South West England Cold Spell Discussion

[littlemissy]

yep ,it is white in Wellington! I posted it on here earlier.

[Jayfromcardiff]

Yes, it's the same small cell and it retained the same PPN intensity as it continued travelling down the A419. Looks like it will fizzle out just south of you.

Ian, are more showers likely to form out in the Irish sea?

[slinky1989]

Yes, it's the same small cell and it retained the same PPN intensity as it continued travelling down the A419. Looks like it will fizzle out just south of you.

Well that's a ridiculously well positioned stroke of luck!

[Ian Fergusson]

Ian, are more showers likely to form out in the Irish sea?

The NAE wants to kill that convergence band into Pembrokeshire (which has turned thundery once or twice, by the way) after midnight if not a tad before; keep showers then more focused into the Bristol Channel later and bringing them inshore at times as the flow shifts slightly to yield them into a broader swathe of Somerset / possibly Bristol and environs. See my earlier NAE graphics posting....but the model prog can't of course replicate the fine detail reality on radar in this complex and locally dynamic set-up.

Well that's a ridiculously well positioned stroke of luck!

Wasn't it just? (see attached)

Edited January 1, 2010 by Ian Fergusson

[robnor1]

-1.6C light shower turned into a dusting now stopped well we have take anything we can get at the moment here in Swindon.

[ronant]

Wasn't it just? (see attached)

That little blob has now just hit Marlborough - was out driving home from Swindon when it hit. Barely anything tho - probably wont notice it in the morn with the frost. A nice surprise tho and something that wasn't forecast, gives plenty of hope for the next week

[slinky1989]

That blob seemed to be perfectly swindon sized! Got a nice dusting here now, settled on the roads but gets blown around whenever a car goes by.

[anvilhead]

haha! - I'm in south cerney - about 3 miles south of Cirencester. Just saw the attached radar image, fell off my chair when I recognised cirencester, looked outside and its all white!

[Ian Fergusson]

That little blob has now just hit Marlborough - was out driving home from Swindon when it hit. Barely anything tho - probably wont notice it in the morn with the frost. A nice surprise tho and something that wasn't forecast, gives plenty of hope for the next week

It was actually a slightly different area that passed over you - there's various speckles on radar so your 'ground truth' obs shows they're not all spurious.

Neither are these intensifying cells into Somerset a short time ago; trajectory takes them towards Wellington. Let's see if they retain identity by then.

Edited January 1, 2010 by Ian Fergusson

[anvilhead]

Incidently the A419 also had whiteout conditions from that Bristol channel snow streamer a while ago just before swindon - made for some spectacular driving conditions, if that's the right word.

I take it these showers are the result of the vorticity you mention, and also a weak trough shown moving through on the fax charts Ian ?

looks great out there

[Ian Fergusson]

That little blob has now just hit Marlborough - was out driving home from Swindon when it hit. Barely anything tho - probably wont notice it in the morn with the frost. A nice surprise tho and something that wasn't forecast, gives plenty of hope for the next week

It was actually a slightly different area that passed over you - there's various speckles on radar so your 'ground truth' obs shows they're not all spurious.

Neither are these intensifying cells into Somerset a short time ago; trajectory takes them towards Wellington. Let's see if they retain identity by then.

These will be a close call for Wellington about now or very soon.... still watching them on radar. Looks like the cells got added 'oomph' with orographic forcing over Dunkery Beacon and part of the Quantocks but they're fading now downstream of there...

Incidently the A419 also had whiteout conditions from that Bristol channel snow streamer a while ago just before swindon - made for some spectacular driving conditions, if that's the right word.

I take it these showers are the result of the vorticity you mention, and also a weak trough shown moving through on the fax charts Ian ?

looks great out there

That's exactly correct plus we're seeing some local convergence and orographic effects at work, too

Edited January 1, 2010 by Ian Fergusson

[Snowfan50]

Damn these showers just keep missing barnstaple. Now that big band is moving most west .

[Dartmoor_Matt]

Did someone mention snow of 5-10cm locally over Devon/Cornwall for tonight?

Temp is down at -3.9C at the moment, which is pretty steady since about 6pm.

[anvilhead]

That's exactly correct plus we're seeing some local convergence and orographic effects at work, too

I see what you mean from the radar I think. The lines pepping up as it hits the marlborough downs to the south, almost looks like the shower behind got out of phase with a faster moving trough and its skipped poor old Marlborough.

[Ian Fergusson]

I see what you mean from the radar I think. The lines pepping up as it hits the marlborough downs to the south, almost looks like the shower behind got out of phase with a faster moving trough and its skipped poor old Marlborough.

Yes, they've invigorated very markedly into Berkshire..... alll these areas of light ppn need watching for signs of activation, rather like those cells with the Taunton/Wellington area in their crosshairs ((looks like one just passed over northern Wellington)

[stewfox]

Yes, they've invigorated very markedly into Berkshire..... alll these areas of light ppn need watching for signs of activation, rather like those cells with the Taunton/Wellington area in their crosshairs ((looks like one just passed over northern Wellington)

Had light snow in north Oxfordshire, very surprised to get anything tonight

[Ian Fergusson]

Latest MOGREPS snow prob output for Wednesday shows the windward coast bias both E and W

[Jayfromcardiff]

Latest MOGREPS snow prob output for Wednesday shows the windward coast bias both E and W

So, Ian.. when do you expect showers to hit around the Bristol channel?

[snowking]

Latest MOGREPS snow prob output for Wednesday shows the windward coast bias both E and W

Cheers for that Ian,

The green swathe down the midlands and into the westcountry is promising on that - certainly indicative of both the RAW and FAX UKMO output this evening

Out of interest do you happen to know how the decision to use certain raw output for the FAX output is made? Just very surprising after the 12z runs that they decided to go with the UKMO which was a little more out on its own with regards to the initial more NEly flow, as opposed to the straight easterly (a la ECMWF)....yet interestingly the 18z GFS has backed this idea up

Being back in cheltenham from sunday i'd certainly take the latest fax output

Kind Regards

SK

[littlemissy]

Just poked my head out of the window and cloud over Wellington now.We might have had a dusting as the path outside my back door is completely covered in snow.

Going to be slippery tomorrow morning :-( .

[Paul T]

Thanks for the input Ian.

Sizeable shower currently in cornwall heading south east, seems to have perked up at its migrating over land, the question i have is - is it strong enough to travel another 20miles to Plymouth, as its bang on course?! we shall see.

I dont see where the 5-10cm's could be coming from tonight? i would say 1-2cm from isolated showers (as above?)

Paul

[anvilhead]

thanks Ian.

I dont know what the sst's are currently in the irish sea/off scotland, but given the predicted 850 temps and the wind direction in the middle of next week, maybe a polar low running down the irish sea isn't entirely out of the question.. 850's of -9 & sst's of 6c would do it id imagine ..

Don't get excited though everyone - you'll learn I dont really know what I'm talking about!

[anvilhead]

thats had some intense ppn rates for a while PaulT - fingers crossed!

[Paul T]

thats had some intense ppn rates for a while PaulT - fingers crossed!

Its still heading this way....!

My missus is telling me to come to bed, she thinks im nuts - this is going to be an interesting couple of weeks for her perception of my sanity!!

[BARRY]

Its still heading this way....!

My missus is telling me to come to bed, she thinks im nuts - this is going to be an interesting couple of weeks for her perception of my sanity!!

Mine thinks the same way, There is a big shower heading my way as well so i am determined to watch it arrive, by the Paul can you put location in your avatar