Cold Spell Discussion

[dogs32]

time for a shovel

[NorthantsSnow]

John, any thoughts as to why the pro's are still silent about this spell??

The Irish Met just said dry all next week

I was surprised when I read the Met Office long range forecast. Snow on hills, rain/sleet elsewhere. I'd expect that to be revised (upgraded) in the morning based on the latest output.

[kold weather]

I wouldn't get too into the long range of what the ECM shows however the models are coming into agreement about a potent easterly shot towards the end of next week, maybe Thursday/Friday as the shortwave pulls away to the south, both models showing -12C 850hpa temps digging into the SE and that probably suggests temps of 0-1C tops, probably would be a lot of snow about in that easterly flow given the lapse rates present, the usual places would get the most snow. Timings and details still can't really be told but that general timeframe looks ok for now.

Anyway very cold night tonight it has to be said!

[dogs32]

I know Kold...Its just the potential could be there it's very exciting..

[Cheese Rice]

Ive come up with a little forecast map for Thursday/Friday/Saturday, this is how I see the situation coming of.

Orange Zone- Definite risk of heavy snow showers, prolonged at times leading to 5-15cm, expect local variations due to the showers. London is highlighted as a snow streamer similar to Feb 09 may happen.

Red Zone- Highest depth likely here due to showers backing up against the pennines/mountains leading to large snow depth of 10-20cm.

Purple Zone- Uncertainly as to whether the showers will fall as snow, due to the North sea been very mild all Autumn this is likely to have a negative impact on the coast but a positive impact inland.

Blue Zone- Showers are likely to make it far inland but will have lost alot of the intensity, so depths of 5-10cm is possible. Possibility of snow showers in Kent but still undecided.

Edited December 11, 2009 by 10123

[Ben_Cambs]

Ive come up with a little forecast map for Thursday/Friday/Saturday, this is how I see the situation coming of.

Orange Zone- Definite risk of heavy snow showers, prolonged at times leading to 5-15cm, expect local variations due to the showers. London is highlighted as a snow streamer similar to Feb 09 may happen.

Red Zone- Highest depth likely here due to showers backing up against the pennines/mountains leading to large snow depth of 10-20cm.

Purple Zone- Uncertainly as to whether the showers will fall as snow, due to the North sea been very mild all Autumn this is likely to have a negative impact on the coast but a positive impact inland.

Blue Zone- Showers are likely to make it far inland but will have lost alot of the intensity, so depths of 5-10cm is possible. Possibility of snow showers in Kent but still undecided.

Very good analysis, Thanks

[cyclonic happiness]

no idea-UK Met forecasters have been mentioning next week as colder with snow for some at various times over the last 24-36 hours.

I it not truethough John, that the meto won't mention snow unless they are more or less convinced that it will?

I've noticed them talking more and more in vague terminology in the past decade, like saying "showery rain" instead of just "rain" and "sleet and snow" instead of just "snow" or "the rain may be sleety".

[chrisbell-nottheweatherman]

Julie Reinger on Look East going for rain on Wednesday, but getting colder - max. 5 degrees. I think WeatherQuest may be deliberately low-key on the snow risk until we get nearer the time; then again, are the models still suggesting a milder day on Wednesday anyway?

[weatherobsuk]

I dont think ive ever seen a Cold Duration thats been so undecided by the Models. Ive kept quiet as generally theyve been in agreement/disagreement all week as to what the next 2 weeks are going to bring.

Myself personally still think this is a Stratospheric Warming Event trend starting, which would explain why so many of the models are struggling in agreement with the precip as the lower moisture in the airmass would limit its convective avaliability.

However saying that, its too early to tell wether this cooling trend is simply a Easterly blast or a lowering of averages throughout this Winter. Many people will only see a bad winter in terms of Snowfall accumulations instead of temperature averaging and variations.

The last SWE brought chaos across much of the South/Central UK last February with roads being closed due to ice, canals and reservoirs freezing up. This time it could be a more widespread impact.

[sundog]

most likely it will be a slow cold build up.

best setup for ireland is northerly arctic or nw and im sure something will come your way at some point.

with easterly it needs to be pretty intense cold but it does happen so i expect your know a little more over the next 24 to 48 hours.

models are indicating a northerly outbreak perhapes a couple.

For my location in ireland -in the east- i usually do ok with an east wind with showers coming in off the irish sea

[John Snow]

Ive come up with a little forecast map for Thursday/Friday/Saturday, this is how I see the situation coming of.

Orange Zone- Definite risk of heavy snow showers, prolonged at times leading to 5-15cm, expect local variations due to the showers. London is highlighted as a snow streamer similar to Feb 09 may happen.

Red Zone- Highest depth likely here due to showers backing up against the pennines/mountains leading to large snow depth of 10-20cm.

Purple Zone- Uncertainly as to whether the showers will fall as snow, due to the North sea been very mild all Autumn this is likely to have a negative impact on the coast but a positive impact inland.

Blue Zone- Showers are likely to make it far inland but will have lost alot of the intensity, so depths of 5-10cm is possible. Possibility of snow showers in Kent but still undecided.

You are way underplaying the NE and SE scotland due to the lake effect

That area will get 50-70cm I would say over the week not 5-15

Rest I agree with though

[Nights King]

Ive come up with a little forecast map for Thursday/Friday/Saturday, this is how I see the situation coming of.

