Eagle Eye

Mean skewed by the few warmer ensembles, I think if the cold spell goes as planned, the 850's mean should be around -6 or-7 on that ensemble spaghetti which as a mean would be fantastic.

This forum buzzing for Winter now, you love to see it. Kudos to all of the professionals on this forum that told us this could come up long before it became a trend on the models.

We will be satisfied when we get the snow. Actually, I think we'd complain then. We could have Narnia and still complain that the uppers aren't -12 .

This is very much a netweather thing lol You will find this happens a lot. You also find that there's a few who do more in depth than just what that one run happens to be showing. You can ignore members so I would advise ignoring members except the ones you trust to be honest unless you want to be taken on the netweather ride. Sorry this is a bit off topic mods.

It's probably just pining for the fjords.

If you were wondering how anomalously cold the GEM gets at 240 hours... A truly crazy run.

The GEM is your friend

Then that is fair enough I'll link some stuff about different topic that might help... MJO Avertissement de redirection WWW.GOOGLE.COM NAO Avertissement de redirection WWW.GOOGLE.COM Essentially, a negative (sometimes shown as -VE) NAO is better for cold synoptics for the UK whereas a +NAO is more commonly associated with Atlantic influenced Stormy weather especially in the Winter. AAM (a copy of my interpretation because I couldn't find many starter documents) " I've shortened a few words because this is the second time writing this after I accidentally deleted the tab first time around. AMB - Angular Momentum Budget AAM - Atmospheric Angular Momentum CI flow (Cross-Isobar flow) LP(High pressure) HP(High pressure) MT(mountain torque) GWT(gravity wave torque) FT(frictional torque) BL(boundary-layer) PGF(pressure gradient force) If AMB increases in the atmosphere it must have been transferred from another source since AMB is always conserved. The sources for AMB are from the Earth, the Oceans and the Atmosphere. One major aspect in affecting AAM are torques. A torque is the rotational force in the atmosphere. The 3 main torques affecting the atmosphere are: Mountain torque (MT) - The turning force applied with the effect of pressure systems on mountains. Frictional torque (FT) - Boundary layer dynamics. Gravity wave torque (GWT) - Subgrid (local) torque, upward movement and downward movement to do with the buoyancy. Now, onto the FT and BL dynamics: BL friction allows the lower atmosphere to flow across the isobars and for air masses to modify their vorticity/ The friction at the BL is what allows the exchange of AAM with FT. This friction allows the atmosphere to, in part, counteract the rotational force and allow the flow of air to be along the isobars. The CI flow brings in its own Coriolis and friction force parameters. The flow across the isobars is left of the geostrophic flow therefore there is a frictional force on the Coriolis force and so surface drag on the wind and so the PGF becomes the dominant force. LP dynamics: Air spirals inwards, creating convergence and so moisture creates clouds and rain. HP dynamics: Air moves away, creating divergence and so moisture 'moves away' and so the typical blue skies occur. Of course, that is an idealised version and because of extreme localised differences, this is rarely the case, instead there is a general pattern of these dynamics. If there is a net westerly surface wind, the atmosphere speeds up the Earth's rotation and transfers angular momentum to the earth and so there is a net decrease in AAM. The reverse happens with a net easterly wind. Further mountain torque: Fluctuation of pressure and orography and the force exerted due to the difference in pressure across the raised surfaces. High pressure on the west and side and low pressure on the east side imparts angular momentum into the Earth from the atmosphere. The opposite happening with the opposite case. In the NH Winter: Global MT anomalies are constructed by sypnotic waves that scatter energy across Asia and North America. These sypnotic waves trap the SLP anomaly and push them towards the south. Driven south and east of mountains. Sypnotic wave centres amplify aloft. MT associated with anomaly air parcel transportation in terms of momentum into latitudes its next to. More angular momentum is therefore moves to the 20-20N band. This is where the AAM anomaly appears significant. The anomaly quickly becoming equally uniform leading to a global FT that weakens the AAM anomalies. An anomalous distribution of mass accompanying the MT acting to balance the zonal winds in the 20-30N region. In the mid latitude, Eddy's are the physical link between those two torques. The two main torques can be shown in a lag correlation and FT "leads" MT. The relationship related as previously mentioned in the last paragraph. SLP anomalies are related to FT and the coupling with MT." Some definitions of some words you may not understand Synoptic is a general summary. Waves here refers to planatery waves which are propagated by the rotational forces of the Earth and transport energy even if not doing it much themselves and they show themselves in the form of a meandering jet stream. Shown neatly in this GIF Hope this helps at least a little bit. You can ask or direct message me if you're wondering about other words as well as I understand Atmospheric Angular Momentum is difficult to grasp but once you get it it's a very useful tool.

Starting to get exciting isn't it . Just don't tell anyone yet otherwise you might jinx it.

Sorry I'm in an angry mood. A lot of what @Tamara talks about is quite advanced yes but you won't get anywhere if you don't make an effort. There's loads of free information for everything online at every depth imaginable. Instead of just aiming to gain reputation points, you could also try and learn as I would argue that learning is the best thing you can do in this situation. As Malcom X said "Education is the passport to the future, for tomorrow belongs to those who prepare for it today."

