Model Output Discussion - January 12th.

[weathergeek]

First thing this morn the Meto websites 5day forecast for me showed Tues temp jumping back up to 8c after cold weekend, updated at 9am to 4c for Tues - does this mean anything?!

H.

[Glacier Point]

If you look at the hemispheric solutions, the GFS is majorly out of kilter with its own ensemble mean and other forecast products which have shown good continuity over the last few days. In particular, look how the GFS op resolves Alaska and the Siberian ridge in the extended range - complete opposite to the strong concensus.

Meantime, the ensemble means (including GFS) continue to back the Atlantic ridge west delivering a pronounced broad trough over Europe.

By day 10, GFS and ECM ensemble means show very good agreement for the pattern in terms of 850 values:

The significance is this. Once a cold block like this is developed, it becomes very difficult to shift, indeed, there is IMO no suggestion of a strong +NAO / +AO pattern during February which will dislodge this.

[bobbydog]

i asked a question about the input of the op runs yesterday, regarding why they are often outliers and if it has to do with human input. Paul gave me the answer- basically, no human input, just slightly different physics. therefore why are some runs, e.g the 06z, seen as less reliable?

computers don't sleep or get tired during the night shift, so why the lower faith in some runs?

[SMU]

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

Long Ensembles from ECM-

Rock solid & colder than the12z yesterday-

As Steward has pointed out the Ensemble MEANS are good-

Although I would like to see more in the way of +Ve over greenland in terms of height anomalies ( doesnt have to be massive )

I feel we are gettign there now- although it has been painstaking.....

Lets see what the 06z conjures up- the worst model of the day! ( generally)

S

[Tom Montalbano]

First thing this morn the Meto websites 5day forecast for me showed Tues temp jumping back up to 8c after cold weekend, updated at 9am to 4c for Tues - does this mean anything?!

H.

I think that's a positive sign. I've just had a look at the METO site myself and the surface pressure charts for midday Tues show an occluded front just clearing the east coast, with a pressure range of 1008mbs to a little under 1020mbs north to south, and nothing like the GFS for midday Tues.

That shows high pressure centred over S.England with pressure ranging from 1025mbs in the far north to 1030mbs + in the south.

The Met Office updated their charts at 7.30 this morning.

How METO would develop synoptically from there hard to say but closer to ECM at Tues midday than GFS, certainly.

Eyes down then for the next episode in this saga, about to roll out!

Regards,

Tom.

P.S. Sorry WG, just read your post properly. I would now suggest they think pressure will remain higher on Tues, after an overnight frost with high pressure perhaps centred over S.England. . All very confusing!

Edited January 13, 2012 by TomSE20

[trisnow]

Sorry this has prob been asked a million times already but what time do the models come out? For both ECM and GFS please?

[Timmytour]

here's how the upcoming GFS run looked at next weekend from last week at the very outstretches of FI....are we hoping it moves back towards something like this?

[Frosty.]

I think it's now reasonable to expect at least a cold snap in around a weeks time but if the ecm verified it would be a pattern changing cold spell with lots of reload potential due to the angle of the jet being nw/se, the gfs 00z is only showing a short sharp cold snap before it resets to average zonal with a mix of mild and cool with brief ridging at times. And not to forget we have a frosty weekend ahead with patchy freezing fog, and the anticyclone lasting well into next week before trouble begins to brew in the atlantic.

Edited January 13, 2012 by Frosty039

[bluearmy]

^{not worried about the} ukmo ^{T144 this morning. its the first opportunity that the model has had to drop the troughing to the east and it sends the jet ne ala} gfs^{. if it does the same at 12z, i will be fairly confused.}

Edited January 13, 2012 by Osbourne One-Nil
First time I've made something bigger in a while.

[Tom Montalbano]

Thanks Tom! Thought it had to at least be a slight positive! Fingers crossed the next runs agree then!

H.

Sorry, my fault WG, think I've confused you, actually think it's a bit of a negative and would suggest they're leaning more towards GFS at that point.

Also I can't access Tuesdays pressure charts on the BBC site, looks like they're about to update those too!

Regards,

Tom.

[OldMetMan]

All the models continue to tantalise with the promise of a significant change of pattern, although there is marked differences in how this is achieved.

One thing I notice all the models showing today is the presence of an intense HP over N Russia by about 120hrs. The upstream developments are a little difficult to fathom, as to which way they will go. The ECM is making more of the deep troughing over and to the E of us, which would favour an eventual pressure build westwards from the intense HP to the NE, as the trough amplifies. The GFS on the other hand is still keeping mobility going with no major blocking.

