Jump to content
Holidays
Local
Radar
Snow?

TonyH's Blog

Sign in to follow this  
  • entries
    150
  • comments
    142
  • views
    172,470

Weather guide (severe weather update): Thursday 17th to Sunday 20th January 2013

Sign in to follow this  
TonyH

1,258 views

[font=arial, sans-serif][size=3]
[b]Headline: Disruptive heavy snowfalls, very cold.[/b][/size][/font]
[font=arial, sans-serif][size=3]
Due to popular request and in view of the upcoming interesting and most probably severe weather here is a mid week update:[/size][/font][font=arial, sans-serif][size=3]

Warwickshire had around an inch of snow on Monday, but so far this Winter the snow has missed West Wales, bar a few flurries. A weak front over the Irish Sea is giving some very light snow to West Wales this evening, although I suspect that near the coast it is drizzle. Freezing fog meant a very cold day for the Midlands today, HIGHS of -3c in Warwickshire. Pembrokeshire on the other hand managed +5c this afternoon, quite a contrast.[/size][/font]
[font=arial, sans-serif][size=3]
Further light snow flurries overnight and even tomorrow morning for West Wales giving a slight but unproblematic covering, with weak fronts close by. Another severe frost for Wednesday night over most of the Midlands, temperatures down to -7c in places again, misty with fog in places again too. A chance the snow flurries could extend into the West Midlands later in the night. Freezing fog lasting through Thursday morning in parts of the East Midlands, but an increasing breeze should lift this by early afternoon, with some sunny intervals possible. Another largely cloudy day for West Wales, a little light rain, sleet or snow at times, most of the snow flurries on high ground, as the weak front nudges slightly less cold air into west Wales during the day. Maxima on Thursday below zero again for the Midlands, and up to 5c for Pembrokeshire.[/size][/font]
[font=arial, sans-serif][size=3]
The fun and games begins on Thursday night with a deep Atlantic low pressure thrusting it's fronts into the cold blocking Scandinavian high. The high is intensifying and unwilling to give ground over the coming days, so with these fronts hitting the cold air the result is widespread snowfalls throughout Friday lasting well into Saturday! Heavy and disruptive falls are expected, something to beware of if planning to travel on these days. Not all of us will see snow, at least not to start with, as the front will make some progress into Wales, and where it gets across to means the difference between where it rains and snows. The likely outcome for Friday appears that the snow proper starts over Wales during the early hours, although over lowland Pembrokeshire it most likely will be rain or sleet. The snow, some heavy, then spreads aross the Midlands during the morning, driven by a strong SE to east wind causing it to pile up and drift.[/size][/font]
[font=arial, sans-serif][size=3]
For Wales then, snow, heavy at times EAST of a line roughly Swansea - Lampeter - Aberystwyth - Lleyn Peninsular, these areas look set to have a lot of drifting snow throughout Friday, many places seeing at least 6 inches on the ground by night-time, and a foot is possible in hillier areas too. A very disruptive snowfall that has consistently been modelled for these same areas over recent days. West of this line, the models suggest slightly less cold air makes it, resulting in generally rain and sleet for much of Pembrokeshire, south and west Carmarthenshire, SW Ceredigion perhaps, and the Gower. However, this 'snow-line' may well shift a little come Friday, so even Carmarthen and Pembroke may see a snowy day, and vice versa, Swansea, Lampeter and Aberystwyth could see less snow than currently modelled. Even given the various permutations, the cold wins out later on Friday, so that disruptive snowfalls then spread west to cover even SW Wales into Friday night.[/size][/font]
[font=arial, sans-serif][size=3]
And what of the Midlands - the majority of this region seeing heavy and persistent snowfalls from Friday midday onwards lasting well into the night. Just the chance that the far NE Midlands, such as Lincolnshire may escape, but this too subject to change, should the front make it a little further east into the block? All in all, for virtually the whole of Wales and the Midlands Friday is looking like a severe snowfall event and probably not a good idea too travel, and best stock up in case you are snowed in over the weekend! Temperatures on Friday perhaps up to 5c for West Pembokeshire, but not higher than +1c for Lampeter and a bitter -2c for Rugby. Wndchill quite severe with all the snow and strong winds, not the best day to venture out for most perhaps? Be sensible take a Snow Day![/size][/font][font=arial, sans-serif][size=3]
[attachment=154659:PPVI89 snow Day Friday.png][attachment=154660:ecmt850_048 heavy snow Fri.png][attachment=154661:prectypeuktopo widespread snow Fri.png][/size][/font]
[font=arial, sans-serif][size=3]
For Saturday, still further snow to come would you believe, as the trough gradually dies a death over the south-west. Wales and the SW Midlands looking like being hardest hit on Saturday, the snow depths piling up even further, and with the 36 hours or more of snow modelled in these areas, we are looking at a foot of level snow quite widely, and drifts many times this that would block roads and railways. The snow should begin to peter out during the afternoon. Light winds on Saturday night over the deep snow cover, means that if the cloud clears some really low temperatures by Sunday morning. Not modelled this evening, but GFS has being showing minima of as low as -14c over Snowdonia, and -8c over the Mildands. Freezing fog in places too on Sunday morning. These figures are easily attainable but depend on the clear skies. Mostly dry and bitterly cold on Sunday, just scattered snow showers, mainly for the East Midlands, few places reaching zero.[/size][/font][font=arial, sans-serif][size=3]
[attachment=154662:ecmt850_072 further snow Sat.png][attachment=154663:ecmt850_096 Ec cold temps Sun next snow threat looms.png][attachment=154664:met_120 next snow threat Mon.png][/size][/font]
[font=arial, sans-serif][size=3]
The very cold weather looks like lasting well into next week too, and with another deep Atlantic low set to hit the cold block on Monday this could herald yet more disruptive snow for the supposed return to work![/size][/font][font=arial, sans-serif][size=3]
[attachment=154665:ecmt850_120 snowy Mon.png][/size][/font]
Sign in to follow this  


7 Comments


Recommended Comments

Seems to have gone to plan today, 9cm here, none/ little further west in Cerdigion towards Cardigan, patchy coverings Pembrokeshire, and a slight covering for SW Carmarthenshire. Quite a heavy fall still underway for the Midlands.

Share this comment


Link to comment
Interesting local effects across the marginl zone yesterday, Carmarthen snow free (low lying, near sea, less heavy precipitation), north Pembrokeshire heavy drifting snow (altitide, heavy precipitation , evaporative cooling, exposure). Officially greatest LEVEL depths close on a foot Powys. We are yet to experience very low minima, that needs this cloudy to clear, in fact surprisingly another gradual thaw underway today here as it has got above freezing.

Share this comment


Link to comment
×
×
  • Create New...