The South West Of England Regional Discussion Thread

[Cakie]

Rain here but 7 miles away its snowing heavily :o

Alex, any chance you could put a rough idea of your location in your profile? The South West covers a large area & it would just help others know what's happening where

Ta

[Frosty_wsm]

http://expert-images.weatheronline.co.uk/daten/proficharts/en/nae/2011/12/13/basis06/ukuk/prty/11121412_1306.gif Wasn't expecting that for tomorrow!

[Evening thunder]

Had a bit of sleet on the car windscreen this morning, then decided to go up a nearby hill that reaches 247m this afternoon and wait for a shower to arrive, yet it was plain rain with a bit of sleet in the odd drop.

At dusk some showers were coming this way, but they didn't look that strong and I didn't feel like staying up there and I had stuff to do at home, but they intensified suddenly and gave a mix of sleet in raindrops and hail blowing against the windows down here. a few people were saying on Facebook that there was snow a bit further north under a 'fatter' area of the shower. Seen more wintriness in 2 showers down here at about 40m and 26m than about 240m. I bet the shower this evening was heavy wet snow up on this hill too. Typical.

[AWD]

http://expert-images.weatheronline.co.uk/daten/proficharts/en/nae/2011/12/13/basis06/ukuk/prty/11121412_1306.gif Wasn't expecting that for tomorrow!

Yup, tomorrow could be a rinse and repeat of today! Has been bitterly cold here today, even though I'm still snowless! Was White temporarily though, hail instead of snow!

I'm watching the track of this LP system on Friday! A nudge more further south and we could be looking at a temporary snow event for our region! As it stands at the moment, with the track the 12z GFS profs, it would only be the Cotswolds that would stand a chance of snow!

Here's hoping and ramping anyway!

Will look at charts properly later and give my thoughts on any likely outcome over the next 24 hours or so!

Enjoy the snow, you lucky ones that have it

[MP-R]

Well we've really had the kitchen sink today. Having not heard the thunder at 8.30 this morning, there were an impressive 3-4 bangs round 2.30-3 this afternoon and another very heavy hail shower. All in all there's 21mm in the guage but that was probably the best storm of this year that I've been here for. Long may December's zonality be of the cold type!

[dancing daisy]

This is dancing daisy's daughter are we going to get any snow here? Sorry if im being annoying but i cant read the maps and I don't understand lol Im just excited that we may get snow

[Severe Siberian icy blast]

Hi every1 , Just to let us all no that its snowing at mine now , started as sleet but now snow , yes im high but i think as the temps and due points drop it wil get more an more wintery , hopeso !!

[jethro]

This is dancing daisy's daughter are we going to get any snow here? Sorry if im being annoying but i cant read the maps and I don't understand lol Im just excited that we may get snow

I don't know if we're going to get any snow, I don't understand all that complicated map/model stuff either. It's not annoying to be excited at the prospect of snow, it's absolutely compulsory behaviour in this thread.

[dancing daisy]

I don't know if we're going to get any snow, I don't understand all that complicated map/model stuff either. It's not annoying to be excited at the prospect of snow, it's absolutely compulsory behaviour in this thread.

Ok thankyou will just keep looking out of the window hahaha

[Andy Bown]

Where in Somerset are you DD?

Best chance for snow in Somerset would be over Exmoor towards the North Coast and maybe on the Mendips. Most overnight showers will be up through the Bristol Channel, along the M4 corridor and Gloucestershire and also along/near to the South coast. There will be few showers inland and more likely a mostly clear/frosty night, unless a trough/weak front moves through in the flow.

[AWD]

Latest NAE suggests a potent Bristol Channel streamer tomorrow afternoon setting up. May provide something for Gloucs. & Wiltshire.

Before it all turns back to rain

IMO tomorrow hasnt got as much potential as today had, but I may be proven wrong. The uppers slowly rise tomorrow ahead of this unpredictable LP on Thursday night/Friday.

A whole load of rain in the Atlantic just waiting for us

More analysis to come soon

[snowking]

Thursday/Friday is just a complete write off at this stage in terms of offering a forecast - there is far too much uncertainty and so man variables that this is simply one that can't be relied upon wholly from standard NWP modelling. My advice would be use the hand drawn UKMO Fax for the time being.

