Model Output Discussions 18z 31/01/2016

[winterof79]

26 minutes ago, Daniel* said:

The weekend is still up for grabs IMO south of the M4 it is not looking great quite wet - expect changes to T24. 

It is not resolved I sense the model fatigue as well, it has been a long winter but hopefully our efforts are rewarded before the door slam shut on winter 15/16.

Weekend aside a flow from the NE, quite unstable I'd reckon with low heights in Low Countries squeezing an NE'ly flow. Driving in sleet/showers from the east perhaps merging into longer spells of s thing not a bad synoptic. Hopefully the quite warm SST in North Sea will help compensate for the lack of very cold 850's which are typically needed to allow convection. 

It is not an ordinary winter that's for sure..it's not over yet. 

 

Good post Daniel,

Lots of twists from the weekend through next week.

[Methuselah]

I still don't see how we, or the models, can influence meteorological reality; it is, as they say, a mystery...That said, the 12Z's oozing out. Eyes down, toys under blankets - away we go!

[feb1991blizzard]

Much better ridging both in the Atlantic and up towards the Arctic on the 12z, could be a good FI this.

12z

6z

Edited February 10, 2016 by feb1991blizzard

[nick sussex]

Nice upgrade by the GFS for next week. Trough disruption near the UK, fronts moving into the cold. You can see the Azores high is more amplified here.

We're trying to squeeze out the mild sector here and this is a good trend.

Edited February 10, 2016 by nick sussex

[feb1991blizzard]

Just now, nick sussex said:

Nice upgrade by the GFS for next week. Trough disruption near the UK, fronts moving into the cold.

Yes, I wonder if that trough could become cut off and dive SE, that would probably be too much to ask but like you say, its moving into already cold air.

[Mucka]

The coming spell does look like a bit of a damp squib but we shall see.

I have notice that the immediate breakdown of the cold is being programmed more and more as a possible widespread snow event with cold uppers attacking from NW and SE.

 

Definitely worth keeping an eye on as it is only a week out and the trend is good so far.

 

The other day I spoke about a weak signal for an Easterly type or at least MLB/HLB end of Feb but since then ensembles seem to have dropped it.

Even so this afternoons run rally isn't a million miles away from having an Easterly flow and although it may be asking too much to bring an Easterly flow in so quickly we could still see better amplification in the Atlantic sector and a ridge extend toward Scandi and join forces with any positive height anomalies in the region.

 

We will have to wait and  see if the signal for that reappears.

At the moment I'm probably more optimistic about the 17th as a possible snow event than the current spell but this Winter seems to always find a way to downgrade any snow chances.

[Tim Bland]

Another GFS run showing that anything that falls at the weekend could be a bonus in the lead up to mid nxt week when most of the U.K. Gets a blanket of snow 

[feb1991blizzard]

The trend I like is that residual small low over Iceland is now just a small surface low wheras on the 6z it was a large PV lobe covering Greenland and Canada.

 

Plus cold pool now building over Norway as well.

Edited February 10, 2016 by feb1991blizzard

[Polar Maritime]

Surface cold seems to hang on in there on this afternoons GFS with a slack N to East flow showing around Mid-Month.

Edited February 10, 2016 by Polar Maritime

[winterof79]

The Strat warming just doing enough to give us some interest with mid/high level blocking

 

 

[Purga]

Anyone get the impression that GFS 12z is trying really hard to develop into a stonker of a run?

UKMO is trying to join the party by building heights towards Scandinavia but the pressure is there from the jet to try to ride over the top and collapse everything into the usual dirge...

Interesting to see what ECM thinks of it all? I can imagine - but let's try to be optimistic!

[Tim Brawn]

gotta give you boys credit , for hanging in there with T168s , snow predicted again , how many times can a promise be made.....

[Daniel*]

As you can gather Saturday is uncertain needs to dig more S along with colder uppers for any interest still a washout! However not as terrible as the 06z. (Slightly better wedge of heights to the north - perhaps causing it to take a more southerly route).

06z

12z

 

Edited February 10, 2016 by Daniel*

[chris55]

12 minutes ago, Purga said:

Anyone get the impression that GFS 12z is trying really hard to develop into a stonker of a run?

UKMO is trying to join the party by building heights towards Scandinavia but the pressure is there from the jet to try to ride over the top and collapse everything into the usual dirge...

Interesting to see what ECM thinks of it all? I can imagine - but let's try to be optimistic!

The run certainly caught my attention as we move into next week!

