Spring Model Discussion 18Z 6/3/13 onwards....

[Staffordshire]

Amazing 12z GFS run for snow potential for the south cost, trip to Iow anyone?

[Mucka]

If we compare how the models have been developing that low we can see it has been moved further North across the output. Here are comparisons for UKMO and GFS 12z runs with yesterdays for the same period. Yesterdays on the left.

UKMO

GFS

Edited March 8, 2013 by Mucka

[cooling climate]

From a personel perspective I am very happy at the synoptics over the next few days

considering I had been calling this since some 12 days ago I think. With the likelyhood

of high pressure to the north of the UK rather than Greenland and a east/northeasterly

flow with some very impressive cold uppers.

It would be great to see a classic UK snow set up with a easterly airflow and and a channel

running low and that is still to play for so to speak.

The models do seem to be keen on prolonging the cold with perhaps a proper Greenland

high as we move into the extended range and FI.

Ground temperatures as the Met mention are not conducive for laying snow and its a pity

there was not a hard ground frost to be had tonight or tomorrow night prior to possible

snowfalls. That does not mean snow will not settle only that it will take longer to do so

because of the warmer ground.

I see there is a slight correction north on the low to the southwest but the actual path of

the low will not be known until Sunday afternoon I would have though and even then it

can change. But it is looking likely that some southern and western areas could get nailed

with upwards of 10cm or more even allowing the time it takes for the snow to start settling.

Edited March 8, 2013 by cooling climate

[Summer Sun]

Snow potential looks quite high for the south now

The coldest uppers are still on track to leave during Tuesday as well

Yes I know the ones behind won't be warm but temperatures should get upto 7c for some especially those in the west

Edited March 8, 2013 by Gavin.

[-uksnow-]

I have to say - as someone living on the south coast a chart like this at only 84hrs away

is something im fairly excited by! Last few runs seems to have brought a northwards shift on the overall track of the low

[AWD]

The channel low could provide some of the best snowfall of the year for southern most counties. Here are the GFS accumulations by noon Monday;

Up to 10cm shown locally there.

[Cheshire Freeze]

Yes I know the ones behind won't be warm but temperatures should get upto 7c for some especially those in the west

Under any cloud, temperatures will struggle. Upper air temp remains around -7. Temps will fall readily in any showers too.

[No Balls Like Snow Balls]

The GFS12z is great for anyone living South of the M4. There could be quite a bit of snow around. However the UKMO isn't quite as good. The precip on the UKMO barely touches the South coast. I wouldn't take the GFS as a dead cert just yet as we are talking such fine margins of LP movement now.

Edited March 8, 2013 by No balls like Snow Balls

[nick sussex]

This Channel Low is modelled differently between the UKMO and GFS so this will have an effect on the northwards extent of any snow.

The GFS develops it a bit more, further north, the UKMO has a shallower feature. Even at this stage I wouldn't trust either model to be right in terms of detail.

A hundred miles either way here makes a huge difference to the UK so I'd be wary of reading too much into the snow line at the moment.

[Cheshire Freeze]

A potential forecasting headache...

Shallow low dives SE. Wrapped in 528 DAM air and marginal uppers. Could be snow in places if it arrives overnight.

Even by thursday, temps around 2-4C on this run

Edited March 8, 2013 by CreweCold

[-uksnow-]

I have to say - as someone living on the south coast a chart like this at only 84hrs away

is something im fairly excited by! Last few runs seems to have brought a northwards shift on the overall track of the low

edit: also quite funny, added it up and in total Metcheck gives my location 22cm of snow between monday and tuesday

[Staffordshire]

All we need now is for the ECM to plonk the low over the north... wonder what will prove right the gfs or ukmo

[snowking]

All we need now is for the ECM to plonk the low over the north... wonder what will prove right the gfs or ukmo

Well the 0z ECM kept the low that bit further south, with the associated precipitation just skimming southern counties.

However, it did make a lot more of the shower potential across Northern and Eastern counties:

SK

[No Balls Like Snow Balls]

A very very localised hard frost down South.

Edited March 8, 2013 by No balls like Snow Balls

[ITSY]

I don't know if people appreciate how good this chart is. Alright, no real snow to speak of, but potential galore, reload up and coming, -12-14c uppers already passed through us, snow on ground for some, mid-march (and all after a below average winter)!

My how things have changed in the last 4 or 5 years.

[Cheshire Freeze]

Possibilty of quite a few seperate snow events next week on the 12z GFS

LP engaging with 522 DAM

Meanwhile heights strengthening over Greenland.

At 174 the low to the W is going to phase with LP way to the SW. How this plays out will be interesting as if the GH manages to stay resolute, the snowline may well straddle the country. Rain to S and snow to N of boundary

Edited March 8, 2013 by CreweCold

[mushymanrob]

Under any cloud, temperatures will struggle. Upper air temp remains around -7. Temps will fall readily in any showers too.

true, but also temps wont fall away so far either, so maybe the severest of the frosts might be avoided.

[No Balls Like Snow Balls]

Still cold across the centre of the UK on Thursday. Less cold towards the East and far West.

Some rain to for the South. Possibly snow The Midlands North.

[cooling climate]

Love the GFS projected temps for Monday,and Tuesday with the south coast and Cornwall the

coldest places in the UK with two ice days.

Can not remember the last time we had a classic channel low runner with a bitting easterly wind

we are so close. Will it or won't it ?.

If it does come off then it will certainly feel like the middle of January for areas affected with

heavy snow and bitter windchill accompanied by below freezing temperatures.

[offerman]

What i like about the next 72 hours is that the look of the low and tight winds is an exact replica of the lows often seen that sit over North Italy and funnel winds form Northeast across alps.

We might get more than just a few flurries that was discussed earlier in the week from M.O They have put out warnings now for south that show more than flurries , possible 1-3cm 3-5 over high areas.

Who knows maybe more could come from this.

GFS has had this right from the start of the week. How come GFS has had this so right from this week yet in the depths of winter it kept failing and ECM was the correct modeller??

[No Balls Like Snow Balls]

Dry for the majority on Weds. Possibly some shower activity in the Afternoon. A mix of rain, sleet and snow depending on location.

[offerman]

Cooling climate, you forgot to mention and in march to!!

[DR(S)NO]

edit: also quite funny, added it up and in total Metcheck gives my location 22cm of snow between monday and tuesday

Yeh,and knowing Metcheck that's more likely to be 2.2cm

[Cheshire Freeze]

That low to the west 144-168 on the models is going to be a hurdle to overcome if we want to prolong the cold. The GFS 12z in low res highlights the issue. It's going to phase with the main jet energy to the SW BUT if we can get heights far enough S&E across Greenland then that won't be an issue as low heights will be able to stream SE into the continent rather than energy spitting NE.

Let's see how the ECM 12z handles the scenario.

[Severe Siberian icy blast]

The gfs is so frustrating when it does this in fi , completely forgets the major negative NAO and whisks up a strong autumn like low pressure and shoots it up the uk toward northern most countries , so annoying because it gives us some implausible outcome that's not even worth looking at.

And NO this isn't because it isn't showing what I want , it's because it's doing its usual trick it does every time , you can see as soon as it get its into low res it just goes wild. The 06 recently have been performing well Iv noticed , picking out trends before the rest