Model Output Discussions 18z 31/01/2016

[Paul]

The 6z NetWx (NMM) model certainly likes the idea of switching a lot of the band to a rain/sleet/snow mix on Wednesday night, but in terms of accumulating snow isn't getting too excited at this point! 

 

As has already been said though, loads of uncertainty in terms of the details of how this'll play out at this point. 

 

[nick sussex]

42 minutes ago, Man With Beard said:

It's like weather pinball this week with that front, isn't it!!

Now I've been reading how it's all going to "back-edge" snow and no front-edge, but can we be sure of that?? I'm noticing this morning a trend to bring colder 850s back towards the SE, especially as the front stalls. Many ECM postage stamps have the -6C 850hpa mark very close to the SE, if not over it - as well as approching from the west.

http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!72!pop!od!enfo!enplot!2016021500!!/

Yes the colder 850's move back nw as the shortwave develops towards the Channel. The models though show no sign at the moment of trying to develop snow ahead of the precip for the UK.

I think the shortwave would need to form a more nw/se orientation as this would then see a more se flow ahead of that precip. It looks more s/ssw surface flow at the moment ahead of the precip.

Interestingly MeteoFrance do have some snow developing for northern France late Wed into early Thursday and that would be ahead of the front, of course theres not the Channel sea track to worry about in this case but it does show that there will be some decent surface cold to tap into.

Edited February 15, 2016 by nick sussex

[chicken soup]

Latest 12z GFS has the front as a rain only affair everywhere ....i fear the biggest let down of a winter full of let downs is imminent.

[karlos1983]

I'm not sure it does actually, looks like snow to me?

 

[andymusic]

3 minutes ago, chicken soup said:

Latest 12z GFS has the front as a rain only affair everywhere ....i fear the biggest let down of a winter full of let downs is imminent.

really?????????????

[Essex snowman]

2 minutes ago, chicken soup said:

Latest 12z GFS has the front as a rain only affair everywhere ....i fear the biggest let down of a winter full of let downs is imminent.

No let down as said before was always likely to be a rain event wouldn't get to down me old chicken can still get snow between now and end of March 

[mother nature rocks]

3 minutes ago, chicken soup said:

Latest 12z GFS has the front as a rain only affair everywhere ....i fear the biggest let down of a winter full of let downs is imminent.

That is not the case at all. Definitely a wintry mix as Wednesday night cracks on. The Arpege seems to have the mix slightly further east.

[Summer Sun]

5 minutes ago, chicken soup said:

Latest 12z GFS has the front as a rain only affair everywhere ....i fear the biggest let down of a winter full of let downs is imminent.

Rain to snow

[Paul]

11 minutes ago, chicken soup said:

Latest 12z GFS has the front as a rain only affair everywhere ....i fear the biggest let down of a winter full of let downs is imminent.

Not sure what's being expected here, but even the snowier model runs have been indicating wet snow/sleet for the majority, so if there's an expectation of much more than that, particularly away from higher ground, I think you've every chance of feeling let down regardless. 

[Captain Shortwave]

Interestingly the GFS actually delivers a dusting of snow to parts of East Anglia on the front edge of the front, the front then stalls delivering 1-2 inches across central/southern England.

Not to be taken too seriously though at this point. But it illustrates that the run is not showing an all rain event.

Edited February 15, 2016 by Captain Shortwave

[chicken soup]

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=48&mode=2

i had just looked at this when i posted ...perhaps i should of waited for a few more frames.

Edited February 15, 2016 by chicken soup

[SMU]

28 minutes ago, Captain Shortwave said:

Interestingly the GFS actually delivers a dusting of snow to parts of East Anglia on the front edge of the front, the front then stalls delivering 1-2 inches across central/southern England.

Not to be taken too seriously though at this point. But it illustrates that the run is not showing an all rain event.

I mentioned this in my post this morning   Ref cambridgeshire etc ( getting snow )

the updated UKMO shows a shallow system over the SE at T72 with low heights & probable snow

I think the models are underplaying the forward edge potential....

