Yorkshire, Lincolnshire And The Pennines Cold Spell Discussion

[Sammy21]

I think there only showers not heavy ones that not enough to settle anything could happen.

Edited February 5, 2010 by Sammy21

[johnholmes]

Sammy first of all welcome to Net Wx and also the regional thread.

I think for you to become a 'fully paid up member' you are going to have to put your town in your avatar as it really helps the interest when we all know where we are reporting from?

thanks

[hapifax kev]

It seems very quiet in here, i thought with whats coming up next week excitement would be building now. Should i expect to see any snow in this part of the world?

I can't read the charts so rely on you guys to help me out.

[Cheese Rice]

It seems very quiet in here, i thought with whats coming up next week excitement would be building now. Should i expect to see any snow in this part of the world?

I can't read the charts so rely on you guys to help me out.

Yes defiantly.

Monday- Snow flurries

Tuesday- Snow flurries with the some snow showers mainly for eastern areas

Wednesday- A trough (band of snow) which should give the whole of Yorkshire some snow, amount of lying snow up for question, perhaps 2-5cm

Thursday On wards- Heavy widespread showers, showers merging together to give longer spells of snow

[Sammy21]

Does anyone know where they are some good animation picture that works for display pic

[Cheese Rice]

Forecast for this week.

Monday- Cold starts to the day with some isolated mist and fog patches, temperatures around -1.c to -4.c. After a clear start it will soon cloud over with extensive cloud cover from the north, leading to a dull and cloudy day with suppressed maxes of 2-4.c. Later during the day patchy light snow will move south, some moderate burst of snow likely in Northern and Western areas. During the night snow continuing for a time with some locally heavier burst, leading to a covering of 1-3cm for most.

Tuesday- During the early hours of Tuesday morning snow will soon turn to rain or sleet, with snow confined to the highest ground (350m+). During heavier bursts there may be periods of wet snow but mostly rain or sleet. Temps close to freezing throughout the night around 1-3.c. Later in the morning the patchy rain or sleet may start to turn to snow, during the afternoon there is likely to be widespread snowfall, mostly light-moderate with the odd heavier burst. Max temps throughout the day of 0-2.c. During the evening the snow may continue in all areas leading to 2-4cm for most with higher ground (150m-200m+) possibly having higher accumulations.

Wednesday- The odd light snow flurry around but mostly clear skies and a very cold morning temps as low as -5.c in central areas. There is a real risk of ice on any untreated surfaces, mostly side roads at risk. During the afternoon cloud increasing from the South West, temperatures again low with highs of 1-4.c.

Thursday- During the early hours of Thursday morning widespread moderate-heavy snow is likely to affect all areas with the heaviest of the snow in the south and west of the region. This will last for a relatively short period (2-3 hours), leading to 4-6cm of snow for most. By morning the precipitation will have mostly died out apart from eastern areas where the snow will linger and slowly turn to sleet, where as in western areas the snow will have gone, leading to mostly cloudy skies, again cold with highs of 1-3.c.

Friday on wards- Alot of uncertainty as to what will happen, there is possibility of milder SW's but not particularly mild, with temps around or just below average. But the models could be underestimating the hight to our east which has already happened this winter so the outlook could be cold.

Looking at my forecast how did I do-

Monday- Pretty much of the mark for Monday, temp peak generally around 4-5.c for Yorkshire. Snow depth was none existence, there was a brief period of very light snow but no lying snow.

Tuesday- Again way of the mark, max temps was 7.c. The rain did turn to snow as predicted and lasted for several hours, resulting in a dusting. Snow depths again were predicted wrongly.

Wednesday/Thursday- Fairly accurate forecast, Snow that was predicted arrived earlier than I forecast, around 6hours earlier. Heaviest of snow was in South and West as predicted, the depths were rightly predicted, around 3cm+ on the ground and 5cm+ on the grass. Falling snow Lasted for around 2 hours which was predicted correctly. Temperatures were right on Wednesday, high of 3.c for most. Temps were wrong on Thursday, high of 6.c.

Overall- Not good at all, I was of the mark on most occasions.

