Cold hunt - models and chat

[Geordiesnow]

ECM shows what could happen if the Azores high ridges that further North and the angle of the WAA is more northwards rather than NE'wards like both the GFS and UKMO are showing. In fairness though, all models are showing a similar pattern but as you expect, the differences become more apparant later on in the forecast period. One thing for sure, it does look like for next week, high pressure will try and nose in from the Azores but just how much influence will it have over the UK. I think we do have to bear in mind the ECM tends to show more blocking situations in general than other models but its evolution looks plausible too me. 

Do hope the ECM is right as that would give the brightest/sunniest conditions, at least initially after the Northerly blast on Sunday but the set up for later on in the week where all the coldest uppers are there could actually be an anticyclonic gloom set up, it is definately NOT a sunshine and snow shower set up as the wind flow is a SE'ly and thicknesses are way too high so the air is very stable. May see some snow grains though if your lucky. 

[Ice Day]

The storm is modelled at 955mb on Friday evening on the pub run.  Could be quite a story this one?

 

[Methuselah]

Rather than watch the 18Z ooze out, I shall once again grade the overnight runs using my early morning grading-system:

0-2 pages = crap; 3-7 pages = fair to middling; 8-10 pages = good to very good to possible stonker; 11+ pages = Shaky's finger got stuck on !!

Night all!

[alexisj9]

What's with all these strong lows. Don't mind week two dartboard lows, but these ones are showing up in what would normally be reliable time frames.

[damianslaw]

1 hour ago, bluearmy said:

I think we head to where we were around third week jan come mid feb. Do we then get proper height rises to our north or just general higher heights to deflect the jet se 

I mentioned a while ago how the effects of this years SSW might draw parallel with those of 2006 and 2013, both produced easterlies nearing at least 6 weeks later, in the case of 2006 mid March after a northerly interlude, in 2013, more than 2 months later... mid Feb is 6 weeks after this years SSW, so a late Feb easterly might well be the long after effect.. indeed easterlies are far more likely from late Feb onwards, there is much plausibility to ECM output today on this basis.

[Singularity]

Another big takeaway for me from the 12z ECM is that it managed to let the vortex split take shape again thanks to the powerful ridge from the Pacific side (MJO-driven). None of GFS/GEFS's suddenly very positive AO tendency to be seen there.

Question now is whether this very logical pattern trend will actually continue - once again it depends strongly on whether the MJO actually does propagate east in line with the recent model trend. The signals this time around (SST pattern, westerly wind bursts, model ensemble spread) have now become the most focused on an eastward propagation outcome that I've seen so far this winter so there's reason to be hopeful as long as the stratosphere doesn't throw a curveball at us... oh no, now I've gone and done it .

[frosty ground]

More amplification from the GFS18z 

[Leon1]

31 minutes ago, Ed Stone said:

Rather than watch the 18Z ooze out, I shall once again grade the overnight runs using my early morning grading-system:

0-2 pages = crap; 3-7 pages = fair to middling; 8-10 pages = good to very good to possible stonker; 11+ pages = Shaky's finger got stuck on !!

Night all!

Lol! Sometimes I've come to this thread and there's been 11+ pages of bickering though! Feel bad for the mods.

Edited February 6, 2019 by Leon1

[MATTWOLVES 3]

19 minutes ago, damianslaw said:

I mentioned a while ago how the effects of this years SSW might draw parallel with those of 2006 and 2013, both produced easterlies nearing at least 6 weeks later, in the case of 2006 mid March after a northerly interlude, in 2013, more than 2 months later... mid Feb is 6 weeks after this years SSW, so a late Feb easterly might well be the long after effect.. indeed easterlies are far more likely from late Feb onwards, there is much plausibility to ECM output today on this basis.

