Model Output Discussion

[damianslaw]

The models are struggling with the prospects for next week. In such situations you tend to get wildly different projections from the major models, hence the divergence between ECM and GFS from Monday next week onwards. In these cases, I tend to look at the teleconnections and longer term signals which I have to say do seem to favour the ECM evolution, those heights to the east will sink south with lower heights becoming quite strong in the Iceland area, hence a westerly airstream looks a very plausible outcome next week. However, I fully expect amplification in the jet as we head towards February resulting in a more meridional period with lows taking a NW-SE path which with heights building to the NW will eventually pull in a northerly flow.

In overview I expect the following

Up to Monday - cold for most tomorrow becoming milder Friday and Saturday but turning cold again by Sunday as we see a light easterly flow by Sunday

Monday through to Saturday - started cold, before rain preceeded by snow moves in then average temps with a westerly flow, it won't be a mild westerly flow, further rain with snow on high ground

As we head into Feb, heights building to the NW northerly flow to follow.

Edited January 20, 2010 by damianslaw

[nick sussex]

Well the plot thickens! You would think if theres a clear signal to push energy further east off the trough that the gfs 18hrs run with newer data would have picked up on this, even allowing for its eccentric nature the major model disagreement starts within 96hrs. Hard to say whats going to happen, so lets hope we can get a resolution to this in the morning.

[Buzzit]

Im now going to take note of how many posters state FI begins in 72hrs (based on GFS 18z)

[The Weather Dragon]

GFS has been 'solid as a rock' over the evolution of the easterly - if anything 18z is an upgrade. I am impressed.

[cold snap]

What is very evident tonight is one model is badly wrong and i mean badly.GFS is stickly with the Easterly for a few more hours anyway.may be gone on tommorow runs.

Very intresting situation,i dont think ive ever look at the models as much as this winter.

[Tim Bland]

Im now going to take note of how many posters state FI begins in 72hrs (based on GFS 18z)

I'll be the 1st! Was just about to write it when I read the above lol! 18z brings snow showers into the East as early as Sat night. If next week is so uncertain then it baffles me why BBC would be sticking their necks out this early and saying it will be cold and mentioning battle ground scenarios! Surely if it was a difficult call then they would just go as far as Sat and keep stum about the rest! I know Rob Mc can't resist though as he's a coldie !

[January Snowstorm]

I think we might be underestimating the cold being shown early next week

Never mind the uppers, that looks like back to ice days to me which will not be welcome

Just look at the minima's over Germany, indeed the maxima's too!!

[bluearmy]

Hopefully it will be sorted out tomorrow but if the GFS at T120 verifies, then nothing very exciting is going to develop thereafter, look at the heights to the North and West.

signs on the 12z's of retrogression with some WAA off the eastern seaboard. i think the 18z is setting up better although once into low res, anything could happen

[john mac]

Hopefully it will be sorted out tomorrow but if the GFS at T120 verifies, then nothing very exciting is going to develop thereafter, look at the heights to the North and West.

I dont think it will ian, the models are struggling at t72 let alone t120, nothing is nailed down cold or mild

[Eugene]

What a great chart to have at just T+72 hrs, usually we get excited over this past T+180 hrs http://www.wetterzentrale.de/pics/Rtavn721.png

Looks cold well into next week with HP dominating, the atlantic is diverted away up north where it belongs

http://www.wetterzentrale.de/pics/Rtavn15010.png - Very nice dewpoints charts

IB is like a car salesman trying to sell unwanted bangers but keeps persisting with it even though he knows full well he`ll never sell them, hows the mild winter forecast going old pal

[shiver]

Hopefully it will be sorted out tomorrow but if the GFS at T120 verifies, then nothing very exciting is going to develop thereafter, look at the heights to the North and West.

yep im looking ian at height rises over greenland hard game trying to second guess the models isnt ithttp://www.wetterzentrale.de/pics/Rtavn1501.png

[John Cox]

Hi JS,

I agree with you.

The European temps are so low this winter compared to recent winters there must be a good chance of a draw from these

regions.

Fingers crossed

I think we might be underestimating the cold being shown early next week

Never mind the uppers, that looks like back to ice days to me which will not be welcome

Just look at the minima's over Germany, indeed the maxima's too!!

[aspire27]

So now the GFS and ECM are 'quite far appart' in their output is a fair comment?

