Winter Model Discussion - Cold Hunting -12Z 06/01/13

[chris55]

Why?

Surely the ensembles will show where it stands later?

It was a question!!! Hence the question mark!

If you need a full explanation, though I thought most would have understood and thought the same, I was intimating tonight's EC det run looks at odds with this mornings ensemble mean and goes against much of tonights output, that says to me it may well be an outlier, but we will have to wait and see where it sits in it's ensembles tonight.

Edited January 7, 2013 by chris55

[SE Blizzards]

Ecm 12z at 192 hours is the exact opposite of the 00z!!

You will struggle to ever see such a huge difference, just highlights the uncertainty at the moment.

yep, exactly what Ian F was saying .... 'wild model flip-flops'!!I

I really wouldn't look much further than 120h at the moment! Models clearly are all over the place right now!

[No Balls Like Snow Balls]

Panicking about charts that are 8 days away, which somebody just said above is the complete opposite of the 00Z = what a waste of time and effort and just a tad mental.

Confidence building of cold air spreading across the UK by the end of this weekend, -8c uppers into Eastern England - Is this not a good enough for start for most!!!

Edited January 7, 2013 by No balls like Snow Balls

[lorenzo]

The ECM powers up a deep low in northern Canada at 144hrs which is totally against both the GFS and UKMO.

This has a big impact on the Greenland area.

If you took away the markers of the charts denoting the model type, that is a couple of times over the last 72 hours or so that ECM has taken on the dartboard guise of the GFS, had to double check was looking at the ECM, another element within the as Ian put it 'curious' output..

[Jupiters Winter]

That greenland feature changes the whole run and also it IS a solution and CAN happen. You rather be seeing such charts against signals and ensembles than the other way around.

[nick sussex]

And as Ian Brown says the Gfs handles Greenland much better than the ECM, bin.

I think we need to wait till we get agreement between the big 3.

The ECM has been dismal recently in terms of continuity between runs but thats not to say its wrong here, its of course disagreeing with the majority of the NWP so for now an outlier solution.

It's becoming apparent that we need to approach the models from a wrong till proven otherwise in the current situation, even at 120hrs I have low confidence in any of their solutions in terms of the detail which is going to be crucial for snow potential.

[TEITS]

And as Ian Brown says the Gfs handles Greenland much better than the ECM, bin.

I don't believe that is true and to be honest none of the models are covering themselves in glory.

Until these differences are resolved I might stop following the models beyond +168. My main focus is whether we see potential snowfall this weekend with regards to the SW tracking SE. Anyone on the NE flank has a chance.

[nick sussex]

I'm beaming my way across to the USA to see what NOAA say about the pattern!

Will report back with news after my pastrami on rye sandwich!

[weather eater]

I really would urge people to just bin all the output past 120hrs.

The upstream differences between the models at 144hrs are laughable and really don't get depressed about the ECM, its hardly covered itself in glory over recent days.

I couldn’t agree more Nick, it’s an oft used excuse, don’t look any further the models are all over the place, but in this instance it really is sound advice, getting some sort of model consistency out to 120hrs is proving to be really hard, never mind about getting in a sweat about the output post that point.

[london-snow]

All these o'dears and useless one liners are giving those less experienced or newbies no chances of learning...

You all ( Those that comment ) should know that it is not advisable to take every frame beyond 96+ - 120+ as pure and utter gospel no matter what the outlook is but especially in these cases where on balance colder weather is on the horizon.

168+ is 8 days away and is therefore highly unlikely to become a reality especially when other factors start filtering through its data.

Dismiss any output past 120+ is my advice and concentrate on what we have in front of us in regards to the possible easterly.

Edited January 7, 2013 by london-snow

[ChartViewer]

I'm beaming my way across to the USA to see what NOAA say about the pattern!

Will report back with news after my pastrami on rye sandwich!

