Winter 2017-18: Discussion

Remember I was saying big energy peak around 2-4 January? If we get into this unsettled W-NW flow that seems to be the current preference of the GFS model after Christmas, then that could be quite a strong storm. I've found that with this developing theory, if the circulation pattern is a known quantity then you can use these energy peaks to fine-tune the details. With the pattern incorrect that attempt is of course negated.

So I'm not counting this as a forecast so much as a research project indicator, that's basically how I approach this as a man of leisure (the leisure of not having to report for duty anywhere but here, that is).

The most compelling part of the next 7-10 days globally is the enormous cold outbreak expected in the central to eastern parts of North America. The 480 thickness contour shows up as far south as Minnesota and Wisconsin at some point around 27th, whether that verifies or not, it looks extremely cold almost coast to coast in North America next week. I am getting ready for 20-30 cms of snow here in the next 24-30h.

With that pattern in place, a ridge over Greenland and the western Atlantic is almost guaranteed which is why I think a cold but maritime NW flow seems likely in Ireland over the last week of the year. If a strong vortmax comes around the top of that ridge or breaks through it around 30-31 Dec then look out ... a very strong energy peak timed for 2 Jan.

I would not expect to see any highly accurate details for this on charts before about 25-26 Dec, these energy peaks may show up in a general sense in the resolution of the global models but since they tend to be transient events of about 7-10 days total this is why computer models, no matter how sophisticated, are not going to show these things 20-30 days in advance, but if they are generated from a predictable source then a theoretical forecast could (in theory) do that. So we'll see what happens.

Fairly foggy in West Clare this morning, making it seem much darker than usual!

The grass is lush and green,Rose buds starting to bloom,patchy sunlight and random fog banks drifting about,felt like an evening in early spring in the early afternoon,very close and sticky.

Amazing similarities with the Dublin and Casement conditions at 7 am.

Dub/Casement

Temp: 11.4/11.4
Dewpoint: 9.6/9.6
Pressure; 1032.1/1032.1
Wind: 240 8 m/s / 220 8 m/s
Cloud cover: 7 okta/7 okta
Visibility: 25 km/20 km
Mood: Dank/Dank

so a white xmas is out of the question

so can we get the next best thing..a foggy xmas?

fraxinus1 wrote: »

Mild and damp and foggy. Heavy depressing gloomy winter weather. Feels just as mild at 12pm as it does 12am. Looks like that the severe cold in the USA is going to start whipping up the Atlantic so it’s looking like weeks of mild windy muck. I think we had the snow for this winter well those few who got it had it. I was scolded the other day for suggesting that if the Atlantic dominates for January then we have had it snow wise for this winter... increasingly looking like it. There’s nothing worse than a damp mild Christmas Day and that’s what we will have on monday. Rotten.

:eek:
Can you lend your considerable expertise to Met Eireann, you seemingly have the ability to forsee what they cannot, as they state can't forecast accurately beyond 12 days.

Elmer Blooker wrote: »

You aren't very popular around here :eek: but I think you are being realistic and I would tend to agree with you.
The Atlantic will effortlessly blast away any potential Arctic blocking as a result of the extreme cold pouring off North America. I wouldn't say winter is over but surely us weather watchers in this forum know by now that when this rot sets in it can go on for weeks on end. Any cold spells will be transient.

I have already described why my posts are so like a million times up to now including my very long Winter forecast. I am not being optimistic, in fact usually I'm extremely pessimistic. I was not looking at this Winter being good at all 'til around October or November when I started seeing what the "drivers" could mean for us. The drivers have still not changed, it's just models being their usual selves. As for the extreme cold in North America, it's more towards the central US than the eastern seaboard and isn't expected to last for very long either.

As for this week, I am not minding it. Sure it's very boring but I prefer it over cold and dull. My least favourite kinds of weather are cold and dull as well as cold and wet where the rain is light to moderate or just drizzle.

There is an awful lot of uncertainty regarding Christmas, that I'm focusing on just tomorrow for now because there are so many likely scenarios. For example, just look at the GEFS for the AO, there's a perfect division between the ensembles on predicting a negative and positive AO for the rest of December into the New Year - one of the ensembles going for a negative AO is the OP run of the GFS which shows quite a block developing over the Arctic whilst this stormy weather is going on.



The GFS is still showing this small SW for the end of December and early January though again far from a SSW.



The SOI is reflecting El Nino right now which is strange because the Pacific is firmly in a La Nina setup. If the La Nina continues, we could be heading for a very blocked Spring - if you were to look at Springs that followed Weak La Nina to Weak La Nina Winters historically.

Zonal winds in the tropics are continuing to be weak.

In fact, the only catch I can see right now is the NAO which according to the GEFS is going to be positive for the next 2 weeks.

P.S. that chart from the ECM you posted is far far from the worst case scenario if you ask me.

George Sunsnow wrote: »

Aye suns shining here near Arklow
I’m actually in a t shirt outside working

As soon as you say that, it has turned sunny here at Grange too.

I know its the Star but there must be something brewing given they quote the UK Met Office.

https://www.dailystar.co.uk/news/latest-news/668612/uk-weather-bbc-forecast-christmas-storms-storm-dylan-eleanor-britain-met-office

BuilderPlumber wrote: »

hurricane

What? Are you confusing a strong gale with a hurricane?

Donegal Storm wrote: »

As I said I'm happy to see some interesting weather, I just don't get why 12C and uneventful is so depressing while 5C and uneventful, i.e most of the month so far, is so much better.

Well 5 c or below has led to snow in some places and some crisp, clear weather, most people here tend to prefer that to mild and cloudy days with mist.

BuilderPlumber wrote: »

Christmas Eve 1997, Darwin and Ophelia were a BIT MORE than a strong gale!!

Far off hurricanes though, you wouldn't be trying to dramatise your post by any chance?

Elmer Blooker wrote: »

I wouldn't say winter is over but surely us weather watchers in this forum know by now that when this rot sets in it can go on for weeks on end. Any cold spells will be transient.

Cold spells tend to be transient every winter here. Easterlies producing heavy snow for a week are rare here. The pattern we have had up to now is cold zonality alternating with milder periods. The Polar Vortex isn't very strong this year compared to last year, as long as there is a tendency for heights to go into the arctic, the jet will still trend south at times, which opens up the possibility of short cold spells from the north or north west. However if we are being imby about it; this is wanting heavy snow from streamers for the east of Ireland then that's unlikely to happen anytime soon without a SSW event

To be fair, the PV was very weak last year nacho libre.