Model Output Discussion - 23rd Jan - 12z onwards

[weather eater]

In terms of the snow prospects over the next few days the BBC via the MO don't seem very keen on getting ahead of themselves, a very cautious one/two day at a time approach. Wise given the way that small synoptic changes will make a big difference between rain and snow, who gets it and who doesn't.

[Nick L]

Yes, the ECM brings a few disturbances south in the arctic northerly flow that sets in over the weekend and lasts into next week. Though we wont know yet to whether any of these disturbances will verify, such is the difficulty of modelling these features 5-6 days off.

 

Anyway, a northerly, without fronts/troughs/disturbances in the flow will generally create a 'wishbone' effect whereby inland areas stay dry. sunny and cold while northern Scotland, eastern and western coasts see the showers. Trains of showers can set up in certain areas too, such as the 'Pembrokeshire Dangler' which can bring continuous showers to SW Wales and far southwest England, bringing large accumulations if it falls as snow.

 

But, there is potential with the northerly for secondary features to run south in the flow from the weekend, late Sat and early Sun, EC shows a low dropping south down the east coast which may accentuate shower activity:

 

EC_0000_96.png

 

Then on Monday, we see a low drop down from Iceland area, bringing a threat of more organised sleet and snow to western Scotland, EIRE/N Ireland. NW England coastal areas, Wales and SW England:

 

EC_0000_144.png

 

maybe a little too marginal across the SW though:

EC_850_144.png

 

However, GFS and UKMO a lot further west with this low.

 

Before then, looks like Scotland, N England and N Ireland sees the lion's share of the snowfall, a lot more hit and miss further south, Wales and SW England fairing better exposed to the westerly veering northwesterly wind.

 

Worth keeping an eye on that low moving south down that North Sea early Saturday which triggers the northerly, though again, airmass is marginal then before the colder northerly sets in later in the weekend

 

EC_0000_78.pngEC_850_78.png

 

Plenty to look forward too for those south of the favoured north and northwestern areas, but you'll have to wait until the northerly sets in for this better snow potential.

 

Here's a cheeky peek at the height of the snowfall risk on the ECM:

 

[Northernlights]

Wouldn't it be good to have a much more detailed service in this country.

Professionals taking time to discuss what the various models show, with longer details.

They get so little time to chat outside the couple of mins they are allowed.

Have to go back to the sixties when you could speak to the duty forecaster on the phone at the local RAF station.

Progrsss today means we only have machines to look at or listen to.

[Stuie]

Pretty consistent 850`s for London into Feb.

[Nick F]

Here's a cheeky peek at the height of the snowfall risk on the ECM:

 

uk_ec8panel_ec_1501280000_1502030600.png

 

We may get a better idea of Monday's low track towards or west of the UK on the freebie EC postage stamps at T+120 this evening, but for now it's there on most of the 51 stamps lurking over Iceland Sunday night, but where will it track?

 

http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2015012800!!/

 

Actually, at t+96, quite a few members with that low moving down the North Sea quite inland across the east of England - so could be some potential there for more organised precip ... though if the lows too far west than it may drag in less cold air with the precip.

 

http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!96!pop!od!enfo!enplot!2015012800!!/

[Brassmonkeylily]

Loooking at the Met Office  pressure chart for saturday ,the troughs and the strong North  winds seem to be to the west  of the UK ,, welcome views on thIs set up

 

 

uphttp://www.metoffice.gov.uk/public/weather/surface-pressure/#?tab=surfacePressureColour&fcTime=1422662400

[Nick L]

We may get a better idea of Monday's low track towards or west of the UK on the freebie EC postage stamps at T+120 this evening, but for now it's there on most of the 51 stamps lurking over Iceland Sunday night, but where will it track?

 

http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!120!pop!od!enfo!enplot!2015012800!!/

 

Actually, at t+96, quite a few members with that low moving down the North Sea quite inland across the east of England - so could be some potential there for more organised precip ... though if the lows too far west than it may drag in less cold air with the precip.

 

http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!96!pop!od!enfo!enplot!2015012800!!/

 

It's certainly one to keep an eye on, and it will chop and change considerably over coming runs.

 

Meanwhile though, the focus is on the barrage of snow showers affecting the northern half of the UK, at least a dusting is possible pretty much anywhere north of Birmingham tonight. ECM doesn't show many showers getting across to the eastern half of the UK but it tends to underdo this so even eastern parts will see at least a few showers.

[Captain Shortwave]

The 06z GFS grazes the south west with that low, more interestingly though again is the wave running south on Monday into Tuesday, this front appears to give a good few hours of snow to most locations as it moves south.

Edited January 28, 2015 by Captain shortwave

[picog]

Here's a cheeky peek at the height of the snowfall risk on the ECM:

 

uk_ec8panel_ec_1501280000_1502030600.png

What does the red shaded area on the top far right precipitation chart mean Nick?

[Nick L]

What does the red shaded area on the top far right precipitation chart mean Nick?

 

Likely areas of sleet/snow.

[SMU]

Morning campers-

 

we have moved nicely along in the last 24 hours, going from wobbling to mild at day 7 to heights aligning to the NE to feed more of a continental flow- ( equally as cold )

 

The 06z at 144 is probably the most progressive with the atlantic-

http://modeles.meteociel.fr/modeles/gfs/runs/2015012806/gfsnh-0-144.png?6

 

but still gets there at day 10 with a decent sub -8c flow -

http://modeles.meteociel.fr/modeles/gfs/runs/2015012806/gfsnh-0-240.png?6

 

The slower models ( UKMO et al ) will certainly retain a better flow should they have run out past 180-

the updated NAVGEM 06z shows what I think will be the end result at day 6 with that slower more amplified flow-

 

http://modeles.meteociel.fr/modeles/navgem/runs/2015012806/navgemnh-0-144.png?28-11

 

As for the channel low prospects- we could do with an uptick further NE, however not to far as it will bring milder air!!

