South West and Central Southern England Regional Weather Discussion Jan 2021 Onward

[offerman]

Just see Darren Bett forecast , snow as far as Soton abd IOW eastward at times but west and southwest according to him and his charts dry all week . 
 

East to get a pasting of snow good luck to them and enjoy if you can and enjoy that weather as I do.

The latest GFS has cold in the south until Thursday before it shows milder air Ingres in to Southern UK at least. 
 

 

[CentralSouthernSnow]

GFS and GEM covers the whole south and ECM scrapes the coast. icon and aspege just off the coast in the sea. This is going to be knife edge with this low

Edited February 6, 2021 by CentralSouthernSnow

[festivalking]

Just now, CentralSouthernSnow said:

GFS covers the whole south and ECM scrapes the coast. This is going to be knife edge with this low

Icon arpege and gfs on board though. Ukmo will be key i reckon

[CentralSouthernSnow]

5 minutes ago, festivalking said:

Icon arpege and gfs on board though. Ukmo will be key i reckon

Have you not seen the 00z for icon and Aspege? It’s in the sea yes met will be key. Bit concerned ECM hasn’t tracked more north but still time to change 

[festivalking]

14 minutes ago, CentralSouthernSnow said:

Have you not seen the 00z for icon and Aspege? It’s in the sea yes met will be key. Bit concerned ECM hasn’t tracked more north but still time to change 

Oh bugger 

Edited February 6, 2021 by festivalking

[CentralSouthernSnow]

10 minutes ago, festivalking said:

Oh bugger 

Let’s see on the 6z 

[That ECM]

Met starting to hint at the south getting something on Tuesday night Wednesday. A few hours of light snow for southern towns. Plymouth Weymouth Bournemouth etc. Still much time for this to change.

[jtay]

Arome still fancies a bit overnight for some of the region.

 

[That ECM]

7 minutes ago, jtay said:

Arome still fancies a bit overnight for some of the region.

 

Met also.

[gower84]

What a lovely crisp cold morning. View from our back garden in Poole.

[jtay]

Nice to have a sunny Saturday. Going to make the most of it, as we might not see it again for a while.

 

 

[Dorsetbred]

Morning All, a chilly sub zero start to the day after an overnight low of -1.7°C at: 06:31..currently -1.5°C, with a good ground frost. Sun is coming up over the yard arm, for a pleasant start to the weekend weather..

[Glenosnow]

Good morning all,currently -0.4°C and quite foggy,98% RH.

Mantra for the next few days...... Expect nothing and hope we get some surprises.......would be good to get more than the dusting we had here a couple of weeks back. ❄

[Choggy]

BBC Currently hinting at a westward shift of the Snow area on Sunday . Currently Western extent seems to be somewhere between Portsmouth/Southampton . Knife edge indeed and still uncertain . 

[wiltshire weather]

Looking through all the overnight runs all to play for this coming week with snow chances aplenty I think!

Tonight/tomorrow looks as though at least the eastern parts of our region may get a covering.

Monday onwards those showers could penetrate well over to our side of the world and if they band together or a disturbance forms (highly likely imho) then who knows what will come our way!

Then Tuesday night into Weds there is potential for snow in the south and west, possibly even reaching up here.

And then we start looking at the end of the week where the breakdown snow may well not get very far across the country before being pushed back.

And to cap it all it's beginning to look like the cold air is going to fight back (or never really go away!) even down here and potentially could turn even colder going into the following week.

Phew!

I'll be glued to my radar from tonight onwards for much of the week I think 

[Kiwi]

2 hours ago, offerman said:

 

The latest GFS has cold in the south until Thursday before it shows milder air Ingres in to Southern UK at least. 
 

 

Latest ECM hinting at a battleground situation developing on Thursday/Friday with the cold trying to hang on - could lead to some heavy snow for a time.

 

 

 

...finally retreating for a day or two before starting to build back in with a big scandi high around 16th

[jtay]

17 minutes ago, Choggy said:

BBC Currently hinting at a westward shift of the Snow area on Sunday . Currently Western extent seems to be somewhere between Portsmouth/Southampton . Knife edge indeed and still uncertain . 

Yep, the Euro4 is keen on that idea.

[lettice]

A lovely sunny day yesterday, spoilt with a few showers early evening.
High of 11.8c yesterday at 1pm, 6c at midnight.
A low 0.9c at 7:30am.
A very slight frost this morning.
Now, 2.2c, lovely clear blue skies. light NW wind, 1007.5 hPa

Forecasts looking good for us for many possible chances of either sleet or light snow from Sunday to Thursday.
So, hopefully we will get something to smile about during that time.

 

[Singularity]

Good to have some subzero temps in parts this morning, to get the ground temps lower.

A good deal of dry weather in parts too, when it could have been a miserable rainy day for most.

Both raise the likelihood that at least some of us will wake up to a covering of snow tomorrow morning.

 

Interesting developments for later next week - yesterday’s update to the Met Office outlook looking as shaky as I suspected it might.

The way it’s shaping up, snow seekers may be urging the front to get in before it fizzles rather than slow and slide.

