London & South East Regional Discussion 16/01/13 18z------>

[Bluebreezer54]

East Sussex Sun Dog this afternoon.......

Edited January 16, 2013 by Bluebreezer54

[hernebaylooby]

cor its like christmas im so excited..just hope im not let down again

[SMU]

Surprised noone has mentioned the NAE- ( although the 18z t48 should be more fun)

http://expert-images...011812_1612.gif

Bang inline with the UKMO & has light snow for the south ahead of the main band- ( midnight tomorrow night)

http://expert-images...011800_1612.gif

maybe a dusting from that- to further surpress the temps friday

S

Edited January 16, 2013 by Steve Murr

[Jezzer]

According to this the swivel/pivet is se england! Which models is this from ecm? Gem?

http://www.meteorada...uk/forecastloop

Centre of a delicious snowy Catherine Wheel!!

[Jo S]

Hum i teach adults with learning difficulties and disabilities,wondering if i should cancel my classes on Friday,i will see what happens tom eve as nothings nailed on yet,just dont want them to walk around and fall over

[abruzzi spur]

Temp: -3.1c

Dewpoint: -5.9c

Bracing!

[Dorset_mist]

On Friday I HAVE (wild horses coudn't stop this) to drive from Brookwood, Surrey to Salisbury Hospital in Wiltshire, and I HAVE to return late in the afternoon the same day. Usually this run takes me 1h 15 mins each way and includes a drive over the notorious Wallops...needless to say I am taking a shovel, snow chains and a prayer book

[manutdmatt1986]

Surprised noone has mentioned the NAE- ( although the 18z t48 should be more fun)

http://expert-images...011812_1612.gif

Bang inline with the UKMO & has light snow for the south ahead of the main band- ( midnight tomorrow night)

http://expert-images...011800_1612.gif

maybe a dusting from that- to further surpress the temps friday

S

What time is the next update of the NAE, Steve?

[Tom Jarvis]

So to tonights update:

Most of use have been around a while, some of us lucky enought to remember 1987, some can remember 79 & some even 47 & 63-

They are the archive charts that we search & find every year when we want to enjoy our memories of cold & snow-

Note its nearly 50 years to the day for the famous winter of 63.....

We stand on the cusp of charts ( like Dec 10 as well) that could stand in the archives years to come..- especially if the ECM vairifies tonight which would see the cold spell stretch to day 13 & beyond ( assuming Monday was day 1)-

Without going into the background of whys & what nots the first thing we might consider is the rarity of this weekends pattern.

We have had a 'few' undercutting type scenarios in the last few years but they all held one common theme - no blocking high to the east- usually we have low pressure in the north sea that allows low pressure from the atlantic to pass through with little or no resistance- so anything coming from the SW is either snow to rain or freezing rain to rain.

last time we had a stalling frontal zone that delivered high quantities of snow was 5th feb 1996- thats 17 years ago. - so whilst theres a chance that it could miss the SE the pattern on the whole is RARE.

Here is the 1996 chart-

Crucially when we talk about 850 temps the -2c line is a good guide-

heres those temps at 12pm that day

http://modeles.meteociel.fr/modeles/reana/1996/archives-1996-2-6-0-2.png

I recall the Kettley forecast saying ' the front is really getting a speed on now & its even snowing in the channel islands-... where we can see the -2line.

So for this scenario if we look at mid term models in THIS scenario- any sliders or creepers along the channel- the -2 line is the guide.

The event for friday for the SE has no marginality in terms of temps- except for the EXTREME SW of the region coastal areas- southampton sort of way- however you only need travel a few miles inland away from any onshore breeze to be secure.

so there she is in all her beauty-

http://www.meteociel.fr/ukmo/runs/2013011612/UW48-21.GIF?16-18

The UKMO chart at T48 shows the low slightly positioned further south than 96 & the upper blocking high further North- this means V 1996 the atlantic should move further east into the country as the amplitude of the jet isnt quite as high. ( slightly lower wave )

The SW taking a beating there with snow friday for 12 odd hours really building up-

Then we enter the fray- around T54/T60 & out to 78/84- so 24 hours is a **POSSIBLE** bet.

http://www.meteociel.fr/ukmo/runs/2013011612/UW60-21.GIF?16-18

The T60 shows the low sliding SE- which is great as the PPN sheild ahead of it isnt actually getting any further east-

The low is also pumping up moisture & instability across the SE which will enhance the PPN rates-

so at T45/48 we are starting out-

http://www.meteociel.fr/ukmo/run/U48-594.GIF?16-18

but at 60 we have that push & onshore flow from the SE

http://www.meteociel.fr/ukmo/run/U60-594.GIF?16-18 &

The Raw output between 12pm Friday & 12pm Saturday are suggestive of 15mm widespread- especially to the south & SW of the region-

Because the air is so dry & he dewpoint very cold the accumulation ration will be higher than your usual wet rubbish we get.

I suspect being very light with high air content the ration could be 1mm : 1.5CM-

That points to 22CM being the mean & 30cm being the TOP END-

SO for forecast purposes & for the fact the low could fragment / weaken & stay west my forecast for the period is

London/essex/ kent / East sussex 5-10cm.

Surrey / West Sussex 7-15cm.