Good Post, 2013 being quite an exceptional set up, I think between the beginning of March and early April we had very low temps, going down as the fourth coldest march since 1910. Mean temps were between 2 and 3 degrees below average from the period between Feb and April. Also noted was a strong continuous Easterly wind, March 31 being confirmed as the coldest Easter day on record with a low of - 12.5 in Braemar. Around the 21st of March one of the worst snowfalls in 30 years hit the NW North Wales and sw Scotland hard. Up to 4 ft of snow fell with drifts up to 10 ft. From the period 11th March to 1st April there was a continuous covering of snow throughout the country and all of this probably being based on a very late trop response to a SSW. Any kind of repeat this year and I think most on here will forget about the doom and gloom of early winter

[Man With Beard]

ECM ensembles - looks like high agreement from members on a continental influence D7-D10 tonight, though most members have flattened the block by D15. 

[nobble]

11 minutes ago, Mattwolves said:

Good Post, 2013 being quite an exceptional set up, I think between the beginning of March and early April we had very low temps, going down as the fourth coldest march since 1910. Mean temps were between 2 and 3 degrees below average from the period between Feb and April. Also noted was a strong continuous Easterly wind, March 31 being confirmed as the coldest Easter day on record with a low of - 12.5 in Braemar. Around the 21st of March one of the worst snowfalls in 30 years hit the NW North Wales and sw Scotland hard. Up to 4 ft of snow fell with drifts up to 10 ft. From the period 11th March to 1st April there was a continuous covering of snow throughout the country and all of this probably being based on a very late trop response to a SSW. Any kind of repeat this year and I think most on here will forget about the doom and gloom of early winter

Had patches of snow in my north facing front garden past mid April 

[Weathizard]

Look at that monster Russian/Siberian high

[bluearmy]

19 minutes ago, Man With Beard said:

ECM ensembles - looks like high agreement from members on a continental influence D7-D10 tonight, though most members have flattened the block by D15. 

Flattened or undercut (slid against) ??

and note the anomolys to our n/nw in the extended clusters .....the scandi ridge could be a temp feature ....... 

Edited February 6, 2019 by bluearmy

[edinburgh_1992]

I can't see the PV staying so strong for long, looking at the AO index there is a clear indication towards a drop around the 16th of February. Ecmwf has picked up on this signal, GFS and the others will probably follow. 

[Nick F]

I guess we are finishing the day on a more upbeat mood with regards to our fortunes around mid-month compared to the recent prospect of zonality as far out as the models went, 12z GEFS and EPS mean supports the idea of the 12z EC operational for height rises over Scandanavia & disrupting Atlantic trough by mid month, whether a surface high over Scandi can build far enough west to bring cold easterly remains to be seen, 18z GFS smelling the coffee, but more runs needed to see if this may be a more fruitful chase than just another close but no cigar chase. 12z EPS suggests potential for slider lows again in the means even if we don't get a full blown easterly.

Whatever the outcome in detail, certainly a move away from mobile Atlantic low pressure dominated pattern to one dominated by high pressure from mid-month, the NOAA CPC prognostic charts back this up

Edited February 6, 2019 by Nick F

[weathermadbarnsleylad]

Looking good 18z gfs follow your daddy the ecm lol nice big high out east.

[MP-R]

Was the January 2013 cold spell not caused by a SSW? Or was there more than one? After the mid-late December Atlantic horror show, the Atlantic didn't seem to come back to life for very long for the rest of that winter.

[ICE COLD]

Yer not a bad effort from the 18z . Scandi Russian High and now coming back west . It’s just lacking in uppers . 

[feb1991blizzard]

2 minutes ago, MP-R said:

Was the January 2013 cold spell not caused by a SSW? Or was there more than one? After the mid-late December Atlantic horror show, the Atlantic didn't seem to come back to life for very long for the rest of that winter.

SSW Jan 6th 2013 destroyed the vortex for the rest of winter, it wasn't cold right the way through, but no longer 1 cold spell had ended, the next one always seemed to be within the semi reliable time frame with decent ensemble support.

[ICE COLD]

And now it’s going for Greenland

[ICE COLD]

Oh yes gfs 

[ICE COLD]

Now that would be worth the wait

[mountain shadow]

2 minutes ago, ICE COLD said:

And now it’s going for Greenland

MJO phase 8 analogue for February incoming.

[TEITS]

How I wish this run would coninue into +400 plus!

[weathermadbarnsleylad]

That 384hr chart is immense for a Greenland high serious cold moving towards the uk F I off course lol