Wales/Cymru Regional Weather Discussion

[freeze for all]

Higher ground snow lower levels wintry mix mainly rain or sleet is wot I c for this 

[pyrotech]

Hi Jay, Andy

BBC graphics for UK show Snow in South Wales

BBC wales shows snow just high ground

 

This will change as we near but could easily be forecast wrong as late as tomorrow morning 

It could even come down to precipitation rate for evaporative cooling to make the difference or not.

Right now it looks like Andy will see snow settle, Jay would see snow at times but not hang about.

That could change thou. Lets see what warnings say around 11-12 today

 

Much netter than last winter thou , guys

[andymusic]

I'd say we should all meet on the top of Pen Y Fan early thursday morning - ok - see ya there 6am start

[andymusic]

8 minutes ago, Penfoel said:

Hi Andy ... are we likely to see a " Pembrokeshire Dangler" 

i currently live in Trefin ..near St Davids right on the coast and I wondered if you can explain the phenomenon to me in layman terms ...

thanks guys ! 

pembs dangler - maybe not quite the right conditions but maybe friday who knows - needs to be more of a straight northerly - it's more nor westerly

Edited January 11, 2017 by andymusic

[Jackfrost]

I'm erring on the side of caution here - there are reasons to be more optimistic than I am - but being Southeast Wales-specific, I wouldn't be surprised if the following happened:

Settling snow of 3-6cm above 200m (particularly stretching in a zone from the higher parts of Merthyr over to Brynmawr/Blaenavon) and, of course, in Andy's back yard (he's pretty high in a non-narcotic sense).

A transition zone covering most of the Valleys above around 100m, with slushy deposits or possibly 1-3cm.

Sleet and cold rain along the coastal belt. Sorry!

 

 

Edited January 11, 2017 by Jackfrost

[pyrotech]

Just for you Andy

Pen y fan 2nd jan 2017

 

I took the easy way up

[andymusic]

7 minutes ago, pyrotech said:

Just for you Andy

Pen y fan 2nd jan 2017

 

I took the easy way up

you are tooooooooooo kind lol

[andymusic]

10 minutes ago, Jackfrost said:

I'm erring on the side of caution here - there are reasons to be more optimistic than I am - but being Southeast Wales-specific, I wouldn't be surprised if the following happened:

Settling snow of 3-6cm above 200m (particularly stretching in a zone from the higher parts of Merthyr over to Brynmawr/Blaenavon) and, of course, in Andy's back yard (he's pretty high in a non-narcotic sense).

A transition zone covering most of the Valleys above around 100m, with slushy deposits or possibly 1-3cm.

Sleet and cold rain along the coastal belt. Sorry!

 

 

not sure whether that's a compliment or not lol

[beatpete]

unlikely i'd say but... http://www.bbc.co.uk/news/uk-wales-38576207   and my house would have to be in the no snow gap!

[pyrotech]

3 minutes ago, beatpete said:

unlikely i'd say but... http://www.bbc.co.uk/news/uk-wales-38576207   and my house would have to be in the no snow gap!

Unstable air mass

Cumulonimbus embedded clouds and warm seas ( 11c - 8c) 

This will cause convection and instability 

The thunder snow is just a thunderstorm with snow falling due to temperature instead of rain.

Why is this important for us?

This leads to enhanced precipitation rates

Each rain/sleet/snow drop brings a little parcel of air with it and even as melting on its journey down it cools the air further and further down.

This evaporative cooling is obviously enhanced as precipitation rates increase.

The added thing is any lighting can look stunning and can often appear to have a pink tint to it.

 

So if this feature moves far enough North and in my opinion it would need to become a full small low with circular feature to really drag in cold air.We could see some significant snow heads of valleys etc. Another area of risk is lower Gwent valleys.

Now for very South Wales its same old story

"areas below M4 likely to see sleet and snow with settled snow above that area

Now that can change if we get full circle of pressure as winds would become Northerly as it moves thru dragging colder temps from mid Wales.

