Model Output Discussions 18z 31/01/2016

[mushymanrob]

11 hours ago, Cleeve Hill said:

Talking of snow fixes next week we are off to Tromso next Tuesday for an artic jaunt. Third time we have gone in search of Northern Lights (2failures so far). Been looking at the charts and those GFS charts were just the job for North Norway but now it looks like changing with the High never really in place. 

At least we'll see some snow but it's clear skies we want. 

you might be disappointed. theres an aurora alert from 00 hours tonight for 48 hours.  you might have more luck driving to northern scotland tonight/tomorrow night.

[fergieweather]

8 hours ago, karyo said:

Thanks, good to see that none of the models taking it to the circle of death anymore 

....EC Monthly does, eventually. The current expectation is for (the lagged) phase 6 influence to perhaps become influential for UK around end of Feb-early March, with *some* GloSea5 members suggestive of an increased possibility of more blocked, colder outcomes into early next month. The risk of a colder than average start to spring has been flagged for a while now.

[Eskimo]

GFS 06z says snow all the way for Scotland and England. 

[BarnetBlizzard]

andddd a bit of an upgrade for next wednesday.  Wait until tuesday morning before getting too downbeat, things will change.

 

[shaky]

On 10/02/2016 at 9:53 PM, weirpig said:

low modled different on this run not so intense

Snow event back on for much of midlands and wales on wednesday!!!

[nick sussex]

So another small change on the GFS 06hrs run. This mid-week forecast is difficult because the models can't make their mind up how much trough disruption will occur.

The key really is how they handle that troughing to the nw. And whether the cold air hangs on for long enough and doesn't mix out ahead of the precip.

[Nick F]

Yes, 00z ECM gives us the best straw to clutch from the 00z suite to salvage some snow from the frontal system passing through on Wednesday. The frontal system shows signs of slowing as it reaches this east and comes up against the retreating high to the east, it's enough on the high res to allow colder air to catch up from the NW, but also allow a cold and dry feed off the near continent ahead of the front, to encourage snow to develop along the front from northern Home Counties northward looking at EC snow charts on  Weatherbell, here's the freely available precip and T850s

But, in the fashion this winter has gone so far, one can't help but think the frontal system will move through too quickly in the end with too much mixing out of colder air ahead of it to allow a transient lowland frontal snow event.

Before then, snow showers to look forward to for those in eastern Scotland, NE England then the risk retreating further south along eastern coasts of England into Monday, as high pressure builds in across Scotland. Some showers penetrating inland at times. Frosts to look forward too for the rest of us.

EDIT, at least the 06z GFS coming round to the EC idea with the slowing and disrupting front on Weds

Edited February 13, 2016 by Nick F

[nick sussex]

You couldn't make it up! Now the GFS 06hrs run is disrupting more energy se'wards at T120hrs.

It also develops that mini shortwave at T114hrs towards the south.

Edited February 13, 2016 by nick sussex

[Polar Maritime]

GFS 6z take on Wednesday snow risk.

Edited February 13, 2016 by Polar Maritime

[Mucka]

5 minutes ago, nick sussex said:

You couldn't make it up! Now the GFS 06hrs run is disrupting more energy se'wards at T120hrs.

It also develops that mini shortwave at T114hrs towards the south.

Starting to look like a nowcast situation, very marginal away from hills but 06z shows widespread snow.

In my experience with these situations what can go wrong will go wrong so I'm in the pessimist camp until and if I see snow falling.

[Ice Day]

Out to 144 and cold moving back westwards again in a fairly slack easterly.  Definite upgrade, perhaps all is not lost from this spell?

 

[winterof79]

The deal is by no means done.

 

[Gowon]

Colder weather hanging around longer on the 06hrs.. 

I hear we heading into phase 6 for mjo, but what would that mean for us?

[Singularity]

At just +96 hours:

00z: 06z:  

Relatively small adjustments - a bit more of a buckle in the jet - tipping the balance... one has to bear in mind that tropical forcing isn't something that the models capture entirely accurately, leaving room for some of the consequential amplification to be overlooked at relatively short range.

Longer term, I believe this could change the general outlook from the models immensely, aside from the broad theme of blocking highs becoming increasingly prevalent and toward the high latitudes, which is already in place. If GFS could handle split jets effectively at such range, the 00z for days 14-16 would have delivered some eye candy. The theme of cold air advancing west from Asia is well supported by the MJO composites for a 5-6-7 progression. Phase 8 is when it gets as far west as the UK, hence the desire to see the MJO make it that far before decaying.

