Model Thread - 14th Jan - Mk2

[sn0wman]

The 18z is definately an improvment regarding the jet stream, but it's not quite there, as the low coming off America is still travelling a bit too fast.

[Geordiesnow]

Apart from a slight change in the tilt of the jet around 84 hours which allowed the NW'ly PM flow edge marginally southwards, I don't see any difference on this run to the 12Z GFS run really.

Again tomorrow morning runs may hold the answer but you do start to get a sneeky feeling the GFS could be more nearer right than the ECM. E.g, we will probably see a much small ridge than first predicted by the ECM and any cold shot will be short-lived with milder air feeding on a WNW'ly flow from the Azores high

I'm just basing that on the ECM 2 runs in a row which has slowly backtracked from its proper ridge and the GFS persistance of not developing any sort of ridge at all!

[chionomaniac]

I can see quite significant changes with the fragmentation of the trough heading east.

Also look at the heights in the Svalbard region at T+162.

Edited January 14, 2012 by chionomaniac

[Matty M]

GFS 18z would probably be more positive going forward but very different to UKM and ECM around T120 T144

[JonMillar]

As a complete rank amateur, but by simply comparing runs, its seems the GFS is showing better definition on the Scandinavian low from t123 to t147 and moves it further south than previously. The ECM of course brings this low further south west, but it is definitely a change in the GFS, albeit still too far out to the east to affect the UK.

Edited January 14, 2012 by JonMillar

[ukpaul]

Totally different shape to the PV on this run for this time next week, clearly a lot of variation even when GFS refuses to pick up on the ridging and slower development of other models.

[Matty M]

Marked differences between the UKM and GFS 18z at T144

UKM @ 144hrs

GFS @ 138hrs

[mountain shadow]

GFS 18z is definetly less flat and more meridonial but not quite there, but near enough. Our islands are small and I guess if we were in the mid west of America we probably wouldn't see much difference in the weather if it was ECM or GFS.

[Cloud 10]

Some slight changes early on in the 18z,but still a fair distance from the ECM,regarding the UK.

18z+144> ECM+144>

[Zakos]

Until the changes actually occur I would hold back on congratulating the ECM or any other model just yet. I have to agree though that the ECM has been pretty consistent over the past week or so. I really do hope the GFS falls in line like you are suggesting.

i do think its still quite possible that the cold may not properly make it to our shores. And yes perhaps it was a bit premature, but i am very confident that the ecm is going to be correct. As to the others who cant see the gfs changes, i fail to see how you cant see this. Just because there isnt -10t850s over the uk doesnt mean there hasnt been significant upgrades to the hemispherical pattern... Edited January 14, 2012 by Zakos

[bobbydog]

Already on the 18z, we can see large changes in the output at very short time ranges. We are finally seeing the gfs fall in line with oter models. It has to be said, although the gfs performed well during december, it has modelled the mid jan pattern change atrociously, determined to hang on to the strong PV which was never going to happen. Hats off to the ecm for spotting the pattern change so early on, and a standing ovation to GP for predicting the pattern change back in November!!

no standing ovations til' the fat lady sings. the fat lady in this case being the actual weather. i think i'll remain seated until i see snow falling outside my window. or at least until all the models show us undisputed agreement of winter arriving properly at +48hrs

Edited January 14, 2012 by bobbydog

[SMU]

As has been said many times whilst the GFS doesnt look very good we have to keep it in the equation but for its general consistency over & over again-

S

[nick sussex]

Good and bad points for cold prospects with the GFS 18hrs run, its pattern over the east Atlantic is more favourable as low pressure at 96hrs isn't so far east, upstream though it refuses to split the PV early enough and flattens the pattern out.

So really theres little time to play with in terms of manoeuvre and if the 00hrs runs don't resolve this then it would be quite unbelievable.

[Grimsby Snow Lover]

I have seen enough of the GFS run tonight but am happier enough to see the changes early on move more inline with the ECM/UKMO/NOGAPS. I know the changes were only at around +94 mark but it was a step in the right direction. Until the GFS shows a buckle in the jet and ridging of the high towards Greenland like the models previously mentioned the overall outcome is likely to be vastly different still. I think it was either Steve or Nick who mentioned small steps. I think we have seen some small steps this evening.

[Duane S.]

the jet at T84 with the low exiting the eastern seaboard slightly weaker and bit more energy into the southern arm. will this be enough to slow it down ????

T96 - the answer is probably yes as i doubt the jet streak at T114 will be as strong, the vortex is slightly further west and there is a bit more amplification. nearer to home, the flow tends se as mentioned above and heights more pronounced around svaalbard. hhmmmm

maybe not then. how i hate commentating on a run .................... i'll get my coat !!

