Model Output Discussion

[BLAST FROM THE PAST]

Hi,

I agree. Its an Atlantic High....too much pressure from the Jet...We see a toppler

and then some sinking High.

Also TEITS - I respect your views but we do NOT see anywhere TRUE GHeights building as I can view

on the GFS, ECM OR UKMO

Too much jet pressure will see the AH pushed South by the Jet energy causing lows.

Regards

CV

That is only projected jet pressure, not actual. Expect changes to model output over coming days, energy will not be in the northern arm sinking the HP.

BFTP

[Geordiesnow]

I think when you see charts showing a cracking easterly 24 hours before to something milder then you know the outlook is uncertain.

No doubt tomorrow runs may suggest something different but i do feel that the chances of any easterly outbreak is fairly small but whilst height rises are there, a cold set up can be achieved.

I bet those who started congratulating some members who were predicting an easterly have got egg on there faces at the moment. It goes to show that you can't jump the gun and think its guaranteed its going to happen. On the other hand, you can't jump the gun if a downgrade occurs and say what the models are showing now will happen.

The only reason why i would say any easterly occuring has slimmed quite alot is because the Azores high is further eastwards and there is always a chance it may not ridge at all resulting in us getting milder weather from the west.

[andymusic]

I don't think this is the end of the model changes - GFS is still bullish about this easterly and it has gone back to an initial trend many many times before - just you wait and see!

[NorthantsSnow]

The GFS brings that small low back on Saturday in the 18z output. Further west though, bringing snow mainly to Wales. Up to 5cm widely, perhaps more in places, clearing south coast Sunday a.m.

[Tom D]

The GFS mean is quite different to the op at +144,

http://91.121.94.83/modeles/gfs/run/gfs-0-144.png?18

http://91.121.94.83/modeles/gens/run/gens-21-1-144.png?12

The control and the mean are almost identical. I expect the 18z op might be a slight mild outlier especially with the positioning of that high at +144.

...and just for the sake of it, the 18z mean and control for +240

http://91.121.94.83/modeles/gens/run/gens-21-1-240.png?18

http://91.121.94.83/modeles/gens/run/gens-0-1-240.png?18

Edited January 27, 2010 by Tommyd1258

[cooling climate]

Above normal heights from say Iceland across Scandinavia and into Russia

would not be classed as a -NAO.

The CPC measures the heights from Greenland to Iceland I think. Steve Murr

knows more about this he did a post on this a good while back now.

[Severe Siberian icy blast]

The trend remains good for a bitterly cold spell late next week

That's all we can ask

At least some one sees the sense , nothin mild about them charts , yes a slight blip next wk but they are two different cold spells we are lookin at , and the signals only point at the bitter easterly developing dunring the 2nd wk of feb,so on cousre . Also the runs change daily and as im told every evening this is a pub run .

We are looking for trends not detail , and the trend is still there .

Regarding this northerly with -10 uppers at times im sure there will be disturbences nearer the time, during sat evening it seems keen on bringing a spell of snow in land toward the mids . We will see .

[swilliam]

A less than inspiring 120 fax - looks like we will have to wait for the possible easterly.

[SMU]

The best chart ever in HISTORY

Ensembles are actually EPIC-

Reverse / Negative Zonalilty at it finest-

http://91.121.94.83/modeles/gens/run/gens-8-1-216.png?18

S

[swilliam]

A less than inspiring 120 fax - looks like we will have to wait for the possible easterly.

but a much more inspiring GEFS control run but unfortunately still in very much in FI

[Severe Siberian icy blast]

I think when you see charts showing a cracking easterly 24 hours before to something milder then you know the outlook is uncertain.

No doubt tomorrow runs may suggest something different but i do feel that the chances of any easterly outbreak is fairly small but whilst height rises are there, a cold set up can be achieved.

I bet those who started congratulating some members who were predicting an easterly have got egg on there faces at the moment. It goes to show that you can't jump the gun and think its guaranteed its going to happen. On the other hand, you can't jump the gun if a downgrade occurs and say what the models are showing now will happen.

The only reason why i would say any easterly occuring has slimmed quite alot is because the Azores high is further eastwards and there is always a chance it may not ridge at all resulting in us getting milder weather from the west.

A very odd comment to make regarding ''egg on face '' considering the chats are still goin for a cold easterly over a long period , fi yes , but its consitantly been showing it for days and for me the gfs has been outstanding this season picking up cold spells and it only detail that has changed this evening , not trends . So certainly nothing to be embarrassed about and no egg on anyone . Especialy considering that things will look different in 4hours when the new charts get released.