Dont forget the top secret model CMA is rolling out...T48

BOM none too inspirational tonight at T144

Edited January 7, 2013 by ChartViewer

[TheHumph]

BBC South has any high pressure pushed away SE'wards towards the Continent and say it will be a wet and windy weekend with temps around the seasonal average. A lot of the models I have seen on here in the last couple of hours are nothing like this at T120. Any suggestions as to why the Beeb are so sure of this?

[lorenzo]

Underwhelming output from the ECM this evening, will be interesting to see NOAA thoughts later as they pick through the scramble of solutions on offer at present, I predict a 2 out of 5 from them.

NAM is worth a look for the Greenland area once it gets into a suitable timeframe, it would be my model of choice in this area, other than that the last 10 days of 12z runs showed no strict bias from either GFS or ECM in the Greenland area that would amplify a tendency in this area.

[Methuselah]

Why?

Surely the ensembles will show where it stands later?

At 8 days' out, does it really matter whether it's an outlier or not? It's not likely to verify anyway...

[tight isobar]

Ecm,has major wobble, after 144. Nothing of concern imo think we may see complete difference on the 18z gfs.as some suggest with atmospheric change occur models struggling somewhat.ecm flagging atlantic back far to quickly to be beileved for my liking.

[swfc]

Anybody got any positives from the ecm?Outlier,pre ssw event.I'm not happy, in fact I'm quite sad look at the mo output

[chris55]

BBC South has any high pressure pushed away SE'wards towards the Continent and say it will be a wet and windy weekend with temps around the seasonal average. A lot of the models I have seen on here in the last couple of hours are nothing like this at T120. Any suggestions as to why the Beeb are so sure of this?

Check out Ian Fs Points West forecast!(I player)

He always does a "look at the week ahead" on a Monday, and although the raw charts suggested a less interesting weekend (Saturday) He said "could be a lot colder than charts suggest. Much in line with the output we are all seeing.

[nick sussex]

Underwhelming output from the ECM this evening, will be interesting to see NOAA thoughts later as they pick through the scramble of solutions on offer at present, I predict a 2 out of 5 from them.

NAM is worth a look for the Greenland area once it gets into a suitable timeframe, it would be my model of choice in this area, other than that the last 10 days of 12z runs showed no strict bias from either GFS or ECM in the Greenland area that would amplify a tendency in this area.

Lorenzo did you know theres an extended NAM that goes out to 192hrs called the DGEX. I will dig around for the link and post it.

Okay in terms of NOAA this is their latest thoughts but that only covers the output upto 00hrs, they no longer do a further afternoon update.

CONFIDENCE IS ON THE

LOW SIDE REGARDING THE DEVELOPMENT/INTENSIFICATION AND TRACK OF A

MID-LEVEL SHORTWAVE EXITING THE CENTRAL ROCKIES ON FRI NIGHT/SAT

MORNING. THIS SHORTWAVE SHOULD DEVELOP A CLOSED SURFACE CYCLONE IN

THE NORTH CENTRAL PLAINS/UPPER MISSISSIPPI VALLEY (ALONG THE

DOWNWIND SIDE OF THE TROUGH AXIS) ON SATURDAY AND SATURDAY NIGHT

A later State forecast for Wisconsin suggests the same low confidence:

ATTENTION THEN TURNS TO THE WEEKEND SYSTEM. YESTERDAY THE ECMWF

INDICATED THE SYSTEM WOULD BE ON SUNDAY. WELL...IT IS NOW A

SATURDAY INTO SATURDAY NIGHT STORM AND IS NOW A LITTLE QUICKER

THAN THE GFS/CANADIAN. DID NOT MAKE MANY CHANGES TO THE FORECAST

AS I SUSPECT MODELS WILL CONTINUE TO JUMP AROUND ON TIMING...STORM

TRACK AND MAGNITUDE OF THE SYSTEM THAT WOULD AFFECT PRECIPITATION

CHANCES AND TYPES FOR SEVERAL PERIODS OVER THE WEEKEND. WILL BE

AMPLE TIME TO FINE TUNE THE DETAILS OVER THE NEXT SEVERAL DAYS.