But to be fair to you though BA it looked for all the world like it was going the produce something a lot more akin to the ECM, then... yet again, it seemed to not follow what you would it expect it to do next based on it's own chart! Thing is we aren't talking about +240, this is +108!! That said, run on run it is creeping towards the ECM and at this rate it should be there at about T+6!

[JonMillar]

From t165 to t189 the GFS is now modelling the trough which it wasn't doing before. This is obviously too late for the UK as it stands, but it definitely now recognises a trough which it didn't show previously, Problem for UK it is 2 days too late!

[Grimsby Snow Lover]

i do think its still quite possible that the cold may not properly make it to our shores. And yes perhaps it was a bit premature, but i am very confident that the ecm is going to be correct. As to the others who cant see the gfs changes, i fail to see how you cant see this. Just because there isnt -10t850s over the uk doesnt mean there hasnt been significant upgrades to the hemispherical pattern...

Trust me Zakos, I do see this but until the charts shown by ECM or indeed the GFS materialise Im keeping the champagne(ECM) on ice. Daft as it sounds and I know the weather gods don't work this way but I don't want to jinx the cold lol.

Edited January 14, 2012 by Grimsby Snow Lover

[SMU]

Good and bad points for cold prospects with the GFS 18hrs run, its pattern over the east Atlantic is more favourable as low pressure at 96hrs isn't so far east, upstream though it refuses to split the PV early enough and flattens the pattern out.

So really theres little time to play with in terms of manoeuvre and if the 00hrs runs don't resolve this then it would be quite unbelievable.

nick have you got the link to the ECM charts that got posted over here last year- it has the UK with the contours & 850 overlays- I loved them chatrs

S

Edited January 14, 2012 by Steve Murr

[Downburst]

Folks, relax, the abosolutist pattern is starting again. People using language that suggests this run must be the definative run. Think of garbage in and garbage out. Think that this run is an independent run built up of inputted observations and as it happens not as rich as other GFS runs. Everything written here will be forgotten on the next run. I think it's a generaltional thing, with younger people tending to rush. Think of "it's the only weahter we've got" or something

I find it hard to nail, but is it the case that the constant waffle is actually a need for attention?

[David-kig]

another poor gfs even after some short term changes. nice ecm again tonight.

Edited January 14, 2012 by David-kig

[Tom Quintavalle]

Meto Fax for t120

http://nwstatic.co.uk/fax/PPVO89.png

Regards,

Tom

[Zakos]

Trust me Zakos, I do see this but until the charts shown by ECM or indeed the GFS materialise Im keeping the champagne(ECM) on ice. Daft as it sounds and I know the weather gods don't work this way but I don't want to jinx the cold lol.

yes i suspected you did i was referring to the others who somehow couldnt. Its not daft, and i may be horribly wrong but i am quite confident on a pattern change. Wheter the uk beniftis benefits from this remains to seen, as is always the case with british weather!!

[Duane S.]

Good and bad points for cold prospects with the GFS 18hrs run, its pattern over the east Atlantic is more favourable as low pressure at 96hrs isn't so far east, upstream though it refuses to split the PV early enough and flattens the pattern out.

So really theres little time to play with in terms of manoeuvre and if the 00hrs runs don't resolve this then it would be quite unbelievable.

Absolutely. At 120 we have a well-defined split which has been modelled now for a few days by the ECM (difference versions of but time-wise not slipped back at all). GFS has, well, a mess.

Unfortunatly though we simply cannot consign the GFS to the bin whilst it remains steadfast. Although I know what my money's on being right!

[Cloud 10]

the jet at T84 with the low exiting the eastern seaboard slightly weaker and bit more energy into the southern arm. will this be enough to slow it down ????

T96 - the answer is probably yes as i doubt the jet streak at T114 will be as strong, the vortex is slightly further west and there is a bit more amplification. nearer to home, the flow tends se as mentioned above and heights more pronounced around svaalbard. hhmmmm

maybe not then. how i hate commentating on a run .................... i'll get my coat !!

LOL! I know what you mean,i've ran out of coats!

Anyway,the latest fax chart (i hope) looks promising,with colder air making an appearance

in scotland during thursday.

http://www.meteociel...fax/fax120s.gif

[mountain shadow]

Meto Fax for t120

http://nwstatic.co.uk/fax/PPVO89.png

Regards,

Tom

Tonight's 120 GFS has the Newfoundland trough around 300 miles further east. These small differences make a massive difference to our small Islands.