[yamkin]

poor run tonight looks like its starting to follow the ECM which is not realy surprising looking more and more likely next week will be quite mild and wet

GFS 18Z is looking good IMO. At 138h - 168h, the temps are slightly milder and then it gets a lot colder again. I can not see where tonight's GFS 18Z run is poor.

[grab my graupel]

The best chart ever in HISTORY

Ensembles are actually EPIC-

Reverse / Negative Zonalilty at it finest-

http://91.121.94.83/modeles/gens/run/gens-8-1-216.png?18

S

That's a belter of a chart Steve, as you say, it's like Zonality in reverse - I'd certainly love to see that come off

[SMU]

TEITS post up the ensembles 18z for 500mb for stockholm- this will show the 18z to be a big outlier at day 8

S

[Guest North Sea Snow Convection]

A less than inspiring 120 fax - looks like we will have to wait for the possible easterly.

That looks primed for a pressure build northwards and the possibilities from that still remain

It is very likely that the models are continuing to have problems evaluating the energy distribution in the jet stream. They may have (prematurely) first over cooked the southern stream - now they may well be doing the same with the northern branch. The polar field is causing problems, and the speed of downwelling negative zonal wind anomalies in respect of the MMW is very much the factor here imo.

Plenty of time for more see-sawing. The ECM is probably not far wrong for the middle of next week - an interlude of cold high pressure has always been on the cards which will actually be very pleasant anyway imo with plenty of frost and winter sunshine. This does also though still remain the same transition that has been on the cards for a day or two to very cold north easterly winds into the second week of February. And not just suggested by snow and cold enthusiasts on net weather by the way!

The delay suggested today is more realistic than the the charts of yesterday

Edited January 27, 2010 by North Sea Snow Convection

[dapick2002]

and just remember folks the evolution before christmas ... started cold, briefly warmer over the xmas period before the cold returned proper. I think there are some similarities and it may be the case this time round too if the charts keep sticking with this theme.

Edited January 27, 2010 by dapick2002

[SP1986]

The best chart ever in HISTORY

Ensembles are actually EPIC-

Reverse / Negative Zonalilty at it finest-

http://91.121.94.83/modeles/gens/run/gens-8-1-216.png?18

S

That particular ensemble is also one of the coldest ensembles, and the coldest longest running ensemble. Still interesting to see an ensemble show that scenario, I don't think I've ever seen anything remotely like that.

Chances of it happening as portrayed there unfortunately are quite low.

The thing is despite the majority of solutions going for an easterly, the upper air temperature are never particularly low, certainly not what would be expected from a long fetch easterly.

[Bobby]

Well looking through the GFS ensembles most go for a pretty potent easterly.

How's that for northern blocking...

[SMU]

not often you see this- infact never

this is the jet mean-

http://91.121.94.83/modeles/gens/run/gens-21-3-300.png?18

S

[LomondSnowstorm]

Great ensembles. My only worry (and this is pretty slight) is the high perhaps ending up too close to northern Scotland, killing off convection, but if uppers are cold enough I'd expect this to be overidden anyway! On the other hand, neither the GFS or ECM are really going for the faster road to an easterly, so maybe caution is advised as usual when these situations pop up in FI.

LS

[cyclonic happiness]

not often you see this- infact never

this is the jet mean-

http://91.121.94.83/modeles/gens/run/gens-21-3-300.png?18

S

that isn't just amazing, it's scarey!!! good job that will never happen!!

[Bobby]

The ensembles really are mouthwatering, and it's not a few but most of them. It's fantasy island for sure but it's hard not to believe something is brewing.

[grab my graupel]

Well looking through the GFS ensembles most go for a pretty potent easterly.

How's that for northern blocking...

Yep, it's still all to play for

[john mac]

Evening all

Well plenty of people getting worried on here tonight which is quite amuzing after last nights action, i cant believe people expected to see it again last night are purely dreaming, like TEITS said last night, the models couldnt have got any better than that for the UK.

Still plenty of potential on the charts tonight, i dont think we should get too far ahead of ourselves, lets enjoy the northerly coming up

[Cloud 10]

The air pressure ensembles for iceland show the 18z operational to be pretty much an outlier,which is excellent news for easterly wanters.

The mean gets above 1030mb for a time.

The partial spoiler on the 18z op. run appears around +144 with a deep low west of iceland which prevents our high from ridging north as much.

Still a pretty good run though,but should have been better.

Edited January 27, 2010 by Cloud 10