Sperrin

Would @bluearmy or anyone else have time to give a quick explanation of a wedge? Am I right in thinking its an increase in application of a high pressure cell that causes the jet to come in on a NW/SE axis causing a PM flow as opposed to full on Greenland block?

Interestingly the radar is already showing a bit of sleetyness as the front moves into the north. Light rain starting here in Omagh. I wonder if higher ground may actually see snow as the front pushes through and the cold further undercuts?

Have to say this is already shaping up to be an excellent thread. None of the bipolar hyperbole of the hunt for cold thread only sensible, balanced and succinct analysis. Great idea that negates the need through dozens of pages of mixed messages.

Light dusting this morning here in Omagh...

Met office yellow warning for ice and possible wintry showers issued for 10pm to tomorrow. Already some wintriness showing up on the radar in the NW. Not great at all in the bigger scheme of things and models having big wobble at the min, too!

@Catacol what a fantastic post on a topic that I wasn't 100% on. Thank you.

We're in a delicate place imo. We're not as cold as Britain but we're much more likely to get moisture off the Atlantic, hence greater snow risk. If the colder air can move slightly further west we could be in Jackpot land. All will be revealed as the week progresses. At least we're in the game!! Neiller, you remind me of this character from Fr Ted. Always looking for the pessimistic angle. Think positive and positive things will happen

Someone put this up on mod thread and it seems like a good site. https://www.metcheck.com/WEATHER/16days.asp?zipcode=BT79&locationID=58465&lat=54.6&lon=-7.2 Does nice graphics for the 16 days ahead. You can clearly see the fall in temps from mid next week onwards. Hopefully, this cold spell solidifies over the weekend.

Good man Steve. Cheers for the update. Exciting times!

I know this is a tweet but interesting to hear a senior met man giving hints at what the UKMO model is showing past +144.

Better clustering in the colder runs and the outliers are definitely the milder runs. Perhaps the median would give a better indication when this is the case?

18z GFS ensembles looking really good now. This is for NW Ireland. Notice the increase in clustering towards the last third of the run between -5 and -10 850s. Some very mild outliers skewing the mean in my opinion.

I do love a good NWesterly, however, it caved my shed in last January so still a bit bitter

Yeah, GEFS still looking solid with the last third of the run below -5 850s on the mean. The Op takes a headstagger towards the end but recovers back cold after 2 days!

GEFS continue to upgrade with the mean now below the -5 line from around the 20th. Hopefully this trend keeps coming closer to T+0

Might you lads have written off the winter too early? Big change today and those EC week 3 and 4 charts looks unreal. Plus we can see the GFS starting to sniff the same coffee. GEFS mean starting to fall nicely. Hovering around -5 850s @ 19th/20th January. I have a feeling the models will take off soon. Before that we might get a PM blast from the NW, too. My shed roof caved in last winter from the snow during January! I wonder what happened on 19th January last winter???

Daniel Kahneman, the world leader in cognitive biases, applied his work to economics and won a Nobel prize. A couple of hours on netweather forums and he would have had enough data to cement his hypothesis and retire 20 years early!

Looking better at 192. Could 216 be a stonker??

GFS ensembles starting to look good. This is for Omagh...

Anyone have thoughts on Dr Cohen's latest post? Seems ok to my (amateur) eyes. I asked him his thoughts on the possibility of HLB building in the vortices gap around Greenland and he said "I think so."

Don't know if you use Twitter but Judah Cohen just replied (favourably) to a question I just posted

@mountain shadow it has been a frustratingly slow process but I still think we'll hit the jackpot sometime soon. You'll be needing aircraft to drop emergency food supplies into Carryduff by the end of Jan following a brutal beasterly while we twiddle our thumbs out West! This time last year we'd already seen a load of snow in the NW, I've missed the PM flows this winter!!

UK Outlook for Thursday 17 Jan 2019 to Thursday 31 Jan 2019: Most of the UK is likely to start this period with predominantly wet and windy weather, and a chance of heavy rain and gales at times, especially in the north. Hill snow is also possible, as well as snow to lower levels at times in the north. In the south though, the weather is likely to be on the mild side. Towards the end of January, however, there is an increased likelihood of a change to much colder weather generally, bringing an enhanced risk of frost, fog and snow. This cold spell is by no means certain though, and in any case, some milder, wet and windy interludes are likely during this period. @mountain shadow is it really a massive downgrade? Seems to me like they're just adjusting to a later propagation date for the effects of the SSW.

This looks like good news to my eyes...room for a high pressure lobe from Atlantic up to Greenland?

Check out @judah47’s Tweet: Total novice here but this looks good from Dr Cohen. Am I right in thinking this backs up what a lot of you guys have been saying about GFS being a dud strat model?