Model Output Discussion - 30th November onwards

[cold snap]

Excellent UKMO at 120

Terrible GFS at same time frame

Differences are vast

[Weathizard]

Can I ask why are people so certain the GFS is wrong, just because it doesn't show what we want? One bitten twice shy three times is just naive, the ECM often moves towards the GFS with these types of scenarios, one of them will backtrack completely and as I wrote this morning, I'm (crazily) backing the GFS on this one.

[gottolovethisweather]

The surface feature which I was speaking about yesterday needs to be watched and will either assist or degrade our chances of seeing anything a bit more prolonged. In fact at t+120 (which is still borderline FI) this image courtesy of the developing GFS 12z run appears to indicate a split flow in the Jetstream, that would be most welcome if things indeed turn out that way, come next Thursday.

 

 

Tuesday 3rd December will see the start of the colder air trickling South but its not until Thursday 5th December and beyond that we see the more entrenched colder airmass working its way South. This is by no means a gimmee but the odds are starting to firmly stack up towards seeing something more akin to WINTER.

 

 

[Cecil Hogmanay Melchett]

Excellent UKMO at 120Terrible GFS at same time frameDifferences are vast

Really?They look similar to me both flat upstream..

[bluearmy]

ukmo at day 5 a tad more amplified than its chart from yesterdays 12z run. closer to ecm than gfs despite what some might see.

[Mucka]

UKMO is better than GFS for sure but still needs to be further West, more amplified with the trough digging deeper. Will ECM move toward it or stick to its guns and bring in the stonking Northerly again?

[Beaufort12]

I'm a complete novice at reading models but I honestly don't see the point. Gfs is released 4 times per day and differences in each run are crazy. By the time you've analysed them they are showing something completely different in the next run. That's my experience anyway

[cooling climate]

The GFS 12Z is showing nothing like the amplification that the ECM

has been showing, in fact there is no ridging from the Atlantic high

at all it is just being shunted away south east.

As I said the ECM run between t96 and t120 looks very suspect, but

then I would not believe everything the GFS shows either.

I do hope there is some truth in what the ECM is showing otherwise

there will be a large question mark over its output in the future

for me anyway rather than a model to trust.

[legritter]

Looking at most modells and Data  we can say a pretty good chance of wintry conditions moving South across the uk next Thursday .As for detail broadly we need to get much nearer the event ,so at this stage i would say if it all comes off many surprises could be had especially IF any northerly stays intact for a couple of days ,of course usual places would fair better but dont forget about Undercuts and many other synoptic surprises .GFS now churning out but i wont look till 4.45 pm when complete .and remember at this range 120hrs plus alot can change for worse or good .

[radiohead]

The 850 chart for the UKMO T120 on Meteociel still has the 0Z for some reason.

[tight isobar]

According gfs 12 It's a cold blink, not even snap...and that's only for northern most....!!!

[bluearmy]

if the result of this is less amplification than ecm shows, why does it make gfs right?  surely the charts have to verify like gfs shows for that to be the case. hang on, that means gfs will be right cos it has thrown out every conceivable solution these past few days !!

[SylvainTV]

The 850 chart for the UKMO T120 on Meteociel still has the 0Z for some reason.

 

Yes sorry, T850 data came a little late. I'm rebuilding the charts. They will arrive very soon as well as +144.

[bryan629]

Can I ask why are people so certain the GFS is wrong, just because it doesn't show what we want? One bitten twice shy three times is just naive, the ECM often moves towards the GFS with these types of scenarios, one of them will backtrack completely and as I wrote this morning, I'm (crazily) backing the GFS on this one.

THE gfs  simply cannot be trusted...

 

this was posted on the 29th on twitter

 

Joe Bastardiâ€@BigJoeBastardi29 Nov

GFS flips to ECWMF ( as usual) on east coast. Now has http://weatherbell.com storm for next week ne. Look at change pic.twitter.com/jo05aLDvyc

[Barry12]

If the GFS is correct it will be rather embarrassing for the Met Office after them saying there will be a strong arctic blast!

Edited November 30, 2013 by Barry95

[terrier]

Sorry but my moneys on the gfs verifying here. How many times has the ecm lead us up the garden path. Expect it to start moving into line with the gfs over next few days.

[A.J]

 

I can understand why those along NE facing coasts, NW Facing coasts and Scotland are getting excited about the snow prospects for 6-9 days time, but I struggle to see why anyone else other than those who live on elevated areas in lets say N .Wales and Midlands ...are getting excited. 

 

I have not really seen a single run that would give the VAST majority of us anything decent in terms of snowfall. 

 

It's well known that a direct northerly or NNW feed creates a wish bone effect and snow showers simply run along the West and East coasts and tend not to penetrate very far inland. 

 

Although it's a slightly IMBY I'm still looking into Mid December and hoping something shows up that would provide a decent spell of cold weather that would deliver most of us snow and not just the usual places that always get it regardless of what direction it comes in (I.E Scotland , the NE and NW Facing coasts).

