SMU

Back in bexleyheath after dropping mini murr off snowline falling to about 40M now- moderate sleet / snow in goals car park !! s

3 hopes Bob hope no hope envelope

Yeah your as high up as it gets lol - gotta go bloody greenhithe sub sea level will be rain all night. In heavier rain it may be cold rain.....

Dont panic people let it come to us next 4 hours it will happen - however elevation is the key For example across welling high street rain & sleet - top of shooters hill snow - ( right at top ) which is about 80m so I think once that PPn hits then everyone will see some snow but only higher parts - like you halstead for a perfect example - maybe 5cm..... s

80% snow here in bexleyheath now -

Halstead whats your postcode ( not to your door lol ) were gonna pop out for a drive!

Rain / sleet on the turn in bexleyheath flakes starting to appear- main band radar return on 10pm increased again- making a B line for South essex & NW kent !!!

Great radar returns moving south ( increasing over peterborough etc at 2115 - 2145 will change the PPN to snow for many as for greenhithe im going for a remeasurement on height i think its sub sea level.- only place to be -Meters anyway.... Have fun

Guys just 2 hours to go & temps will be quickly on the slide.....

Yes mate although ive hung up my crayons as mini Murr has taken over my life !

Thanks in terms of track of PPN - clarity probably around 4-5 pm.... see all later s

Morning - Im in here tonight deffo - my wording is currently 'optimistic' about a bit of snow- timings - any time past 1am please, as we want ideally clear skies from 7-midnight to get the surface cold going a few things to remember this system is very shallow so minimal wind turbulence creating mixing - so surface cold wont get lifted out also that harsh frost last night ( first of the year ) has taken a fair old chunk of the surface warmth out of the top soil ( maybe down to 5cm ) so lets have a clear eve then go for gold after 1-2 !! see everyone later !! s

So ECM joins the APERGE image from earlier - those that get the snow Mon will keep in tues weds as deep frosts develop ECM 120 - atlantic missing in action.... S

Will do Ed although will reply to catacol on my post later..... although will be late !

Tamara I will write a reply later - the fact that you took the time to reply to me Nick phase 2 looks to be a slider bymut perhaps at a slightly more northery location - not sure yet - S

So, going on from this morning then i said I would base a first forecast for Monday on the blend of JMA / NAVGEM & aperge - With ALL things considered it is my belief that the aperge run of 06z is pretty close to the final 500mb solution Heres the NH plot & the euro plot - at t60 we can see neutral tilt ( so Its pretty vertical ) minimal residual energy closing off to the North & disruption extendes down to biscay so Monday Morning ) currently T72 I would expect a final outcome close to this Because the low DOESNT close off ( see it in the channel at 1000mb ) then all the winds ahead of the low into the PPN belt are still cold continental ones - The Theta chart shows this well - so expect a band of snow ( no moisture rates included yet or distribution ) to straddle the UK from London up to the Borders of Scotland with the eastern extent London - Northampton - east Midlands - Yorkshire up to SE scotland- Of course some may think well Pointless to do a forecast now with such volatility in the models - well the volatile point isnt the location of the PPN belt so much as how far North the milder SW flow gets into the front - remember the models keep stalling the front out so where that stall point is will obviously deliver the most snow but perhaps increase the chances of snow to rain in the south - The worst case is the low closes off over say the SW or wales + stalls -then the forward winds over the Southern part of the UK quickly turn the snow to rain - This option is still on the table & is what I call a quick 'shallow' slider that doesnt get south of the UK- I dont think thats the preferred option as it stands - although the GFS does - The aperge above does it for me. In terms of blending the 3 models the JMA is on the same page as the APERGE but the PLUCKY NAVGEM is the best scenario ( I think its slightly over amplified because there a patch of 552 heights that get into southern Greenland at T54 ) The reason why its the best scenario apart from the positive greenland heights is theres no residual energy or PVA left north of our slider low at 72 so whilst the slider does just about close off into a shallow low its track SE is almost optimum for snow over the whole of the UK -as it slides into the continent- this is a great chart for the bulk of the Uk So there you have it summary for Monday as it stands * rain steaming in from the west - Turning to snow over the SW, wales, The midlands & NW before more than likely running out of juice - very similar to Feb 96. Even 12 hours before you may be in the zone to wake up & wonder why you missed out - Risk counties for snow to rain - obviously all south facing coasts along cornwall to Kent & even if your the next county inland upwards you may not escape... The places that tend to do the best here are the west Midlands at elevation.... Theres my punt as it stands for phase 1