Orange Zone- Definite risk of heavy snow showers, prolonged at times leading to 5-15cm, expect local variations due to the showers. London is highlighted as a snow streamer similar to Feb 09 may happen.

Red Zone- Highest depth likely here due to showers backing up against the pennines/mountains leading to large snow depth of 10-20cm.

Purple Zone- Uncertainly as to whether the showers will fall as snow, due to the North sea been very mild all Autumn this is likely to have a negative impact on the coast but a positive impact inland.

Blue Zone- Showers are likely to make it far inland but will have lost alot of the intensity, so depths of 5-10cm is possible. Possibility of snow showers in Kent but still undecided.

You forgot the heavy shower that is going to make it all the way over to somerset and dump 10 inches on my door step...

[Ben_Cambs]

Weve still got a bit of a ride before this event is going to happen

The 18z GFS pub run will be interesting for sure

Edited December 11, 2009 by Snowman0697

[Nick L]

Absolutely no point in looking for specifics until it is nailed on. Details should be looked at 36 hours beforehand - and any earlier than that is just plucking numbers out of the air.

[NorthantsSnow]

CNN weather forecast coming up in a few minutes. Freeview channel 84, Sky Digital 506, Virgin Media 607.

[Alex95]

You are way underplaying the NE and SE scotland due to the lake effect

That area will get 50-70cm I would say over the week not 5-15

Rest I agree with though

This is an OTT ramp imo, the possible easterly blast towards the end of the week would dump around 15cm here if it comes off as the ECM / GFS predicts, possibly 20-25cm if we get very lucky with some very intense precipitation, but 50-70cm wouldn't happen within a couple of days. Having said that, 50cm fell in 2/3 days in March 1979 around here but that was exceptional. When you bear in mind 30-40cm fell in Jan 1987, and this time round doen't look as potent (back then it was record breaking for the south in particular) anything more than 20cm looks to be pushing it.

Edited December 11, 2009 by alza

[Geordiesnow]

Fog has lifted into mist now and viability is the best it has been all day, whether this means the clouds are breaking up or what i don't know but hopefully we will get some breaks for those temps to fall.

[Dartmoor_Matt]

Mmmmm me likes the ECM 216... if only.

[SteveB]

From what I can make out, most should do well if this set up verifies. Not expecting much for my area, maybe the odd shower might make it far enough west, but that's about it until the monster low shown in ECM comes in to play next weekend.

If this pattern was to set in, then our best chance would be from lows trying to push in to the cold air. Some of the best snow falls from yester year come from that scenario.

[Mark Bayley]

I think i may win my bet about it snowing at the end of next week if the runs come off as predicted Quite foggy here with the temp at 3.9c

[kold weather]

Looks pretty solid to me 10123, I'd probably go for something similar, though of course the streamer situation is a little uncertain yet but it all depends on the exacts of the wind and the angles, that sort of stuff, however I think there is going to be at the very least a 12hr period where we see conditions condusive for such an event. Generally I favour the east coast in general to get some decent falls, as should E.Scotland of course.

Coldest temp right now at Aboyne at -5.1C, an increasing number of places now reaching 0C and this will continue, some palces closer to the SE still proving very stubborn to decrease right now, still quite a large range of temperatures across the UK, some areas still at 7-8C.

[John Snow]

The BBC are way behind the times, pathetic

Monday 14 December 2009 to Sunday 20 December 2009

Probably staying drier and colder than of late

The probabilities have changed for this week and now favour continued quiet weather, i.e. light breezes, bright or sunny conditions, and dry days following frosty nights. Fog is less likely.

There is a very slight possibility of a chilling southeasterly breeze coupled with frontal rain in Scotland.

Monday 21 December 2009 to Sunday 3 January 2010

This bit covers Christmas Day!

And as usual there is no strong probability of either wet or white!

Indications are for below average temperatures, but for most at least an average amount of rain. So more often than not we will have high pressure giving us frost and sunshine, but with one or two incursions of frontal rain.

If a cold southeasterly wind met Atlantic rain over us then you have the pretty white scenario. Sadly, there is no reason to forecast this at the moment.

[Stuart]

I will miss it all i will be away

[NorthantsSnow]

CNN forecast only went as far as Saturday in the end but showed the cold plunge making progress. Snow for Germany in particular, but that high keeping Britain cold.

[chrisbell-nottheweatherman]

The BBC are way behind the times, pathetic

Monday 14 December 2009 to Sunday 20 December 2009

Probably staying drier and colder than of late

The probabilities have changed for this week and now favour continued quiet weather, i.e. light breezes, bright or sunny conditions, and dry days following frosty nights. Fog is less likely.

There is a very slight possibility of a chilling southeasterly breeze coupled with frontal rain in Scotland.

Monday 21 December 2009 to Sunday 3 January 2010

This bit covers Christmas Day!

And as usual there is no strong probability of either wet or white!

Indications are for below average temperatures, but for most at least an average amount of rain. So more often than not we will have high pressure giving us frost and sunshine, but with one or two incursions of frontal rain.

If a cold southeasterly wind met Atlantic rain over us then you have the pretty white scenario. Sadly, there is no reason to forecast this at the moment.

Maybe they know something we don't?