Model Output Discussion - cold spell to end Autumn

[The Enforcer]

40 minutes ago, feb1991blizzard said:

early jan 13 - cant remember exact date - guessing 6th = 10th ish

I had a discussion with a couple of members about this yesterday and then looked the archive chart up earlier - 11/12th Jan, but slider came in from WSW rather than NW and met polar continental air that was pushing in at the same time from the ENE which meant fronts were negatively tilted and why it was successful in these parts.

All the sliders since then have approached from the NW and had a positive frontal tilt resulting in rain. Jan 2013 was the last accumulation that lasted a day (Feb 2015 conjured up a trough which gave an overnight covering, but it had melted by lunchtime).

Edited December 4, 2017 by The Enforcer

[Duane S.]

I always thought that Ian Brown moment came courtesy of the lead up to December 2009? When, up until that point, such HLB was supposed to be a thing of the past (according to his MW theory)

Edited December 4, 2017 by s4lancia

[Froze were the Days]

7 minutes ago, s4lancia said:

I always thought that Ian Brown moment came courtesy of the lead up to December 2009? When, up until that point, such HLB was supposed to be a thing of the past (according to his MW theory)

Agreed it was well before 2013...could have been late Nov 2010?

 

By the way it always seems to be the GFS 06 and 18z runs that show the more 'outlandish' runs, if I can call them that.

Edited December 4, 2017 by Froze were the Days

[stewfox]

1 hour ago, Steve Murr said:

What date was the Ian Brown infamous WTF - that was a similar slider event..

Does he still hold the record for the most 'liked' post ever? I think it was 170+ likes for his "WTF" post? I can find it or more 'I dont know what to say' December 2009

Edited December 4, 2017 by stewfox

[Rocheydub]

Absolutely sure it was the winter of 12/13 but can't prove it!

[Daniel*]

56 minutes ago, karlos1983 said:

Ens London 

Ecm whilst no outlier, does taker one of the more milder routes from around the 10th. 

My mind still says it will back west with the slider low. 

 

Slightly colder than yesterday’s so all in all a very good day. I see one of the members in the suite is a cobra run I can infer that is caused by a beasterly, maybe the start of a trend?  

You can not get gather that depth of surface cold from a northerly airstream - continental.  

 

[cheese]

1 hour ago, s4lancia said:

I always thought that Ian Brown moment came courtesy of the lead up to December 2009? When, up until that point, such HLB was supposed to be a thing of the past (according to his MW theory)

Pretty sure it was January 2013, which, although not an overly cold month, was very snowy for a lot of places.

[Timmytour]

UKMO 12z 15/01/13 - 144 undercut ( ian brown WTF moment )

[Sparkiee storm]

Excellent runs lately for snow, ice, frost and significant wind chill , no matter how long it lasts it will be the most noteworthy cold spell we have had at least for the past few years.

Really have a good feeling about this spell with possible lying snow and maybe possible icicles going well with all the Christmas decorations up.

Let the models continue with the awesome outputs all the way to T0 

[CanadaAl]

2 hours ago, feb1991blizzard said:

early jan 13 - cant remember exact date - guessing 6th = 10th ish

It was Sunday 20th of January. Similar event on the 18th as well 

[northwestsnow]

GFS sliding the low to our South west meaning a very cold weekend- esp for places with snow-cover.

144-

Not seen UKMO but i refuse to believe it could be as good as GFS thats for sure!!!

Its not until monday evening that the colder uppers leave our shores...

Edited December 4, 2017 by northwestsnow

[Spah1]

There you go mate. 

[Weather-history]

19 hours ago, Summer Sun said:

I don't know what UKMO's success rate is at t168 but coldies will be hoping this mornings run ends up in the bin and isn't repeated tonight

What UKMO 144hr is showing compared to yesterday's 168hr 

[northwestsnow]

6 minutes ago, Spah1 said:

There you go mate. 

Nope- nowhere near as good as GFS...GFS much colder through the weekend.

[Mark Neal.]

Rinse and Repeat? 

Colder air hangs around alot longer. Heights drop temporarily to the NW then as Low Pressure moves across North of us and then heads E/SE pressure builds again! 

Edited December 4, 2017 by Mark N

[northwestsnow]

3 minutes ago, Mark N said:

Rinse and Repeat? 