All I would say about Stewarts forecast ( without being accused of trolling ) is both he & Tamara put a forecast out for 17 jan - end of jan delivering 1983 synotics + quote 'a classical -NAO showing' Yet no review on that ( or at least commentary on how that period is set to look ) just move onto the next projection of cold - with the caveat of 'strat allowing' - surely thats the caveat of the whole of the winter - Anyway back to the models - NAVGEM & JMA performing well ATM - I would also throw the Aperge in the mix Snowline 72-84 is the key

The 06z struggles still at 72-96 to resolve the energy so whilst it moves to the right scenario ( we hope ) im- the mid term it fails if we blended the 00z heights to the North & the 06z jet flow to the south ot may have got close my tip - JMA & NAVGEM 06z's at 78 is where our snowline will be there not out yet BTW so its a forecast not a cut & paste..... S

06z Small changes at 36 creeping in- very hard to see unless your flicking between 2 runs at 36 now as Alex gets absorbed into the main low the CAA under main low where out slider develops is angled more NW SE - the 00z had a similar angle but less acute... that angle ( maybe 5 degrees) should help at 72 & 96 S

Just adding to singularity post from earlier this feature which the GFS hopefully over develops is the reason for the positive tilt it needs to disapear sharpish ( for the south anyway ) make the image as clear as possible !! s

Another spectacular GFS fail on the cards for the UK yest 156 12z Todays 00z 144 The signal overnight is a strong swing to cold - without scouring the ENS the JMA is my favourite S

A nice atep back from the GFs from its 12z shallow solution - now moving to ECM territory- not enough for a full swing to UKMO but happy its moving back- remember let the theta E charts be your friend as a reault in one swoop instead of the ejecting out NE towards Norway its now held back over scotland - look how far south East the cold has come out of Norway- * remember 2 or 3 more eastward corrections of alex will pull that cold air all the way back - 12 t96 18z t90 S

GFS initialises the hurricane east of 12z plots - by 24 this starting position is manifesting in the fact that the track is taking it further east of main low in the atlantic reducing the phasing - remember weather is about timing... remember track changes at T6 by 50 miles become 400 miles at 120..... s

If anyone fancies doing this also it would be interesting to see the locational plot of the hurricane & the pressure at 500mb at 12z v the locale & initialised conditions on all the models - Whatevers closest may reveal the early favourite..... S

Ok so this is the summary for tonight * with HUGE model uncertainty at 72 & 96 ( still phase 1) then any output after 120 can be disregarded for what it shows as the angle of attack of the atlantic across the UK will determine where the WAA is * Tropical storm track is notoriously difficult to pin down so errors in track at 72 of say 100 miles are amplified at 120 to perhaps 500 miles - that 'cone' of track for the models sees the UK at the top & bottom end meaning that over the next 48 hours ( yes 48 hours ) the guidence of error will reduce significantly - the 72 hour charts at 12z tomorrow will pin the angle down I believe. * in terms of model tracks tonight GFS is the most shallow & positivly tilted over the UK at 72 you will 2 things * the tilt is positive & the trough disruption only extends into Ireland - Next is the ECM a slight positive tilt at 72 & with more disruption towards the south I guess somewhere along the lines of the channel - The GEM is here as well now for the colder clustering runs - The aperge, UKMO, NAVGEM NAVGEM Is vertical with tilt & disruption gets will down towards spain UKMO is slightly negativly tilted & disruption is to spain lastly APERGE is the most negativly tilted run with disruption down to spain - The JMA has just updated at 96 with no grib file for 72 but is cold so along the lines of the clusters. so there we are - no resolution - no real guidence other than waiting for a resolution tomorrow evening.... S