Shunter

Try this.....https://www.aer.com/science-research/climate-weather/arctic-oscillation

Same here in Bromley too....some heavy spots of rain and a cool 3c ...estimate dew point at around 1c so the forecasted switch to a more Easterly based breeze later could lower the DP and enhance convection in to Kent and east London as it moves in off the estuary....seems to be a lot of convective activity in the Southern North Sea today as seen on the radar and causing the light snow/sleetfall on the South Essex coast from the southerly draw.

SE Perspective: Well this so called "Wintry" ( really more like an Autumnal Cold spell ) appears to be over by Friday Morning. Pretty lame affair in the grand scheme of things. Although no HLB in evidence a number of other factors ( recent minor SSW, MJO phase 7/8, Southerly Jet etc ) all seemed to be in our favour, coupled with normal mid winter expectations I would have thought a minor snowfall and a couple of days of frost would have been the norm but once again another OVERRIDING factor has scuppered our chances of even seeing a flake or two.. Just what is this missing piece of the jigsaw that prevents the UK from a "Normal " Winter? ( AGW, Climate Shift ) ? . I have been monitoring weather charts since the beginning of the Internet age and the only factor I can think of is what appears to be a strengthening of the Northern Jet Stream. Does anyone know of any historical records in regard to NH Jetstream strength that could be referenced to provide better clarity? Meantime we ( In the South East ) probably have one more window of opportunity in around the first week in February for an entrenched Wintry period after that solar warming will do its thing and it'll be snow showers or temporary accumulations at best for another year.

Not sure if this has already been posted but the latest AER report was published yesterday ( interesting that they confirm the recent warming as a SSW ). Summary...... A positive AO will continue for the next week along with a positive North Atlantic Oscillation (NAO). Meanwhile, higher in the atmosphere, the polar vortex remains perturbed following a sudden stratospheric warming (SSW) event which peaked a week ago. Further perturbation of the polar vortex is predicted, at least in the near term. Extreme cold over the Central and Eastern US in the near term should relax to seasonably mild by the end of the week into early next week. Overall mild temperatures will continue across northern Eurasia including Europe. The downward propagation of negative AO conditions in the stratosphere should begin to influence the tropospheric circulation in about a week. Therefore, we anticipate positive AO conditions to trend more negative the second half of January. This will promote more high latitude blocking and colder temperatures hemispherically for the remainder of the month. The biggest change should be felt across northern Eurasia including Europe, where temperatures should turn significantly colder from what has been observed so far this month. Prospects for a negative AO remain fairly high into February given the recent and ongoing weakening of the stratospheric polar vortex, though some uncertainty on timing and the eventual strength of the negative AO state still remains. full report here: https://www.aer.com/science-research/climate-weather/arctic-oscillation

Seems to be easier getting Snow in the desert regions than it is in the South of the UK..........the GFS is a real disappointment this morning as it moves the pattern further East and doesn't push the slider trough out of situ meaning the South and SE are left in a col of a damp,Raw & Rain before no doubt the heralding of a rejuvenated PV , record cold in the USA and a 250mph jet battering as we go into February. Checking the 0z run in the SE for the next 7 days on XCWeather there is 0 snow forecasted ! Really need some retrogression of the trough further west asap

I think the (lack ) of comment from seasoned professionals on this forum or elsewhere today highlights the current status Quo in its entirety ....nobody has any degree of confidence in the mrf for Western Europe after Boxing Day.....so not prepared to "stick their heads up over the parapet" for fear of retribution or loss of credibility ! It just goes to show with all the best minds and supercomputers nobody can really forecast the weather for our shores any better than they did 40 or 50 years ago bar the "Zonal express scenarios".

Not sure if this has already been posted...... "Potential" for rapid change still in place despite poor operational guidance in the past 24 hours.................. Latest summary from AER issued yesterday..... December 19, 2014 Summary • The AO will remain positive for the next 5-7 days but then turn sharply negative near or just after Christmas. This negative state is expected to remain in place through the end of December and into early January. • The North Atlantic Oscillation (NAO) will weaken substantially and also turn negative by the start of week 2 as ridging over Greenland builds during the period. • Collectively, these changes will mean below to much below normal temperatures will invade the Northern Hemisphere continents after Christmas and lasting into early January. Colder than average conditions will also overtake much of Eurasia, with eastern Asia remaining cold. • The state of the AO in the long-term (i.e., into mid-January) is uncertain given the lack of forcing from the stratosphere and current model run-to-run volatility

