SnowStorm(Jamie)

The main threat for most of South Wales is the the snow pushing NE-SW. You can see this on the radar- the Metoffice one is here: http://www.metoffice.gov.uk/weather/uk/radar/

Here the GFS 18z for Midnight and the early hours: http://www.wetterzentrale.de/pics/Rmgfs063.gif http://www.wetterzentrale.de/pics/Rmgfs093.gif http://www.wetterzentrale.de/pics/Rmgfs123.gif Its has been very keen to place precipitation over Wales (mostly South) and has been for some time. Although these charts are becoming less useful to us at this time range, best option- Satelite + Radar.

UKMO 12Z gives some light snow to South Wales with the heavier stuff still East though. http://www.meteociel...8-594.GIF?05-17 < UKMO 12Z Precipitation- Heavier precipitation touching SE Wales

Looks like South Wales could see some light snow pushing in later tonight & the early hours of Wed: http://expert.weathe...010600_0512.gif < NAE @ 00 GMT http://expert.weathe...010606_0512.gif < NAE @ 06 GMT Looking at it the Low looks slightly more to the North than some previous runs. http://expert.weathe...010606_0512.gif More of an E flow which should help push more precipitation in to SE Wales.

You can see it on the NAE: http://expert.weatheronline.co.uk/daten/proficharts/en/nae/2010/01/05/basis06/ukuk/pslv/10010518_0506.gif Just to the South of Wales @ 18 GMT Looking at it on the radar its to the West with precipitation wrapping around it in to Pembroke. The feature is heading South- W Wales most effected

Still looks as if those in SE Wales will see more snow tonight: http://expert.weathe...010600_0506.gif < NAE Precipitation So a spell of snow is likely before the low then starts to sink Southwards away from the UK: http://expert.weathe...010609_0506.gif

Was in Swansea was a wintry mix, it did turn to snow for a short period before reverting back to sleet on the back edge. Looks like some will see some more snow (away from the coast) as another band pushing SW, though i havent looked at this much yet.

That is interesting it does seem to focus the larger precipitation amounts on more SW/Western areas which is good for us. Good luck everyone, hope we all see the snow.

Heres a link to the Netweather guide to the ensembles: http://forum.netweat...__fromsearch__1 < This explains it well The ensembles can give you confidence in a situation if many of memebers are going for the same situation: http://charts.netwea...e~-~Swansea.png Notice how all them lines (members) for upper air temps (T850) go below -5C and down to -10C up until the 13th Jan so you have more confidence in it staying cold until around then. After this they become more spread out as they often do indicating some uncertainty, although you can see the general trend is for them to rise above -5C later in the period.

Not yet convinced by the shown situation on the GFS 18z which had snow covering all of South Wales and reason for this is because of the ensembles: 18Z Precipitation ensembles for cardiff are below: http://charts.netweather.tv/ensimages/ens.20100104/18/prcpCaerdydd~-~Cardiff.png And then for Neath: http://charts.netweather.tv/ensimages/ens.20100104/18/prcpNedd~Port~Talbot~-~Neath~Port~Talbot.png Looks to me as is the GFS Operational run went out on its own here in terms of amount of precipitation So its right to say allot of caution is needed, remember this development has only just appeared today and is open to change. Going to check this in the morning because yes it could be shifted west towards us or east further away from us.

The latest NAE run still wants to develop heavy snow for SE Wales. http://expert.weatheronline.co.uk/daten/proficharts/en/nae/2010/01/04/basis18/ukuk/prty/10010606_0418.gif I did however notice Low pressure is slightly further south on this run, risk areas remain largely the same though. The GFS has it further west so not a nice one to call really. As for that front pushing SE you can see it here: http://www.metoffice.gov.uk/weather/uk/radar/ allong with what the NAE thinks of it in terms of precipitation type @ 18h : http://expert.weatheronline.co.uk/daten/proficharts/en/nae/2010/01/04/basis18/ukuk/prty/10010512_0418.gif Sleet and Snow but looking quite patchy to be honest.

GFS brings the front down and on this run yes it does look heavier: http://www.wetterzen...cs/Rmgfs243.gif The latest NAE shows Sleet and Snow for most of Wales: http://expert.weathe...010512_0412.gif The Sleet falling on the coasts of the W and SW, away from these coasts and snow will be the most likely outcome This front pushing down from the north isnt going to bring allot of snow so dont expect that- however it could give a light covering in places. Keep up to date with the latest advisories issued for Wales by the MetOffice: http://www.metoffice...ings.html?day=3 Watch out for the ice.