Colder air hangs around alot longer. Heights drop temporarily to the NW then as Low Pressure moves across North of us and then heads E/SE pressure builds again! 

Gfs is brill...but im not keen on ukmo...

[feb1991blizzard]

3 hours ago, CanadaAl said:

It was Sunday 20th of January. Similar event on the 18th as well 

No I was talking about the actual run coming out when he said wtf, it was after an ecm run.

[Mark Neal.]

Bit further out and in FI.. 

Low Pressure in Atlantic looks to be sliding SE on this again. Flirting with Southern England. More in the Atlantic but good alignment? Edit. Then blows low up and comes up across UK. 

Edited December 4, 2017 by Mark N

[geordiekev]

3 minutes ago, Mark N said:

Rinse and Repeat? 

Wow, I have to say I've been so impressed with the GFS these past 4 weeks despite a couple of wobbles. When it comes to latching onto cold patterns beyond 144 which, we all know, professionals have very little confidence in, it has been smoking hot,  or should I say Ice Cold. 

There's certainly alot to keep us interested well into December which is a rarity indeed. To have a second year in a row with such a lack of storms through Autumn and into Winter certainly suggests something has changed on a macro scale. Please let it be the new norm 

[northwestsnow]

Lets hope gfs is correct..the isobars look much slacker on ukmo presumably meaning less showers..added to that gfs looks colder on the 850s...

Over to EC.

[knocker]

Today with  the high pressure centred to the south west a generally quiet day, cloudy after early morning patchy fog has cleared. with sunny intervals in most places  A bit windier in the north west with the odd shower floating around. along the west coast. This will continue into tomorrow in many places but it will become windier with heavy rain in Scotland, which clears during the day, as fronts approach from the west and from the north with the latter marking the boundary between the warmer and colder airmasses.

By 12 Wednesday there is a complex area of low pressure to the W/NW with a front pushing into the north west heralding the arrival of rain and strong winds which traverse the country overnight and through Thursday when by 1800 the front has cleared the south east and the whole of the UK is in the colder Arctic airstream with strong north westerlies/northerlies and plenty of wintry showers in the north

As can be seen in the last chart a little shortwave () has developed in the flow to the north of Scotland and this tracks down through Scotland and into the North sea overnight and if this materializes could bring a fair amount of snow with it. But in any case there will be frequent wintry snow showers in the strong northerly wind during the day, concentrated more in the north and along the coasts and feeling very cold with max temps around 5c in England but the wind chill must be factored in

Over Saturday a weak ridge moves east thus the wind abates but it remains very cold with max temps around 3C in England but the ridge is very fragile and is quickly dissected by a trough that has been emitted by the Canadian vortex and is being rapidly transported south east on the 160kt jet and thus by T144 we have this position.

But wait the plot thickens as this is nipped in the bud by the Bermuda high pressure once more briefly surging north east. I say briefly advisedly as this appears quite quickly to subside opening the door to a flatter flow and for systems to arrive from the west. Best if this upgrade is left here I feel

 

 

 

Edited December 4, 2017 by knocker

[bluearmy]

1 hour ago, geordiekev said:

Wow, I have to say I've been so impressed with the GFS these past 4 weeks despite a couple of wobbles. 

Looking very isolated this morning  - ec too Far East with the slider which becomes more of a diver with too much oomph behind it and not enough wedge ahead of it

[Gustywind]

ECM is poor after the initial northerly, pattern too far east again, rain for all from the sliders and less cold from Monday.

[Iceberg]

It’s not what most want to hear but there isn’t quite the blocking to the north to sustain the cold spell later this week. A few folks I am sure will get some snow, but for me it’s a decidedly timid affair. These two anomaly charts show that all isn’t lost though. In around 9-10 days time the blocking around Svalbard etc it much more pronounced and we might be able to tap into this to magic up a 2 week potent cold spell. 

A bit more waiting and at least it’s an interesting and potential radar watching few days. 

Edited December 4, 2017 by Iceberg

[blizzard81]

7 hours ago, Steve Murr said:

I think you need to be careful with just assuming a lobe of the vortex over Canada is going to have the same impacts as the entire vortex setting up in the same locale, especially when there is so much opposing force coming back at it out of Russia ... 

The forcing from Russia is becoming less and less with each ecm run. The Canadian vortex is beginning to run the show as far as the ecm is concerned. In turn that makes me very concerned. We have had 6 years of this now.