Wales Cymru Cold Spell Discussion

[Marcus_surfer]

Here are some pictures from the walk, taken at around 12.15PM.

[Cymro]

Here are some pictures from the walk, taken at around 12.15PM.

Lluniau hyfryd iawn chi di cal bach yn fwy na ni wedwn i

Lovely pictures youve had a little more than us i would say.

[andymusic]

????

MO prediction was spot-on so not sure which forecast you watched / read / heard. Read my blog entry yesterday evening regarding our opinions at that stage on the likely easterly spread of the feature overnight from classic 'Pembrokeshire Dangler' positioning. And it did exactly as anticipated - including delivering light snow as far east as Bristol into the early hours. See the UKV high-res PPN accumulation prediction I added at http://bbc.co.uk/ianfergusson yesterday evening. Note also the prog for tomorrow's snow showers.

Best

Ian

Initially the met office had the risk over pembs and carms in yellow as an advisory - when the streamer really got itself together later into the night all of a sudden oranges appeared on the meto warning systems to cover swansea and further east of that - meaning intially they were not expecting the streamer to go that far east only advising that pembs and carms were going to be effected - the orange warning came on as the situation was happening!

[J10]

????

MO prediction was spot-on so not sure which forecast you watched / read / heard. Read my blog entry yesterday evening regarding our opinions at that stage on the likely easterly spread of the feature overnight from classic 'Pembrokeshire Dangler' positioning. And it did exactly as anticipated - including delivering light snow as far east as Bristol into the early hours. See the UKV high-res PPN accumulation prediction I added at http://bbc.co.uk/ianfergusson yesterday evening. Note also the prog for tomorrow's snow showers.

Best

Ian

Your blog and associated graphics really did hit the nail on the head. Also looking interesting to tomorrow. Would you say that 5-10cm are again possible in places. Or is that later time of day of the snow means that accumulations are less likely.

[andymusic]

Seems to me last night that forecasters on news 24 and elsewhere were updating their forecasts for last night as the amount of snow coming through and areas affected changed a bit! - It wasn't a huge amount as intially I don't think they were expecting as much as did fell, but as it got going forecasters were changing their immediate forecasts!

I understand snow is not the easiest of things to forecast!

Edited January 30, 2010 by andymusic

[Ian Fergusson]

Initially the met office had the risk over pembs and carms in yellow as an advisory - when the streamer really got itself together later into the night all of a sudden oranges appeared on the meto warning systems to cover swansea and further east of that - meaning intially they were not expecting the streamer to go that far east only advising that pembs and carms were going to be effected - the orange warning came on as the situation was happening!

No - the oranges, in this case, came as FLASH warnings and are the almost inevitable end result, as opposed to advisories, when it's a finely-balanced forecast of such subregional scale.

They're only issued when the short-range, high res modeling has taken the confidence bounds up into the pre-established % values that determine FLASH warning status. Inevitably, it's thus more a nowcast situation.... MO would rarely issue an 'early warning' (orange) for the likes of last night's lower confidence smallish-scale set-up.

However, the risk certainly would (or should) have been mentioned in any forecasts you read or heard by around 6pm yesterday.... i.e., when I was penning yy blog using the very same MO data talking-up the prospects.

Edited January 30, 2010 by Ian Fergusson

[andymusic]

No - the oranges, in this case, came as FLASH warnings and are the almost inevitable end result, as opposed to advisories, when it's a finely-balanced forecast of such subregional scale.

They're only issued when the short-range, high res modeling has taken the confidence bounds up into the pre-established % values that determine FLASH warning status. Inevitably, it's thus more a nowcast situation.... MO would rarely issue an 'early warning' (orange) for the likes of last night's lower confidence smallish-scale set-up.

However, the risk certainly would (or should) have been mentioned in any forecasts you read or heard by around 6pm yesterday.... i.e., when I was penning yy blog using the very same MO data talking-up the prospects.

No worries Ian - Nice to see you on our thread and have your further expertise to add to ours

[Cymro]

Why agree, would like Ian to adivse the bbc to remove their 5 day forecasts off the internet mind because they really are never accurate and tbh we all know automated forecasts are useless but its ever so frustrating trying to tell you mum its going to snow and she checks and says no and then it does and she always has egg on her face. People take it as the bible.

[marclt]

No worries Ian - Nice to see you on our thread and have your further expertise to add to ours

A lovely covering here in west carmarthenshire - about 2inches as it has snowed most of the morning. Similar picture over the Preseli hills down towards Narberth and Tenby!

[andymusic]

A lovely covering here in west carmarthenshire - about 2inches as it has snowed most of the morning. Similar picture over the Preseli hills down towards Narberth and Tenby!

Come to Tenby for the snow covered beach - snow capital of Europe!!!!!!!!! - you got more snow than they got in Vancouver (Olympic Games 13th Feb 2010) - Canada, that's for sure!

[J10]

I was surprised that Swansea was not included in the Severe Weather Advisory for Last Night into today, the set-up was conducive for us, (it has delivered in the past) and the NAE showed the potential of a snow streamer.

There is definitely a thaw now, roads in the sun are thawing, while on grassy areas, the snow is thinning in the sun, with round 90% of the back garden covered, the snow is not shifting at all in the shade.

[Bobby]

I was surprised that Swansea was not included in the Severe Weather Advisory for Last Night into today, the set-up was conducive for us, (it has delivered in the past) and the NAE showed the potential of a snow streamer.

There is definitely a thaw now, roads in the sun are thawing, while on grassy areas, the snow is thinning in the sun, with round 90% of the back garden covered, the snow is not shifting at all in the shade.

The NMM is showing quite a lot of precip for tonight and tomorrow... more widespread too than last night. Could be 5-10cm in the favoured areas.

Our dusting is not melting at all in the shade despite temp of ~3c. I expect the dry polar air is helping.

[Methuselah]

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