Areas like the downs- all around banstead etc- ~ 20cm.

this is based on the UKMO-

For the ECM knock 3/4cm of all totals-

**** remember the biggest caveat to this ISNT temperature for once- but how far east the PPN goes & holds together.

**** Where it stalls will get persistent snow for 30 hours before it fragments ****

So does it end there????????- NO, for this to be special & one for the archives you need a sustained period over 2 weeks- so lets open the ECM curtains for next week - after sub -10c minima sat night-

Snow approaching from the west-

http://en.vedur.is/photos/atlant_evr_urkomuspa/130116_1200_114.png

http://en.vedur.is/photos/atlant_evr_urkomuspa/130116_1200_120.png

http://en.vedur.is/photos/atlant_evr_urkomuspa/130116_1200_126.png

another 12 / 18 hour event that rolls into convective snowfall post that- & very cold out to day 10-

In Summary then:

A snow event friday- DONT ramp it up to much on the PPN front as the ECM is fast through with no real stall- so amounts are in the sub 10cm camp- where as the UKMO is VERY aggressive with PPN..

until then- total ice day tom & friday- freezing the ground & some ponds/lakes ready for the snow...

S

Steve if I remember the Ashdown forest does quite well as it is Quit high up compared to the surrounding areas

[Jimmyh]

Ok much happier with the forecast now shows snow on Friday and Saturday remaining cold throughout will say this now zero rain on Sunday did regard anything Cockcroft says

[Redmc13]

cor its like christmas im so excited..just hope im not let down again

Same here...we usually miss out in Sandwich... Hope to get something this time

[SMU]

NAE updates about 915 to 945 ish-

The 12z NAE out to 48 was obviously 12pm Friday afternoon-

Now the 18z 48 will go out to 6pm Friday- so it will give us a window of the NAEs thoughts into the PPN rates in the SE- also an update on the band of light snow ahead of the main band-

S

Edited January 16, 2013 by Steve Murr

[A Wintry Mix]

Quite a of snow being wasted in the channel!

temp 0.80c

[Bluebreezer54]

I hope Im not boring everyone with my photo's, but this afternoon in East Sussex was a glorious day to be out with the camera. Having trouble downloading them though so please bear with me.

BB

[Robbie Garrett]

Something quite not right, I'd say we are not just on the cusp of something special, but more so something quite serious...

A lot of it depends on the snowfall this weekend, going by the MetOffice warning it could have a very significant impact. At this stage a very low possibility, but I await the upgrade. Winds will strengthen and blizzard conditions are a possibility,with the potential for some severe disruption, though currently there is a good deal of uncertainty about intensity of snow. Icy conditions and low temperatures throughout. Snow accumulations expected Monday and Tuesday with snow showers later. Strengthening winds later exacerbating the cold feel.

If ECM is to believed then come Wednesday, we are ****ed!! GFS got this one correct last week by showing a severely deep low heading into the UK sometime early next week.

Something quite not right, seeing temperatures that low for London next week. Minimum of -8*C could be reported. But I suspect with accumulations as much as they could be Wednesday Morning, the temperatures could start to fall quite a bit for London & South East. I wouldn't be surprised if this weekend and early next week dumps a good bit of accumulation and temperature plummet that a Red Warning wouldn't be issued as the threshold for the home counties is quite less than most of the rest of the country.

Red — National Emergency

Reached when a period of cold weather is so severe and/or prolonged that its effects extend outside the health and social care system. A level 4 warning would be issued on advice from, or in collaboration with, our Government partners. At this level, the health effects may occur among the fit and healthy, and not just in high-risk groups.

http://www.metoffice...oldWeatherAlert

[london-snow]

Hmm my company has booked me a cab to and from a meeting friday morning wimbledon ~ central london anyone know the eta for snow to hit the capital? Hopefull that the meeting may get canceled or the cab driver refuses to take me.

[2810lollypop]

The met office for hastings had snow from 6pm on friday ,they have now updated that to snow from 12 lunchtime ! i think the commute home on friday is going to be a nightmare for most ! Might be a good time to tell all bosses that u have a dentist appointment at 12.15 pm friday

[Jezzer]

Hmm my company has booked me a cab to and from a meeting friday morning wimbledon ~ central london anyone know the eta for snow to hit the capital? Hopefull that the meeting may get canceled or the cab driver refuses to take me.

Morning may be ok before it gets too severe although subject to change of course. I'm set to get a cab to the BBC for a 6am start so may be ok although I'm not sure how I'll get home; South West trains aren't the most reliable in snow

Huskies ready and waiting!!

Edited January 16, 2013 by Jezzer

[Southender]

Nae on the roll...

[fluid dynamic]

Im quite looking forward to being stuck WFH on Friday, might get the dreaded tax return done !

Although, there is a Quattro with Winter tyres on the drive, might go out and take some piccies

[sarah7meme]

Partner returns from 10 month injury to ambulance for Friday night shift lol bless him

I will be on here with bottle wine and take an impromptu walk in the snow

[95 Degrees]

The met office for hastings had snow from 6pm on friday ,they have now updated that to snow from 12 lunchtime ! i think the commute home on friday is going to be a nightmare for most ! Might be a good time to tell all bosses that u have a dentist appointment at 12.15 pm friday

Met Office updates good for here too, they are showing snow friday and heavy snow friday night no longer sleet, and 1C on saturday so wouldn't melt, but still won't ramp until friday morning, then i might just believe.

[sarah7meme]

And I'm on call Friday 9-5 which means I have to work and anything occur in Shepway Dover Ashford districts I have to sort out

[EML Network]

The met office for hastings had snow from 6pm on friday ,they have now updated that to snow from 12 lunchtime ! i think the commute home on friday is going to be a nightmare for most ! Might be a good time to tell all bosses that u have a dentist appointment at 12.15 pm friday

HA HA HA HA I have one actually, but it's at 5pm tomorrow...tooth extraction :-(

[EML Network]

Well I'm supposed to be going to a party in Surbiton on Saturday night, but I have a feeling I'm not going to have much luck with the trains...and I can't afford to get stuck there as I need to be back Sunday lunch time at the latest.

Beginning to wonder if I should cancel now ....mind you if we do get less snowfall down here on the coast, it's a good opportunity for me to go somewhere where they might have more of it ..mmmm...decisions decisions