Model Output - General Discussion

[Thundery wintry showers]

have to say it

some of you lot-and some should know better gobsmack me

we have the daddy of cold spells about to start-frost-snow for many and we are already looking to T+300+ for the breakdown-come on kids give everyone a break-talk about the next 24-120 hours perhaps out to 168 hours-salivate-enjoy-watch each b- run if you want but for heavens sake stop wishing your lives away on manyana land.

enjoy this week if you are a cold fan-get real

end of another jh rant

tara

Quite right John, and I must admit I got caught up in the heated debates over those those far-away charts, though I only made speculative judgements.

For the foreseeable future (T+168) there isn't even a breakdown in sight!

[Snowyowl9]

I`ve just had a look at february 2006 easterly snow day on this fax for the first time.

http://www.wetterzentrale.de/archive/2006/brack/bracka20060224.gif

Fax chart looks very interesting and complex feature coming in from the NE,and looks even better to what it did a few nights ago,maybe upper air will be abit marginal for low ground,but sub 528 is there.

http://91.121.93.17/pics/brack2.gif

Upper air early stage.

http://www.wzkarten.de/pics/Rmgfs602.gif

[TEITS]

Very cold day on Wed.

http://www.wetterzentrale.de/pics/Rmgfs664.gif

Some may wonder why so cold when upper temps are around -6C. Well the answer is because we start the day with low mins and the short daylight hrs supress the max temp. This is another reason why Dec 81 was so cold.

[Shiny_Bottom_1]

Hmm maybe somethings been overlooked, the gfs 18z is now predicting mod/heavy precipitation in northern england tommorow with temps of 1 degrees??

http://www.wetterzentrale.de/pics/Rtavn1817.png

http://www.wetterzentrale.de/pics/Rtavn184.png

could be interesting especially on high ground.

Unfortunately H500 and 850hpa's dont really support any snow.

The ppn type charts available probably show a realistic scenario. The further s/e you are, the more chance of a 'wintry' mix.

Just like it can snow at 4oC 2m temps, its can also rain at 1oC 2m temps.

I could be wrong though.

[chionomaniac]

Tomorrow night/Tues morning does need to be watched closely.

http://www.wetterzentrale.de/pics/Rmgfs362.gif

http://www.wetterzentrale.de/pics/Rmgfs364.gif

Possible to see snow on the E flank of the precip with E Midlands most at risk.

That is a good call TEITS. There may be snow forecast under our very noses that we should look at before looking too far ahead.

Edited December 13, 2009 by chionomaniac

[SMU]

Unfortunately H500 and 850hpa's dont really support any snow.

The ppn type charts available probably show a realistic scenario. The further s/e you are, the more chance of a 'wintry' mix.

Just like it can snow at 4oC 2m temps, its can also rain at 1oC 2m temps.

I could be wrong though.

18z looking nice now-

Also short term snow prospects looking better- I would plum for somewhere in the home counties to get a good dusting Tues eve...]

The 18z then has a good easterly from T84 until t108- with heavy snow in the t102 range- for the SE cornerovernight thurs)

Steve

Edited December 13, 2009 by Steve Murr

[Harsh Climate]

Unfortunately H500 and 850hpa's dont really support any snow.

The ppn type charts available probably show a realistic scenario. The further s/e you are, the more chance of a 'wintry' mix.

Just like it can snow at 4oC 2m temps, its can also rain at 1oC 2m temps.

I could be wrong though.

Dont think it will be anything significant, but I wouldnt be suprised to the the odd flake of snow.

[morfius]

Friday looks like an upgrade to me, will have to see how cold the uppers get, but it's looking like sub -10 should make it

[Lincs Observation]

not looking as good for us up the coast a bit, Mind you will the lincs wolds to cross everyday less is a good thing regrettably. However the cold theme is pretty much set but a few more runs to firm up the length of this spell me thinks.

LO

[johnholmes]

That looks unrealistic to me, a low of that intensity south of 50N? Me thinks not....

I think not either-what one has to look at is beyond the apparently obvious

what is the model playing with?

is it picking up a signal for low pressure to lie across that part of the Atlantic?

does the upper air pattern support this-not at the time it shows the deep low but in the lead in to the situation?

interesting

[TEITS]

Well the 18Z extends the E,ly for another 6hrs compared to the 12Z.