I would hate to be the chief forecaster in Exeter right now, I very genuinely feel for him/her. My guess at the moment would be a channel track with some back edge snow north of the M4....though I should imagine the uncertainty in the track is probably give or take 100-200 miles north/south at the moment which can drastically alter the strength of the low and any associated precip (200 miles further north and we're back towards 100mph territory I'd have thought along with far more mixing in of milder air under the stronger flow). And all this is assuming that the models we can see are even deepening the low enough in the first place!

Definitely a week to stay glued to the forecast religiously

SK

Edited December 13, 2011 by snowking

[Paul T]

Ah, the start of my 2011/12 winter posts!

Well, what a day of Atlantic winter energy today;

From my commute into Bristol with sleet showers and thunder and lightening, to hail covering the roads and pavements during the day.

This week could have snow potential, in theory. However, the bottom line is that temps will be 2 or 3 oC's to the bad. What we have in essence is a very cold south westerly. You don't often get snow from that unless its Feb, and the sea temps have dropped another 2/3 oC.

The 'Channel low' event on Thurs/Friday is unlikely to produce snow for lower levels (less than 250m) as there is no 'engrained' cold around the UK and the low is moving into 3/4oC daily temps....if it was moving into temps hovering around zero it may produce. We can only hope for a gradual drop in temps during this week (more so than expected) and then some serious evaporative cooling effect from some very heavy precipitation, coupled with a perfectly placed low: its like hoping a pair of two's will beat a pair of kings on the flop.

What i am liking at the moment is the way the charts are gradually going for an ever increasing colder outlook. Although i do believe the Christmas period will be a SW'rly 10oC affair.

One more thing,,, the fact im posting on here means there must be SOME chance of snow, as its the only thing that really gets me posting!

Paul

[Chris K]

Thanks for the information Paul

This week certainly has been interesting and still continues to be whilst waiting to see how the models continuously change as we approach thurs/fri.

[Jane Louise]

Yes, thank you all for your input. Much appreciated.

[alex12]

I didnt want to say this but i will, do you think we will see any snow in somerset anytime soon?

[AWD]

If its wanted on here, I will do a novice forecast each evening at around 10pm ish detailing what is in store for our region in the next 24 hours, plus a brief summary of 72 hours ahead. Just basically transferring what the charts say into plain English.

Friday 14th December

A day not to disimiliar to today, although showers will tend to ease later in the day ahead of a unpredictable LP system later on Thursday. Areas on the Bristol Channel coast as well as Urban areas, such as Bristol and Bath, to the East of the region are likely to see showers of predominatly rain, with hail and sleet possible on the heaviest of the showers. Thunder and Lightning again is possible in the heavier showers. These showers start to form a quite potent Bristol Channel Streamer by midday and run along the M4 corridor, into Gloucs. & Wiltshire, as well as affecting North Somerset. On higher elavated groundd these showers have the potential to fall as sleet and wet snow, although no accumilations are expected, with the exception of perhaps the Forest of Dean and the north Cotswolds. In the heaviest showers, under evaporative cooling, sleet and snow may get down to modest levels in Gloucs. & Wiltshire. For the Mendips, Dorset, South Somerset, Devon and Cornwall, fewer showers can be expected here, but occassional showers of predominately rain can still be expected, perhaps something wintery on Exmoor and Dartmoor. The wind wont be quite as strong at it has been recently, although a gusty breeze will still be evident. Windchill, as like today, will make it feel quite bitter at times, especially under any showers. Temps will be below average for December, although too windy for a frost for most tonight, tomorrow night as a higher chance of frost and Icy conditions where any showers have fallen as skies clear into the evening. Temps will range throughout the region, typically peaking between 4c - 7c in the north and east of the region, and between 7c - 10c in Devon and Cornwall. During showers, expect to knock a good degree or two of these temps. Tomorrow night expect temps to dip close to freezing in Urban areas, slightly below freezing in more rural areas.

