Model thread discussion - cold spell looming

[MJB]

12 minutes ago, Lukesluckybunch said:

Hi there how would you rate my chances living in bicester?

I will ..........................I think we will get some sort of covering , just depends if we get lucky and be get under a line of showers , I am more looking towards Thursday as the Atlantic tries to get in 

[SqueakheartLW]

The good thing about those ensemble charts on wetterzentrale is how you can deselect certain elements and runs from the charts. As I have done here to help show up the average trend for specific things

2m Temperature average for GFS 06z in Scunthorpe

The colder spell clearly shows up here with average 2m temperatures generally below freezing for several days from the 8th to 12th February. Even when the milder spell shows up the average 2m temperatures are not that high really and the highest is in fact just 5.9 with minimums still showing the risk of ground frost

2m dewpoint average for GFS 06z in Scunthorpe

This clearly shows a big crash in the dewpoint during the rest of today so hopefully these showers I keep getting today should turn more and more to sleet, then snow. We keep the dewpoint on average below freezing until at least the 16th based on this average and when it does finally get above freezing it isn't that far above and there are even signs we could be sending the dewpoint back below freezing by the end of the run.

New snow depth average for GFS 06z in Scunthorpe

This is probably the most interesting chart, the new snow depth in every 6 hour block between now and 384 hours away on average. I have labelled up every single 6 hour point to help the totals stand out. Even though the individual amounts look small they soon mount up once you add them together and the totals I have come up with assume no melting or sublimation of the snow during the next few days. These totals are at 6am each morning after the previous 24 hour period

Date                                       Addition       TOTAL DEPTH

By 6am 7th February          +0.7cm          0.7cm

By 6am 8th February          +2.0cm          2.7cm

By 6am 9th February          +2.4cm          5.1cm

By 6am 10th February        +1.6cm          7.7cm

By 6am 11th February        +1.0cm          8.7cm

By 6am 12th February        +1.6cm          10.3cm

By 6am 13th February        +0.9cm          11.2cm

This is only the average figure. It could end up close to this or could be a lot more but then maybe much less too

 

[Purga]

UKMET now fully behind the prolongation of the cold ala model developments i.e. cold blocking dominating, with mild incursions only possible in the extreme W / SW.

The 12z's are awaited with relish... we hope!

[MJB]

3 minutes ago, Malarky said:

Source please?

Met Office website and the BEEB monthly forecast very similar 

[Paul]

Can we keep it to the models in here please. And on that subject, UKV 12z looking really interesting for Monday with snow showers making it right across the country..

[Howie]

Big props to everyone who said the low in the Atlantic would struggle rather than sweeping its way through

[phil nw.]

The 00z runs did indeed pick up the baton from the 18z last night.They continued with the trend towards a renewal of blocking and this carried through to the 06z GFS run. 

Look how far we have moved away from the Atlantic coming in over the last 3 06z runs for Friday the 12th Feb.

Thurs 06z                                                Fri  06z                                                  Today  06z

This is promising move from the GFS considering it can be the most progressive in pushing too much of the jet ne in a mild v cold battle.

Of course we are still a little way from any certainties but with other suites and their ensembles on the move to a more blocked scenario with developing Scandinavian heights the picture is looking much more promising for cold to fight back,maybe never leaving by the end of next week.

It brings to mind the old saying-the trend is your friend.All we need now is for the 12z runs to follow it!

 

[Singularity]

6 hours ago, Uncertainy said:

 

@SingularityJames I read your excellent article about this spell and you mentioned you thought the snow showers would penetrate much further than most models would suggest, do you think this chart is realistic?

Thanks @Uncertainy, y'know I just noticed your username is not uncertainty! Ha - yes I still expect showers to reach further than most models indicate, although for the southern half of the UK this has become more relevant to Mon-Wed than tomorrow, when the shower limitation is more to do with the flow and vertical motions in the area around the low being unsupportive away from the main moisture surge that affects the southeast.

The example chart you show seems to be a bit short on convection travel in the south but otherwise looks a decent effort. I guess that particular outcome is more toward GFS in terms of the 850s i.e. they don't drop as much Monday night?

For me, Sunday interest has fallen by the wayside in light of greater snowfall potential in the following days in my area... and what may take place later in the week.

[bluearmy]

13 minutes ago, Paul said:

Can we keep it to the models in here please. And on that subject, UKV 12z looking really interesting for Monday with snow showers making it right across the country..

Very important to take the general message there and not the actual chart ......

[Griff]

1 minute ago, phil nw. said:

The 00z runs did indeed pick up the baton from the 18z last night.They continued with the trend towards a renewal of blocking and this carried through to the 06z GFS run. 

Look how far we have moved away from the Atlantic coming in over the last 3 06z runs for Friday the 12th Feb.

