lorenzo

Nice work again BUS, you should link the you tube vids in your signature, that way regardless of where the thread is folks will be able to find them..

To save you getting dummies, teddies, alphabet bricks, moshi monsters etc etc off the head. Great post from Fergie on the mid term outlook - it would seem some people are misunderstanding the word Mild.

The Shaw paper above is a good read, whilst the main part of the paper goes about examining the difference between low and high top models in order to recognise the new methodology proposed i.e quantifying impacts based on heat flux between 60-90 degrees North. HLSHF - High Latitude stratospheric Heat Flux. The key points I guess relate to the relationship between Heat Flux anomalies and the positioning of the Jet. +ve Heat Flux anomalies leading to an equatorward shift in the Jet, with -ve Heat Flux leading to a Poleward shift. Heat Flux plots from Berlin Site - Wave 1 / Wave 2 / Overall Re the Wave 1 and Wave 2 queries this excellent explanation by Forecaster may help paint a picture, also this loop is currently showing the Wave 2 500mb anomaly nicely. Shaw writes that the -ve heat flux events are likened to the NAO and the downward wave coupling is similar to the positive phase of the NAO.

Just found that one this morning too, you beat me to it Interitus

BUS said he was going to take a drive to find his first snow. Wonder where he will end up !!

Have a scan of this one CH, wave 1 generated via wave 1 pattern in NH, wave 2 due to wave 2 pattern. http://www.phys.ocean.dal.ca/people/po/Whistler/waugh.pdf It is also widely recognized that planetary-scale waves control almost all aspects of the extratropical stratospheric circulation during Northern Hemisphere winter and play a key role in dynamical troposphere-stratosphere coupling [Plumb, 2010].The waves originate in the troposphere due to topography and land-sea contrasts and have vertical wavelengths that span the troposphere andstratosphere during winter, consistent with linear theory [Charney and Drazin, 1961]. The stratospheric planetary-scale wave heat flux, which is related to the vertical group velocity of the wave,exhibits considerable variability about its time-mean value. http://www.columbia.edu/~tas2163/Shaw_etal_2013.pdf

It's looking lively for later on, low pressure currently anchored at Iceland

Morning All, car needed a good scrape this morning, good decent frost. No Snow to report here, great to see the pics coming in from all over.

NIce work BUS, enjoyed that, the 62-63 reel of charts still bakes my brain !!! Unreal ! Welcome along Shanta, thanks for joining in - you can't go much better than hitting up the snow in your first post !!

Am pretty confident that I won't see anything better than that by way of mode output from anywhere for this entire Winter. This is excellent work. When we get some SSW activity these will simply be stunning. Amazing.

Have no plans to start a new one until December BUS fire away.. Edit - Mentioned to the other Regional hosts that I planned to let this one run til start of December so hopefully there won't be any changes til then.

The Daily Mash strike back at the Daily Express.. http://www.thedailymash.co.uk/news/environment/britain-to-be-hit-by-entirely-typical-weather-201110174431

GFS ramps things up at 168 hrs, formidable jet streak exiting US. Then the modelling gets very messy around the Greenland and on to Iceland, this was also evident also on last nights pub run. Looking at the bias in this area there is a clear lowering of heights. 00z then 12z - 00z further west then 12z pushing the tendency to lower heights all the way east. I know there has been much debate around this, the shaded areas below detail this well. Looking into the depths of FI, a huge chart at 240. Wonder what other options will lie in the ensembles at this timeframe.

