Winter Model Discussion 12Z 15/1/13 onwards.

[EML Network]

Quick one in relation to the Netweather PPN type charts.

I have found them to be remarkably accurate over the past 2 years in particular.

Take last Feb for example, for a few days before we saw that snow event in the SE ..the PPN type charts had my area slap bang in the middle of the snow/rain line and this was continued to be modeled right up until the event itself

What eventually came to pass was spot on, everything East of here got snow, everything West got rain, and I got sleet.

They were also very accurate with yesterday's event, even as far as 36 hours out, and I'd go as far as to say that they were far better in terms of predicting rain/snow type than the NAE charts were on both occasions.

just my pennies worth

Edit, the NAE charts failed to pick up on the snowfall we had in Late November too

Edited January 15, 2013 by EML Network

[Barry12]

complete novice question but what is the SSW and how will it effect our weather?sorry for posting this question here

This explains it well

http://www.bbc.co.uk...atures/20998895

Edited January 15, 2013 by Barry95

[SMU]

LOLOL- another slider with more snow-

best place out of all this- elevation in the midlands- telford somehwere like that??

WATCH ONE OF THE SHORTWAVES BREAK AWAY EAST AT 216

S

[dbaloo]

This explains it well

http://www.bbc.co.uk...atures/20998895

many thanks.that helps a very confused and still learning man out a lot!

[weirpig]

http://www.meteociel...H1-192.GIF?15-0

LOLOL- another slider with more snow-

best place out of all this- elevation in the midlands- telford somehwere like that??

WATCH ONE OF THE SHORTWAVES BREAK AWAY EAST AT 216

S

lol now i know your joking

[Downpour]

Quick Question Steve

Do you think this is the main blast for the UK or more too come as I really don't see this lasting any longer than Monday.

Just from experience I'd say the Atlantic tends to break through by Day 3. But I'll defer to Steve's fat greater knowledge

[Panayiotis]

http://www.meteociel...H1-192.GIF?15-0

LOLOL- another slider with more snow-

best place out of all this- elevation in the midlands- telford somehwere like that??

WATCH ONE OF THE SHORTWAVES BREAK AWAY EAST AT 216

S

Yes I expected that, as its similar to the GEM but the GEM had stronger heights to the north which means that the low was shunted further east than on the ECM, still an amazing pattern nonetheless. Edited January 15, 2013 by Panayiotis

[bluearmy]

and the angle of the occlusion at day 8 is pretty well the same as days 3 and 5. i wonder if the london ens will reveal sub zero temps all the way through on this run.

[TEITS]

Looking at the ECM and the rest of the models I think back to something GP said many days ago or it might of even been last week.

GP said we might see a shortlived break from the cold spell before a reload from the NE during the last week of Jan. Well looking at the ECM this is quiet possible.

http://www.wetterzentrale.de/pics/Recm2161.gif

[Cecil Hogmanay Melchett]

this could be breaking news come friday mark my words ecm is a snow fest

Edited January 15, 2013 by happy days

[manutdmatt1986]

http://www.meteociel...H1-192.GIF?15-0

LOLOL- another slider with more snow-

best place out of all this- elevation in the midlands- telford somehwere like that??

WATCH ONE OF THE SHORTWAVES BREAK AWAY EAST AT 216

S

Steve, in your opinion, would the snow likely affect only the midlands and western areas or would areas further east likely be affected?

[ChartViewer]

Meanwhile the CMA Consistant in its output is fantastic at T72

[NorthNorfolkWeather]

Just from experience I'd say the Atlantic tends to break through by Day 3. But I'll defer to Steve's fat greater knowledge

I know he thought that he needed the fat for the winter

Well, everything points to a substantial dump of snow for quite a few of us, as for the slider lows, we wait years for one, then it's predicted we will get 3

Edited January 15, 2013 by NorthNorfolkWeather

[SMU]

ECM ends on what could be a SUB -20c night over the snowfields of the midlands... ( & hopefully the IMBY SE)

S

[Panayiotis]

At 240hrs and the cold is still with us (25th) and this chart still has the continental feed and would mean very low temperatures.

Fi however but nice to see the cold still with us.

[Continental Climate]

Meanwhile the CMA Consistant in its output is fantastic at T72

Looks like a minus 12 into kent at 72

[Mucka]

Looking at the ECM and the rest of the models I think back to something GP said many days ago or it might of even been last week.