 

A great start to the day with the seasonal bounty of snow beginning to come into the close timeframes-

S

[Roy]

I'm hoping for some advice please on the best free radars available please?  The only one I use at the moment is "will it rain today", which I find ok as it updates every 15 mins, but it doesn't seem to show precipitation type?  Are there any alternatives.  Thank you.

[MPG]

I'm hoping for some advice please on the best free radars available please?  The only one I use at the moment is "will it rain today", which I find ok as it updates every 15 mins, but it doesn't seem to show precipitation type?  Are there any alternatives.  Thank you.

NETWEATHER RADAR!!!!!!!!

[*Stormforce~beka*]

Someone asked yesterday for paint jobs,as someone who isn't skilled in any way at reading the models,and relies on clear interpretation from the main posters in here...... Can we have some more piccasos please?

It really does make things so much clearer for a visual learner like me.

I do know it's time consuming.

Thanks in advance guys.

Seconded! It really does help to visualise. Thank you x

[Tubs]

I'm hoping for some advice please on the best free radars available please?  The only one I use at the moment is "will it rain today", which I find ok as it updates every 15 mins, but it doesn't seem to show precipitation type?  Are there any alternatives.  Thank you.

If you want an app you could check out Met desk's Home and Dry and Snowfall radar http://www.metdesk.com/?page_id=1722, which I find pretty good. Have to pay for it though.

G

[Nick L]

If you want an app you could check out Met desk's Home and Dry and Snowfall radar http://www.metdesk.com/?page_id=1722, which I find pretty good. Have to pay for it though.

G

 

I would definitely recommend it 

 

Anyway, let's get back to the models folks!

[offerman]

Just bought the App, looks very good so far although the slider for the times keeps resetting back automatically.

 

Anyway, Charts are looking good for cold but snow is always going to be unpredictable in terms of amounts and areas affected, especially further south where elevation is crucial at times.

 

Nice charts and not seen the likes of these for longevity  since December 2010, of course charts can change so much 3 days out let alone two weeks.

[TEITS]

Surprised this hasn't been picked up on this thread.

 

Area of snow moving SE tomorrow night across Wales, Midlands towards the SE.

 

http://www.wetterzentrale.de/pics/Rmgfs453.gif

 

Another band of snow moving S across much of the UK.on Monday night.

 

http://www.wetterzentrale.de/pics/Rmgfs1443.gif

 

Subject to change but just highlighting the snowfall potential is for much of the UK.

 

Have to say a well done to BFTP though. Several days ago I was dismissing this cold spell and yet BFTP was adamant it could be noteworthy and based on the evidence he was right.

[legritter]

I am very happy with current charts and Data but as is the usual putting the meat on the bones is very hard at the moment .but here we go the expected cold air is flooding south and snow showers for some and little features could pop up now we have colder temp crossing warm seas .so friday looking a day of milder temperatures and this weekend brings an arctic blast with the possibility of sudden developements which will i think be a very nowcast situation .interesting start to next week if we get a low track south east to our west ,but probably very frustrating for many posters as the track and many other synoptic variables could give a hit for some and a miss for others .and the prospect of a good cold spell developing as the models swing in our favour .realy hope we all get our Fix from some feature ,great forum and its only late January ,cheers   

[West is Best]

The 6z ensembles continue to give me cause for concern re. next week, even more than the previous 8. I'm not sure how long this will be sustained before the op breaks and goes the way of the others? Perhaps it's on the right path but it would be good to see the many milder members head south to join their big brother:

 

Edited January 28, 2015 by West is Best

[Troubleatmill]

Not the best ensembles, control a bit out on its own past the 3rd, lets hope its higher resolution means everything 

 

*edit* sorry just seen yours WIB

Edited January 28, 2015 by Nicholas B

[Neilsouth]

 

 

Have to say a well done to BFTP though. Several days ago I was dismissing this cold spell and yet BFTP was adamant it could be noteworthy and based on the evidence he was right.

 

Do you have a link for this? Thankyou kindly

[Jason M]

I've only looked beyond 192 hours and the GEFS are dire, but again I don't think it really matters in this scenario. They are also showing wide scatter rather than a strong signal for any one scenario.

In this scenario its 'opp runs' all the way. The ensembles are a very useful tool but I suspect they will add very little for a couple of days. So much so, that I never even bothered looking at last nights and I use them a lot.

Only my opinion of course and others will take a different view :-)

[Duane S.]

It's always nice to see better GEFS support but as Jason says above, in this scenario, I wouldn't read too much into it (yet). Seen it plenty of times before, my money is on them pulling in towards the GFS Op's way of thinking by the weekend.

 

That said, they are there for a reason, so cannot be wholly discounted. So the sooner they do pick up on the signal sniffed out by the higher res ops, the better!

[weather eater]

Never bothered with the GEFS myself preferring to make a judgement on an ensemble in my head of recent operationals. The operational runs are just that for a good reason, they are the best guess the model can make based on the data. The ensembles are tweaked data presumably to a preset set of parameters. To my mind I start getting twitchy when the operationals start jumping around or when there is a wide spread of opinions across model output, at least across the big three anyway. At this point of time we have as good a consensus across the model spread for the next week as you are likely to see. I remain cautiously optimistic and my interested is now in relation to the models is what happens Tues Wed  and onwards next week. For the next few days the regional threads and what's out of the window will be my focus, I would say lamp post watching except we don't have one, maybe if I'm lucky making tea and coffee for benighted travellers stuck in their cars.

Edited January 28, 2015 by weather eater