Afternoon NAE - what a messy picture this is... a real look oot the windae and see what is actually falling situation for some areas. Great to see more folks re-appearing & Welcome to any of our new visitors over the next day or so. Cracking sunset - time to watch those temps plummet.. New model thread just launched for the evening runs, as earlier things went a bit... Here is a link to Fergie's latest thoughts from how the MOGREPS sees the next wee period of weather. http://forum.netweather.tv/topic/78461-model-output-discussion-131113/page-92#entry2838409

Lookng at the definition here http://www.atmosp.physics.utoronto.ca/SPARC/News15/15_Labitzke.html , For me this doesn't help take it from vague to easy to identify, will attempt an analysis, but could do with some expert input here. Looking at the re-analysis for November to date at 50mb and comparing to the analog years for recorded CW's you are looking at two completely different plots for the half way point of the month, surely would need to be a massive change to offset the profile for November so far this year. November 1st -15th. Analogs Also, from the Labitzke page there is this, indicating a change in atmospheric 'mode', are we in a new period where the poleward translation of the Aleutian high for whatever reason is in itself an anomaly now? [*]At the same time, the Canadian Warmings which in November/December took place in 18 of the 31 years until 1981/82, are missing during the last 18 winters, except for 2 cases. Am happy to look at things and say, yep that's a Minor Warming event, rather than get further confused ! [*]The Canadian warmings can reverse the meridional temperature gradient and sometimes briefly change the zonal wind direction over the polar cap, but nevertheless they do not lead to a breakdown of the cyclonic polar vortex.

Wave 2 definitely the place to watch just now.. Something looks like happening on the 10hPa run, only one way for that pulse to go surely. CFS still all over that Aleutian high with strong anomalies out into weeks 3 and 4, perhaps continuing to pressure what will be a split vortex with further displacement. The vorticity chart out at 216 displays the separated vortex and also some fragments left in a 'traffic jam' over Greenland. Intriguing to see Weds. morning strat plots, wonder if any marked difference with the upgrades going live. GFS today and out to 192.

Not sure what would be the benefit of 2 regional threads, HC? Think it may dilute this thread a little as a point of reference? LS - fantastic post !

I like the ECM when it is being guilty. In fact it can keep committing these terrible crimes against Greenland Highs as much as it wants.. Much easier on the eye than a 200 km/h bulldozer Jet streak..

Full stadium at Soldier Field, and this is the view from ????? Tornado on the ground in Chicago travelling 50-55mph

Twitter saying potentially EF5, areas levelled. This pic is just insane.

LS is the snow guru. Hopefully he will furnish us with Skew T analysis and one of his legendary maps. With that tricky low in the mix am sure even the Meto are finding it a tricky one to forecast. At least we now now that when we see stuff on the telly it derives from the NAE. Those 950hpa temps did this area in for a lot of last winter. Model Thread has been wobbly today, toys being accumulated for later, bit like the ebb and flow of the model output over the last couple of days. Pretty much like clockwork have found the 00z runs dilute the cold solutions and the 12z upgrade them., thus ensuring a complete rammy every evening.

That's an interesting score card, well found. Some 'significant' improvements, will be good to keep an eye on the verification over Winter to see if this moves it even further ahead of the pack.. This paragraph was of particular interest. Cycle 40r1 has a statistically significant positive impact on the monthly forecast skill scores in the stratosphere due to the increased vertical resolution and on the prediction of the Madden Julian Oscillation thanks to the ocean-coupling from day 0. The impact on the other monthly skill scores is generally neutral.

Amazing wealth of material there Interitus, superb finds. The blocking paper is a good read, I like that they have identified the blocking pre-cursors into different categories. The Kelleher poster on heat flux is too much for my brain today. As if there isn't enough going on in the strat at present and on the models ! Need to employ a researcher to get through that lot !!

Knew there was a NetWx guide 'planked' somewhere. This is much easier to follow than the hardcore stuff earlier. https://docs.google.com/document/d/1ClkAme7CLzViv51_1r8KQINHoendcxYbHJh2Ya2zQzI/edit?hl=en

On the subject of spreads and the conclusions drawn from the 12z ECM run, grabbed this GIF, this runs from 72-144 hrs, and you can see the increasing uncertainty in the solution as the run develops, This as alluded to determined by the modelling of the Jet and the different ways the models deal with the split flow and how much energy goes North and how much digs south. The ECM mean indeed is looking very good this evening. Another way I find useful is reading the ensembles for different parts of Europe via this link, just click the map. http://www.meteociel.fr/modeles/gefs.php?carte=1 Although tonight somewhere in Scotland has a 26,245 % chance of Snow !!!