Downburst

The MJO in the pacific/indian ocean tropical region goes through 8 defined stages. In each phase there is an amplitude for that phase, so already we are talking two dimensional. The forecast is that as December progresses we will move into Phase 7 to 8 which based on pervious patterns observed lend itself to an average of these type of pressure patterns shown below, not certain it will lend itself at all. This is a very brief summary and there are other variables at play, but one can ponder if towards the end of December whether this might happen, higher amplification of the phases, the phases happening at the predicted speed and the average pressure pattern showing and aligning. In summary yes, over the Christmas new year break there is a better chance at this time for northern- heights given the forecast Nick showed. No guarantees at all though.

This will be the first below average rainfall month following 4 pretty hefty anomalously wet months. Very happy on that front. December starts dry and frosty for at least a week, in fact many days never getting above 3c, even then only an hour. Chance of snow and even if on the mountains, I can drive. Nick F points out the interest we can have for end of month period. Won't be long before that may or may not be coming into view. Plus surprises aplenty always pop up in the interval. Like this shot of cold. And I'd be suffering hyberbolics if I'd forgotten my thermals at 450 m in this weather too. So sympathies there

I’ve been watching that low spawn on the last few runs. Bottom line on this run is the negative oscillation with higher heights to the north as we can see on your chart. Let’s keep watching this area to the north and see if this does slide, after it slides if it does then possible shenanigans are on the cards.

The pub run doesn’t have worse verification stats than the other GFS runs btw, and it’s only the pub run so to speak in Zulu time as it’s run from the US and in Zulu time, but not at pub time, but 1.00 pm US time east coast. Just for those that keep discounting it based on the local name it has on this forum.

Well I can't help you out there as if I give my driver the night off I usually walk home with one on either arm and I haven't time of a Friday evening to get over to Warwickshire, forgive me. But in other news the seasonal forecast is in some doubt in my opinion. I am not saying at this time it is wrong on monthly averages, but if what ever is causing this setup we are in, Canadian warming or whatever, if it persists or reloads and it very well might I can see reloads in December. Then we have possible background signals showing possible cold drivers in Jan/Feb. So very early days, but the seasonals I am not sure had this picked up.

This current setup is very much a disrupted Polar Vortex. As long as it's disrupted we are in the game. No question about it.

That chart is the tropics. So we want the MJO to get its MOJO back and get into some amplification as it moves through phases. 8 to 1 in December and moving fast to get there it

It's all eyes on the next ECM to see how it handles the deep low at around 200 to 220 hrs off new found land. GFS has it push through to us, 00 ECM has it also deep but looks to orientate it north easterly as there is a ridge in the way to the east. Very hard to see what will happen so far off, but interesting to see where this might break down if at all. I'm interested in weeklies too as I think accuracy will be a little shot for a few days.

Keep Calm I don't like the look of the low off the east American sea board the way it sits, in terms of it doesn't look correct. But in saying that it does move over during next week as the High north of Scandi moves into Central Asia, very slowly. Heights lost to the north lost somewhat too. But that is a long way off and it will be very cold for 10 days. Just would like to see something cleaner. LOL, it comes back and a north pole High also comes in in deep FI. Someone got any teleconnections to explain this? No idea what is going on here, but the PV has 5 lobes right? So longer wave and less west to east energy as a result.

Gone too far south, which is probably a good thing in the medium term

Dew Points Thursday 6.00pm Temps - 2 meter same time. To put the cold into perspective the temp anomalies paint a good picture Saturday midnight and widely 5 to 6 lower than climate average as the northerly sets up. As others have said the next low in might bring chances. What is notable though is there seems to be a lot of high pressure knocking around, the end of the GFS going mad with a strong Scandi High, so always have a chance on these runs in FI. I think the entire winter will be like this. Who know's what the chaotic atmosphere might do mid to end December Total SnowFall from start to finish of the 06Z means skiing in Scotland is back on the menu With shooting season these guys are delighted with snow in the highlands

I'm crossing fingers and toes for everyone that is hoping for snow, at the very least for everyone it will be winter as the week progresses that's for sure. It was intriguing looking at the ECM 00 run and into next week. You can see the Nino energy in southern USA/Mexico (just look at the pressure anomaly there) get a real push on as next week progresses and the end result is a fired up Jet, so it is pretty clear that first couple of full weeks in December are likely to be more westerly dominated. No idea what happens after that. I am not saying winter is over, in fact it's starting with a bit of a bang.

Bftp says permanent ice age imminent due to sun spots, he’s at the ICCP UN offices explaining it all.

Latest ECM shows the air flow in north Atlantic end of run. Looks nice. Not arguing about snow though

But it is a nice chart still. I love seeing the flow from the east at anytime, it's almost counter intuitive, you have to look twice

Of your sledge?

My response seems embedded in your post somehow January Snowstorm. The Atlantic is not primed.

Yep, and there’s been many a end of January over the years when we haven’t even had a sniff of a chart like that even by then. To have it in November, we’ll thank you. BTW, in between meetings and the rest today I have continued to trawl the webs most inner sanctums on teleconnections folks. I have to point out in brief, they aren’t mentioned on the telly forecast for very good reason.

How low down south can the polar front go? ECM 240hr GFS 240 hr I see arch waffling is back now on the pseudo professional front retrospectively explaining all this. That’s far more predictable than the weather. I am sure most will understand what I’m talking about. Enjoy the winter weather folks.

Yes, high over Scandy and low over us. Could be worse though. Doesn't hang around either, moves SE, with Azores high maybe connecting with Scandy ridge later in the week.

If he isn't I think I can promise you it will be at least "Cold" in Crew in a few days

I'll be looking at a glut on Mediterranean/mid east area early crops for Spring now. Thanks for the tip GFS 06z and it's high pressure near or over the top nearly all the way. Great news for farmers who in many cases can't get into fields etc. Rainfall accumulation looks great Interesting that the charts at the beginning and the end of the run seem very similar indeed, at least in north atlantic and it was the same on the 00z run, given the total lack of confidence in the end of course, but isn't this suggesting not much forcing is happening. Beginning and End side by side

I don’t know about the rest of you, but I’m excited to have over a week of dry weather. Imagine you might see some dust on the road if you can remember what that looks like, judge the depth of a pothole, walk a muddy path, rake up some leaves….etc. Next Thursdays 850 temp chart still looks good, should be relatively dry to end of the month and a reasonably robust 1036 high to the west. It will possibly move slowly south east, that will take time we’ll into end first week December.

Re Teleconnections: "The issue is that these teleconnections are themselves a product of a forecast. So we build a forecast built on another forecast and consequently we get accuracy mayhem." The other issue is one could take todays weather and say this is as a result of these specific phases in the global weather. I never particularly see that exampled, I can only see posts forecasting far out and often ludicrously assertive certainties from some, on the distant future, i.e. lots of talk of high AAM into later December and Phase 8 to 1 MJO etc then and ignoring the current conditions which are about to go cold. It's not that I don't totally agree on these forcings and % pattern probabilities, , it's the use of them from amateurs to try to dictate the NWP 15 day models with put downs, they also tend to attack the Mot Office, ECM and GFS etc as not having a clue.