Edited February 7, 2010 by 10123

[Cheese Rice]

Essentially its a cold front catching up with a warm front, which forces the mild air to move over the top. This is an occluded front and generally means it should stay pretty cold at the surface but uppers arent really too favourable after it passes over. This is why areas further south have experienced rain and sleet as the temperature has warmed up behind the front. Up here the situation is better.

Please excuse the crap diagram but it shows very well whats going on:

Thanks

Edited February 7, 2010 by 10123

[sunny scunny]

I'll be pleased when i finally get my internet back at home, and i can keep up to date with the charts etc

It's nowhere near as good using my mobile phone

[Harsh Climate]

I think as things currently stand, snowfall amounts mon-fri next week will be pretty trivial... maybe with the exception of the north york moors.

http://www.wetterzentrale.de/pics/Rtavn421.png

http://www.wetterzentrale.de/pics/Rtavn1261.png

These flows really are quite dry/drizzly flows and with the air being cold rather than being on the right side of very cold, I would except temporary accumulations to thaw inbetween showers. Obviously these charts arent going to be spot on at this stage, so there is a lot of potential down the line

We need a flow where where at the focal point of the squeeze of NE/ Easterly winds, something like this: http://www.wetterzentrale.de/pics/archive/ra/2009/Rrea00120090202.gif

This would allow for showers to 1.develope in the north sea widely, 2.spread right inland 3.not being under any part of high pressure allowing full convective cababilities...

As things stand at the moment heavy snow mon-fri will be confined to Kent, il try n do a map later

[johnholmes]

hi Jed and others with a similar view

The mistake you are making is simply to look at the surface/500mb flow without taking into account what is happening 3 dimensionally.

I tried to illustrate this yesterday or may be the day before in my blog.

As the cold air moves in it DEEPENS. Even if you don't understand skew-t diagrams just take a look at them-the 06z is available and the 12z will soon be. Like the surface charts they do change but what the consistently show is that the air becomes more and more unstable to sea temperature. These are currently 6-8C along with dewpoints that are predicted to fall to around zero later below zero C. The convection created by this process is clear to see.

I'll put a post in this thread sometime this evening to show it using the 12z skew-t data and explain it in simple terms so all can understand it. Essentially what they are already showing is that the dull type weather with a sheet of Sc (Stratocumulus) is going to be replaced by a more convective type Cu (Cumulus). Initially cloud tops will be about 3-4000 but by mid week will be around 10-12000ft which with a zero C isotherm around 1500ft will give showers-wintry, a mix of wintry type hail and snow for most perhaps more wintry hail/sleet right on the coast line.

anyway I'll post in more depth this evening.

[Harsh Climate]

hi Jed and others with a similar view

The mistake you are making is simply to look at the surface/500mb flow without taking into account what is happening 3 dimensionally.

I tried to illustrate this yesterday or may be the day before in my blog.

As the cold air moves in it DEEPENS. Even if you don't understand skew-t diagrams just take a look at them-the 06z is available and the 12z will soon be. Like the surface charts they do change but what the consistently show is that the air becomes more and more unstable to sea temperature. These are currently 6-8C along with dewpoints that are predicted to fall to around zero later below zero C. The convection created by this process is clear to see.

I'll put a post in this thread sometime this evening to show it using the 12z skew-t data and explain it in simple terms so all can understand it. Essentially what they are already showing is that the dull type weather with a sheet of Sc (Stratocumulus) is going to be replaced by a more convective type Cu (Cumulus). Initially cloud tops will be about 3-4000 but by mid week will be around 10-12000ft which with a zero C isotherm around 1500ft will give showers-wintry, a mix of wintry type hail and snow for most perhaps more wintry hail/sleet right on the coast line.

anyway I'll post in more depth this evening.

Thanks for that John, ye I see what you mean. I may have been a little guilty of talking a quick glance and basing what I have said on surface/500mb flow. But at the moment I just cant see any significant snow before friday away from Kent. I believe the cold air deepening should just be sufficient for that area, but any snowfall predictions at this stage is just speculation..