Brief Summary for Thurs - Sun

There is the potential ( potential being the keyword here ) for a severe storm to hit our region Thursday night into Friday. If the worst case came off, we could be seeing wind gusts upto 100mph in exposed locations, with gales and severe gales quite widely. I dont want to go into much detail here yet, because this is far from certain yet, and it may end up no more than just a breeze, so I'll talk more about this tomorrow evening, So briefly, a possible storm in the next few days. What does look more favourable is a good amount of rain sweeping across the region during Thursday nightFriday morning, affecting all areas. With high river levels and saturated ground, localised flooding is distinctly possible. If the LP tracks far enough south ( ie with the centre in the channel or over northern France ) and we end up being on the northern flank, there is a possibility that enough cold air could get wrapped around to provide a snow event to some of us, chiefly the more north and east in the region you are. Elevation would also be a great advantage too. So Basically be prepared for very strong winds, this i would give as 50/50 happening at the moment, and heavy rain, this i would give at 75/25 for at the moment, with the possibility of snow for some, this I would give at 75/25 against at the moment. I will update more on this tomorrow when hopefully the picture will be a bit clearer.

I hope this helps some of you. I'm no GP or John Holmes etc, I'm just trying to translate what the charts show into laymans terms. Let me know what you think etc, and If approved I will try to do them daily ( time pending of course )

Thanks

[Jane Louise]

If its wanted on here, I will do a novice forecast each evening at around 10pm ish detailing what is in store for our region in the next 24 hours, plus a brief summary of 72 hours ahead. Just basically transferring what the charts say into plain English.

Friday 14th December

A day not to disimiliar to today, although showers will tend to ease later in the day ahead of a unpredictable LP system later on Thursday. Areas on the Bristol Channel coast as well as Urban areas, such as Bristol and Bath, to the East of the region are likely to see showers of predominatly rain, with hail and sleet possible on the heaviest of the showers. Thunder and Lightning again is possible in the heavier showers. These showers start to form a quite potent Bristol Channel Streamer by midday and run along the M4 corridor, into Gloucs. & Wiltshire, as well as affecting North Somerset. On higher elavated groundd these showers have the potential to fall as sleet and wet snow, although no accumilations are expected, with the exception of perhaps the Forest of Dean and the north Cotswolds. In the heaviest showers, under evaporative cooling, sleet and snow may get down to modest levels in Gloucs. & Wiltshire. For the Mendips, Dorset, South Somerset, Devon and Cornwall, fewer showers can be expected here, but occassional showers of predominately rain can still be expected, perhaps something wintery on Exmoor and Dartmoor. The wind wont be quite as strong at it has been recently, although a gusty breeze will still be evident. Windchill, as like today, will make it feel quite bitter at times, especially under any showers. Temps will be below average for December, although too windy for a frost for most tonight, tomorrow night as a higher chance of frost and Icy conditions where any showers have fallen as skies clear into the evening. Temps will range throughout the region, typically peaking between 4c - 7c in the north and east of the region, and between 7c - 10c in Devon and Cornwall. During showers, expect to knock a good degree or two of these temps. Tomorrow night expect temps to dip close to freezing in Urban areas, slightly below freezing in more rural areas.

Brief Summary for Thurs - Sun

There is the potential ( potential being the keyword here ) for a severe storm to hit our region Thursday night into Friday. If the worst case came off, we could be seeing wind gusts upto 100mph in exposed locations, with gales and severe gales quite widely. I dont want to go into much detail here yet, because this is far from certain yet, and it may end up no more than just a breeze, so I'll talk more about this tomorrow evening, So briefly, a possible storm in the next few days. What does look more favourable is a good amount of rain sweeping across the region during Thursday nightFriday morning, affecting all areas. With high river levels and saturated ground, localised flooding is distinctly possible. If the LP tracks far enough south ( ie with the centre in the channel or over northern France ) and we end up being on the northern flank, there is a possibility that enough cold air could get wrapped around to provide a snow event to some of us, chiefly the more north and east in the region you are. Elevation would also be a great advantage too. So Basically be prepared for very strong winds, this i would give as 50/50 happening at the moment, and heavy rain, this i would give at 75/25 for at the moment, with the possibility of snow for some, this I would give at 75/25 against at the moment. I will update more on this tomorrow when hopefully the picture will be a bit clearer.

I hope this helps some of you. I'm no GP or John Holmes etc, I'm just trying to translate what the charts show into laymans terms. Let me know what you think etc, and If approved I will try to do them daily ( time pending of course )

Thanks

Thank you and please do keep us updated. :smiliz19:

[Paul T]

Rather than me/other posting if it will snow and where, if i could just try to guide you with a simple way to figure out if it will snow in the SW:

Basically, apart from the obvious requirement for precipitation you need 1) The 528 dam line to be over us, and 2) -6oC or lower 850 temps.

i.e:

Attachment 1 shows the position tonight = 528 DAM over us = good (by the way, its 528 or lower...510 is very rare and WILL give snow!)