 

s

[A.J]

1 minute ago, IPredictASnowStorm said:

Looking as if it is going to stay more west and stay as rain for most of the south

south east, I think you mean......................looks rather wintry elsewhere across England.......anyhoos, eye's down for the full house, sorry GooFuS12z, lets see what it giveth and taketh away 

[karlos1983]

2 minutes ago, IPredictASnowStorm said:

Looking as if it is going to stay more west and stay as rain for most of the south

Am I missing something here? That chart shows mainly snow lol. Although I wouldn't be taking any of it as gospel. Very knife edge, almost nowcast situation 

[Mair Snaw]

Im a little confused here.. the BBC has my area down as snow all day Wednesday and dry but cold all day Thursday... but models showing the snow for Thursday not Wednesday....

[johnholmes]

37 minutes ago, chicken soup said:

Latest 12z GFS has the front as a rain only affair everywhere ....i fear the biggest let down of a winter full of let downs is imminent.

I honestly feel you need to look at the GFS output a little more closely as others below your post have suggested. It is also useful for others reading posts to drop the relevant charts in that you are referring to.

thanks

 

[IPredictASnowStorm]

Same here

4 minutes ago, bigsnow said:

Im a little confused here.. the BBC has my area down as snow all day Wednesday and dry but cold all day Thursday... but models showing the snow for Thursday not Wednesday....

 

[chicken soup]

2 minutes ago, johnholmes said:

I honestly feel you need to look at the GFS output a little more closely as others below your post have suggested. It is also useful for others reading posts to drop the relevant charts in that you are referring to.

thanks

 

i have explained my error in a new post....the 48hr GfS precip chart showed all rain.

 

[IPredictASnowStorm]

waste of snow Really as it is Showing Rain Before it turns to snow  on the  Gfs Charts so It is going to be Wet snow. So it probably wont lye anywhere 

[Essex snowman]

4 minutes ago, IPredictASnowStorm said:

waste of snow Really as it is Showing Rain Before it turns to snow  on the  Gfs Charts so It is going to be Wet snow. So it probably wont lye anywhere 

May be a waste for u but many on here just want to see any snow be it big flakes little flakes or wet snow 

[IPredictASnowStorm]

true true 

3 minutes ago, Essex snowman said:

May be a waste for u but many on here just want to see any snow be it big flakes little flakes or wet snow 

 

[Ben Sainsbury]

8 minutes ago, IPredictASnowStorm said:

waste of snow Really as it is Showing Rain Before it turns to snow  on the  Gfs Charts so It is going to be Wet snow. So it probably wont lye anywhere 

Not neccesarily the case, a few years back a low pressure system sat over CS England for a few hours giving rain, the intensity picked up of which the precipitation turned to snow, and it stuck on every surface! As long as the ground surfaces are cold enough, we can all hope!:)

[snowhope]

 A flake would be Amazing, Lying snow would be too much to ask.... surely!

Looking at the last few runs though there is a chance over the midlands to see some snow. All dependent on mixing out the warm sector and as others have mentioned the intensity of the evaporative ecooling effect to see it to low levels.

 

[kev238]

There is clearly a chance of snow falling and potentially sticking in lucky areas ( not huge amounts)

It also appears that there will be a large precipitation total for the period Wednesday / Thursday across large parts of the country where the ground is still saturated after a wet winter thus far 

 

Edited February 15, 2016 by kev238

[snowangel32]

1 hour ago, chicken soup said:

Latest 12z GFS has the front as a rain only affair everywhere ....i fear the biggest let down of a winter full of let downs is imminent.

Don't worry we have all made mistakes as we learn, the front at first is expected to be rain but with back edge snow as the colder air mixes in a very unusual set up and one that is to close to call. 12z stays with theme from this morning of sleet and snow Wednesday night into Thursday morning for central England and East Anglia.