[johnholmes]

I'll try to prove otherwise, ASSUMING the 12z actually shows it on the skew-t diagrams

[johnholmes]

the post is below as a pdf

Skew-t for doncaster for week 7-11 feb 2010.pdf

[on the coast]

Excellent post John. Thankyou.

[Lewis]

Yep thanks john, very informative and well structured pdf once again

[johnholmes]

tks-ask questions if you want-not done the Doncaster video but it will be out sometime this evening

[Cheese Rice]

Light-moderate rain here for last 20minutes, all surfaces wet. Not showing up on radar, any ideas?

[yorkieblade]

Hi all, new to this thread , I have been reading it though for a while, I am based in south Sheffield nr to the border with North East Derbyshire, if anyone would like weather updates from this region I will be happy to supply.

Regards

[johnholmes]

Hi all, new to this thread , I have been reading it though for a while, I am based in south Sheffield nr to the border with North East Derbyshire, if anyone would like weather updates from this region I will be happy to supply.

Regards

welcome-they will be well recieved but it would help if you put your location in your avatar please

thanks

[Grimsby Snow Lover]

I know this is a BIG question but could anyone give me some idea as to when the stuff falling from the sky will have a wintry mix. I have read through page after page on the model output discussion and that seems to be focussing on the end of next week. I know it is difficult to predict snowfall in this country but would really appreciate an answer from some of the more experienced members. Thankyou... and if you're about Lewis congrats with the win last night!!!

Edited February 7, 2010 by Grimsby Snow Lover

[PMPhotography]

I know this is a BIG question but could anyone give me some idea as to when the stuff falling from the sky will have a wintry mix. I have read through page after page on the model output discussion and that seems to be focussing on the end of next week. I know it is difficult to predict snowfall in this country but would really appreciate an answer from some of the more experienced members. Thankyou... and if you're about Lewis congrats with the win last night!!!

From what I can gather at the moment any PPN from now could be wintry. The snow risk for the next couple of days could be marginal on the coast but any showers that make it inland should be snow.

There are some reports of hail and sleet from Newcastle just recently and the temp is dropping away here now too. currently 2.7C with a dropping dew point of +0.4C. I think the risk really increases from Wednesday though.

Lewis, If you're about would you have time to explain 0C Isotherms? I noticed you mentioned them in last reply, Iv'e found the charts and from what I can guess 0C Isotherm <1000ft is a good snow marker if dew points, 850hpa's and Dam are marginal?

Paul

[Grimsby Snow Lover]

From what I can gather at the moment any PPN from now could be wintry. The snow risk for the next couple of days could be marginal on the coast but any showers that make it inland should be snow.

There are some reports of hail and sleet from Newcastle just recently and the temp is dropping away here now too. currently 2.7C with a dropping dew point of +0.4C. I think the risk really increases from Wednesday though.

Lewis, If you're about would you have time to explain 0C Isotherms? I noticed you mentioned them in last reply, Iv'e found the charts and from what I can guess 0C Isotherm <1000ft is a good snow marker if dew points, 850hpa's and Dam are marginal?

Paul

Thanks for the reply, really hope we get a good covering this week. It would just put the icing on the cake for this winter. I have noticed the forecasts from the bbc show most snow activity from Wednesday onwards, really hope this doesn't get put back or downgraded.

[PMPhotography]

Thanks for the reply, really hope we get a good covering this week. It would just put the icing on the cake for this winter. I have noticed the forecasts from the bbc show most snow activity from Wednesday onwards, really hope this doesn't get put back or downgraded.

Me too! It's been a craker ey!

I'm always wary about margins here after being dissapointed many times, especially in an easterly setup with air modification from the North Sea, from what I can tell though the cold really sets in from Wednesday and the markers are good for all of us to see some snow from then onwards. It looks like the cold is here to stay too, if anything getting colder into next week.

[johnholmes]

for those wanting to know about snow this week then try my post above

No 188

Edited February 7, 2010 by johnholmes

[galba]

Not too bothered about more snow - we've had our fair share already this winter.

What would be welcome is some sunshine - is it too much to hope for from a relatively stable HP system ?

Or would settle for sunshine and occasional wintry showers.