Still every little helps!

[benb]

Friday looks like an upgrade to me, will have to see how cold the uppers get, but it's looking like sub -10 should make it

The short wave seems a little delayed on this run, perhaps giving longer for the really cold uppers to arrive from the east.

[swfc]

Just a quick question.Why will the area of low pressure delivering the northerly slip sse.???.thanks

[Simon SWales]

Well the 18Z extends the E,ly for another 6hrs compared to the 12Z.

Still every little helps!

Lol, but it does make a change, usually the other way around!

[benb]

Less of a plunge with the northerly on this run, too- also giving more time for the uk to tap into the really cold stuff to the east.

[LomondSnowstorm]

18z looking nice now-

Also short term snow prospects looking better- I would plum for somewhere in the home counties to get a good dusting Tues eve...]

The 18z then has a good easterly from T84 until t108- with heavy snow in the t102 range- for the SE cornerovernight thurs)

Steve

Let's not forget some decent snow showers along eastern Scotland

The precipitation charts are beginning to look a bit better as they move closer to the time, as I believe you and others have said before the models tend to underestimate north sea convection precipitation events so this bodes well for Thursday.

[03jtrickey]

Well there's a huge amount of interest in the models over the coming few days! First of all a possible spell of snow for the Midlands overnight Tuesday-Weds, supported by the 12Z and 18Z runs today from the GFS. It currently looks like a rain to snow event as cold air undercuts. Then into Thursday and Friday, the "Easterly proper" looks like bringing showers, and on Friday the 18Z shows -10hpa flirting with Eastern coasts: http://charts.netweather.tv/gfsimages/gfs.20091213/18/117/h850t850eu.png

I think that is as far as anyone can reasonably predict at the moment. Easterly of some sort of intensity looks pretty certain - exciting times. Beyond that, a potential northerly, then who knows?? For me the best thing about the UK winter is not knowing exactly what will happen!

[TEITS]

The only real difference between the UKMO & GFS is if you look at the UKMO the LP over France/Spain is further N hence maintaning the E,ly for longer.

The detail for the end of the week is nowhere near certain yet!

http://www.wetterzentrale.de/pics/Rukm1201.gif

[chrisbell-nottheweatherman]

I'm pleased to see low 500hPa heights then easterlies for the second half of the week plus cold 850 temps by Friday evening.

[SMU]

Something I Want to throw into the mix-

If the small ridge at around t100 holds the Easterly in place for longer- even 12-18 hours more , apart from the obvious advantages it brings-

* Further snowfall

* Colder uppers-

* Lower dewpoints from the continent-

It also does the same with the southerly progression of the active cold front from Scotland-

So one for the Scots & the folks from t'up North- is that trough will come south slower with the ridge ahead of it ( PPN heaviest on the Eastern flank)-

May even snow in Carlisle....

S

Edited December 13, 2009 by Steve Murr

[benb]

Obviously the Iberian low is far more developed on this run. What effect is this likely to have on how things develop?

[Harsh Climate]

http://charts.netweather.tv/gfsimages/gfs.20091213/18/153/uksnowdepth.png

I wouldnt say know to that lol

Edited December 13, 2009 by Jed Bickerdike

[SMU]

Midday temps Sat-

Anyone want to throw the Marginal curve ball at me again-

http://www.wetterzentrale.de/pics/Rmgfs1384.gif

yes thats -3 MAX in the HIGH res @ 138.....

& -8 Max the next day-

http://www.wetterzentrale.de/pics/Rmgfs1624.gif :o

S

Edited December 13, 2009 by Steve Murr

[Weather-history]

A white Sunday morning if this was to come off

http://www.wetterzentrale.de/pics/Rmgfs1563.gif

[Harsh Climate]

http://www.wetterzentrale.de/pics/Rtavn1685.png

woahh never seen a minus 10 on the 2ms before lol!

http://www.wetterzentrale.de/pics/Rtavn16217.png

And a maximum of minus 4 of the snowfields would do nicely!