Model Output Discussion

[MKN]

I think people are underestimating the snow potential for the low pressure next week, certainly areas to North and West are favoured but a small eastward push which is possible and possibly even seems likely according to the tele-connections at the moment, could result in a more widespread snow event.

In all fairness the gfs 18z is poor in comparison to the 12z however if the 12z tomorrow doesnt back this up i wouldnt worry to much as there is still a good chance of it being further east.

[robert]

I really like the 00z run it looks really good with plenty of snow around and cold for a good while to come!

[Frosty.]

I really like the 00z run it looks really good with plenty of snow around and cold for a good while to come!

I agree, low pressure and cold air next week can only mean snow in many areas, especially in the north but with the jet over north africa the uk is in cold air all next week and with low pressure in control, that's a potent mix, I would still prefer the whole set-up to be further east so we see a bitter N'ly or NE'ly direct hit but the consolation prize is good enough as long as there is no more western movement. The current ecm 00z out to T+144 shows the arctic air returning around the low pressure over the uk.

[karyo]

The much desired shift eastwards does not seem to want to happen! Certainly not in the 0z output anyway...

GFS and ECM have the low over the country while the UKMO places it to the west. So, it is becoming increasingly likely that the cold plunge will be waisted on the Atlantic! The bbc northwest forecast showed rain showers for Sunday and Monday with 7c! This may be overdoing the temperatures a bit but as things stand I don't see widespread snow!

Karyo

[snowmadchrisuk]

It is surprising how little precipitation is showing for the amount of low pressures that would be in charge of the UK . Before someone points it out I realize precipitation charts change all the time but with that overall patten you would expect things to be alot more showery than is currently shown .

[Bolton67]

I agree, low pressure and cold air next week can only mean snow in many areas, especially in the north but with the jet over north africa the uk is in cold air all next week and with low pressure in control, that's a potent mix, I would still prefer the whole set-up to be further east so we see a bitter N'ly or NE'ly direct hit but the consolation prize is good enough as long as there is no more western movement. The current ecm 00z out to T+144 shows the arctic air returning around the low pressure over the uk.

@ T+144 on the ECM 00Z most of the country are under -4 uppers

ECM T+144

@ T+ 168 we see -4 uppers north of the M4 and -8 uppers coming into northern Scotland.

ECM T+168

Last feb we had -4 uppers here in Northants and it gaves us very heavy snowfall.

Edited February 11, 2010 by Lancs_Northants

[Bolton67]

The much desired shift eastwards does not seem to want to happen! Certainly not in the 0z output anyway...

GFS and ECM have the low over the country while the UKMO places it to the west. So, it is becoming increasingly likely that the cold plunge will be waisted on the Atlantic! The bbc northwest forecast showed rain showers for Sunday and Monday with 7c! This may be overdoing the temperatures a bit but as things stand I don't see widespread snow!

Karyo

UKMO 00Z 850hPa @ T+72

-4 uppers from a line north of Lincolnshire down to south wales and -8 uppers south of that line. and -12 into kent

[Blizzardo]

I'm finding next weeks set up facinating and think that their could be a few surprises around as we move through the week. Normally it would be logical to look for the low moving down from the north to move east to open up the possibility of a north easterly but I actually like how the low is slowly pulling colder air in to our south west. The pattern then seems to be moving towards a north easterly flow regardless of the initial low moving south east or not.

Bags of potential at 144 hours on the ECM.

Edited February 11, 2010 by Blizzardo

[Frosty.]

@ T+144 on the ECM 00Z most of the country are under -4 uppers

ECM T+144

@ T+ 168 we see -4 uppers north of the M4 and -8 uppers coming into northern Scotland.

ECM T+168

Last feb we had -4 uppers here in Northants and it gaves us very heavy snowfall.

It looks plenty cold enough next week for widespread snow, even John Hammond said that and I agree with him. I'm astonished it's so quiet on here considering we have such amazing snow potential just beyond the weekend unless everyone is on snow watch down in east kent!

[Bolton67]

It looks plenty cold enough next week for widespread snow, even John Hammond said that and I agree with him. I'm astonished it's so quiet on here considering we have such amazing snow potential just beyond the weekend unless everyone is on snow watch down in east kent!

Agree 100% with you frosty!

[I remember Atlantic 252]

It looks plenty cold enough next week for widespread snow, even John Hammond said that and I agree with him. I'm astonished it's so quiet on here considering we have such amazing snow potential just beyond the weekend unless everyone is on snow watch down in east kent!

still cant see where snow is coming from next week for low levels , we have Atlantic winds, need the low to move East, UKMO especially shows SW winds with rain

unless models move the low East, snow to me will be only for 300m+ for southern areas, but the trend on all models has been to move the low west with S or SW winds

[Weather-history]

The bbc northwest forecast showed rain showers for Sunday and Monday with 7c! This may be overdoing the temperatures a bit but as things stand I don't see widespread snow!

Karyo

I take those BBC NW forecasts with a huge pinch of salt especially the 5 day ones. I have seen some strange ones such as max and min being the same temperature, the minimum being higher than the maximum, rain and sunshine symbol with 3C but a wintry symbol with 6C in the same 5 day outlook

Edited February 11, 2010 by Mr_Data

[The Weather Dragon]

It looks plenty cold enough next week for widespread snow, even John Hammond said that and I agree with him. I'm astonished it's so quiet on here considering we have such amazing snow potential just beyond the weekend unless everyone is on snow watch down in east kent!

