Model output discussion - 21st Jan Onwards

[mulzy]

GFS 6z - horrific.

The low heights remain to out north west pretty much through the run - even when they do wane a bit, they soon return. 

Any movement of the negative height anomaly from Greenland to Scandinavia MUST be accompanied by the the absence of a PV segment over NE Canada / Greenland.  If not, then the negative height anomalies will eventually draw back to the Greenland vicinity.

Edited January 22, 2016 by mulzy

[ItNeverSnowsInWindsor]

Unsurprisingly the positive NAO setup remains until FI in the GFS 6Z but there are signs of the PV shifting towards Scandi. When this happens we need to see some changes in the NE America / Greenland to allow more optimal setup in February for us.

Not sure whether the teleconnections support this but at least over the Strat the PV is predicted to shift towards Scandi.

Edited January 22, 2016 by prolongedSnowLover

[nick sussex]

Theres one thing getting the main chunk of the PV towards Scandi, however any PV lobes left behind can mean that it will still be difficult to advect any deeper cold into the UK.

The ECM T240hrs from this morning, note the PV lobe circled green over the ne of Canada, last nights ECM had this lobe further nw.

This lobe stuck there will not allow any ridging to get north. We often see this problem with left over PV lobes and especially at longer ranges where initially theres either a complete clearance of these or they're much more favourably placed before the models backtrack and bring the lobe further east.

You really need to see this lobe centred over Hudson Bay which gives some breathing space for a mid Atlantic ridge to get further north, this then can help pull a colder nw/n flow into the UK.

 

 

Edited January 22, 2016 by nick sussex

[MP-R]

Not much to say other than the models continue to make for very arduous reading. Cherry picking some charts based on anything other than cloud and rain:

 

Although very westerly, largely dry away from the northwest and perhaps less windy in the south.

Briefest of northerly air streams on the 03rd followed by a briefest of ridges with cold air in place so maybe even a frost (shock horror).

 

I suppose one positive being shown is the increase in Pm air coming into play later in the run but a lot of the coldest air is scuppered by irritating lows forming rapidly off the eastern seaboard. Patience is going to be necessary while waiting to see anything that resembles this time of year... sadly, in my case, there's no patience left!

[Weather26]

Back to naming storms then if the models are anything to go by.

[nick sussex]

The outlook putting aside any possible SSW  breaks down into two possibilities.

With the main PV over Scandi you're unlikely to get stuck in a mild pattern because the jet will dive se and move the Azores high further west, however if the PV lobe sets up too far east then you'll have a mobile, cooler/milder alternating pattern, snow mainly for the far north and higher ground.

If the PV lobe is further towards Hudson Bay, the Azores high will displace further nw this will help pull the Scandi troughing further west and you'll likely have a better chance to tap into some Arctic air rather than just PM.

Regardless of the PV lobes as long as the main chunk of the PV is over Scandi then you can't have a repeat of the December horror show in terms of the relentless very mild conditions.

At this point and with really just one month of winter left I'm not sure chasing around some PM incursions is going to be much fun so we need to see any PV lobes set up favourably. If a SSW does occur then the above still holds because you either need any split or displacement of the PV to set up favourably.

However if you get those then of course some proper wintry weather would be likely.

[Redwood]

Can we shift our Isle over to the East coast of America?

 

[Yorlum11]

57 minutes ago, Minus 10 said:

It's ok found one

Link?

[West is Best]

2 hours ago, Frosty. said:

I saw it on the news there was snow with children sledging or was that stock footage from the 1970's?

Being picky but until 78/9 the 70's weren't all that snowy were they iirc? The 80's had some epic winter spells.

And to mushymanrob: Hi back, Rob!

One of the problems we have at the moment is the Bartlett to our south. Apart from a brief interlude this past week it has been sat there, earning its eponym of 'slug.' The damned thing appears unmovable. I mean, some of these charts are ridiculous:

 

 

 

[geoffw]

did I read it and understand it properly that last night tamara predicted NWwinds for early feb veering n then ne as feb progresses?

[Summer Sun]

10 minutes ago, Yorlum11 said:

Link?

 

Hi please see the north America thread here

 

[Frosty.]

The Gfs 6z op run is certainly not without interest for coldies, indeed it has more wintry charts than the 00z with severe frosts and some snow too!

[Hammer]

3 minutes ago, West is Best said:

Only if we can swap Donald Trump

East is best? Or the fact we'd have to move West from our location proves you right. :-)

[Spurry]

13 minutes ago, West is Best said:

Being picky but until 78/9 the 70's weren't all that snowy were they iirc? The 80's had some epic winter spells.

And to mushymanrob: Hi back, Rob!

One of the problems we have at the moment is the Bartlett to our south. Apart from a brief interlude this past week it has been sat there, earning its eponym of 'slug.' The damned thing appears unmovable. I mean, some of these charts are ridiculous:

 

 

 

It's miserable reading I agree , but I'd be happy if we were in Iberia,that HP is bringing settled warm conditions down there.

