Model Output Discussion - 30th November onwards

[Severe Siberian icy blast]

I think rather than getting too caught up with one set of runs we need to chill a bit. First off the scandi high is progged for about 15 days time or so. The ecm 240 chart means nothing because its very fickle like any fi charts and very rarely verifies. Yes we can look for building blocks and they have all been there. We will not be seeing cold uppers in our shores for while yet. By the weekend I think we have some eye candi fi charts . But not yet.

[Mucka]

Perhaps the best way to judge the horrors of the ECM operational run is to compare it with

its own ensemble mean,which more than likely will give better guidance and thankfully

tonights 12z is a poor match for the ENS 00z mean at day 10.

 

12z op.run..ECH101-240.gif  00z ens..EDH101-240.gif

 

Great post, that puts things into perspective, especially when you consider the NE blocking shown is only a mean.

The London ensemble graphs should confirm the Op as very much out on the mild side if not pretty much an outlier by day 10

 

Edit

 

Unless they have flipped. 

Edited December 3, 2013 by Mucka

[Ian Brown]

Yes indeed. QBO was different and we dont have strat charts for 1962, but I wonder if those who woke up on 8th December 1962 knew what was on the horizon. This must have been a rather pleasant and mild day back then as heights tried to build towards Scandy. 

 

 

What ended up happening, over 2 weeks later was estimated to be a 1 in 250 year event. I could show similar charts from the last 26 years, and well, what followed became a nearly every year event for 22 years.

[Skyraker]

Ensemble watch.

 

[Methuselah]

What ended up happening, over 2 weeks later was estimated to be a 1 in 250 year event. I could show similar charts from the last 26 years, and well, what followed became a nearly every year event for 22 years.

Of course you can, Ian - which was my point: the weather can, and does, do the unexpected?

[cooling climate]

I think it would be a first to see such ensemble support at t240-384 that is why I am less than convinced by what they are showing.

[Severe Siberian icy blast]

As I've said in a thread somewhere yesterday Roger - I'm fascinated to see how your December forecast fronts up against reality. There is a fair amount of data mid month pointing to height rises too far north to suggest mild to very mild - but if your methodology should trump all the models then hats off to you once again. What looks very likely is that after a dull week this week we finish with a short sharp blast of cold before tapping into a much milder feed for at least 72 hours. Beyond that we will have to see whether pressure builds north or sinks south ala ECM 12z. Personally I cannot believe that the strat charts screaming height rises to our north and east can be completely wrong. Trop models often misfire, but the strat predictions tend to be less variable, If we get heights as far south as the ECM has it this afternoon then we truly will have a bit of a "disconnect" between the two. Either that or the strat models are going to look very different in the morning!

absolutely top post. I dont need to say anything more to this excellent post. Apart from remember this northerly was looking very potent 3 days ago. Only now does things look different. I dont think for one minute we will see unusually mild air next week. Maybe 2 days or 3 max before cooler air comes back. Models change very very quickly and why ones post with confidence anything past t120 at the very most is beyond me especially after the last 3 days of model watching . We have gone from a 4 day severe cold spell to a 24hr event. The strat simply didnt fit the profile it was suggesting with regards high lat blocking and low an behold we have witnessed the models coming to terms with this as come closer. And now we are left with the strat pointing to a more favourable position with the vortex moving away from siberia ,im sure as they get to grips with the changes aloft then we will see this reflected in the output.

[Frosty.]

A trip back in time to Dec 3rd 1986.......what a horrible pattern...........run it forward to mid January 1987...dream charts, even from a yuck set up things change when you least expect it.

want to see how a pattern can change, look no further

 

The EC32 signal, mentioned earlier, has high pressure favoured to become established to the north/ne of the uk...well, Jan 1987 did the same thing. From mild mush to icy, snowy bliss.

[IDO]

Great post, that puts things into perspective, especially when you consider the NE blocking shown is only a mean.

The London ensemble graphs should confirm the Op as very much out on the mild side if not pretty much an outlier by day 10

 

Edit

 

Unless they have flipped. 

Verification supports that scepticism:

OP at T240:

Mean at T240:

Edited December 3, 2013 by i'm dreaming of...

[Ali1977]

When are the ECM ens released?

[Summer Sun]

When are the ECM ens released?

