Model Output Discussion - cold spell to end Autumn

[shaky]

3 minutes ago, AWD said:

How can it be like the GFS & UKMO when they are both rather different regarding Sunday?

Sorry what i meant to say was it will probably look like ukmo more further on into the run!!

[SMU]

The GFS T96 mean appears to me the safest place for the track sliding SE through Ireland - across the SW & exiting the SE- UKMO goes a little further North around Norfolk

The only issue with the UKMO is it has more positive tilt ahead of the low hence more WAA into the front- thats the area more up for resolution ..

ECM exit point as planned- KENT

bang in line with GFS

[radiohead]

A closer look at T96 on the EC shows multiple lows. 

 

[That ECM]

Ecm like gfs is trying to build heights to the north/ northwest. I understand the sliders are getting the headlines for obvious reasons but this is interesting moving forward.

 

your explanation is better than mine shortwave, it is very interesting.

Edited December 6, 2017 by That ECM

[SMU]

19 minutes ago, radiohead said:

A closer look at T96 on the EC shows multiple lows. 

 

Yes

this is good - the elongation acts as a barrier to the milder air!

[Captain Shortwave]

This set up is a real mess, the ECM actually has another seconday low which runs around the Azores highand ploughs in France which drags the trough further south resulting in a cyclonic north easterly for day 5.

This is very different from the UKMO or GFS, so again no real agreement though the ECM and GFS both have a similar track for that frontal system on Sunday. Also the ECM has managed to link the Atlantic ridge up to that pocket of higher heights towards Iceland, a few GEFs members did that and resulting in a sustained showery northerly until the following weekend. Lets see how this develops.

[The PIT]

I wonder if the gradual southward movement of these lows in run has now come to an end or will it continue being pushed further south. At the moment we may see some light snow and flurries here. ECM really winds the low up at T120 over France which may bring snow showers to the east coast.

[igloo]

8 minutes ago, radiohead said:

A closer look at T96 on the EC shows multiple lows. 

 

great looks to be a fair amount of rain/snow from that the ECM looks more like the UKMO at 96h with very similar uppers its looking more and more likely if you are north or east of those lows you will get a good covering otherwise its just plain old rain im afraid

Edited December 6, 2017 by igloo

[Daniel*]

The Met Office text forecast for Monday mentions outbreaks of rain, sleet and snow in southern & central areas clearing later in the day. EC reflects that.

[Frosty.]

The Ecm 12z could be described as a mess but a lovely cold mess rather than an ugly mild mess..I'm loving this output!

[The Weather Dragon]

Taking the current big 3 model output into account - it’s going to get colder - Snow and ice likely for Northern and upland areas. Marginal for the rest of us with a mixture or rain,sleet & snow. No sign of a nationwide freeze in the reliable timeframe - fingers crossed for later into December and early January 

[winterof79]

A more organised band of snow showers heading south and not showing on Euro4 yet

 

[Daniel*]

Possible snow event there at T168 for the far south v marginal uppers but the flow is very slack ideal for evaporative cooling.

[shaky]

20 minutes ago, Steve Murr said:

The GFS T96 mean appears to me the safest place for the track sliding SE through Ireland - across the SW & exiting the SE- UKMO goes a little further North around Norfolk

The only issue with the UKMO is it has more positive tilt ahead of the low hence more WAA into the front- thats the area more up for resolution ..

ECM exit point as planned- KENT

bang in line with GFS

Where would the snow line be on that steve!!amazing ecm so far!!upgrade galore!!

[Snow and storms]

Not sure if this is the right thread, I had a good look but couldn't find a more suitable place to post it. Although it's not discussing the model outputs I think it's relevant to a forecasting discussion.

I am intrigued to know what the more experienced members think of this early season colds effect on the sea temperatures and the consequences down the line. Compared to the last few years we had a reasonably cold end to autumn and with the shots of northerly blasts it's been a cold beginning to winter at times.

Surely the lack of autumn storms also plays a part as this season the seas have been a lot calmer than usual. Does this have an effect on the sea temperatures? For instance a calm pond will freeze a lot easier than a slow flowing river not just because one is continuously moving but because the cold will be mixed a lot more in a flow.

Will this tie in with a more probable shot of a long term cold winter and has a quiet autumn with a cold start to the season led to colder winters as a whole in the past?

Also could someone point me in the direction of some SST charts that I and others can monitor to see if it has any effects in this current spell.

Thanks!

 

 

[winterof79]

1 minute ago, Daniel* said:

Possible snow event there at T168 for the far south v marginal uppers but the flow is very slack ideal for evaporative cooling.

I would suggest the uppers will be colder over UK depending on snow cover and cold pooling.It will probably be different anyway.

One thing looking more likely is a filling low somewhere e/se of us

[Paul_1978]

25 minutes ago, radiohead said:

A closer look at T96 on the EC shows multiple lows. 

 

Indeed! And here is is from Wetterzentrale. I don't think I've ever seen anything like this! 

[Fiona Robertson]

2 minutes ago, Paul_1978 said:

Indeed! And here is is from Wetterzentrale. I don't think I've ever seen anything like this! 

What on earth is going on there? It's like a conga line!

[Dancerwithwings]

1 minute ago, Paul_1978 said:

Indeed! And here is is from Wetterzentrale. I don't think I've ever seen anything like this! 

I know you wait 4 years for one and then four come along on the same chart 

[winterof79]

Rinse with snow and repeat 

[Singularity]

How very intriguing that ECM has found a lot more stretching of the low and now forms two dominant LPs with one tracking a little north of GFS and the other a fair bit south. 

Makes things even more complicated for Monday's outlook. 850s very marginal on ECM and stay that way through Tue with snowfall perhaps reliant on evaporative cooling and downward drag of air... I have some suspicion though that ECM may over-modify 850s a bit with time, but I can't be sure until we find out what actually transpires on Friday as GFS still has sub minus 10 making it down while ECM stays short of that.

[weirpig]

Snow-lovers EC12z has hit the mother lode for Sunday. Widespread disruptive #snow including parts of south, perhaps 10-20cm. Caveate that there is still lots of uncertainty with crucial track of low . This is taken from Chris Fawkes. So all in all descent ecm 12z 

[SMU]

31 minutes ago, shaky said:

Where would the snow line be on that steve!!amazing ecm so far!!upgrade galore!!

Approx in a line SE from manchester to essex

Edited December 6, 2017 by Steve Murr

[swebby]

10 minutes ago, Paul_1978 said:

Indeed! And here is is from Wetterzentrale. I don't think I've ever seen anything like this! 

The T120 fax chart, a little out of date now,  was also indicating multiple centres running south of iceland.

[Fiona Robertson]

Earlier someone asked what was going on with the stratosphere and polar vortex so I went and looked

https://www.netweather.tv/charts-and-data/stratosphere

Animation shows PV being displaced and landing on us and Europe and a Canadian warming.