Model Output Discussion 01/09/17

[nick sussex]

In case people are wondering about this warning system! Lol it did appear a few years back but I shelved it because so few decent cold synoptics ever appeared in recent years there was nothing to warn about ! 

Red - low margin for error , liable to implode at any moment !

Amber- medium margin.

Green- prepare to dust off the ear muffs, scarves and ice scraper.

Green Plus-  as above but include the sledge !

[BLAST FROM THE PAST]

ECM, much more like it.  Very interesting Countryfile forecast.....the potential gathering of a colder surge noted.....it’ll be more than noted before long......however we have copious amounts of rain this week...won’t be pleasant at all and certain areas to be on watch 

 

BFTP

Edited November 19, 2017 by BLAST FROM THE PAST

[Methuselah]

Taking the past four winters into consideration, I think I'll save my excitement until I see the first flake (or grain) of snow fall?

[Frosty.]

Mayday  mayday  we have a netweather  meltdown situation...Ecm  12z turns into a peach run for coldies  and snowlovers..including me!

[Britneyfan]

This has all changed rather quickly?

[knocker]

At T96 the ecm has a complex positively tilted upper trough from the UK running south west which is about to deconstruct under pressure from the Azores ridging north towards Greenland. This leads to a complex area of low pressure which is over the UK at that time, giving gales and heavy rain in many places, to track NE over the next 24 hours and becomes more organised to be 960mb adjacent to the Norwegian Basin This leaves the UK in a strong north westerly airstream, gale force over Scotland, accompanied by squally wintry showers. Simultaneously the high cell that has emerged seals the cut off low to the south west

By Saturday 12 everything has moved a tad east veering the surface wind a little with still squally wintry showers affecting the north and western coastal regions. There could be some significant falls in the Scottish mountains and even the high ground in the NW England and north Wales. By 12 Sunday the ridge has moved further east but is coming under pressure from the eastbound  energy. The events after this I will leave until the ens are available.

[Longtimelurker]

Just curious according to ECM run would Eastern(central and northern) Eastern France likely see snow from it? Above 200m

 

Anyone know which site uses ECM for its daily forecasts? Like accuweather uses GFS. TY 

Edited November 19, 2017 by Longtimelurker

[Mucka]

JMA is much closer to UKMO at 144 so ECM a little on its own with the amount of amplification through the mid term at the moment.

[knocker]

12 minutes ago, Longtimelurker said:

Just curious according to ECM run would Eastern(central and northern) Eastern France likely see snow from it? Above 200m

You couldn't rule out some flurries in north east and eastern France, Belgium, the Netherlands and N. Germany but to be honest I'm not totally sure what all the excitement is about.

Edited November 19, 2017 by knocker

[SLEETY]

And how many times does ecm cold weather charts at the late stage of its output ever verify.

 

could mention countless times in the past it shown a cold output and never verifying 

[Geordiesnow]

Does look like the models are wanting to break down this west based NAO quicker than perhaps first thought although the GFS is still sticking by it hence why its showing a somewhat milder outlook than the ECM.

Assuming the breakdown of the west based NAO occurs, question will be how much ridging will we see and in turn how much cold air can be pulled down from the North West. The threat of a significantly deep low pressure has somewhat waned although I still would not rule out any sting in the tail so to speak but the rainfall is likely to be the main talking point for the start of this week. Either way its an interesting period of weather and hopefully the switch to those cold NW'lies occured but they were forecast to occur last weekend but we ended up with high pressure closer to the UK therefore the convective weather was just limited to the Western half of Scotland

[Frosty.]

16 minutes ago, SLEETY said:

And how many times does ecm cold weather charts at the late stage of its output ever verify.

 

could mention countless times in the past it shown a cold output and never verifying 

Well all I can say is the Gfs  looks wintry too longer term..hopefully cold is coming..after all the recent / current cold eye candy, it's about time it verified!

Edited November 19, 2017 by Frosty.

