South West/Central Southern England Regional Discussion 15/01/13 12z---->

[Brad]

Up against it even before the usual Poole Harbour snow shield has been deployed!. Going to be a nowcasting Friday I think!

I know what you mean snowlight. As a Landscape Photographer I can't wait!! The coast will always be iffy but I will be pushing inland. Up in to North Dorset could be awesome. a few miles can make all the difference! Lets hope this all verifies!

[AWD]

I dont think so. I was typing my post at the time!

Still a bit of uncertainty i think, as he did mention threat of slightly milder air poss changing the forecast.

Yes, that showed up on tonight's ECM run as well as some other previous output so its something to look out for, for sure.

[MR EXTREMES]

nice graphics on south today - snow right across the south coast

for when i missed that?

[Beasterly]

BBC Points West forecast by Ian

http://news.bbc.co.uk/weather/hi/news/newsid_7760000/7760862.stm

[PompeyFC]

for when i missed that?

on the south today forecast bbc1 at 6:50pm

[SteveB]

I'm hoping Friday's event pans out like the one I remember in the early 80's

I was in the car with my dad going to visit my Aunt and uncle in Weston (we were living in Worle) On the way in it started to sleet, we thought nothing of it and carried on. When we got there it was still sleeting, it was only about 30mins later that my mum phoned and suggested we should come home because it was snowing heavily.

Woke up the following morning to around 30cm's of snow.

There must have been a mild element to the weather at the time for it to start of sleeting, maybe it was a slider low like the one forecasted for Friday.

I bet the charts looked dicey if we were able to look at them back then like we do now.

[AWD]

I haven't got much time so I will do a quick look at 850hpa temps for now, just to show how the threat of less cold air could come across the SW and turn any PPN to rain, especially the further SW one is.

Here are the GFS 850hpa temps for midday Friday;

You can see the -5c 850hpa line gets pushed back into eastern counties of our region, with less cold uppers over Somerset, Devon & Cornwall

Here are the ECM upper temps for Friday afternoon and evening;

The -5c 850hpa line gets shunted into the Midlands, Hampshire here, with less cold uppers over much of the South West increasing the risk of PPN turning to rain.

The UKMO is what we want. Here, away from Devon & Cornwall, the uppers remain cold (-5c or below) and all PPN would be snow. This is what we want the GFS and ECM and nearer the time, the NAE to start showing.

So you can see the uncertainty of the extent of snowfall and how much would be snow/rain at this stage across the South West. Uncertainty which Ian rightly highlighted in his forecast.

The 12z model data has improved on the 0z model data, and we have a good possibility of seeing snowfall on Friday now. How much falls and how much settles all depends on how long the cold air hangs in for.

All to play for still, but caution required as there are still hurdles to overcome by some models.

[SNOWYLAD]

Im predicting a brief spell of snow for everywhere south of Bristol and West of Salisbury, will be more rain than snow, the met office are playing it safe as usual with blanket warnings.

[windseeker]

Long way off, but some very low minimum temps next week and this is at lunch time! Maximums are well below freezing.

Very interesting model watching over next few days to see how things pan out

[Blizzardof82]

I still dream every winter of a January 1982 event, I was 10 years old and remember my late father telling me it was going to snow but then turn to rain. My memory might be slightly rose tinted but I think a front pushed in from Atlantic and stalled over west country dumping loads of snow in blizzard like conditions it then attacked again the following day I think dumping more. All I know is we had wide spread distribution, very deep snow, time off school and lots of fun. One thing I do wish for was my Dad to be with me now sharing the excitement as he introduced me to lamppost watching in the 70's as a kid and at 41 now every time I look at the lamppost I think of him.

[dec10snow]

Did he give any hints of accumulation depths at this stage?

Bit of a slow reply, but he basically just outlined what the met warning was! Playing it safe... Good plan at this stage!

[Frosty_wsm]

For all those with weather stations, for the possible snow event at the end of the week, keep an eye on the wind direction, if the wind stays south easterly then it'll stay as snow as your pulling in cold dew points off the near continent, if you see the wind swing round to a southerly or south westerly then say goodbye to the snow and hello to the rain.

In these battleground events it's all about maintaining that se wind if you want the snow to stay as snow.