All the data points to a very marginal event next week - rain & sleet is the highest probability - snow only for favoured locations - That's why it's so quiet.

[MisfitDog3]

interesting charts this morning. Because of the marginal nature of snow events (especially in the south) I suspect a lot of people are keeping their views to themselves until the weekend. There is a lot of flux in the medium to long term and we could even see a straight return to Atlantic SW's out of this set up.

[Winter Monsoon]

I think its marginal for next week up here in the north west. Looks to me that the low is dragging in warmer air but thats my inexperienced opinion. Even if it does snow it doesnt look like it would stick either. Of course im probably wrong and if i am can someone explain to me why.

Does the GFS over do the temps i.e does it end up being colder than what the GFS shows?

[MisfitDog3]

though I should say I suspect the cold may re-load rather than a return of the Atlantic!

[January Snowstorm]

It looks plenty cold enough next week for widespread snow, even John Hammond said that and I agree with him. I'm astonished it's so quiet on here considering we have such amazing snow potential just beyond the weekend unless everyone is on snow watch down in east kent!

It looks barely cold enough for highground on ALL charts this morning.

Rain with hill sleet and mountain snow is whats showing, if your lucky!

[chionomaniac]

still cant see where snow is coming from next week for low levels , we have Atlantic winds, need the low to move East, UKMO especially shows SW winds with rain

unless models move the low East, snow to me will be only for 300m+ for southern areas, but the trend on all models has been to move the low west with S or SW winds

Perhaps if this low was sourced in the Atlantic then your comments would have a ring of truth to them. There is no predominantly SW winds on the UKMO run for next week. This trough is dropping from a cold air source bringing the colder air with it. The jet stream is still well to the south and there will be enough cold air in the system to deliver snow events any where in the country even to low ground on occasions. The marginality will mean that some less favoured locations may get sleet or rain but I bet that there will be many reports of snow with some surprise snowfalls. Remember as well the trend to move this system west is around T+144 which is far too into FI to have complete confidence with the exact positioning of the trough. If the jet stream stays south then the opportunity remains for further snow events as cold air will never be too far away.

Furthermore I can see signs that there is potential for heights rises towards our north extending towards Scandinavia in the extended period. Now that will get TEITS talking about easterlies again!

Edited February 11, 2010 by chionomaniac

[Nick F]

I think its marginal for next week up here in the north west. Looks to me that the low is dragging in warmer air but thats my inexperienced opinion. Even if it does snow it doesnt look like it would stick either. Of course im probably wrong and if i am can someone explain to me why.

Does the GFS over do the temps i.e does it end up being colder than what the GFS shows?

Hard to be specific, even the most experienced forecaster will have a hard time trying to be specific to where it may snow away from high ground next week, as it looks a very marginal set-up for lower levels. Low heights and thicknesses next week look conducive for snow at times to lower levels, but a wind shift off the Atlantic will bring moister air and raise those dew points making it a bit of nightmare forecasting. Calm conditions and heavy precipitation would most likely be most conducive for snow for lowland UK in the kind of set-up shown next week.

[TEITS]

I personally can't see much to be excited about in this mornings model output. The problem is its difficult to get excited about marginal snow events because you won't know what will fall until it arrives. Also whilst under any spells of sunshine the temps will rise to around 4/5C with a rapid thaw of any lying snow. My last gripe with the model output is the continuing suggesting of it eventually turning milder.

I have woken to a covering of snow which was pleasantly surprising.

[johnholmes]

I would agree with that overall view Nick-I'll do a blog this morning using the Extra charts with some views on what the models currently show.

[cooling climate]

Perhaps if this low was sourced in the Atlantic then your comments would have a ring of truth to them. There is no predominantly SW winds on the UKMO run for next week. This trough is dropping from a cold air source bringing the colder air with it. The jet stream is still well to the south and there will be enough cold air in the system to deliver snow events any where in the country even to low ground on occasions. The marginality will mean that some less favoured locations may get sleet or rain but I bet that there will be many reports of snow with some surprise snowfalls. Remember as well the trend to move this system west is around T+144 which is far too into FI to have complete confidence with the exact positioning of the trough. If the jet stream stays south then the opportunity remains for further snow events as cold air will never be too far away.

Furthermore I can see signs that there is potential for heights rises towards our north extending towards Scandinavia in the extended period. Now that will get TEITS talking about easterlies again!

Quite agree, at six days out the synoptics could look very different come next Tuesday, Wednesday time.

In fact I would be very surprised if they didn't.

All to play for still.

[Weather-history]

Its a very unusual set-up thats for sure.

Look at GFS 06z and note that pool of -10hpa air close by and with low pressure around. It could be a very interesting week.

Edited February 11, 2010 by Mr_Data

[cooling climate]

Very interesting developments on the 06z GFS run t120 with the low moving even further

southwest but with a continental feed into the southeast and higher pressure to the north.

If this is a new trend we could be looking at a east,northeasterly come next week.

[Southender]

Look how much further west the low is on the 6z GFS.