 

Very interesting 06z GFS rolling out. The potential could be seen in the 00z ECM run as the NW-SE jet orientation was maintained days 5-7 and trough disruption occurred - but it wasn't far SW enough to place more than the far N/NE of the UK in the snow zone.

[Polar Maritime]

Yes the cold air hangs on to the South by weeks end.

Edited February 13, 2016 by Polar Maritime

[Timmytour]

doom to gloom to loom. to boom to doom to gloom....etc etc 

quick summary of the past 24 hours  days  weeks!!!!

[winterof79]

2 hours ago, Ben Lewis said:

I expect the models to rid of any potential snow for England next week during this weekends runs. 

The GFS 06z doesn't comply with your thoughts, fortunately.

[nick sussex]

The changes we are seeing on this GFS run are mainly to do with this here:

You need this to run ne, this shears some of the eastwards momentum as well as energy away from the troughing.

The difference between this GFS 06hrs run and the earlier 00hrs is  the handling of this troughing.

Its quite remarkable how this relatively small change on a global scale can make such a difference to the weather on the ground for the UK.

For this reason I'd urge people to not view this as the definitive solution because as you can see the models are making a lot of drama over this troughing.

It could still go either way in terms of any snow for the middle of next week.

 

 

 

 

Edited February 13, 2016 by nick sussex

[Ben Lewis]

12 minutes ago, winterof79 said:

The GFS 06z doesn't comply with your thoughts, fortunately.

That would also be the BBC and Tomasz Schafernakers thoughts as well then.

Whilst your correct that the 06z brings a snow risk back in mid week it's still 4 days away. If this winter has taught me anything it's not to believe cold is coming past 48hrs. 

I admire your optimism and your quick post to highlight mine. Let's hope the 12z still has the snow risk there. 

Im with a lot on here, show me the 12z on Tuesday with the potential snow for Wednesday then I might take notice. 

[weather09]

7 minutes ago, nick sussex said:

The changes we are seeing on this GFS run are mainly to do with this here:

You need this to run ne, this shears some of the eastwards momentum as well as energy away from the troughing.

Hi Nick

Silly question as you've circled it, but are you referring to the surface low? If so, how is that the driving force behind slowing the CF's progression? You've mentioned energy and troughing, but...

[Lukesluckybunch]

3 minutes ago, weather09 said:

Hi Nick

Silly question as you've circled it, but are you referring to the surface low? If so, how is that the driving force behind slowing the CF's progression? You've mentioned energy and troughing, but...

We need that low,to yes circulate up to the north rather then east! If it travels quickly east then it stops the high over Scandinavia to build properly and effectively guts squashed further south and east

[Polar Maritime]

Plenty of cold air to the N/W waiting to sweep through by the 23rd on the 6z.

With a nice channel Low to finish the run..

Edited February 13, 2016 by Polar Maritime

[Mucka]

4 minutes ago, Polar Maritime said:

Plenty of cold air to the N/W waiting to sweep through by the 23rd on the 6z.

 

Yes GFS FI is quite different run to run but fairly consistent on another possible cold shot

Edited February 13, 2016 by Mucka

[Snowy L]

4 hours ago, January Snowstorm said:

It's hard to see where any proper cold will come from between now and end of February. Looks like the ecm had the right call letting the atlantic in so swiftly. Just look at how strong that azores high is mid next week. It's been a very stubborn feature throughout (indeed the last 3 winters not just this one)

Cold week coming up though with at least some transient snow (for some)

http://www.ann-geophys.net/33/207/2015/angeo-33-207-2015.pdf

This might be interesting. In the last 3 winters we've had ENSO neutral and El Nino, we've had W-QBO and E-QBO we've had low snow advance and high snow advance yet all winters have been mild with a positive NAO throughout. Maybe the solar cycle has a larger than expected part to play in winter. This paper shows the North Atlantic is the main area affected by solar activity and during solar cycle peak the Azores High/Icelandic lows are strengthened.

Edited February 13, 2016 by Snowy L

[blizzard81]

48 minutes ago, nick sussex said:

So another small change on the GFS 06hrs run. This mid-week forecast is difficult because the models can't make their mind up how much trough disruption will occur.

The key really is how they handle that troughing to the nw. And whether the cold air hangs on for long enough and doesn't mix out ahead of the precip.

I find the gfs 06z to be the most unreliable of all it's runs. I will be shocked if the 12z doesn't return a more unfavourable run for snow chances. Another damp squib of a cold snap. This so called winter cannot end soon enough. Wait a minute though - it's going to be a cold start to spring! Lets all celebrate - not, lol. Cold springs just don't do it for me.