[geoffw]

did I read it and understand it properly that last night tamara predicted NWwinds for early feb veering n then ne as feb progresses?

[MP-R]

2 minutes ago, geoffw said:

did I read it and understand it properly that last night tamara predicted NWwinds for early feb veering n then ne as feb progresses?

That would appear to be the most likely evolution, other than being stuck in this rut longer than anticipated. All associated with the PV slowly moving east and eventually (hopefully) weakening and moving to our east. A long drawn out process though I think.

[Carl46Wrexham]

9 minutes ago, Spurry said:

It's miserable reading I agree , but I'd be happy if we were in Iberia,that HP is bringing settled warm conditions down there.

 

23 minutes ago, West is Best said:

Being picky but until 78/9 the 70's weren't all that snowy were they iirc? The 80's had some epic winter spells.

And to mushymanrob: Hi back, Rob!

One of the problems we have at the moment is the Bartlett to our south. Apart from a brief interlude this past week it has been sat there, earning its eponym of 'slug.' The damned thing appears unmovable. I mean, some of these charts are ridiculous:

 

 

 

Huge high pressure belt stretching from the Azores into Europe - Ladies and Germs...give a big hand for the Bartlett High. Lets see how long this slug hangs around.

[blizzard81]

Just now, geoffw said:

did I read it and understand it properly that last night tamara predicted NWwinds for early feb veering n then ne as feb progresses?

Yes, she did. The problem is that originally this was meant to happen within the next few days. It then got pushed back to the very end of Jan, then the first week of Feb. I hasten to add that these were GP's dates, not Tamara's. At the moment, even the first week of Feb looks increasingly over optimistic! I have noticed in the past that when cold spells are pushed back by weeks at a time, it turns into a rainbow chasing excercise and we either end up not finding our pot of gold at all or at best some cold scraps that the yanks would just laugh at. A little like the cold snap we have just experienced.

 

[geoffw]

5 minutes ago, MP-R said:

That would appear to be the most likely evolution, other than being stuck in this rut longer than anticipated. All associated with the PV slowly moving east and eventually (hopefully) weakening and moving to our east. A long drawn out process though I think.

10 days is not long away at all 

[MP-R]

10 minutes ago, geoffw said:

10 days is not long away at all 

Well assuming that's when it happens then no, you're right. Still uncertainty as to when it will happen though.

[mb018538]

http://m.accuweather.com/en/weather-news/lack-of-wind-storms-continues-united-kingdom-winter/54872370

brave of accuweather to say there will be a complete lack of windstorms through the remainder of winter, especially looking at the last day or two output! 

[wishingforsnow]

I think some of the posts here belong in the 'moans' thread.

Also I know I was guilty of doing this a few days ago but writing off summer now is a bit of an over reaction, no? All we're facing according to the models which are still 10 days out so who knows if it will be all 'wet and mild'  is hopefully a period until early February of milder conditions. 

[bluearmy]

not wanting to stick my oar into other peoples stuff but I suspect events in the strat have taken over re telconnection timings.  the uptick in strat zonal flow to huge levels at the moment prior to the sudden drop off expected next week has impacted in the trop by firing up the jet big time. could this have been anticipated ?  well I expect GLOSEA did a decent job as it has done thus far this season. however, GLOSEA didn't see an SSW early feb which looks to be increasing in likelihood.  outside of the metoffice, I doubt any models were showing this big increase in upper zonal flow (and more pertinently the coupling back between strat and trop)  more than two weeks away.

[Timmytour]

Just a quick reference to the winters of the seventies some alluded to earlier.....  The winter of 1969/70 had mean CETs of  3.3C (DEC)  3.7C (JAN)  and 2.9C (FEB)...... For the next 6 years there was not a winter month below  3.9C.....  that's 18 months in total which is the longest such period in recorded history....the next nearest is the run of 13 such months which ended with the Feb of 2006.

With reference to the Euro slug.......   do the models take into account things that may be happening underneath....on the equator and into the Southern hemisphere?   Or is this all too stable to be of any concern?   What would make those heights disappear as quickly as any heights over Greenland seem to!

[blizzard81]

30 minutes ago, bluearmy said:

not wanting to stick my oar into other peoples stuff but I suspect events in the strat have taken over re telconnection timings.  the uptick in strat zonal flow to huge levels at the moment prior to the sudden drop off expected next week has impacted in the trop by firing up the jet big time. could this have been anticipated ?  well I expect GLOSEA did a decent job as it has done thus far this season. however, GLOSEA didn't see an SSW early feb which looks to be increasing in likelihood.  outside of the metoffice, I doubt any models were showing this big increase in upper zonal flow (and more pertinently the coupling back between strat and trop)  more than two weeks away.

That's all well and good as long as it only causes a delay (preferably slight delay) as opposed to totally derailing the much touted cold spell to come.