NOAA's latest extended forecast discussion ( updated as 6am GMT this morning )still favours the higher amplitude scenario for the US so continue to follow 19/12 EC & 19/18 GEFS Ens mean. "THE WPC MEDIUM RANGE SURFACE FRONTS/PRESSURES AND 500 MB PROGS HAVE BEEN PRIMARILY DERIVED FROM A BLEND OF THE 12 UTC ECMWF ENSEMBLE MEAN WITH SMALLER INPUT FROM THE 18 UTC GEFS MEAN AND 18 UTC GFS/12 UTC ECMWF TO ADD MORE DETAIL. THIS BLEND IS WELL CLUSTERED NEAR GUIDANCE COMPOSITE EARLY IN THE PERIOD...BUT OFFERS A BIT MORE AMPLITUDE AND DECENT WPC CONTINUITY THROUGH LATER NEXT WEEK AT LONGER MEDIUM RANGE TIME SCALES. THIS STRATEGY SEEMS CONSISTENT WITH UPSTREAM FLOW AMPLITUDE. RECENT DETERMINISTIC MODEL RUN-RUN CONTINUITY ISSUES HAS IMPROVED ENOUGH TO NOW LEND NEAR AVERAGE PREDICTABILITY LEVELS." There is no mention of either EC or GFS Operational models in their discussion. Full details here: http://www.hpc.ncep.noaa.gov/discussions/hpcdiscussions.php?disc=pmdepd As stated too many times previously, too much faith ( and emotion ) is placed on each Operational model run when experience tells to follow ensemble guidance. Ops are ok for identifying "possible" new trends and for fantasy eye candy purposes only. Keep the faith....it is after all the most magical time of the year !

Is there a delay to the GFS 6z ( somebody giving it a good kick hopefully )?

The latest AO update seems indicative of potential pattern change.... moving into a negative value around 23rd Dec ( 1st -4 ens showing also ) . The NAO swings from slightly positive to a neutral value around the same time.

The METO MRF is again very underwhelming with talk of a 'short lived' colder interlude the middle of next week before the Atlantic resumes- Temperatures average or slightly above. Wintry Showers reserved for scotland and higher ground. Clearly the Exeter pro's are not seeing even the potential for something akin to GFS/ECM between christmas and new year as there is absolutely no caveat involved in their script?

The recently updated Meto 6-30 day forecast regards next weeks cold interlude as a snap followed by a return to a milder zonal flow. They also advise of temperatures around or Slightly above average and have removed the possibility of a colder incursion in the new year . Quite bizarre given the latest 12z cycle runs but emphasising again the need for monitoring trends rather than focussing on every run. Some clarity from "those in the know" would be most welcome at this juncture however ?

I see the latest Meto 6-15 forecast and strangely there is no mention of Mild in fact temperatures are forecast a little below average (generally)for the period. Given their recent accuracy in MRF I would tend to take more notice of them than most of the other models

2.9C here now after maxing out at a sweltering 3.1c today. Drizzle all day. Dew point around 1c so not quite low enough to become snow grains. Definately the coldest day since the winter before last though.

Exactly my sentiment too, so despite the optimism of OPI, SAI , +PNA, -AO and a potential early season SSW we end up with.........BAU ! Looks like the experts may have to rewrite some of the composites, cos mother nature dont follow song sheets.

Cool continental air feeding into the SE now. A raw breeze and 6.2c here. The air is drying everything up nicely . Despite 850pha temps of 8c is does feel cold, so maybe an inversion setting up. Either way it's going to feel bitter come Thursday/fri.

Given NOAA's latest updates....I think some of this mornings comments on this forum regarding medium term flows are really irrelevant. Quote: USED THE MOST RECENT EUROPEAN CENTRE ENSEMBLE MEAN AS A SYNOPTIC BASE AT THE MEDIUM RANGE. NONE OF THE ENSEMBLE SUITES OF THE PAST FEW DAYS HAVE PROVEN PARTICULARLY ACCURATE OR STABLE, WITH THE ECENS MEAN THE LEAST VOLATILE. THE OPERATIONAL MODELS, OF COURSE, HAVE BEEN EVEN MORE SUBJECT TO THE WHIPLASH CHANGES THAT HAVE COME WITH EACH NEW DATA CYCLE. Shannon Entropy continues

And we all know, it wont be the persistence of this single weather pattern that Winter 2013/14 will be remembered for either !

Just to add that January's CET is currently at 6.2C. If it stays around that mark it will be the mildest January since 2008. FYI...the warmest January ever recorded stands at a mean CET of 7.0C

FWIW ....in NOAA's preliminary discussion this morning for Thursday -Sunday ( 05-08th Dec ), they are still favouring the Euro solution ( 01 12z EC Ens mean ) over their own models. So ECM may still be the most likely solution for this ! http://www.hpc.ncep.noaa.gov/discussions/hpcdiscussions.php?disc=pmdepd

Coldest ever April's were 1701 & 1837 with an average CET 0f 4.7C. We are currently at 2.5c.....................I wonder

medium intensity graupel here . Temp 2c

No I totally agree...Wind turbines are ugly monstrosities......cost more to maintain than they generate.....a jobs creator...sooner they are replaced the better...

A few flakes in the wind here but temp has risen quickly to +3c

Thames Estuary seems to be firing up a bit of convection in the last hour