I suspect if it happened as shown Cardiff would see snow falling for a short time around 5pm but it would be too little and too late

We need that low to completely form The dew points right now are too high near the Bristol channel coast

Lots to play for and this could easily become a significant event with snow fall capturing out commuters returning to the valleys from the Capitol"

 

[SnowStorm(Jamie)]

Currently awaiting the 06Z Euro 4 data to see how it handles the frontal wave that develops Thursday and runs east across the south of the UK. 

My current thoughts are upland areas of South Wales will see some sticking snow e.g. Merthyr, Dowlais, Tredegar. That being said as it develops further and colder air digs down areas of SE/E Wales could see some falling snow for a time. Ice becoming a real risk also for most areas.

 

 

 

 

 

[andymusic]

Yellow Warning of Snow for Wales

 

Yellow Warning of Snow for Wales : Blaenau Gwent, Bridgend, Caerphilly, Cardiff, Merthyr Tydfil, Monmouthshire, Neath Port Talbot, Newport, Powys, Rhonnda Cynon Taff, Swansea, Torfaen & Vale of Glamorgan valid from 1000 Thu 12 Jan to 2355 Thu 12 Jan

 

Yellow Warning of Snow for Wales

 

Yellow Warning of Snow for Wales : Bridgend, Carmarthenshire, Ceredigion, Conwy, Denbighshire, Flintshire, Gwynedd, Isle of Anglesey, Neath Port Talbot, Pembrokeshire, Powys, Rhonnda Cynon Taff, Swansea, Vale of Glamorgan & Wrexham valid from 0005 Fri 13 Jan to 2355 Fri 13 Jan

[andymusic]

take a look at the gorgeous GFS 06 - OMG OMG OMG OMG - the BEASTERLY is alive and well and heading our way - lock it down folks - get your larders stocked it's gonna be a cold icy winter after all

Edited January 11, 2017 by andymusic

[andymusic]

Yellow Warning of Snow for Wales

 

Yellow Warning of Snow for Wales : Carmarthenshire, Ceredigion, Conwy, Denbighshire, Flintshire, Gwynedd, Isle of Anglesey, Pembrokeshire, Powys, Wrexham, Neath Port Talbot & Swansea valid from 0005 Thu 12 Jan to 2355 Thu 12 Jan

[andymusic]

[andymusic]

 

and the above are guesses un all - found it on uncle dancing derek's twitter feed lol

Edited January 11, 2017 by andymusic

[SnowStorm(Jamie)]

Just an update on the situation now EURO 4 06z data is in:

Colder air wrapping around the low as it heads east, rain to snow risk *possible* for low areas of south Wales much dependant on exact track and precipitation intensity. 

 

Met Office graphic shows the risk of potential snowfall very nicely.

[Pembroke Dangler]

Winds are starting to get some bite to them WNW now temp fell from 9.5 to 8.5 in last hour. It's coming 

[Fujita scale]

We are still in warnings if you look at the graphics - but we are not where I have highlighted - are we going to be removed from them...... hope not!

 

 

[Pembroke Dangler]

3 minutes ago, Fujita scale said:

We are still in warnings if you look at the graphics - but we are not where I have highlighted - are we going to be removed from them...... hope not!

 

 

That's today's warning area that applies to 

[Marcus_surfer]

7c here with a dew point of 0.7c. Cold air starting to dig

[Fujita scale]

43 minutes ago, Pembroke Dangler said:

That's today's warning area that applies to 

Yes the graphic on the left is - but I have circled the Wales link - there is nothing by the side of it if you look - but the graphics for the other days show it should have the snowflake icon indicating a warning !

[pyrotech]

9.5c here in Cardiff

dew point minus 0.4c

[pyrotech]

4 minutes ago, Fujita scale said:

Yes the graphic on the left is - but I have circled the Wales link - there is nothing by the side of it if you look - but the graphics for the other days show it should have the snowflake icon indicating a warning !

You mean like this?

 

Change day on maps and then it will appear so highlight second map

[pyrotech]

13 minutes ago, Fujita scale said:

 

Ten mins ago i gave temperature details here at my location

Was 9.5 C

Now 9.3 C

 

Dewpoint was -0.4c

Now      -1c

So cold air moving in nicely

Thats a dew point i would love to see at this time tomorrow