That means there would have to be a big turn around by the GFS to follow the ECM tomorrow

or

a big turn around by ECM to follow the GFS

or

Stays as it is...

interesting times..

[nick sussex]

Hopefully it will be sorted out tomorrow but if the GFS at T120 verifies, then nothing very exciting is going to develop thereafter, look at the heights to the North and West.

Yes that maybe the case but i'm still very surprised at the differences within 96hrs, normally if the ECM wobbles it does so for one run not several, however several other models have trended towards it so maybe we'll find tomorrow a backtrack by both models towards agreement. If the gfs verifies it looks quite dry but very cold regardless of the upper air profiles.

[Snowyowl9]

Im now going to take note of how many posters state FI begins in 72hrs (based on GFS 18z)

http://91.121.93.17/pics/Rtavn721.png

See what the jet is doing

http://91.121.93.17/pics/Rtavn7215.png

Fax for the same time.

http://www.wzkarten.de/pics/brack2.gif

Models always struggle with HP anyway.

[Tim Bland]

I suspect this run will show a strong Northerly to welcome in Feb!

http://91.121.94.83/modeles/gfs/run/gfs-0-156.png?18

Have to applaud the GFS IF it has got this right, it has stuck by its guns unlike most other models.

[Paul Sherman]

What a great chart to have at just T+72 hrs, usually we get excited over this past T+180 hrs http://www.wetterzentrale.de/pics/Rtavn721.png

Looks cold well into next week with HP dominating, the atlantic is diverted away up north where it belongs

http://www.wetterzentrale.de/pics/Rtavn15010.png - Very nice dewpoints charts

IB is like a car salesman trying to sell unwanted bangers but keeps persisting with it even though he knows full well he`ll never sell them, hows the mild winter forecast going old pal

Eugene

Ian has already posted a Thread about his Bust forecast and owned up as such, Is there really any point in dragging the Model Thread Off Topic with your last Sentence!

After all the Seagull and Arctic Tern posts from the last few days lets try to keep to Model Discussion and not "Let's get a Mod to delete every other off topic post"

Paul S

[Liam J]

gfs 18z looking like a cold and cloudy scenario to me after the initial shot of cold 850's which would produce snow showers along eastern areas and with not to much wind they wouldnt get to far inland. through monday the 850's recover to 0 and -2 or so less likely for snow and temps at the surface are not looking to cold, we have been spoiled so far this winter and now many want a repeat of the wonderful synoptics...

and until we see them anything else will feel like a let down, theres plenty of time for upgrades, but i think if your looking for a re-run of 2 weeks ago (me included) the prams will be empty of toys...

being the uk there will be more surprises with the winter still to come and thats why we all like the weather with such a variety on offer!!

[snowingtequila]

http://91.121.93.17/pics/Rtavn721.png

See what the jet is doing

http://91.121.93.17/pics/Rtavn7215.png

Fax for the same time.

http://www.wzkarten.de/pics/brack2.gif

Models always struggle with HP anyway.

unless I have a bad memory when both models are stubborn like this the ECM normally has been right, particularly when going against an easterly

[January Snowstorm]

Hi JS,

I agree with you.

The European temps are so low this winter compared to recent winters there must be a good chance of a draw from these

regions.

Fingers crossed

Yes john, but as i say not welcome for our economy or anyone

Snow is fun, but not frozen pipes, fractures & lethal roads

[Tim Bland]

http://www.wetterzentrale.de/pics/Rtavn1802.png

http://www.wetterzentrale.de/pics/Rtavn1804.png

http://www.wetterzentrale.de/pics/Rtavn18017.png

good news for the Northerners with widespread snow showers moving south. Anyone for a polar low? - http://www.wetterzentrale.de/pics/Rtavn2161.png

If we had seen these charts (even in in deep Fi) during most winters then this forum would be in meltdown!

Edited January 20, 2010 by Tim Bland

[Cloud 10]

Good old 18z!!!!

[conor123]

Excellent 18z with several days of very cold weather under the influence of the High Pressure which then retrogresses to Greenland to give a long awaited Arctic Blast, seems a fairly realistic run in the Lower Resolution aswell.

[Frosty.]

Hmmmmmm what will the occluded front do after saturday, it might push back west and pull in cold air behind it but friday looks a milder day in most areas.

[bluearmy]

go on then Nick, give us a medium term 'middle ground' outcome based on gfs/ecm at the moment !!!