Later on they do another update so will see what that says.

Edited January 7, 2013 by nick sussex

[Isolated Frost]

Anybody got any positives from the ecm?Outlier,pre ssw event.I'm not happy, in fact I'm quite sad look at the mo output

Urm... maybe the -5c line from 96 to 168 and -8c line from 120 to 168 across eastern parts with a E flow, with colder temperatures from today onwards.

And the fact that post d4, model guidance is very unstable and will throw up different solutions daily. I recall someone saying yesterdays 12zs would be 'big'. They are not big, like todays and tomorrows, because Wednesday's will be different again.

I say Jan 15 before the models get a grip with current downwelling and stratospheric signals.

[TheHumph]

Check out Ian Fs Points West forecast!(I player)

He always does a "look at the week ahead" on a Monday, and although the raw charts suggested a less interesting weekend (Saturday) He said "could be a lot colder than charts suggest. Much in line with the output we are all seeing.

Thanks Chris, I'll take a look. Just a bit shocked to see the BBC South forecast going against everything I have read on here for the last hour! Plenty of time for a turn around.

[london-snow]

Underwhelming output from the ECM this evening, will be interesting to see NOAA thoughts later as they pick through the scramble of solutions on offer at present, I predict a 2 out of 5 from them.

NAM is worth a look for the Greenland area once it gets into a suitable timeframe, it would be my model of choice in this area, other than that the last 10 days of 12z runs showed no strict bias from either GFS or ECM in the Greenland area that would amplify a tendency in this area.

Lorenzo,

How can you say that the ECM is underwhelming tonight?

Because fantasy island is not showing the right pattern you expect?

I am a fan of your views however i do fail to see why there is so much misery in the thread after the ECM. Allow me to explain why i am not despondent.

- A trend to colder condition's maintained in the output from the weekend with possible snow chances.

- The output post 120+ showing no clear trend = Anything can happen good or bad.

Maybe i have been injected with the happy feeling dose but come on -

- First chance of the winter for some to see snow.

- Temperatures dropping back to below average quite possibly.

I will take that with the chance of some more down the line possibly.

[Shunter]

BBC South has any high pressure pushed away SE'wards towards the Continent and say it will be a wet and windy weekend with temps around the seasonal average. A lot of the models I have seen on here in the last couple of hours are nothing like this at T120. Any suggestions as to why the Beeb are so sure of this?

Yep and this mornings BBC forecast showed 11c for the SE today, it reached 8c in Croydon ( and that includes urban heating ). Regional and national forecasts differ widely even when shown minutes apart at times......ignore !

[Barry12]

Anybody got any positives from the ecm?Outlier,pre ssw event.I'm not happy, in fact I'm quite sad look at the mo output

You're acting like that run was terrible..it's not, infact it's pretty good up to +144, anything other than that, which has been said a million times is FI and is highly unlikely to verify. Possible Easterly this weekend with snow for places.

[UV-RAY]

Are we looking at another game over chart.

On a serious note I would say FI starts around t+96, all we still know is it will get cold, for how long who really knows.

[ITSY]

after checking out the ens, the ECM and UKMO, I must once again point out what Ian said earlier - that the models will wildly flop all over the place. Don't be surprised to see, regardless of whether or not this 'event' materialises this weekend, a rather sudden switch to a cold blocking scenario at some point in the next week or two - much is still to be decided, especially since this is still phase 1 of the SSW which may not affect the troposphere for some time yet. This, like Ian said, is a normal winter 'will it won't it' event, the real fun and games could yet to be even showing in the charts yet.

For now, many models still suggest potential snowfall either sat/sun or monday for even southern areas so lets focus on the immediate and not get hung up on useless FI 'random' scenarios until the professionals have greater confidence in what may or may not happen.