[AWD]

It's not often I do these sort of posts anymore as experience has taught me that forecasting the great British weather in regional detail more than a few days ahead is difficult at best.  However, I will make a small exception here (not necessarily a forecast though, more an observation).

I've come to quite like the EPS meteogram suites, as they essentially show what the highest performing ensemble suites model, and show forecasting in terms of probability, rather than a specific outcome modelled by a deterministic run, which as we know, can change daily. 

Below are all EPS meteogram suites for Bristol, but the story is similiar for many inland areas of the region, with possibly the exception of Cornwall.

Firstly, the latest 0z EPS from this morning's output;

I've circled part of the bottom 2m temperature graph in red.  This shows small pillars of spread, which demonstrates high confidence in the forecast ahead.  So for my location, it shows temperatures only getting a degree or two above freezing (at best) on Sunday, Monday, Tuesday, Wednesday & now Thursday too.  A minimum 5 day cold spell forecast for Bristol.

Next, I've matched the same meteogram as above, but also highlighted the precipitation graph alongside the temperature graph, for Tuesday first;

2m temperatures clearly demonstrate a high risk of any PPN being snow, so that's not the issue, the issue being, the lack of PPN.  Each pillar on these graphs show the likelihood of range of weather for that particular day.  The "thicker and shorter the pillar, the higher confidence for that particular weather type it shows, the longer and/or thinner the pillar, a larger spread and thus, lower confidence in that particular weather type.  You can see from above, as I've said before, high confidence on 2m temperatures being cold, so that's not the issue.  Go up to the PPN pillar graph, and we have much longer and thinner pillars, forecasting a larger spread and lower likelihood of PPN over Bristol.  The graph, does however, highlight a small risk of PPN on Tuesday (note the fact there are a few options there compared to the days either side), so a small chance for snowfall in Bristol on Tuesday.  This could be a higher chance further south over Dorset/Devon etc.

Now, the same but for Thursday;

Same rule applies as to what I've said above.  As you can see, a larger range of 2m temperatures for late Thursday and more especially, into Friday.  Align that with a larger increase in the probability of PPN, and there is a period of time there (most notably on Thursday) where the PPN risk increases whilst the 2m temperature remains cold.  Result - an increased chance of snowfall on Thursday for Bristol (and I expect other inland areas of the region).

Beyond Thursday, and as you can see, longer pillars, therefore lots more uncertainty.  Take the mean route (the thickest parts of the pillars, ignoring the extreme thin parts of each pillar), the even Friday has the potential to remain on the cold side, at least at the surface, for more northern and eastern parts of the region. 

Below are the EPS meteogram from 48hrs ago (Thursdays 0z run);

Look at the spread in temperature there, on Thursday and beyond, compared to the spread we have now for the same time.  Thursday has trended colder and colder, and Friday is starting to go the same way (although not quite there yet).  This demonstrates the eagerness for model output to easily "blow" cold blocks away, when in reality, it is somewhat more difficult.  This gets shown as we come closer to the date(s) in question.  My gut feeling would be for it to remain cold on Friday too, especially in northern and eastern parts of the region, therefore giving some of us a near week of cold weather.

So to summarise, going by the above.

- becoming cold for all tomorrow, and remaining so for all until Thursday.  (Perhaps less cold for Cornwall later on Wednesday).

- mostly dry to start with for all, although eastern most districts of our region may see a little snow tonight into tomorrow morning, nothing significant though.

- small risk of snowfall on Tuesday, especially the further south in the region you are.  Just a small risk for now though, but needs watching.

- snow flurries are possible anywhere and at anytime, I'd like to make that clear.  The wind (and therefore wind-chill) will be brisk and capable of blowing rouge flurries/showers to anywhere from the east.

- increasing risk of more significant snowfall for parts of the region on Thursday.  Too far off for detail obviously, but essentially the further north and east you are in the region, the longer you keep the risk of snowfall.  Further south and west, there is a chance that snow could turn to rain as temperatures recover somewhat quicker.

That's about as far as I will go for now. Like I said, this is more an observation as things stand, especially when talking about later next week.  Just highlighting the fact that things 5/6/7 days away do change.

[festivalking]

Snow risk increased with 6z icon run. Further north too. Dare I say purbeck might get some too?

[SteveB]

Interesting that the showers further North are showing as sleet/snow mix already. 

Really hope everyone in the thread sees snow this week. 

Fingers and toes crossed 

[That ECM]

8 minutes ago, festivalking said:

Snow risk increased with 6z icon run. Further north too. Dare I say purbeck might get some too?

Gfs just to far south for most. Nerves are going to be shot as this is 90 hours away.

[gman88667733]

Just now, That ECM said:

Gfs just to far south for most. Nerves are going to be shot as this is 90 hours away.

Puts me directly in the firing line though!

[dec10snow]

My only experience of freezing rain is from March 18 in that BFTE. We had a lot of snow before hand but it ended up transitioning to freezing rain which ended up in a layer of ice on top of the snow. Was very odd, see an example below! I believe this was Storm Emma when we were just outside the red warning zone.