Thanks for the delivery just don't throw it at my door.

This GFS run makes a lot of sense in its evolution (maybe my bias coming in). Look at the mean at 150 hours and you can really see that the Greenland high is arguably the best positioned on the GFS mean it's been since it got into a time space where we start getting fairly accurate.

ICON coming into range for first easterly, not looking brilliant as expected but might deliver the first snow for us to higher grounds in Kent and East Anglia, could bring sleet with those dewpoints especially to non built up areas.

Thanks to @Liam Burge for linking this to me.

Taking it on the face of it and a complete turn around from the GWO. We get one more round of +VE (Nino-esque) AAM. An increasing chance of another -VE NAO in late December after this potential one. Beyond that we go back through phase 8 and a loss of frictional torque before a significant loss of mountain torque. Eventually northwards momentum transport, probably helping to also increase the southerly drag and an increased zonal wind suggests that on this run the Atlantic will end up having more influence going into January. A highly -VE AAM, very Nina-esque in terms of phases. Based off the latest run, December will probably end up favouring cold but January may end up being a lot more Atlantic dominated as a return back to a more normal pattern in recent years. It's only 1 run and will likely change next run but I'd like to remind you that this chance needs to be taken as if its the last chance this Winter because it might end up being just that.

Favoured just means an increased chance of cold, theoretically, Atlantic driven is still our main driver. I think the fact that we have a Nino AAM has meant that that combined with the MJO phase lag has significantly driven our recent and forecasted weather.

I'm not going to be looking at distant means just yet but if you aren't taking that 144 hour ECM mean then you really are nitpicking.

No long words or teleconnections now, just two words... Calm down.

Exactly, it's still very much on a knife edge at the moment.

4 Panel view. Hail has trended more significant due to the increasing discreteness and better lapse-rates. Look at how curved those hodo's are getting... Just seen the SPC's text "Multiple rounds of severe thunderstorms -- some capable of long- tracked tornadoes with EF3+ damage potential -- will be possible this afternoon into tonight over parts of the lower Mississippi Valley region and Mid-South. Large, locally damaging hail and strong-severe thunderstorm gusts also are expected over the region"

AAM is forecasted to go into a -VE anomaly (Nina-esque) for a couple days by early December from the lag of losing frictional torque to the eventual weakening of the AAM. The weakening of the AAM into a negative (Nina-esque) seems inevitable at the moment but it'll be so weak that we may as well define it as a 0 AAM. Anyway, I don't think it'll affect our pattern significantly, so it just depends on what our local dynamics are at that time. Then it looks to re-enter the positive (Nino-esque) phase further into the month so another interest may arise. Member 4 seems to have the slowest weakening and based off the actual AAM, this may be the closest and it suggests the strongest Nino-esque AAM going into late December which would have lag correlations close to my birthday. The GWO is fairly weak but I think that's more a product of the varied outputs from the different members other than anything. Anyway, Olivia prefers anything other than cold weather (possibly the only ginger that does lol) so I'm supposed to be finding something that doesn't support a -VE NAO state in the future so, the fact that the other members show a weaker Nino state when(if) it re-enters the +VE AAM means that a -NAO is still less likely than member 4 would suggest. Anyway, member 4's strengthening of the AAM +VE anomalies is so far off in the future that changes can be significant by the next run. A bit for everyone in the models at the moment but it's actually favouring the coldies long-term and short-term it's favouring the coldies as well, interesting model watching upcoming...

It tends to be fairly accurate in Europe so if it gains support then this really is concerning although I'm not sure what it's latest runs are looking like. Dewpoints and WAA are surging from the gulf now, stream of moisture is looking to be a bit more significant than forecasted on the NAM so I would suggest the Swiss may gain support with it's environment supporting significant Supercells, the low-level jet will increase over the next few hours as well.

I'm not entirely sure what you expect. Way too far out (for the second easterly) to go speculate and the first easterly is only really the taster. The second easterly is better placed time wise as we've got it further into December so theoretically shorter days and colder air. Yes the timing of this wasn't perfect but you could argue that 2010 wasn't. On about half of the recent runs uppers have reached at least -8 at the start of the second easterly and the mean has consistently shown a good setup to get a feed of cold air from the East. With everything, it's all about patience right now, we can speculate on what the professionals are saying, we can speculate on what the models are doing but right now it means nothing. If you're expecting the models to get everything perfect within a 50-100 mile radius at a day 9/10 range then you haven't seen how wrong they can go. Everything sets up nicely in the mid term and the teleconnection signals are there, now we just wait and see what happens. Of course, I will speculate if I see a significant trend popping up but for now I really don't think it's worth talking about the uppers.

Still too far out to worry about minute details in my opinion, wait a week or so and everything will be 90% sorted then you can worry about the details, for now, I'm not seeing much trend especially on the para when talking about the Iberian low so I wouldn't be worrying too much on its exact positioning just yet.