 

Here's a good example shown by Netweather's Own charts ..

 

 

I don't understand why so many people seem to think that somehow on the day itself things will somehow change and (for example) someone living in the South East gets disappointed; when they don't get any snowfall.

feel free to delete this post it's it's not model related enough, It's just that every year people fall into the same trap, get their hopes up and then feel let down when they don't get snow. 

80% of us will not see snow falling from the sky by next Monday from this sort of set up

 

Maybe where you live you won't see any snow but for where I live (North West England), Scotland & Northern Ireland this is the perfect setup for snow, I for one can't wait.

 

that's good, so be sure to post in the relevant regional thread, as this thread is for model output discussion 

Edited November 30, 2013 by ajpoolshark

[Mokidugway]

Took some pics on my phone while out with dog of sunset ,got home to look at them and realised there was a blob of ptaint on camera lens ,gutted!!!...woops wrong thread !

Edited November 30, 2013 by Mokidugway

[Methuselah]

Can I ask why are people so certain the GFS is wrong, just because it doesn't show what we want? One bitten twice shy three times is just naive, the ECM often moves towards the GFS with these types of scenarios, one of them will backtrack completely and as I wrote this morning, I'm (crazily) backing the GFS on this one.

I try not to 'back' any model, WW...If I interpret things wrongly, then so-be-it...Taking all of the models, in a kind of 'mental mush', it looks like we're in for a two-, perhaps three-day, blast of Arctic air...? Enjoy! 

Edited November 30, 2013 by A Boy Named Sue

[Purga]

GFS 12z so far a brief nippy shot for the north but remains largely mild for the much of the UK especially the south next weekend

Some very mild uppers encroaching on the SW.

Heating bills set to tumble...

 

UKMO a very brief affair before the whole thing looks set to flatten.

 

Edited November 30, 2013 by Purga

[Cloud 10]

ukmo at day 5 a tad more amplified than its chart from yesterdays 12z run. closer to ecm than gfs despite what some might see.

 

Yep,a small step towards the ecm perhaps.

 

yesterday 144 hrs..  today 120hrs..

[ChartViewer]

I try not to 'back' any model, WW...If I interpret things wrongly, then so-be-it...Taking all of the models, in a kind of 'mental mush', it looks like we're in for a two-, perhaps three-day, blast of Arctic air...? Enjoy! 

Im backing the CMA...Sorry couldn't resist ABNS

Edited November 30, 2013 by ChartViewer

[gottolovethisweather]

The surface feature which I was speaking about yesterday needs to be watched and will either assist or degrade our chances of seeing anything a bit more prolonged. In fact at t+120 (which is still borderline FI) this image courtesy of the developing GFS 12z run appears to indicate a split flow in the Jetstream, that would be most welcome if things indeed turn out that way, come next Thursday.

 

GFS 12z 301113 Northern Hemisphere Jetstream at t+120.png

 

Tuesday 3rd December will see the start of the colder air trickling South but its not until Thursday 5th December and beyond that we see the more entrenched colder airmass working its way South. This is by no means a gimmee but the odds are starting to firmly stack up towards seeing something more akin to WINTER.

 

Further to my post above, our problems BEGIN with the developing surface feature off the Eastern seaboard of the USA, see yesterdays post below as its exactly same for ALL MODELS, look towards there come Monday/Tuesday.

 

http://forum.netweather.tv/topic/78508-model-output-discussion-18th-nov2013-12z-onwards/?p=2848668

 

Where this then tracks and how it develops will effect us downstream in subsequent days, i.e. Thursday through to next weekend. This is how it was viewed by the GFS 12z yesterday, look at the attachment.

 

http://forum.netweather.tv/topic/78508-model-output-discussion-18th-nov2013-12z-onwards/?p=2848749

 

This may be a delay in us simply receiving to the coldest uppers or the GFS might be correct in its reasoning of the HP cell being hard to budge. All just on the border of FI right now, by tomorrow's Farming forecast we might know more, or it may have to wait until Monday or Tuesday. ANYTHING COULD HAPPEN!

Edited November 30, 2013 by gottolovethisweather

[Thundery wintry showers]

My current opinion is that tonight's UKMO will probably be nearest to the mark- a 36-hour northerly with some potent low temperatures, cold enough for snow showers in most of the areas that get showery activity, but the northerly probably won't sustain for long enough to get much advance on showers affecting the usual coastal areas.  Perhaps north and west Wales will be most in the firing line for this one because of the likely westerly component to the wind direction.  I think the ECMWF might stick with its three-day northerly tonight but then back down tomorrow (either on the 00Z or 12Z) to showing a 36-hour northerly.  I have a feeling that the GFS is overdoing shortwave activity to the north and therefore being too dismissive of the northerly.

[SMU]

http://www.meteociel.fr/ukmo/runs/2013113012/UN144-21.GIF?30-17

 

UKMO 144 - not bad.

 

Poised nicely for down continued cold.

 

S