Further west the US has most of the jet energy across the mid-west but over the E Pacific there is increasing signs of a deeper trough developing, which would tend to amplify the downstream pattern. Alternatively, if this fails to materialise then we can expect the GFS to be nearer the mark in the long term with the polar jet still pushing LP NE out of the US and keeping pressure high over and to the west of the UK, cutting off any potential easterly from heading our way

I think we need to keep a close eye on US developments, especially the latitude and strength of the jet. I suspect that we may end up with a major trough off the US east coast, as the US jet heads on a more southerly track That would make the ECM the most likely outcome.

Either way, HP looks set to dominate our weather for some days. Interesting times ahead.

[Radiating Dendrite]

Sorry this has prob been asked a million times already but what time do the models come out? For both ECM and GFS please?

It says underneath the model charts on the Netweather Date Centre.

[kold weather]

As GP said the GFS has lost the plot a little in terms of how its handling certainm features. When an op run goes against its own ensembles as well as other model runs, thats never a good sign for its solution!

06z GFS having none of it though so far...

[Guest Kent-Weather]

Sorry this has prob been asked a million times already but what time do the models come out? For both ECM and GFS please?

If you click on the datacentre and go to the preferred model your looking at, the model run times are displayed on the page itself

http://www.netweather.tv/index.cgi?action=nwdc;sess=

Model: GFS Created By: NCEP Daily Updates: 4 Update times: 03:30-04:45 | 09:30-10:45 | 15:30-16:45 | 21:30-22:45 (GMT)

http://www.netweather.tv/index.cgi?action=ecm;sess=

Model: ECMWF Created By: ECMWF Daily Updates: 4 Update times: 6-7AM || 6-7PM (GMT)

[SMU]

Another GFS run drifts past with no change-

This is getting very tedious now- we need to take stock at the end of this & remind ourselves next time what model was totally hopeless-

lets hope its the GFS OP & not the ECM & its ensembles....

S

Edited January 13, 2012 by Steve Murr

[Matty M]

6z looks very bullish and backs away from any thoughts of an ECM solution within 180hrs.

[Tom Montalbano]

Still GFS seemingly sticking with its own script and nothing like ECM at t144. It doesnt allow that high to pull west and let that trough dig SE into Europe.

We really need those heights to lower over C.Europe and that high to retreat west but the jet just too strong and badly aligned again on this run.

Regards,

Tom

[Matty M]

http://modeles.meteo...306-0-168.png?6

Another GFS run drifts past with no change-

This is getting very tedious now- we need to take stock at the end of this & remind ourselves next time what model was totally hopeless-

lets hope its the GFS OP & not the ECM & its ensembles....

S

I don't think it is as easy as that though!

One wins sometimes and one is made a fool out of the next.

[UV-RAY]

ECM 32 dayer apparently paints a very cold outlook according to our Matt Hugo, looks more and more like the GFS is in need of a good kick in order too bring it up to speed.

[shedhead]

One thing I've learnt over time is that ignoring GFS is foolhardy. We've been in similiar situations many, many times, indeed even when UKMO and ECM have been solidily against GFS at T+144hrs they have been dragged back into line pretty quickly, almost like a pair of naughty children testing out their boundries with a parent. That's not to say I think GFS it's going to be right on this occasion, but it's not a 90/10 situation or even an 80/20 for my money, indeed I'd suggest it's a 60/40 at best as thing currently stand.

Edited January 13, 2012 by shedhead

[Zakos]

GFS has embarrassed itself further, Its now bordering on farcilce, and there remains to be almost zero support for its outcome.

I for one would bet heavily against the 06z verifying.

[ITSY]

just looked at models - another outrageously good ECM this morning and another zonal GFS - though even that did produce a very snowy northerly in FI. ECM's cold now well within 180hrs so lets keep fingers crossed. 06Z run not any different from GFS so one of them is gunna look very silly indeed. Meto update may give some indication what way they think this is gunna go!

[UV-RAY]

One thing I've learnt over time is that ignoring GFS is foolhardy. We've been in similiar situations many, many times, indeed even when UKMO and ECM have been solidily against ECM at T+144hrs they have been dragged back into line pretty quickly, almost like a pair of naughty children testing out their boundries with a parent. That's not to say I think GFS it's going to be right on this occasion, but it's not a 90/10 situation or even an 80/20, indeed I'd suggest it's a 60/40 at best as thing currently stand.

Normally I would agree, but this time it really has gone off on one. Expect it will be playing catch up all weekend.

[Radiating Dendrite]

The GFS certainly goes off on one in the 6z, with nothing more than topplers and no sustained cold.

If it does back down eventually then it will be nothing but embarrassing for the GFS and the programme that is uses surely? It would arguably be better placed in the NOGAPS camp?

Edited January 13, 2012 by Radiating Dendrite

[weathe20]

Can someone tell me if any of this cold being shown on the ECM is in the reliable timeframe? What happens if the GFS still shows the opposite in the reliable, or can this not happen? (newbie here, thanks.)