12z model discussion - snow or sleety rain?

[KTtom]

ECM now out on wetter...maybe a little more enthusiasm now its in the forematt most relate to......

http://www.wetterzentrale.de/pics/Recm961.gif

http://www.wetterzentrale.de/pics/Recm1201.gif

http://www.wetterzentrale.de/pics/Recm1441.gif

Still don't thin its quite as good as UKMO though Nick, unless your in Scotland?

KTtom

[nick sussex]

Oh wonderful

Could you ask them to have the courtesy to let us know earlier next time

before we start discussing it.

Well Brian the gfs 12hrs operational run got so many key details wrong that its a non starter , there shouldnt be such a problem however with the GEFS ensembles but the gfs 12hrs run is likely to be way off the mark because of criticisms by NOAA.

This is why I slated the gfs earlier today , but somehow in here the gfs is god and everyone seems to believe its every move, this is liable to cause alot of trauma, alot of this can be avoided if people take a broader view of the models rather than this fixation with the gfs. Its great for its free info but as we've seen can be prone to huge mood swings!

Edited February 5, 2007 by nick sussex

[Frosty.]

It's looking a lot better for the north as well, especially the north east with a constant feed of snow showers and increasingly strong easterly winds later in the week. North East England as far west as the pennines should get some frequent snow showers on wednesday and especially thursday with a few cm's of lying snow possible. Southern england, wales, and the midlands look in the firing line for rain turning to heavy snow in a knife-edge situation which could result in major travel disruption. The Scandinavian High will build and hold firm with a huge mass of very cold air sitting to the north and keeping most of the uk in cold air right up to the end of the week. South West England may become milder. All in all, a GREAT OUTLOOK and one that seemed impossible to even dream about a few weeks ago.

[Matty M]

But it'll be fantastic up in the Dublin Hills. A lovely part of the world made all the lovelier by snow.

Regards,

Mike.

Dont think it'll just be the hills myself

[johnholmes]

final blog no 10 is now out and so am I just about.

[yamkin]

The fax chart is out for thursday and because of the confusion this is our most reliable chart at the moment and i've drawn who would get snow/rain.

Don't be at all surprised for the snow to penetrate further South.

[Cloud 10]

The model rollercoaster is certainly in high gear at the moment,it really can do your head in sometimes!

The 00z ecm looked to be going the way of the previous gfs runs and was much improved,however the gfs then throws in a poor 00z and 06z run which almost got me reaching for the medicine cupboard ,then i viewed the stunning fax charts,and almost cracked open the champagne!

As for this evenings models,the strong potential for many of us to see some snow is certainly there,how much and exactly where is another question.

The ukmo tonight has to contain the best charts of winter so far.

[kold weather]

Hi supercell, I think you'll probably be right, the exact track won't be certain until it probably happens!

On a global scale this is but a small adjustment but as i mentione din the other model thread because the front is moving northwards faced W-E it means that the snow-ain line is very tight indeed in terms of lattiude and slight shifts in the frontal boundary can make on a local level huge differences in the actual weather.

Richard, its mighty close and i think we'd better be very careful writing off anywhere right now, main problem is just as i said before, small adjustments make large differences. If anything though i suspect nowadays these set-ups tend to end up further south then actually progged, the main problem as I also mentioned in the other thread is that these have been very uncommon set-ups in recent years and so we have a small sample from recent years which means we won't really have a good idea about exactly how the models handle these set-ups, will be intresting to see whether they are too far north or south or if they are dead right, hard to call right now, i wouldn't like to be a forecaster for the Midlands tonight thats for sure!

[Alkyd]

Around weds/thurs I see 500mb temps of circa -30C and 850mb temps of circa -5C, do we really think this is conducive to a major snow event?

From my past observations I've always looked for -35 to -40C at 500mb and -10 at 850mb for a real risk of decent snow.

Am I wrong?

[Yeti]

Around weds/thurs I see 500mb temps of circa -30C and 850mb temps of circa -5C, do we really think this is conducive to a major snow event?

From my past observations I've always looked for -35 to -40C at 500mb and -10 at 850mb for a real risk of decent snow.

Am I wrong?

Tbh -7 is fine as an 850hpa temp, and -5 can also easily see snow if other factors are right. In this setup, pressure is very low and so -10 is not needed for snow. It's always going to be marginal at lower levels, although anywhere midlands or N'wards looks fine IMO.

Minor changes in the low's position could make all the difference, but I as say all I am dreading is the low being progged too far N.

[shuggee]

Around weds/thurs I see 500mb temps of circa -30C and 850mb temps of circa -5C, do we really think this is conducive to a major snow event?

