely to the ECM ensembles, the GFS blowtorch is one of the mildest members on offer for that suite.

2+2 = uncetainty reigns supreme.

No clear signal.

[cooling climate]

The northerly at the end of next week all depends on the movement of the vortex over

the Arctic,the crucial time range looks to me to be t144 to t168.

The ECM breaks the vortex into segments allowing some ridging from the Arctic to support

the ridging high in the Atlantic where as the GFS keeps the eastern side of the vortex up over

northern Scandinavia together and then transfers this back over northern Greenland and the pole

again which has the knock on effect of lowering heights in this area.

If you look at the northern hemisphere charts for the ECM and the GFS in this time period it looks to

me anyway that the ECM model has the more believable solution I think, of course others may not

agree.

Edited January 23, 2010 by cooling climate

[john mac]

Conversely to the ECM ensembles, the GFS blowtorch is one of the mildest members on offer for that suite.

2+2 = uncetainty reigns supreme.

No clear signal.

Totally agree with you, nothing has changed with regards to the models. People need to stop overreacting on here,its getting a bit boring.

[cold snap]

Happy to see what ECM offers this morning the constant time delay in tapping in the pool to the east has chewed up some ten days.

There does seem something a little more trustworthy on the horizon via ECM.

But if another battle comes into play we may once again be stuck in between the two sets of airmass come Febuary.

Frustating if anything.But this winter wont got down as Mild one if this constant war keeps up.

Would love to Tap into to that cold ECM Pool.

[Strider]

The GFS 06Z op is a mild outlier from 1st Feb...