South West and Central Southern England Regional Weather Discussion 03/03/2018 Onwards

[Man With Beard]

We are now settling on all surfaces and totals going up fast. WHERE WAS THE AMBER WARNING??

Edited March 18, 2018 by Man With Beard

[That ECM]

1 hour apart. To give some idea of the speed of the heavier band. Definitely moving west and slightly north.

[snowysouth]

5 minutes ago, Mike Poole said:

AND IT'S HERE. 

Busy snow, very small flakes, in Wantage, now!

Go the mini-beast!

Mini beast. That makes me laugh. If we get snowfall tonight then this is way worse than the beast! The only difference was the freezing rain. But it had all but gone the next day 

[Guest]

 UPDATE ON THIS EVENING'S SNOW PROSPECTS

Having done a comprehensive post on our snow chances for this evening 6 hours ago, I see that I might have been a little too cautious! I did spot the small breakaway area of snow and I stated that it might brush the south-east. I also said that "unless there were further developments" we could probably ignore looking east. The band of snow over western Germany and northern France "was" fizzling out as it spread westwards towards Belgium at the time I started writing that post (1130). Just as I was finishing off the post and was proof reading it, I noticed that the band of snow was re-invigorating again. Hence my edit at the bottom. I also said that I would be back with an update if there were any developments. Well there have been and here I am again  So, let's have another good look. Please refer to my post on page 94 for some of the details and I'll pick it up from there:

            Live Radar - UK view                          Live Radar - NW France view                Live Radar - NE France view                  Live Radar - All France view                     Live Radar -  Germany view                         

        

Firstly, the current south-west snow. There have been some interesting changes this afternoon. The main snow area continued its westward progression. It reached east Devon around 0800, here in Exmouth at 0930, south-west Devon around 1030 and into east Cornwall by 1130 and westwards since then. Meanwhile it cleared west Dorset and the far east of Devon around 1400 to 1500. At 1600 it stopped here and I took a few pics (see at the end of this post) but by 1630 it started again and has been moderate at times. I have about 16 cm to 18 cm now, almost matching "Beast 1" and it's still snowing - temp is still -1.5c and it has been an "ice day"! What has happened is that the snow which was always being enhanced by being pumped up on the eastern side in the circulation of the minor LP disturbance (now centred in the middle of the western Channel has developed a couple of snow streamers. One is running from Cherbourg towards central southern Devon with Exmouth and Exeter near its eastern edge and South Hams on its western edge with Torbay in the centre. The second one, which is not so well defined, runs on a roughly parallel route about 50 miles further west into the Lizard and down to Land's End. The whole snow area is beginning to weaken and break up very slightly and it is also pivoting within the circulation. It's still making some north-west progress but is moving out of south Wales. The circulation of the minor LP shows up very well in the second chart. The snow shower activity further north is gradually dying out as the HP pushes down towards northern Scotland.

Now this evening's snow. The band of snow that is moving out of Belgium and north-west France is not only spreading into south-east England but it's showing sings of developing and expanding. It doesn't look very potent in France or Germany but the very cold dry air is picking up some moisture and instability as it cross the extreme south of the North Sea and the eastern Channel. it's now extended northward to Essex and Suffolk, the south Midlands, through London and and it's on a westward journey (EDIT: 1915 - it has now reached Hants and just east of the IOW and it's still expanding and intensifying slightly). It's actually being dragged into the wider circulation of that minor LP in the western Channel as well as the general circulation of the main LP which was centred over central France but is now over northern Italy - you can see the mini and the wider revolving patterns when you view the whole of the European view in the first two charts below. The last three images show the depth of the cloud and the areas of snow and snow showers around and over the UK.  

                   Live Satelitte                                    Live Infra Red Satelitte                           Pay To View Satelitte Images (I have permission to copy these but cannot provide the source or the link)

      

               Met O Fax 1200 at Sun                       Met O fax for 1200 Mon                  Fronts & Troughs at 1200 GMT Sun          Live NW France View Pressure     24hr to 1648 GMT France View Pressure 

        

There have been minor changes in the position of the fronts and troughs. The wriggling front is now shown to be closer to the south coast and even by 1200 tomorrow the front is not as far south as it was shown for this time on the last fax update. The live pressure chart shows what I was describing above with that small LP gradually slipping southwards into the Brest Pensinular but a trough is extending north-westwards towards the Lizard. The 24 hours chart shows all this very nicely. Now we need to look slightly ahead. The Arpege 12z has changed slightly from the 6z run. The minor LP in the western Channel deepens a little more and holds its north-westward and then westward trajectory a little longer. That change was probably sufficient to set up the two streamers. The LP then dives southwards and links up with another centre intensifying over Biscay and looks set to merge later on with the LP centre over Italy. There is still not much that shows the minor changes in the flow further east. The upper flow on the jet chart does now match rather more the surface flow. The upper LP and cold pool moves from SW England to the south of France during tonight and tomorrow. There is a further revolving pattern to the north (the white area). In fact you can now see all this wider circulation in all four charts below. The surface pressure, the upper flow, the wind direction and convergence and finally in the precipitation chart. So, I would now say, that some (at least) light to moderate snow looks likely to spread from the south-east and east into our region later this evening. The exact extent, timing and intensity will be very difficult to pin point. If there's any snow left in the south-west the new feed might invigorate that briefly too. This still may not come to that much or it could develop further. Nowcasts, radar and satelitte charts at the ready again!  