Thurs 06z                                                Fri  06z                                                  Today  06z

This is promising move from the GFS considering it can be the most progressive in pushing too much of the jet ne in a mild v cold battle.

Of course we are still a little way from any certainties but with other suites and their ensembles on the move to a more blocked scenario with developing Scandinavian heights the picture is looking much more promising for cold to fight back,maybe never leaving by the end of next week.

It brings to mind the old saying-the trend is your friend.All we need now is for the 12z runs to follow it!

 

Glad to see others are trying to fill their time before the next runs come out. No doubt posted many times already... 

144s

And 240s

 

 

[phil nw.]

2 minutes ago, Griff said:

Glad to see others are trying to fill their time before the next runs come out. No doubt posted many times already... 

144s

And 240s

 

Lol,Yes Griff i have just come back on line and thought i would look back 3 days to remind myself how quickly the outlook has changed on the prospect of any Atlantic win.Thought it was worth posting those.

It was only 3 days or so ago when it looked like an Atlantic push winning through most of the Uk.Now we are looking east again. 

[JBMWeatherForever]

The models are starting to smell the coffee, and a good cuppa it's going to be. The next few weeks looks like being exceptional for weather watching, especially if you like very cold and snowy weather. 

[Penrith Snow]

4 hours ago, Drifter said:

1055hpa over Scandinavia. Must be almost record breaking?

edit - now 1060hpa!

Very unusual but a Scandy reached 1061mb on 29th January 1972, needless to say the UK was swept by 3 days of heavy snowfall in an otherwise mild winter.

Andy

[phil nw.]

Just a heads up a number of posts without model discussion/charts have been moved over to here

We may get quite busy soon so it would be very helpful if posts in here are on topic and focused around the model outputs.

Anything else please consider the other threads,including the one linked above if it's general chat about will it snow and where etc.

Thanks all.

 

[Battleground Snow]

Icon at 180,

Looks good, but could do with the WAA and high a little West.

[Sky Full]

For your enjoyment......the next 10 days surface temperatures according to the GFS 0.25 HR. 06h.......

It’s spot the positive surface temperatures time - even during the day - as cold air digs in for the next 10 days.  My 1.9C February CET forecast might be looking a little too high.....

 

[sheikhy]

1 minute ago, Battleground Snow said:

Icon at 180,

Looks good, but could do with the WAA and high a little West.

Fantastic start to the 12zs!!!!cmon gfs keep with the 06z!!!!fun and games about to start hopefully!!

[MJB]

1 minute ago, sheikhy said:

Fantastic start to the 12zs!!!!cmon gfs keep with the 06z!!!!fun and games about to start hopefully!!

where can I find the snow ppn for those charts?

[sheikhy]

Just now, MJB said:

where can I find the snow ppn for those charts?

https://wxcharts.com/?panel=default&model=gfs,gfs,gfs,gfs&region=uk&chart=snowdepth,850temp,wind10mkph,snowdepth&run=12&step=003&plottype=10&lat=51.500&lon=-0.250&skewtstep=0

[CentralSouthernSnow]

6 minutes ago, sheikhy said:

Fantastic start to the 12zs!!!!cmon gfs keep with the 06z!!!!fun and games about to start hopefully!!

What’s so exciting about that chart?

[Cold Winter Night]

19 minutes ago, Penrith Snow said:

Very unusual but a Scandy reached 1061mb on 29th January 1972, needless to say the UK was swept by 3 days of heavy snowfall in an otherwise mild winter.

Andy

GFS 6z created an impressive Scandinavian High just 8 days away.
Indeed that is close to record values. So was 1972.

Norway (1061.3 mb), Sweden (1063.7 mb), Denmark (1062.2 mb) reached their pressure records on January 23rd, 1907, Finland (1066 mb) one day earlier.

Will we see pressures like that next week? It's a possibility with the pattern we see in the output now.

Interesting to see what the 12z's make of it. Besides the hunt for cold, we might hunt for pressure records as well.

[Notty]

UKMO -v- GFS Op - 12z T+96

[bluearmy]

it’s all the way across the map from east to west ! 

[Singularity]

 

Slight step toward the 00z ECM there. Low every so slightly more west, as is the surface high's western nose.

UKMO looking decent to the west with the low now as deep. On the other hand, the low to our southeast isn't quite as well positioned - but this is nitpicking!

[SLEETY]

Going to be a brutal cold feburary looking at that update,the worst is yet to come,or best depending on your viewpoint if you look at that bitter cold pool out East waiting to pounce the following week,epic snow showers spring to mind plus battlegound snow in SW possibly spreading to other Southern most counties at times during the next few week.

 

UKMO looking too progressive,watch it backtrack in the morning.

Edited February 6, 2021 by SLEETY