 

20:30

[forecaster]

Personally I think that 12 - 72 hour forecasting is dull. By then the pattern is set and there is not much mystery to it. If snow is about to fall, or a gale is about to blow, or a scorcher is about to strike - then that is exciting to see it approach and count down to 0. That;s the lamp post watching evening or the one spent staring out at branches as they start to bend... but general forecasting? Only the medium to long range for me. 95% of what happens within the 72 hour range is mundane.

 

Almost all my career has been looking at the 0hr to 48hr range. It's really not dull or mundane. There's always something. Apart from the times when there's not.

[Cloud 10]

Tonight's NOAA 8-14 dayer seems to give a slightly stronger signal for height anomalies

to our east/north-east than yesterday.

 

[Summer Sun]

ECM ensemble doesn't look as good for an easterly tonight

 

 

+5 850's widely as well

[Captain Shortwave]

ECM mean will probably show the op was at the top end of the ensembles temperature wise. Core heights sort of over Germany/Low countries with a deep trough in the Atlantic/Russia. 

AKA the definitive perfect summer profile 

 

Calm and chilly would be the reality here. Hoping for a drier south easterly flow to come along.

Edited December 3, 2013 by Captain shortwave

[shotski]

There is no chance with charts like this of a cold pattern developing, +8 850's into

the south of England.

 

You cant make a cake without cracking a few eggs   

[mcweather]

What ended up happening, over 2 weeks later was estimated to be a 1 in 250 year event. I could show similar charts from the last 26 years, and well, what followed became a nearly every year event for 22 years.

 

Yes Ian but unlike some I could mention. The rest of us didn't fall into the trap of thinking those nearly every year events meant harsh winter weather would never return to lowland England.

[Ian Brown]

Yes Ian but unlike some I could mention. The rest of us didn't fall into the trap of thinking those nearly every year events meant harsh winter weather would never return to lowland England.

 

It was being widely discussed on the forum at the time that HLB in winter may never occur again, this was a serious topic on weather forums.

 

ECM ensembles strongly back the OP.

[IDO]

DeBilt ens for ECM:

No surprises there. One of the milder runs in the ens, early and late. Two temp patterns (mild or cold) but dry throughout (D5-10), so how far north the High travels probably the big question.

[Weather-history]

ECM ensemble doesn't look as good for an easterly tonight

+5 850's widely as well

Under high pressures during winter, the 850s are close to academic. During the December 2007 anticyclonic spell which looks similiar to that ECM mean, the 850s were above 0C but it sure was chilly. Depends on how clean the high and how much mixing there is.

Forecasts from December 2007

Edited December 3, 2013 by Weather-history

[I remember Atlantic 252]

Under high pressures during winter, the 850s are close to academic. During the December 2007 anticyclonic spell which looks similiar to that ECM mean, the 850s were above 0C but it sure was chilly. Depends on how clean the high and how much mixing there is.

 

also Jan 2002. opening days were ice days, -10 nights with mild uppers, just need the cleat skies

[BLAST FROM THE PAST]

With regards to thoughts of Scandi HP later this month, my outlook suggests block to the east but not a cold Scandi that will really impact the UK and a flow from southern quadrant developing and I remain with my Dec outlook even with an enticing update such as provided by Ian F.  I have also touted that Jan really interests me and have mentioned a possible cold impactual period like 1987 but am not full on for that yet. However, I have pricked my ears up reading RJS recent post.

Funnily enough my outlook has big similarities to RJS.

I think the models will toy with the Scandi HP down the line with it 'looking good' for us but will eventually ease back on its direct cold influence this month.

Anyway we aint got our cold blast yet.

 

 

BFTP

[Methuselah]

It was being widely discussed on the forum at the time that HLB in winter may never occur again, this was a serious topic on weather forums.

 

ECM ensembles strongly back the OP.

It was also wrong!

[bluearmy]

Do you think the mod thread on netweather.co.aleutians is full of talk about the UK ridge ?

And Ian - what are you talking about re ECM ens??

The only support is the high spread nw of Iceland indicating a cluster of low heights. The mean is not supporting and the op is clearly not supported in holland by day 10

Edited December 3, 2013 by bluearmy

[JCP]

ECM ensembles strongly back the OP.

Sorry Ian, but that is simply not true and is very misleading. Edited December 3, 2013 by JCP