Arpege 12z - Pressure 30 hrs to 1800 Mon      Arpege 12z - Jet 30 hrs to 1800 Mon          Arpege 12z - Wind 30 hrs to 1800 Mon        Arpege 12z - Wind 30 hrs to 1800 Mon 

                             

It's still snowing lightly here (1930) and still 1.5c. I'll close with the pics that I took at 1600:

              

it was (at 1600) about 14 cm deep on my front path. The paths, pavements and the road got less due to the earlier melting (above zero ground temps) and the depth on the grass was around 17 cm to 18 cm but my pic of that measurement did come out (I'll get another one tomorrow when it may be over 20 cm!).  There are some 40 cm to 50 cm drifts which I'll photograph tomorrow too. 

     

    

      

The last three were taken by my brother who lives about a mile away from me. He had similar depths but it looks snowier than here - I'm further inland and about 10 m higher. btw that's not me  - it's a snowman  

Edited March 18, 2018 by Guest
Correct typos and check charts

[karlos1983]

@Mapantz if we continue like this we will be marrying the ppn to our west and east 

[matt111]

Nothing here yet. Waiting in anticipation.

[A.J]

man, we are kicking some serious booty!

[That ECM]

1 minute ago, matt111 said:

Nothing here yet. Waiting in anticipation.

Not long. Look at the 2 small red blobs just east of the iow??

[jtay]

7 minutes ago, ajpoolshark said:

and we're off to a flying start....lol

£1 in M&S. Bargain. Bingo.

[MidnightSnow]

All nighter on the cards. Maybe even some BEER

[A.J]

Just now, jtay said:

£1 in M&S. Bargain. Bingo.

*sigh* you need to the word....lol

[Argyle1980]

4 minutes ago, karlos1983 said:

@Mapantz if we continue like this we will be marrying the ppn to our west and east 

Unbelievable Jeff ❄️?

[Man With Beard]

2 minutes ago, ajpoolshark said:

man, we are kicking some serious booty!

Nice spot on the "Amber"

Like a mass of confetti falling from the sky here. Wouldn't call it heavy.

[snowdog]

I'm a little confused after seeing a brief BBC forecast before Countryfile. The forecaster said just a few snow flurries overnight for Southern England. Has she not looked at the radar or does she know something we don't?

[Climate_Eyes]

7 minutes ago, matt111 said:

Nothing here yet. Waiting in anticipation.

Must be imminent, it's practically on your doorstep.

Actually just fell a*** over t*t in the kitchen after one too many and slippery snowy shoes.

Unbelievable Jeff

 

Edit, beaten to it!

 

Edited March 18, 2018 by Climate_Eyes

[Argyle1980]

I think the forecast was written a few hours ago. Correct me if I’m wrong?

[snowysouth]

1 minute ago, snowdog said:

I'm a little confused after seeing a brief BBC forecast before Countryfile. The forecaster said just a few snow flurries overnight for Southern England. Has she not looked at the radar or does she know something we don't?

My guess is that's pre recorded

[A.J]

OMG, 2 lines already....top work!....I need a lay down 

[jtay]

2 minutes ago, ajpoolshark said:

*sigh* you need to the word....lol

Pedant. 

Radar wise, don't worry about anything that looks like it's fading west of Winchester. The station is FUBAR, so it always does that.

[khodds]

Just now, Argyle1980 said:

I think the forecast was written a few hours ago. Correct me if I’m wrong?

Yes - the models have seemingly let this once creep up on the forecasters. The forecasts would have been recorded earlier.

im thinking it’s GAME ON. 

[TropicThunder]

The flakes are tiny here, won't get much of a top up if they stay at this size. Anything now is a bonus anyway.

[matt111]

The dry gap between the 2 areas is rapidly decreasing in size. 

[karlos1983]

Not heard from knocker for a while, He’s probably seen the forecast overnight. RIP Sidney ????

[jtay]

2 minutes ago, Climate_Eyes said:

Must be imminent, it's practically on your doorstep.

Actually just fell a*** over t*t in the kitchen after one too many and slippery snowy shoes.

Unbelievable Jeff

 

Edit, beaten to it!

 

Countyfile are in your backyard. And it's snowing!

[Leon1]

Just now, karlos1983 said:

Not heard from knocker for a while, He’s probably seen the forecast overnight. RIP Sidney ????

@ajpoolshark