From my past observations I've always looked for -35 to -40C at 500mb and -10 at 850mb for a real risk of decent snow.

Am I wrong?

Have a read of these matey - tells you all you need to know

http://www.netweather.tv/forum/index.php?showtopic=2235

http://www.netweather.tv/forum/index.php?showtopic=27989

[nick sussex]

The ecm De Bilt ensembles are out, the ecm was a mild outlier for the end of the week and what with the gfs 12hrs operational run being slated by NOAA then back the ukmo to verify! looks like great news for some lucky people up north. I'd back the ukmo upto 120hrs to deliver as the trend looks to take the jet further south, as long as its not too far south then the north looks like getting some fun weather, of course dont shoot the messenger if things end up being a little further south. As with supporting a football team each region is cheering on the synoptics that will deliver for it except me as I'm an impartial observer!lol

Edited February 5, 2007 by nick sussex

[Harsh Climate]

Tbh -7 is fine as an 850hpa temp, and -5 can also easily see snow if other factors are right. In this setup, pressure is very low and so -10 is not needed for snow. It's always going to be marginal at lower levels, although anywhere midlands or N'wards looks fine IMO.

Minor changes in the low's position could make all the difference, but I as say all I am dreading is the low being progged too far N.

lol, my fear is that itl be too far south and we miss all the snow, while the likes of sheffield get hammered!

Anyone got a link of the NOAA's talks about the 12z?

Edited February 5, 2007 by Jed Bickerdike

[carnoustie]

This has gotta be one of the 'charts of the day'

[Snowyowl9]

Theres no point discussing the gfs 12hrs run, its a dead duck! basically given the discussions at NOAA they're likely to ditch it as its got so much wrong.

So does that mean it`s bringing the low too far north Nick?

[Yeti]

This has gotta be one of the 'charts of the day'

No you're wrong. It's chart of the year

[MKN]

This has gotta be one of the 'charts of the day'

that fits into line with the easterly being shown for here (midlands) on saturday on the bbc 5day forecasts

Edited February 5, 2007 by CatchMyDrift
Chopped image from quote to save space

[kold weather]

carnoustie, thats one of the best charts in the last 5 years, yet alone today, the only problem is that at the moment its not got a lo of support however thats not to say it can't happen!

Nick, very intresting to hear about the ECM ensembles, that suggests to me that some had that easterly flow further west which is very intrestring becuse the ECM was mighty close and if that was a mild outlier at the end then thats very good news indeed.

I did suspect that while the ECM isn't far off it that the set-up will eventually end up further west as the models reduce the expected strength of the jet stream, that only further increases the chances of that idea I mentione din the other thread. Intresting times coming up when it comes to watching the models I feel, much joy or sorrow though, thats the question?

By the way, the NOAA discussions are for the longer term and they pretty much are saying that the GFS+ECM is pushing everything too far east too quickly, which only adds to the great intrest we have at the moment, because if you drag the ECM set-up west then we have a rather intresting little set-up.

Edited February 5, 2007 by kold weather

[tinybill]

Have a read of these matey - tells you all you need to know

http://www.netweather.tv/forum/index.php?showtopic=2235

http://www.netweather.tv/forum/index.php?showtopic=27989

its not wednesday we need to worry about i think things could get they interesting at the week end if the gfs is any thing to go by

[Yeti]

lol, my fear is that itl be too far south and we miss all the snow, while the likes of sheffield get hammered!

Anyone got a link of the NOAA's talks about the 12z?

No lol that's what I meant - I fear it being predicted too far N and then it dives S at the last minute, and we watch the TV forecasts showing blizzards literally 50miles S of here!

How gutted we would all be.

[nick sussex]

lol, my fear is that itl be too far south and we miss all the snow, while the likes of sheffield get hammered!

Anyone got a link of the NOAA's talks about the 12z?

Heres the link for you.

http://www.hpc.ncep.noaa.gov/discussions/pmdepd.html

[Harsh Climate]

Heres the link for you.

http://www.hpc.ncep.noaa.gov/discussions/pmdepd.html

cheers fella

[tom_f123]

Edited as off topic - please post into the relevant areas on the forum.

[The PIT]

I prefer this for Saturday hate to work out the windchill on that. By the way don''t look at the charts for Friday as they're mild and rubbish. Doesn't look like they know what they're doing either.

Edited February 5, 2007 by Paul

[MisfitDog3]

A lot of people seem to have no learning curve! This is one scenario based on data now which could reverse quite as easily as data changes over the next 24 hours. You would think things had been set in stone the way some people are carrying on.

Take a chill pill, some of the charts look a tad over-cooked once again, so unless you want to risk being let down big time I would be extremely cautious....