London And The South East Regional Discussion Thread - II

[Marie]

Some hefty showers showing up just off the Kent coast on the radar, i certainly would be interested if i lived down there, unlikely to affect anywhere too far inland but certainly worth keeping an eye on.

Anything worth waiting up for in my neck of the woods? Good luck guys Edited January 30, 2012 by Marie

[Whether Idle]

Sleeting increasingly heavily and getting windy. I think there must be something upwind.

[sarah7meme]

Incoming streamer ? What sort of streamer - a channel one ? Will it brush by, give off lots???

My partner is with emergency services on night shift tonight and have told him to call and wake me if it is amazing out there

Anyone know what tomorrow may bring ? Tomorrow night?

Oh and btw- settled on cars.

[kold weather]

As Darren says showers now pepping up, a few more further up the coast along North Essex and Suffolk as well, not so much in the Thames Estaury yet though for areas North of the Thames

Wind angle is still shifting, next few hours it should be at a very good angle for a Thames streamer...indeed there are a few hints of showers forming further east of the Esturary already and I think as that line moves closer that will be the area to watch.

[Roger J Smith]

Wow the 18z GFS looks epic, snow potential easily 30-50 cms over three-day period there (mid-Wed to mid-Sat). There's even a near-perfect gradient wind speed, not too light and not too strong, would cultivate some good streamers then not disrupt them too violently. If this model is not totally wonky, you can almost guarantee a heavy snowfall in perhaps two-thirds of the target area. Some of this could carry a good distance overland and come back out into the Channel around Brighton to Shoreham too despite the terrain. Almost looks like a mesoscale type event rather than streamers, which would make it perhaps heavier in places.

You guys and gals must be beside yourselves (have a look, nobody's beside me).

[Paul Sherman]

Oooh

Now this is getting interesting!

Lol why does it have to happen at 1130pm!

If you run the sequence the wind vector has completely changed over in Eastern Kent and out in the Southern North Sea. At about 6pm it was a NNE, Then this veered to a NE at around 8pm, the ENE Was brief and has now swung around to an Easterly backing ESE.

You can clearly see this with the showers off the East and North Coasts of Kent and further up off the coasts of Essex and Suffolk. The decaying precip along the estuary is still moving WSW With an ENE Which will be shunted away soon to be replaced with probably an ENE To ESE Wind vector!

[Paul Sherman]

Wow the 18z GFS looks epic, snow potential easily 30-50 cms over three-day period there (mid-Wed to mid-Sat). There's even a near-perfect gradient wind speed, not too light and not too strong, would cultivate some good streamers then not disrupt them too violently. If this model is not totally wonky, you can almost guarantee a heavy snowfall in perhaps two-thirds of the target area. Some of this could carry a good distance overland and come back out into the Channel around Brighton to Shoreham too despite the terrain. Almost looks like a mesoscale type event rather than streamers, which would make it perhaps heavier in places.

You guys and gals must be beside yourselves (have a look, nobody's beside me).

Roger

Pub Run - It has got totally Pi$$ed up tonight

[feb1991blizzard]

Anything worth waiting up for in my neck of the woods? Good luck guys

I would say probably odds against but i havent got access to the NMM model and the NAE has been useless up here this winter so i have binned using that for PPN until it improves. The Met forecast is only for snow showers for Kent but with these type set ups i certainly wouldnt rule out the odd one getting further west, the next radar is out in 15 mins so might be worth looking at that.

[username home]

Wow the 18z GFS looks epic, snow potential easily 30-50 cms over three-day period there (mid-Wed to mid-Sat). There's even a near-perfect gradient wind speed, not too light and not too strong, would cultivate some good streamers then not disrupt them too violently. If this model is not totally wonky, you can almost guarantee a heavy snowfall in perhaps two-thirds of the target area. Some of this could carry a good distance overland and come back out into the Channel around Brighton to Shoreham too despite the terrain. Almost looks like a mesoscale type event rather than streamers, which would make it perhaps heavier in places.

You guys and gals must be beside yourselves (have a look, nobody's beside me).

how reliable is this guy???

high post count and reads well but has he got a decent track record???

[HighPressure]

Snowing in Sevenoaks Kent

[yamkin]

no snow in Kingston upon Thames...

have a feeling yamkin and others are bending the truth...

There has been light snow flurries here for a few hours now which prompted the gritters to go out tonight and first thing in the morning before rush hour. No bending the truth here I'm afraid

[Kentish Kiwi]

how reliable is this guy???

high post count and reads well but has he got a decent track record???

Haha, RJS is most certainly a credible forecaster... But I'm inclined to think he's possibly over-ramping things and exaggerating the potential snowfall on offer just a little.

Snowing in Sevenoaks Kent

That's irritating... Bone dry here ten minutes down the road (to the North) from the high street.

Edited January 30, 2012 by Kentish Kiwi

[Roger J Smith]

how reliable is this guy???

high post count and reads well but has he got a decent track record???

Take 90% of my snowfall estimates, I tend to be an optimist on ratios. )

You can check it out in real time, I didn't comment on Tuesday but potential there would seem to be a bit lower although a few scattered 5-8 cm reports are possible. The main event will kick off when the Siberian squad piles out of the coaches and onto the field.