Attachment 2 shows the 850's situation = 850's around -3 or -4, with the -5/-6 uppers around 350 miles to our west

Basically, as we havent hit the 2 important factors tonight, then its a no go.

Have a flick through the latest gfs graphs, and see what you think....

This applies to 90% of the potential scenarios for snow, but not all! i.e i have seen snow in North Plymouth with circa 540 uppers from a channel low. (Very cold temps remained from a NE'rly that under cut the milder uppers and gave 4 inchs of snow in Jan 2010)... its all very complicated really.

To put things in perspective, last Dec we had a 516DAM over us for many days and had upper 850's of -10. Now that equals snow!

[Nights King]

Rather than me/other posting if it will snow and where, if i could just try to guide you with a simple way to figure out if it will snow in the SW:

Basically, apart from the obvious requirement for precipitation you need 1) The 528 dam line to be over us, and 2) -6oC or lower 850 temps.

i.e:

Attachment 1 shows the position tonight = 528 DAM over us = good (by the way, its 528 or lower...510 is very rare and WILL give snow!)

Attachment 2 shows the 850's situation = 850's around -3 or -4, with the -5/-6 uppers around 350 miles to our west

Basically, as we havent hit the 2 important factors tonight, then its a no go.

Have a flick through the latest gfs graphs, and see what you think....

This applies to 90% of the potential scenarios for snow, but not all! i.e i have seen snow in North Plymouth with circa 540 uppers from a channel low. (Very cold temps remained from a NE'rly that under cut the milder uppers and gave 4 inchs of snow in Jan 2010)... its all very complicated really.

To put things in perspective, last Dec we had a 516DAM over us for many days and had upper 850's of -10. Now that equals snow!

Good post but you don't need -6 or lower for snow you can get snow at -4c if other conditions are good. Today saw snow at even low levels with -3/4 although it was hit and miss and elevation helped as well as precipitation intensity.

[Paul T]

Oh yeah, if course, but as a rule of thumb, generally the -5 line should be over the desired area to have snow...

Like I said, I could name 10 occasions when I have seen it happen without the two factors in place, but I could name 90 more occasions when I have seen snow with the two factors...it's just much much more likely that's all!

[SNOW CRYSTAL]

Hi I've just driven between Postbridge and Yelverton, South Dartmoor and there was snow on the moorland but not on the road, so I guess its pretty wet stuff but it was definitely snowing as I drove. First snow if the year, really excited!!!

[Nights King]

Oh yeah, if course, but as a rule of thumb, generally the -5 line should be over the desired area to have snow...

Like I said, I could name 10 occasions when I have seen it happen without the two factors in place, but I could name 90 more occasions when I have seen snow with the two factors...it's just much much more likely that's all!

Like I said it was a good post just was a little cocerned you were being abit wishful with those 850's being -6 or lower as from experience the west country apart from last december rarely get below that like -10 and more so often we are looking at very marginal situations here to achieve snowfall.

[dancing daisy]

Oooh it's all got a bit technical on the straw chewers thread, I like it! I don't understand it though.

I shall try to read Paul T's post again later when I am awake, I would love to learn how to read these charts properly instead of just nodding at the laptop screen like I know what everyone is talking about.

It is a lot colder here this morning, it's the first morning that I can remember opening the back door and feeling a real chill. Still no frost though, we haven't had a frost here at all this winter.

[snow drift]

Oooh it's all got a bit technical on the straw chewers thread, I like it! I don't understand it though.

I shall try to read Paul T's post again later when I am awake, I would love to learn how to read these charts properly instead of just nodding at the laptop screen like I know what everyone is talking about.

It is a lot colder here this morning, it's the first morning that I can remember opening the back door and feeling a real chill. Still no frost though, we haven't had a frost here at all this winter.

Had to drive across Salsibury plane last night and it was sleeting hard. During one two min spell it was nearer to snow than sleet. I think this shows that there will be a few surprises. Esp if the low tracks along the channel. The north side could get some unexpected snow IMO.

Edited December 14, 2011 by snow drift