Model Output Discussion - 8th - 14th January

[Matty M]

Trough in Atlantic is not as far south at T132 GFS

[ITSY]

yes but the high is by the same margin further north - and the area of LP to the SE of scandinavia is lower as well. Not sure on implictions for these 3 differences though

[Matty M]

There is not too much difference at T150 but the pressure over Europe is higher, the trough in the Atlantic isnt as far south so thus jetstream further north.

Edited January 7, 2012 by Matty M

[bluearmy]

Trough in Atlantic is not as far south at T132 GFS

or at T144. almost a carbon copy of ecm 12z apart from that so a reasonable chance to see if we get a build of scandi heights, though without the trough digging south as much, the shape of the ridge probably wont be quite as impressive as the ecm.

[ITSY]

in fact the frontal system in the south of scandinavia sinks into Eastern Europe much more quickly by +150 - again, not sure on the implications of this - sure someone will though

[bluearmy]

it isnt the same as the ecm, or the 12z gfs but its a reasonable continuity of pattern with the 06z and the 12z. that leaves the gfs 00z suite looking isolated at the end of today. wonder what tomorrow will bring ??

[Matty M]

Jet is diving south out of NE USA at 162hrs

I think BLUEARMY hit the nail on the head, 2 similar runs in a turn around in model output.

Things about go nuts at T180hrs........

Time to get the prozac

NetWeather kills wetterzentrales server!

[J10]

I hope people won't be too disappointed if this possible easterly doesn't come off, its just appeared today and there is a history of these turning into a complete nerve shredding experience for many of the members here.

These are often the most complicated synoptics for the models to cope with and although sometimes the rewards in terms of snow and cold can be good they are all different in nature.

To get good snow off an easterly that just doesn't cling to eastern coasts you need very cold uppers and a strong flow, for this reason even tonights ECM needs a good correction westwards.

It's a start and of course given the winter as a whole is very welcome to see even these synoptics but for newer members please take my advise, never count on an easterly until within 96hrs.

I disagree about the 96 hours comment.

We have seen it disappear at closer range than that.

Seriously though you are right to be cautious.

[Jayces]

Jet is diving south out of NE USA at 162hrs

I think BLUEARMY hit the nail on the head, 2 similar runs in a turn around in model output.

Things about go nuts at T180hrs........

Time to get the prozac

NetWeather kills wetterzentrales server!

Snow in the SE at 240 on the meteociel percip chart, that will certainly cause meltdown here....

It's nice to see these things being finally forecast for the winter, it's been a long wait however still a very very long way to go.

[bluearmy]

use meteociel - its ahead of wz anyway. fi almost delivers a snow seekers nirvana. given that the end of high res is sniffing another bout of trough disruption and WAA, i'd suggest that the solution would be different to what we see by T240. not at all shabby though. good trends to end the day.

[Cloud 10]

Look at those cross-polar heights.

Sliced clean in half. :o

[Matty M]

If we go from this @ 96hrs

To this @ 168hrs - I think we will all be happy bunnies

[ITSY]

very similar thus far - perhaps even better by +216 with the cold pool slightly closer to us and more lows to undercut?

[kold weather]

Interesting looking charts from 168hrs, looks like we are getting a very 50-50 type set-up which I've seen go either way before. The jet does look quite strong though at 216hrs still so may need another reload attempt...

[nick sussex]

A decent run from the GFS 18hrs in the higher resolution, the trigger shortwave is too far east but at least the trends been maintained from the earlier output.

Indeed this is much better in the lower resolution upto 240hrs than the ECM, note here your more likely to see further trough disruption and the PV is unlikely to sink the high, you don't get the quick easterly here but the PV is likely to give up the ghost and head off much further to the west!

Anyway this is well into FI and I'm not a great advocate of the GFS lower resolution but a good end to the day.

I expect there will be a good turn out tomorrow morning for those who can cope with the stress!

[Bobby]

Imagine if everything was a few hundred miles further south in the GFS 18z FI... epic, rerun of 1947 stuff

[mountain shadow]

If we similar charts tomorrow morning I expect the Meto daily update will be interesting. Certainly shades of some classic winter charts. Bitter easterlies coming up against distrubted atlantic low pressures systems.

[BLAST FROM THE PAST]

This is a Jan 87 event......if only eh?

BFTP

[kold weather]

A good run from the 18z but obviously room for improvement with regards to what happens around 240hrs, a weaker jet with some sort of under-cut would put the forum into mass hysteria!

[bluearmy]

i keep thinking - that'll be my last post of the day' and then another crazy chart pops up. fi gfs is full of diving troughs as many gefs members have been all day. the end of the run is as good as you'd want to see from a snow perspective, given where we've come from in 24 hours. low res is low res though and just as we would treat the zonal express with disdain, i;m afriad we must do the same with the polar one.

[Tom Quintavalle]

Looked very good for most of the run but became a "Kettley" easterly soon after.

No point in getting hooked up on detail yet though. The background signals and trend are there for all to see, will be interesting to see the other ensemble members.

Certainly its been a fascinating days model watching. Lets hope we wake to find the trend still going in the right direction!

Regards,

Tom

[J10]

A decent run from the GFS 18hrs in the higher resolution, the trigger shortwave is too far east but at least the trends been maintained from the earlier output.

Indeed this is much better in the lower resolution upto 240hrs than the ECM, note here your more likely to see further trough disruption and the PV is unlikely to sink the high, you don't get the quick easterly here but the PV is likely to give up the ghost and head off much further to the west!

Anyway this is well into FI and I'm not a great advocate of the GFS lower resolution but a good end to the day.

I expect there will be a good turn out tomorrow morning for those who can cope with the stress!

I tend to agree the heights from Svalbard to Greenland are far better on this run, compared to ECM 12Hz, and IMO if the low pressure came in a slightly different angle further south, we would be on the cold side.

With this better blocking there would be better potential down the line.

The above chart shows the 500HPa profile at T+288 for the GFS 12Hz run to the 18Hz, completely different.

[kold weather]

Actually if your looking at the pure weather, its probably not that great of a run...temps broadly average throughout, Europe isn't even that cold after the intial Arctic burst around 192hrs.

An OK run but I'd not say anything more...the potenial is clearly there though!

Shift everything 200 miles SW and things would become very interesting!

[nick sussex]

I know people might be thinking how can this GFS be better than the ECM even though the latter did bring in that easterly flow, if you put aside the GFS blowing up that low near the UK the NH pattern is far better at 240hrs.

If you want a cold spell that delivers we must see the PV edged away, and the block further north, the ECM was great at 168hrs but then the PV was eventually going to sink the high.

I'd certainly take the ECM 168hrs and the GFS NH pattern at 240hrs, not too much to ask is it!

[kold weather]

I know people might be thinking how can this GFS be better than the ECM even though the latter did bring in that easterly flow, if you put aside the GFS blowing up that low near the UK the NH pattern is far better at 240hrs.

If you want a cold spell that delivers we must see the PV edged away, and the block further north, the ECM was great at 168hrs but then the PV was eventually going to sink the high.

I'd certainly take the ECM 168hrs and the GFS NH pattern at 240hrs, not too much to ask is it!

My problem is we effectivly still don't have anything that cold till maybe 360hrs out...it might be borderline cold enough for some sleet/snow at 216-240hrs but other then that we are once again controlled by the Atlantic.

However if we use our heads and think that FI does tend to overdo low pressure systems....certainly lots of chances from the 18z run. If only that jet didn't come on so strong.

However the 18z really is NOT that cold...as surprising as that may be to some!