[dec10snow]

I know we have moved on from the comment said yesterday aimed at Ian F, but it really would have been class if he said "but I don't want to overhype the potential event" or something like that!

Edited January 15, 2013 by dec10snow

[Sainsbo]

Long way off, but some very low minimum temps next week and this is at lunch time! Maximums are well below freezing.

Very interesting model watching over next few days to see how things pan out

I really can't see -18C coming off next Wednesday at lunchtime...That would be crazy!

Temperature here is dropping off still, all be it more slowly. -2.6C and dropping slowly.

[AWD]

Positive news is that the NMM doesn't support the NAE but is actually similiar to the UKMO at T48 with the -5c 850hpa line through Devon.

[slinky1989]

If I remember the 2010 event correctly, in swindon it was supposed to be a snow to rain event as there was supposed to be a mild sector mucking things up, but it never happened.

Then I remember that 3 days later there was supposed to be a mild breakdown, and that didn't happen either! Instead it was just more snow which then stuck around for several days before a very slow and gradual warming up.

So even at T0, things can be considerably different from what's expected.

[kent]

For all those with weather stations, for the possible snow event at the end of the week, keep an eye on the wind direction, if the wind stays south easterly then it'll stay as snow as your pulling in cold dew points off the near continent, if you see the wind swing round to a southerly or south westerly then say goodbye to the snow and hello to the rain.

In these battleground events it's all about maintaining that se wind if you want the snow to stay as snow.

Absolutely agree and more so for us coasties.

[jessandjon]

Apparently cma model Has moved things westward ???

[philglossop]

Interesting that Ian's gone to show a potential snow chart for Friday, whereas David Braine's didn't even show his 3 day forecast.

Could this mean the battleground is Devon???

[AWD]

Looking long term and there is nothing mild about the GEFS suite. I'll pick Somerset now, as that's sort of in the middle of our region.

The 850hpa mean temp stays -3c to -5c for the whole run;

With the mean surface temperature not rising above 6c at all;

So a cool outlook. No mild SWerly winds there.

[Stoxs]

Well the check list for a decnet snow event is being ticked

Cold Air embedding into the area ( definiatlly tonight it`s getting real cold out there)

PPN heading in off the Atlantic (yes as long as the track is still current in 72hrs)

Looking good so far still plenty of time for Pete tong to rear his head .

Keep upto date with the latest muttering round the forum, for our area an upgrade will be a 100mile shift south west.

A down grade would be a 100 mile shift east or a 300 mile shift west!

both still possible right upto the PPN heading in T6 to T0

now wheres my sledge!!

[karlos1983]

Why do some posters feel the need to completely poopoo the event they COULD happen Friday in the SW in the mod disc?

I know we are largely forgotten by people on there but it makes me laugh, tha they just skirt over it and look at the models from another point of view.

I know a lot of people look at models from IMBY view, but it makes it hard to read and understand the posts in the mod thread.

First sub zero night in quite a while here. Now -1.7 with dp of -2

I read all the post in mod thread for a giggle, but pick out and really take notice of people like Lorenzo, Nick Suusex, Steve Murr, Chio and alike, as well as the knowledgable guys in here, at that point you can generally find a good idea of what's going on and make a more informed decision based on there views and keep a level head, otherwise emotion really clouds the mind, I for 1 have been guilty of this, which is why I tend to only comment in here now.

That's my view anyway, hopefully a few more seasons and ill be having a stab at it myself :-), take note of that and remember to ignore everything I say in future winters lol

[khodds]

Ok. So when do I call off my weekend trip to London?! Meant to be driving up on Friday afternoon. Seriously! I don't know what to do! I'm meeting family for the first time.... Help!

[karlos1983]

Long way off, but some very low minimum temps next week and this is at lunch time! Maximums are well below freezing.

Very interesting model watching over next few days to see how things pan out

That screams snow cover

[AWD]

Ok. So when do I call off my weekend trip to London?! Meant to be driving up on Friday afternoon. Seriously! I don't know what to do! I'm meeting family for the first time.... Help!

As things stand, getting out of Wiltshire will be the tricky part. Get out of there and you should be fine as the snow shouldn't have reached further east at that stage.

However, a lot can still change in 72 hours so don't make any rash decisions at this early stage.

That screams snow cover

The only thing that screams is one maoooosive heating bill. I'd be bankrupt!