Model Output Discussion - cold spell to end Autumn

[nick sussex]

Wow even more upgrades with the pattern edged further south and the trigger low further south. I think the GFS has overblown the low but apart from that what a great start to the evening.

And will the Svandi block appear? 

 

[radiohead]

This is an incredible winter storm. Inland gusts 130 km/h with heavy snow away from the coast. Coastal flooding could be a very serious concern too.

[Mucka]

2 minutes ago, northwestsnow said:

Its too far out to have confidence but if GFS12z is on the mark the hills round here will be absolutely pasted!!

Yes too far out but if GFS and UKMO are anywhere near correct it won't be reserved for hills. A lot of cold Arctic air could be in the mix

Edited December 1, 2017 by Mucka

[northwestsnow]

Just now, Mucka said:

Yes too far out but if GFS and UKMO are anywhere near correct it won't be reserved for hills. A lot of cold Arctic air could be in the mix

Indeed!!

Need that low to do one though its eventually dragging less cold uppers into the mix, down south please mr low...

[feb1991blizzard]

5 minutes ago, northwestsnow said:

GFS 12z shows biblical amounts of rain or snow depending on where you live, and how much altitude you have !!!

Its a pennine burial job, nothing would be getting in or out of my area, 669 and 62 would have 20ft drifts on - look at the windspeeds and snowfall!!  in March 2013 we had a ridiculous blizzard, it was only 4 inches in some parts but 7ft drifts in others!

[karlos1983]

I like the look of the 144 UKMO chart,looks like fun all the way to the south coast to me, cold air digging in 

 

Edited December 1, 2017 by karlos1983

[beng]

3 minutes ago, Iceberg said:

It’s impossible to over state the effects of gfs from t144 to t180 or so.  The amount of snow and 70-80mph winds would be a story for the next 50 years. 

The really unusual point is that it’s all quite realistic given the Synoptics and timeframe, if still unlikely at this range. 

GFS tends to overcook lows of course - but even a slightly weak version would be quite something.

[Frosty.]

4 hours ago, Frosty. said:

 I think we are going to see plenty of stellar cold model output inching closer to the reliable timeframe..happy days are here again!

And we are, super output this afternoon if you're a coldie

I'm heading out to stock up on the essentials including a new snow shovel this weekend so I can hunker down when the blizzards hit.

Edited December 1, 2017 by Frosty.

[Gustywind]

Is the same system for next Thurs/Fri showing on UKMO and GEM?

[Singularity]

  

Well then. That's the most serious storm I've ever seen modelled inside 7 days' range. 

The high intensity of precipitation coupled with lower 850 hPa level with 850's of -5 to -7*C brings about widespread snowfall even to low levels. With gusts to 70+ mph well inland. Even 80 mph in a few spots.

WHAT ON EARTH.

Meanwhile, UKMO is only about, what, 100 times less intense 

[beng]

1 minute ago, northwestsnow said:

Indeed!!

Need that low to do one though its eventually dragging less cold uppers into the mix, down south please mr low...

Assuming the reality was to be a less deep low, then the warmer uppers coming in off the N Sea may not be an issue in the end - fingers crossed.

[northwestsnow]

Just now, feb1991blizzard said:

Its a pennine burial job, nothing would be getting in or out of my area, 669 and 62 would have 20ft drifts on - look at the windspeeds and snowfall!!  in March 2013 we had a ridiculous blizzard, it was only 4 inches in some parts but 7ft drifts in others!

Feb can you imagine what it would look like up the isle of sky road/top of Moorside if 12z gfs comes off???

Like you say, its got to be unlikely, or has it?

The track of that low will nowhere near be resolved yet though, dont want corrections north..

[karlos1983]

@Gustywind

Edited December 1, 2017 by karlos1983

[Cloud 10]

Yes,some real drama from the GFS at day 6,with some crazy temperature contrasts telling a part of the story.

 

850's.. 2m temps..

[West is Best]

I guess we all know that the chances of this happening, even at T150 are on the slim side. But it's worth pointing out that if it did, unlikely though it is, it would be blizzard conditions such as we've not seen for a veeeeery long time in this country:

It's unlikely, but still a fun spectator feast for cold lovers:

 

 

[northwestsnow]

1 minute ago, beng said:

Assuming the reality was to be a less deep low, then the warmer uppers coming in off the N Sea may not be an issue in the end - fingers crossed.

Yes don't think ukmo has it as vigorous -

[beng]

Just now, Cloud 10 said:

Yes,some real drama from the GFS at day 6,with some crazy temperature contrasts telling a part of the story.

 

850's.. 2m temps..

Presumably that's part of the reason the model is blowing up the low so much. Reality is probably somewhere in between UKMO and GFS - so hopefully the ECM will deliver that later.

[beng]

1 minute ago, West is Best said:

I guess we all know that the chances of this happening, even at T150 are on the slim side. But it's worth pointing out that if it did, unlikely though it is, it would be blizzard conditions such as we've not seen for a veeeeery long time in this country:

 

Probably since Dec 1981 on such a large scale

[nick sussex]

The GFS is better for backedge snow as it doesn’t develop a shortwave in the flow from the north . The UKMO because of that has a slower push south of the cold.

[Yarmy]

That storm on the GFS is horrendous, and reminds me of this:

 

One of the worst natural disasters to beset the UK in living memory.

[Singularity]

Warm-core low? 
Okay, I'm not being serious, although it's origin a long way south - bringing a lot of warmth and moisture for the time of year into the equation - is a factor in the incredible deepening being depicted by GFS.

Not so sure about this run now - I've gained a sense that any model run evicting a large-scale trough from N. America should be viewed with suspicion. Smaller lows splitting away and jumping on the slide seem more realistic at the moment.

[northwestsnow]

1 minute ago, beng said:

Probably since Dec 1981 on such a large scale

UKMO 144 looks primed to drag in the colder uppers Beng- either GFS/ukmo look fabulous at 144-

Now you just know EC will throw a wobbler !!

Either way of we can get these 144 charts down to 96 (2 more days) then its game onnnnnnnnnnnnnnnn

[beng]

This produced a big 'real' blizzard in 1981 - although it turned to rain in the south (much to my annoyance at the time).  It's very rare to get the wind and snow to combine like that across a large area in the UK.

 

Edited December 1, 2017 by beng
fixed typo

[❄️❄️❄️❄️❄️❄️❄️❄️❄️]

Could be worse! 

[Rickoza]

Next Thursday's drive into work might be on hold............