[kold weather]

The 18z is epic but the flow is probably a smidge too northerly for most of this area to get the big snows looking at the 700hpa vectors...I suspect for the main part E.Kent would get the big snows, but there is a window or two for a ENE to occur, on Thursday and again maybe on Saturday.

By the way even the high resolution models are badly under-estimating precip strength at this stage...just 6hrs later!

[SMU]

http://www.meteociel...&mode=0&carte=1

PUB RUN AWARD

lots of runs hitting -16c in the SE part of kent ( 850 HPA ) & I think 1 -18c

S

Rogers totals in terms of locations wise are dependent entirely on windflow angle

S

Edited January 30, 2012 by Steve Murr

[Neilsouth]

Snowing :D

[SMU]

Streamer heading for Herne bay, Whitstable , canterbury + Ashford-

Things improving fast & all chunking west

S

Edited January 30, 2012 by Steve Murr

[kold weather]

Steve, I can't believe we have a mean of near -15C at just 96hrs...think of all those times we creamed ourselves over getting -10C onto our shores in an easterly flow!

Even with high pressure its hard not to imagine there'd be some very interesting precip around, even if there is a cap to break through first...

[HighPressure]

That's irritating... Bone dry here ten minutes down the road (to the North) from the high street.

Only light and I am half way up the downs looking down on Sevenoaks town - but snow is snow!

[Kentish Kiwi]

The 18z is epic but the flow is probably a smidge too northerly for most of this area to get the big snows looking at the 700hpa vectors...I suspect for the main part E.Kent would get the big snows, but there is a window or two for a ENE to occur, on Thursday and again maybe on Saturday.

That was my main concern with the 18z. If the winds turn just a hint too far northerly, East Anglia will eat up all the moisture for my area while Maidstone eastwards gets hammered. It is fair to say an ENEerly is generally a better wind direction for the SE region as a whole, giving a better spread of snowfall, particularly further inland?

P20 from the pub run looks like an amazing evolution in terms of potential countrywide snowfall from an undercutting low, it's a shame no other operational run has hinted at something like that.

Only light and I am half way up the downs looking down on Sevenoaks town - but snow is snow!

Ahh, your height is probably the significant factor there. If you're looking down on Sevenoaks Town you must be well above 200m.

Edited January 30, 2012 by Kentish Kiwi

[Roger J Smith]

My estimates factor in some mesoscale trough development that I feel has never been 100% depicted on even the GFS let alone the less aggressive models, those very same low temps (surface to 850 mbs) out over the 8C waters of the North Sea, can be expected to kink the flow around trough lines oriented NNW-SSE moving southwest, and this will tend to give intervals of more favourable wind as well as setting up convergence and meso-scale bands. Does anyone recall seeing 850s this low in recent outbreaks? I tend to think of -12 C as the thresh-hold for major snow streamer potential and -16 C in UK terms is exceptional, somewhat garden variety in the Great Lakes but then so would be 30 cms in 24 hours off lakes not quite as warm as the North Sea. Anyway, I've been riding this horse for days since the outbreak was first signalled and it all depends on a full shot of unmodified Siberian air coming through, obviously it will bust if the solution is less aggressive, but an upgrade at 48h? That sounds like late Nov 2010.

[blackprince]

Snowing :D

Hi Victor I stopped lamp post watching a while ago but as you are only just up the road I am going to start again,looks like we are in for it later in the week,

SM is ramping it up for us so I might stay up a while after it seems a long wait since we had any snow,

[Paul Sherman]

Snowing :D

It's all gone Orange to my East. Am North West of Herne by about 35 miles as the crow flies! Going to be an Intersting few hours if those showers can get cranking in the Estuary. Easterly steering flow now, just need that to push more towards the Essex coast for a bonus Mini Streamer for London as well.

[kold weather]

Precip still strengthening, and this is with 850hpa temps arlound -8C. Its very pleasing to see that and the thermal gradient is working its magic already...

[Kentish Kiwi]

My estimates factor in some mesoscale trough development that I feel has never been 100% depicted on even the GFS let alone the less aggressive models, those very same low temps (surface to 850 mbs) out over the 8C waters of the North Sea, can be expected to kink the flow around trough lines oriented NNW-SSE moving southwest, and this will tend to give intervals of more favourable wind as well as setting up convergence and meso-scale bands. Does anyone recall seeing 850s this low in recent outbreaks? I tend to think of -12 C as the thresh-hold for major snow streamer potential and -16 C in UK terms is exceptional, somewhat garden variety in the Great Lakes but then so would be 30 cms in 24 hours off lakes not quite as warm as the North Sea. Anyway, I've been riding this horse for days since the outbreak was first signalled and it all depends on a full shot of unmodified Siberian air coming through, obviously it will bust if the solution is less aggressive, but an upgrade at 48h? That sounds like late Nov 2010.

So your view on things is that the undeniably high pressure will hardly factor into things given the potential lapse rates on offer?

Personally the idea that shower activity will be limited in a general sense but those that break the cap will be quickly develop into intense cells seems a reasonable assumption. It is pretty much unknown territory for the UK though, and will more than likely come down to a now-casting scenario, even more so than usual!