Not much more to say at this point, the thread is so quiet, but given a few more runs heading in this direction and we'll be away!

[Man With Beard]

5 minutes ago, Purga said:

Anyone get the impression that GFS 12z is trying really hard to develop into a stonker of a run?

UKMO is trying to join the party by building heights towards Scandinavia but the pressure is there from the jet to try to ride over the top and collapse everything into the usual dirge...

Interesting to see what ECM thinks of it all? I can imagine - but let's try to be optimistic!

Are we jumping the gun on the weekend being snowless? UKMO has a better angle for getting cold in and a second incoming low for Sunday.

[chris55]

i know its not strictly on topic, but the met and bbc raw data apps are showing snow for Saturday for my district (just north of m4 - 50 meters elevation) this highlights the potential! 

Looking at the three main models without seeing all the high res data and high res close range models just highlights how difficult it is to forecast the weekend snow risk without assess to the best close range models.

 

 

 

 

[feb1991blizzard]

6 minutes ago, Man With Beard said:

Are we jumping the gun on the weekend being snowless? UKMO has a better angle for getting cold in and a second incoming low for Sunday.

The UKMO is the driving model behind this.

http://www.metoffice.gov.uk/public/weather/forecast/map/gcw2hzs1u#?map=SignificantWeather&zoom=8&lon=-2.25&lat=53.48&fcTime=1455354000

 

And that has snow as far North as Bradford although not very heavy and has a Rainy sleety slushy mess for the south, this would be  based on the 0z though I would think, but the text forecast only mentions PPN for the south on the Friday to sunday forecast, this chart will update at 6 and 9pm, not sure if the 12z would be used for the 6pm update - should be - if not then definitely by 9pm.

EDIT : The updates wont be viewable though until 7.20pm and 10.20pm.

Edited February 10, 2016 by feb1991blizzard

[frosty ground]

30 minutes ago, Tim Brawn said:

gotta give you boys credit , for hanging in there with T168s , snow predicted again , how many times can a promise be made.....

I don't belive any promises are made... heat and kitchen comes to mind

[Mucka]

36 minutes ago, Tim Brawn said:

gotta give you boys credit , for hanging in there with T168s , snow predicted again , how many times can a promise be made.....

Certainly no promises and the usual caveats* apply.

We can only report what the model output shows and has the potential to show and don't forget those who post about snow potential are mostly coldies as well and it is just as frustrating for them when things don't come off.

* actual experiences may differ

[The Enforcer]

28 minutes ago, chris55 said:

i know its not strictly on topic, but the met and bbc raw data apps are showing snow for Saturday for my district (just north of m4 - 50 meters elevation) this highlights the potential! 

I thought this looked like the hand of 'Dougal', I mean, rain at 2C at first light and yet snow at 3C in the middle of the day?

I checked BBC Website for Saturday and there is this:

Dougal has put snow on the southern edge of the modelled band of precipitation, whereas if it was going to be anywhere it would be on the northern edge of the band.

Result - Zero confidence in Saturday's forecast.

Edited February 10, 2016 by The Enforcer

[chris55]

^^

2 minutes ago, The Enforcer said:

I thought this looked like the hand of 'Dougal', I mean, rain at 2C at first light and yet snow at 3C in the middle of the day?

I checked BBC Website for Saturday and there is this:

Dougal has put snow on the southern edge of the modelled band of precipitation, whereas if it was going to be anywhere it would be on the northern edge of the band.

Result - Zero confidence in Saturday's forecast.

So many factors could come into play on Saturday, nearly an impossible forecast to be honest!

[The Enforcer]

1 minute ago, chris55 said:

^^

So many factors could come into play on Saturday, nearly an impossible forecast to be honest!

I agree with that, but these are a result of errors and this is very basic stuff.

[nick sussex]

A really nice run from the GFS, the UKMO not as good at T144hrs.

The ECM really has been a bit strange over the last few days, what the GFS has been doing today in terms of sharpening up that trough to the north was what I expected to see from the ECM today but its cooled on that idea.

Hopefully it brings this back tonight.

In terms of the MJO, after yesterdays ECM suggestion of low amplitude it has increased this today:

 

 

 

[Methuselah]

3 minutes ago, The Enforcer said:

I agree with that, but these are a result of errors and this is very basic stuff.

And your super-accurate forecast is?

[wishingforsnow]

Snow for my location too on Saturday according to my weather app but I'm not counting chickens by any means because for providing consistent predictions these apps are pretty much useless - they forecasted snow during the last cold spell which then flipped to sun then rain.