[weirpig]

7 minutes ago, SLEETY said:

And how many times does ecm cold weather charts at the late stage of its output ever verify.

 

could mention countless times in the past it shown a cold output and never verifying 

Yes agree. However this starts at t96  and at this time range  ecm is definitely the top dog   Certainly something more wintry showing. How much we will see over the next few days 

[Summer Sun]

UKMO extended shows a westerly flow for the UK with some fairly strong winds and rain for some

[Ali1977]

Great ECM run, FI is medium term going off the different models this evening though. Let's hope the ECM is on the money. That 240 chart has plenty of potential too, although nothing too cold to our NE yet but a WAA/Siberian high link up would be nice!! 

[January Snowstorm]

One thing I've learnt over the years is using a mix of all models is quite a useful tool in predicting beyond 5/6 days. Quite often the end result is a half way house between what gfs and ecm predict.

Interesting times, just we've all been burnt so much over the years I think energy levels are waning!! Particularly after last year promising so much

Edited November 19, 2017 by January Snowstorm

[northwestsnow]

27 minutes ago, knocker said:

You couldn't rule out some flurries in north east and eastern France, Belgium, the Netherlands and N. Germany but to be honest I'm not totally sure what all the excitement is about.

From my perspective possibly becasue the EC shows the chance of snow showers for hilly NW England

[Summer Sun]

Looking at the GFS mean the peak of the warmth this coming week is likely to be around Wednesday afterwards it is a steady drop down for temps

[karlos1983]

20 minutes ago, Summer Sun said:

UKMO extended shows a westerly flow for the UK with some fairly strong winds and rain for some

Also shows some nice ridging in the Atlantic...

[bluearmy]

55 minutes ago, Longtimelurker said:

Just curious according to ECM run would Eastern(central and northern) Eastern France likely see snow from it? Above 200m

 

Anyone know which site uses ECM for its daily forecasts? Like accuweather uses GFS. TY 

Yr.no

[Man With Beard]

Runs like tonight's ECM remind us - first, D7-D10, look for a general synoptic pattern to get in place, then D4-D6 worry about the detail. The potential could be seen for something like this ECM the past couple of days, the consistency of the ops in not showing it may have persuaded us it wasn't worth keeping up the "watch" - but it now looks like there may have been a last minute development - not completely invisible in the ensembles earlier in the week but never the favoured option. We'll be looking for the other models to follow in the next 24 hours if this really is the new direction (or for the ECM to fall back to the others).

Snow chances are good for many on the 12Z run! By Sunday first thing, areas modelled to see falling snow included: most of Scotland (quite a decent fall for many), most of northern England north of a line Birmingham to Hull (but not areas directly to the east of high ground), all of N Wales, high ground in S Wales, Dartmoor, Bodmin and Exmoor - and a few flakes for the highest ground further south (e.g. Chiltens, some parts of N Downs).

[Summer Sun]

ECM mean trending down from later next week and gets no higher than 0 for the remainder of the run

[booferking]

7 minutes ago, Summer Sun said:

ECM mean trending down from later next week and gets no higher than 0 for the remainder of the run

Central Scotland & NI

[damianslaw]

A much more unsettled spell in the short-term, heavy bouts of rain and wind, but also mild, though it won't feel especially pleasant. The other side of late autumn, the wet dark side..its been an autumn with the odd bout of heavy rain, but mostly fairly light stuff so hopefully not too troublesome.

Reliable timeframe remains very short at the moment, 96 hrs tops, uncertainty thereafter, but the trend shown by all models is for the flow to back more to the NW, and hence it will become colder for all by the end of the week, with potential for wintry precipitation down to quite low levels in the north. Much will as others have commented depend on the extent of any amplification of the flow, it could end up being quite a cyclonic end to the week, if we see further shortwave development to our SW, conversely we may see a clean sweep of low heights as shown by ECM and advect a direct cold shot from the north. The dominant forcing is coming from those strong heights to our NW.

 

[Dennis]

anomalies by EC