Model output discussion - deep cold inbound?

[Eskimo]

The GFS really drags its run out these days. I remember when by 9:45 it would already be up to 72 hours. 

[sheikhy]

Gfs further south and west with the low as aswell at 48 hours!

[Lukesluckybunch]

I'm looking at the 18Z the low even at 48h is further South,surely a better thing for keeping the cold further down the line!

[Lukesluckybunch]

2 minutes ago, sheikhy said:

Gfs further south and west with the low as aswell at 48 hours!

Agreed hopefully will enhance the cold more and more long lasting also!

[Tim Bland]

Icon gives more widespread snow on Sunday than the Europe view suggests. 

[sheikhy]

Looks much further south at 66 hours!!

[Jason H]

Just now, CreweCold said:

Yep and this is the point I am trying to make. A more protracted spell suits everyone better but given those in the E are 100% nailed to see snow, a shorter spell doesn't affect them as much.

Still, the responses in this thread to a genuine piece of model commentary has reminded me why I don't post in here as much anymore. A bunch of infants!

Steady on old bean. You did say that the best of winter could be behind us earlier on this week? It certainly is not from what I can see. Don't give up hope. The METO see the colder weather hanging around. The longer the cold persists, the more chances everyone will have.

[bobbydog]

1 minute ago, CreweCold said:

It is but people don't want to discuss the possibility...perfectly fine for those in the E and S of the UK that are guaranteed snow during the initial spell of cold. However it is more concerning for those of us in the west who will be reliant on something just that little bit more special in order to see a decent snowfall. 

Hmmm... not all of us Aaron...

The 2018 "BFTE" delivered about 0.5 cm to my location. It lasted less than 24 hours.  The snow which hit the south a couple of weekends ago, delivered about 1cm which lasted about half an hour before it turned to rain. My youngest daughter who will be 9 in just over a month, has never built a snowman. (She cried after getting all dressed up to go out and then watched it melt before her eyes within minutes...)

I really hope you, and everyone everywhere else, gets a decent chance at some significant snowfall. I just wouldn't mind seeing some myself for a change... 

[nick sussex]

The Committee meeting is over ! 

Conclusions .

Depth of cold .

Generally in the range -7 to - 10 , although a brief spell of less cold air could effect southern and se areas in relation to the low due on Sunday .  Some sub -10 readings are possible with this extending further south and east post day 5 .

Duration of the cold spell. 

Starting properly late Saturday and minimum length expected to the following Thursday .

Snow potential .

Significant snow for eastern areas of the UK , highest convection rates from EA north . A window further to the se once the low clears east se . Also there’s a possibility of more e/se flow could develop for a time towards the south this would be ahead of an incoming shortwave disrupting from the upstream troughing so snow showers could effect the sw especially towards Devon and Cornwall. 

Overall the strong east to ne flow should drive snow showers well inland .

Frontal snow likely late Saturday for the southeast and east . A caveat here is a possible less cold sector moving in for a time towards the south and se. After this another shortwave is likely to move in on Tuesday and the highest risk is for southern and sw areas but historically these are a nightmare to forecast !

Blizzard warning ! 

The official definition looks to be met for higher parts in the north and ne of the UK.  Also ground blizzards with blowing snow.

Possible breakdown .

The models vary here, often they will prematurely try to displace the cold air . The angle of any Atlantic attack is crucial so you want to be looking at a more negatively tilted trough approaching , so for newbies , one that runs more nw se . This is more likely to disrupt energy se under any wedge of heights to the north or ne .

Overall a very interesting spell of weather coming up ! Stay safe and enjoy the snow .

Edited February 3, 2021 by nick sussex

[MJB]

01:00 Sunday morning snow becoming more widespread

[phil nw.]

OK chaps let's keep posting about the  charts and leave the other debates incl climate stuff. 

Thank you. 

[ICE COLD]

T90 gfs looking good in the east

[Mike Poole]

Hey, pub run T90;

Greenland high, cross polar flow, weakening features going under right now!  

[ICE COLD]

T102 cold uppers in

[NewEra21]

EA, especially Norfolk taking a dumping on Sunday according to the GFS 18z

[Snowman.]

9 minutes ago, CreweCold said:

Yep and this is the point I am trying to make. A more protracted spell suits everyone better but given those in the E are 100% nailed to see snow, a shorter spell doesn't affect them as much.

Still, the responses in this thread to a genuine piece of model commentary has reminded me why I don't post in here as much anymore. A bunch of infants!

Just got to hope the UKMO is right then as it is by far the best output today.

 

[snowbob]

If the easterly  kicks in properly then the snow will spread across the whole U.K. like a pandemic.

everyone should get a dumping.  wait till the morning runs

everyone will be happy

dont think this will break down as soon

and certainly do not think come fri that any model will be showing any (milder as some of you like to call it )air will be any where over the whole of the uk

Edited February 3, 2021 by snowbob

[kold weather]

Frontal system on GFS 18z not quite as far west , which seems to be the biggest difference I can see thus far on the GFS compared to the 12z GFS.

I'm just a little too far SW based on this run, which may well be the case in the end for much of this upcoming week.

Edited February 3, 2021 by kold weather

[Snowjokes92]

Just now, CreweCold said:

You're correct. But remember 2 days ago when it looked like the SE would miss out due to a mild sector? There was uproar in here; post after post. So why can't members from other locations express the same frustration like the SE lot were able to?

You have a point, I rest my case. But seriously, things can change so quickly and short notice. Look at that surprise snowfall the other week when the North West and even blackpool got a covering. I think that was the one with the front moving up north? Think it might have been a marginal event overall, but was underestimated by all the models

[Tim Bland]

3 minutes ago, CreweCold said:

You're correct. But remember 2 days ago when it looked like the SE would miss out due to a mild sector? There was uproar in here; post after post. So why can't members from other locations express the same frustration like the SE lot were able to?

Don’t forget though mate that there’s a lot of people in the south who haven’t seen a single flake so far this winter and this maybe their last chance, Northern areas have seen a lot of snow this winter, even if it was transient at times. Charts like this are very rare (perhaps once in every 3 years) in the south ...

[ICE COLD]

Looks good to me a 114 

[radiohead]

A significant upgrade on the 18Z GFS at 114 hours. Uppers are a full 6 degrees colder in some places.

[DAVE_ALLEN]

One aspect to bear in mind. Away from the occlusion moving slowly away SSE. Where the precip ends there will be a dry shield where convection is unlikely to form. A typical example of a dry zone on any one chart might look like this. You can see this is reflected in a lesser radar return forecast.

[sheikhy]

What a freezing gfs so far!!

[nick sussex]

The flow is strong and unstable so this isn’t just a coastal scenario. Any troughs that move sw in the flow are able to maintain more potency.

You often get surprises , get the cold in , and keep it for around 5 days minimum and more time for those surprises !