Model Output General Discussion

[chrisbell-nottheweatherman]

Perhaps this would be a good opportunity for a forecast or senior member to explain the differences and why the parallel is supposed to be better?

[loadsa]

Question, how come the 12z starts at 3.30 and the times given for example +9 hours give 2100 hrs. Is it the case that it actually takes 3hrs plus to hit netweather am I right in saying the 3hr mark is what supposed to be happening now if that is the case

[conor123]

The 06z is never the most reliable of the GFS output and it was something an outlier in bringing in milder conditions sooner than the rest of the ensemble members.

What we are looking at though is a significant -ve height anomaly to the SW and fronts are inevitably going to try to push in, to slow these down or force them to spino off we are going to need to see a pressure rise to the North.

Hopefully the fronts will just wack into the Midlands and stall for once.

There's seem to be an upgrade already in precipitation intensity for tommorow on the cold front.

[MKN]

Question, how come the 12z starts at 3.30 and the times given for example +9 hours give 2100 hrs. Is it the case that it actually takes 3hrs plus to hit netweather am I right in saying the 3hr mark is what supposed to be happening now if that is the case

The data was taken at 12pm therfor +9 would be 9pm, we just have to wait 3 and a half hours for the charts to come through to us.

precip types go for rain tomoz for most atm

[andy_leics22]

I fancy some heavy snow for central southern England tomorrow night. Places like Reading could be in for something.

[snowray]

Upgrdates already at T42 for the initial Easterly, looking a fair bit more intense.

[Lynxus]

Upgrdates already at T42 for the initial Easterly, looking a fair bit more intense.

Sorry i dont understand most of these charts.

Could you link to the one thats showing an "upgrade?" and what your looking at?

[PompeyFC]

I fancy some heavy snow for central southern England tomorrow night. Places like Reading could be in for something.

yeah sadly as it moves further south - dewpoints and 850's are not favourable

[MKN]

upgrade for thursday thats for sure, stronger easterly flow, precip stretching far inland from the east and very cold 850s.

[Southender]

More of an intense ENE so far. Northerly to be delayed slightly I reckon, prolonging the ENE flow.

[NorthantsSnow]

Looks like the GFS has come into line with UKMO suggesting heavy snow showers for eastern counties throughout Friday, particularly Lincolnshire.

[chrisbell-nottheweatherman]

Upgrdates already at T42 for the initial Easterly, looking a fair bit more intense.

Isobars and 650hPa temps look good for early Friday morning. Unfortunately it appears that the southely arm of the jet does start heading north, though the northerly arm is still just about OK given what Steve Murr said yesterday, I think.

Edited December 15, 2009 by chrisbell0033944

[Eugene]

http://www.wetterzentrale.de/pics/Rtavn662.png

Stonking chart to have at such a short term, hopefully will shut up the cold never arrives crew for abit.

Friday looks like we could record a widespread ice day with bone chilling dew points and night to follow

[kold weather]

A much perkier run in terms of precip, may well be a sign of an improvement with regards to getting to grips with convective set-ups in an easterly airflow, which was a big issue wit hthe GFS in under-estimating precip, the GFS is stronger on just about every front which I'd imagine is the paralells doing...or now the op.

[snowray]

Sorry i dont understand most of these charts.

Could you link to the one thats showing an "upgrade?" and what your looking at?

Sorry but I dont know how to do links.

The extra 12 hours of cold on the 12z makes all the difference, lots of snow showers establishig themselves in Eastern areas, these moving a fair way inland.

This should also create a nice cold pool for the next lot to arrive over the weekend.

BBC now also ramping away!!

[Southender]

Much better run.

Strong, biting Northerly across the UK by Sat night.

Snow for most, looking at the temps.

Edited December 15, 2009 by LeighShrimper

[Thundery wintry showers]

The new version of the GFS continues its trend of throwing up cold snowy scenarios- this run, so far, is an absolute cracker for cold/snow lovers. The ENE'ly is much stronger and brings the sub -10C 850hPa values across a large part of the country together with a fair crop of snow showers for eastern areas and the cold air comes in sooner- widespread accumulations of snow by Thursday evening I would've thought.

The northerly looks like it's oriented more like the UKMO and ECMWF versions instead of the probably-faulty GFS 06Z run, which is what I expected- but I didn't expect the upgrade to the easterly!

[Eugene]

OMG definate upgrade this run with heavy snow showers moving southwards on saturday with temps around 1C

http://www.wetterzentrale.de/pics/Rtavn1021.png

http://www.wetterzentrale.de/pics/Rtavn1024.png

http://www.wetterzentrale.de/pics/Rtavn1022.png

[liltbrockie]

Seen enough already.... massive upgrade as far as i'm concerned :-D

[dvdfjojo]

I'm loving the Thurs Night/Fri morning charts - low, low 850s and snow for the Midlands.

[trevw]

looks like more snow potential for the south from the northerly compared to the 6z, how does it compare to the runs we were having before? (didnt't get a chance to look at the model output from any of the previous obviously good runs)

[MKN]

If this run verifys very few members will be complaining, absolute cracker, Im not gonna get over excited though as the 18z could easily look like the 06z.

[03jtrickey]

GFS 12Z is looking very optimistic so far. First of all, there is a much stronger flow which should propel showers further inland

http://charts.netweather.tv/gfsimages/gfs.20091215/12/54/h850t850eu.png

the cold pool covers more of the UK

http://charts.netweather.tv/gfsimages/gfs.20091215/12/72/h850t850eu.png

prolonging the easterly. Then the northerly arrives, which out to T105 is considerably less slack than on the 06Z run

http://charts.netweather.tv/gfsimages/gfs.20091215/12/105/h850t850eu.png

and is full of ppt. In all, a lot to look forward to!

Edited December 15, 2009 by 03jtrickey

[nick sussex]

A much better run so far and the Greenland high is pushing further south. We want it to keeps its shape as much as possible and not to be eroded from the sw.We need the Siberian high to ridge west and help the Greenland high sink the trough and keep that mild muck away!

Edited December 15, 2009 by nick sussex

[Jan 87]

Block looking stronger. Should be a better FI