GP said we might see a shortlived break from the cold spell before a reload from the NE during the last week of Jan. Well looking at the ECM this is quiet possible.

http://www.wetterzen...cs/Recm2161.gif

I don't see any break from the cold except in the far SW. There is actually the prospect of the cold intensifying from the NE through the final week of January if the block holds through the mid term.

[lorenzo]

Think that would qualify as a reload.

[bluearmy]

Looking at the ECM and the rest of the models I think back to something GP said many days ago or it might of even been last week.

GP said we might see a shortlived break from the cold spell before a reload from the NE during the last week of Jan. Well looking at the ECM this is quiet possible.

http://www.wetterzen...cs/Recm2161.gif

where's the break coming from dave ? i've yet to see convincing evidence that anything that falls over the weekend will thaw. each ecm run appears to cement the cold even further. very low heights and a succession of occlusions interspersed with cold slack deep troughing.

[TEITS]

Just going to post the JMA but some members came to the wrong conclusion about the 12Z NAE.

As you can see at +48 the JMA is like the NAE.

http://www.wetterzentrale.de/pics/Rjma482.gif

Look what happens though at +72 when the front pivots.

The cold backs W. However SW England/S Wales would miss out.

http://www.wetterzentrale.de/pics/Rjma722.gif

[Mark Bayley]

ECM precipitation charts for those interested > http://en.vedur.is/w...ntic/#type=prec

Fridays band gives a country wide event (although more marginal in South Wales and South west), with the heaviest snow in the western counties.

A further band of precipitation on Sunday night, giving further snow to many

Edited January 15, 2013 by Mark Bayley

[cheeky_monkey]

Cold uppers pushing back at 192....blimey

Exceptional cold through the eastern seaboard of the states and Canada stays mild here out west

[SMU]

Steve, in your opinion, would the snow likely affect only the midlands and western areas or would areas further east likely be affected?

there seems to be some tweeting going on M.Hugo et 'al-if you look close :

UKMO & ECM BOTH have the front through the Uk

ECM :

the only area to miss maybe Eastern Scotland-UMKO

A bit more of the NE & scotland miss:

The guidence based on the OPS only- ( remember I havent got the ECM or MOGREPS)-Is that snow will become wisespread across ireland + Wales & England late Friday & in the early hours of Sat-The Snow may turn back to rain for Southern Ireland

The SW- devon/ Cornwall etc

Some southern Counties- direct adjacent to the onshore southerly flow....

The synopsis would be that low pressure with associated atlantic moisture & warmer air will move ESE across the UK-

Milder upper air will be mixed out by cooler air tucked in behind & the Very cold uppers over the UK will get mixed out to less cold uppers- say -9 moving up to the -5C line-

Because the cold is embedded at the surface & the flow is continental SEasterly the undercut & low dewpoints will cause the rain to turn to snow for all of us for a time, but slowly turn back to rain in the above mentioned areas-

The reason it stays for snow over the UK is for continued southerly flow ahead of the warm air which is is in the channel- + the fact there is a sharp gradient change away from that front-http://www.meteociel.fr/modeles/ecmwf/runs/2013011512/ECM1-120.GIF?15-0

( cold air cannot just go around a corner like that)

In summary-

Snow sliding East south East across the UK on friday-Some models will be further NE that others, the NE could miss & stay very cold-

the midlands are always prime locations in this

the SW need a large correction SW to stay all snow- which is now unlikely at t72

-cheers

S

Edited January 15, 2013 by Steve Murr

[Habsish]

Although watching with great interest and anticipation I get a certain feeling of deja vue concerning some of the postings. I have seen all this unrestrained hype before where model out put has suggested a possible cold snap. Any chance that eventually somebody (or more than one model) might get it right?

Possibly more restraint and unbiased consideration might be the the order of the day.

Edited January 15, 2013 by Habsish

[TEITS]

where's the break coming from dave ? i've yet to see convincing evidence that anything that falls over the weekend will thaw. each ecm run appears to cement the cold even further. very low heights and a succession of occlusions interspersed with cold slack deep troughing.

Sorry I was rather vague in my post.

When I referred to a short lived break I was meaning more for some locations such as SW, Extreme S counties of England. This could extend further N or S yet although you have to fancy the general pattern to be pushed further S.