Looking at the dewpoints on the gfs 18z it seems the further west you are the more marginal it becomes GFS 18z Dewpoints as the front comes through: http://www.wetterzen...cs/Rmgfs368.gif < @ 36h - look at them dewpoints in west wales around 1C however colder in N wales with Snow. http://www.wetterzen...cs/Rmgfs398.gif < @ 38h - Dewpoints lower as the front clears through E wales looks all snow so does N and S away from the coast. Uppers on the GFS & NAE arnt a problem as we know. These are the Max temps at 36h from the NAE: http://expert.weathe...010506_0318.gif Apart from areas around the coast i dont see a problem given these are the max temps. Also the wind direction at 33h on the 18z here: http://charts.netwea...8/33/ukwind.png Wind From the west coming off the sea where temps are milder, explains the milder dewpoints in the W. A direct Northerly flow would be better no milder sea air getting forced through from the west in that case and we would see the cold front pushing through allone instead of a warm front being involved aswel.

More precipitation around with the front pushing down on tuesday. GFS 18z: http://www.wetterzentrale.de/pics/Rmgfs363.gif 24h fax chart: http://www.meteociel.fr/ukmo/fax/fax24s.gif You can see the cold front coming down from the North and the warm front is just south of it, could well become more of a feature again it seems. Latest NAE: http://expert.weathe...010506_0318.gif Looks like a wintry mix on this run as it pushes through still with snow involved for some. So for snow we dont really want to see the addition of that warm front- hopefully it will stay to the west of us. But even if this warm front does come over us i would still say those who are on high ground and away from the coast will still see some snow. EDIT : fixed links

Yup the latest fax charts dont make much of that warm front and its further west- which is good. Heres the 48h fax chart: http://www.meteociel.../fax/fax48s.gif Cold front pushing through and 528 Dam line covering the country. The GFS Operational run hasnt been making much of this front i have noticed however the ensembles go for more precipitation http://www.wetterzen...cs/Rmgfs423.gif < GFS 12Z PPN chart http://charts.netwea...thyr~Tydfil.png < PPN ensembles for Merthyr http://charts.netwea...mbrokeshire.png < PPN ensembles for Pembrokeshire Again the NAE run shows cold upper temps around the UK: http://expert.weathe...010506_0312.gif Certainly one to watch, hopefully the warm front idea isnt placed in the situation again- but keep an eye out for it I suppose its fair to say as this cold front pushes south then most will see snow, however it still isnt clear how intense the front will be- hopefully it will be more than what the GFS Op run makes of it.

True about the 60h chart: http://www.meteociel.fr/ukmo/fax/fax60s.gif With a bit of luck the warm front will be pushed even further west, upper air temps either way look very good.

As for the front pushing Southwards Tuesday i have just noticed something when looking at the fax charts. 36h: here you can see the front to the north. http://www.meteociel.../fax/fax36s.gif 48h: Notice the warm front develop on the western flank of the front, you can also see that the flow is not true northerly more to the NW. i think the warm front is due to slighly warmer air being pulled in off the sea over locations in the west. http://www.meteociel.../fax/fax48s.gif Will check the updates later. Edit: corrected text

With a bit of luck it will die out before coming this far South, it looks a lot more patchy now. Its mostly rain anyway apart from the high ground.

Heavy snow here again

Had snow here to got quite heavy for a time and a light covering now. Very nice to have it on new years.

Happy New Year everyone!!! Hope for many snow events as we go through the winter Jamie

I to was quite surprised this morning at the metoffice warnings being extended for heavy snow around Swansea, Neath, Carmarthen etc.. Perhaps just being cautious, i do know though that upper air temps wernt supporting snow for much of the coastal areas in South Wales (Though slightly better in SE Wales im sure). Again i did see snow at 250m though it was wet and didnt last long quickly turning back to sleet. Looking around and it seems as if most the hills below 300m and closer to the coast experienced much the same. Couldnt see over towards the Brecon Beacons- higher up and further north and east of me- Snow was on the cards there. If this block over greenland can stay around long enough allowing a cold theme to continue then so our chances of wintry weather are increased, but first we need to establish the cold then look for the precipitation.

Nice looking at those webcams, quite a few lucky people. Upper air temps from the NAE @ 0h: http://expert.weathe...122912_2912.gif You can see these have been lower in East and Mid Wales, if that low had been further South then snow would have been more widespread across S Wales. More Snow to come for Mid Wales and some for North Wales i think as that front slowly pushes Northwards. GFS 12z: http://www.wetterzen...cs/Rmgfs123.gif

Just a damp squib here on low ground likely to stay that way now upper air temperatures are going to be increasing. Had some wet snow on the hills earlier so didnt go without

If you look at the radar there is a front in the SW, which is coming towards us. This is the front that will hold the most snow potential. Mid Wales looking best for Snow- Dont expect much at all away from here on low ground