Winter Model Discussion 18Z 8/1/13. The hunt for cold (is closer).

[chionomaniac]

Right.

It's been a great day model watching with some kind of agreement now from the main operationals for day 4. There are still a few banana skins to get though though before we get to any definitive cold (snow) forecast so lets hope the pub run delivers....

As always try and keep on topic, try and curtail any over excitement (or disappointment) and remember the chat room for general chat!

Wishing us all the best of luck!

[ChartViewer]

Ill post this.....latest anomaly charts from NOAA....

Discussion here

http://www.cpc.ncep.noaa.gov/products/predictions/610day/fxus06.html

[AWD]

Solid short De Bilt ens;

London ens will be interesting later.

[snowking]

Slightly better pressure anomalies at 192:

Yesterday

Today:

Overall ensemble mean very diluted, but certainly better than yesterdays 12z:

SK

This from Matt:

12Z EC ENS now on board. EC clusters definitely more grouped around the blocking pattern. Hence EC ENS support the UKMO, GFS, ECM Det models

[SMU]

Against some other opinions I think the model output confidence is as high as you can get it out to 130 tonight-

Post this time there is only 2 solutions on offer- the ECM & GFS big guns- & the others that take the greenland evergy along the northern flank of the scandi high as opposed to sliding south down the western flank-

The timing of this cold is perfectly alligned to a downward propergating warming- as posted in the strat thread the best analogue from my findings was 1985- I think this came up a few times-

As for the greenland high we have cause to be very optimistic, the GFS operationals are now at least 6 runs on the trott for a GH & the ECM has now jumped on board-

As for the Warming not having any effect on this first bout I do slightly disagree- the zonal wind has decreased as an imeadiate response so the jet will respond by decelerating- it is no coincidence that the first high appeared as the fiurst effects were felt & now as we get full propergation so the greenland high can show its hand.....

snow in the forecast as early as day 3 18z- so theres not much more we could ask for-

What can we want-

just a slightly deeper low to the east at 96-120 like the gem just to force the upper level cold pool into effecting more of the UK- also that would bring snow showers further inland over the weekend.

Post that the slider low if it varifies could hit the same areas that the northern edge of the band effects friday night- so a possible double whammy-

Expect more of the same from the pub run- remember if the split flow is there at 96 then 100% varification of the GH & wham bam for the UK

S

[chionomaniac]

It's still the 8th Chiono....lol

Err thanks!

[Cloud 10]

Solid short De Bilt ens;

London ens will be interesting later.

Those are stunning ensembles,even a couple of "mental cold" members in there!

ECM ensemble mean height anomalies at 240 hrs.

[Bobby]

ECM ensemble mean uppers at -6c to -7c for most at +168

Stronger blocking over Greenland also at +168 which strengthens if anything out to +240

(pressure anomalies)

[ChartViewer]

CMA120 Excellent

[Long haul to mild]

CMA120 Excellent

That Chinese model is leaving me hungry for more! Ahem.......

Anyway, good to see that we have almost across the board agreement tonight; imagine there will be a few more dramas to follow but looking promising going into the weekend and next week.

[smogonthetyne]

Evening All,

Just a quick line to thank you for all your informative posts, a great way to start learning more about our weather. I just hope it all comes together for you this time, waiting for each model run must be as heart stopping as watching the boro in injury time.

fingers crossed

[Kentish Snowman in Yorks]

All I know is we have a cold and potentially snowy weekend coming up and that is all within T120 folks.

If we had cross model agreement at T96 showing a mild outlook, anyone urging caution re the output or generally cold ramping would be accused of desparation so regardless of the output post T120 I think we may have weekend coming up that most of us have been craving since November!

[stodge]

Evening all

Well, quite an evening after quite an afternoon. I have to say I was unprepared for the forecast longevity of cold into next week. I need more convincing of the likelihood of snow in my part of lowland east London though the probability for eastern higher ground looks quite high.

As always, more output is required and I still feel 48 hours away from being able to call this for certain.

[ITSY]

In the words of Liam Dutton: Could this be the moment?!

If this pattern persists by morning (which is to be considered, IMO, likely given cross model support from EVERY model operational at the very least - and some stunning ECM ensembles), we could be on the brink of something very special indeed.

Ian Fergie, if you're watching, I am awaiting the overall jist of your weekend heads-up from the Meto with more interest than ever!

[BLAST FROM THE PAST]

As Steve says watch for split flow, and don't worry about any LP to our NW, trigger LP scenario...always worked in the past. IMO any model that does not support GHP height rises down the line are off the mark. Hopefully this is now getting borne out.

laters

BFTP

[chionomaniac]

Short ensembles right down the middle of the fairway

Lovely.

[kev238]

It looks really good this evening... Details cannot be really pinned down for the weekend in terms of snow potential. However, ifmthe weekend goes as is suggested then a sustained period of wintry weather looks inevitable. Some of the runs look epic.

[Frosty.]

The crucial part of the Ecm 12z is at T+120 to T+144 hours with the icelandic low slipping southeastwards to the southwest of the uk and enabling a massive undercut which sucks the bitter cold air from the cold block to the northeast southwestwards across the uk, from there it's winter wonderland uk with all parts of the uk likely to have snowfalls and severe frosts with widespread ice days, just typing it feels good, the coming weekend looks very cold with increasing snow risk and then next week looks even colder with more snow and very frosty.

[Backtrack]

Ian F's weather update. The last minute is worth the watch for the entire UK, such an excellent forecast, professional as you're going to get,

http://news.bbc.co.uk/weather/hi/news/newsid_7760000/7760862.stm

[goosey007]

can anybody give me roughtly the chances of seeing the whitestuff in south east wales this weekend after these amazing model outputs??

amazing Day of model watching best i can remember!!

Just wish the M office would back these charts up with some sort of forecast!!

[Met4Cast]

Ian F's weather update. The last minute is worth the watch for the entire UK, such an excellent forecast, professional as you're going to get,

http://news.bbc.co.u...000/7760862.stm

Other forecasters really need to start taking note. Ians forecasts are easily some of the best I've seen!

[Rocheydub]

can anybody give me roughtly the chances of seeing the whitestuff in south east wales after these amazing model outputs??

amazing Day of model watching best i can member!!

Just wish the Mo office would back these charts up with some sort of forecast!!

Probably best asking that in the regional threads dude.

[Backtrack]

Other forecasters really need to start taking note. Ians forecasts are easily some of the best I've seen!

It's a shame the rest of the forecasters can't be like him; professional, tidy & doesn't dumb it down completely, even goes into Met Office thoughts at the end there. Wish our regional forecaster was half as good.

[mcweather]

Ian F's weather update. The last minute is worth the watch for the entire UK, such an excellent forecast, professional as you're going to get,

http://news.bbc.co.u...000/7760862.stm

Brilliant. The great thing about Ian is that he presents the forecast as though he knows we're actually interested in weather. If only we had anyone half as good on South today.

[on the coast]

Other forecasters really need to start taking note. Ians forecasts are easily some of the best I've seen!

I agree very informative. We have Paul Hudson who is also very good but can be a bit childish at times.