Model output discussion - Post SSW - Will it turn cold?

[Duane S.]

I really admire and enjoy the likes of GP, Tamara, SH and Catacol etc on here giving their teleconnection interpretations. But what a mind bending task they have trying to figure out the relationships (and feedbacks) between the Enso state, the SSW, equatorial convection and the GWO. Never mind the then impact on our weather. Good luck!

Edited February 14, 2018 by s4lancia

[Duane S.]

2 minutes ago, Badgers01 said:

Interesting to me at least that even contributors whom we probs all hold in high esteem are flagging up the fact the clock is ticking if we are going to get anything interesting from this !!

Yes but there are often good reasons WHY these events happen at this stage of the winter and NOT on January 1st.

[Badgers01]

Just now, s4lancia said:

Yes but there are often good reasons WHY these events happen at this stage of the winter and NOT on January 1st.

I am curious as to whether this warming is the final warming , will the pv reform or is it simply too late now ... of course when they do happen earlier we often have had memorable cold spells . It is a reminder also that when Catacol says its a shame it’s not the 1st Jan nothing is to be taken for granted....!

[Frosty.]

I've placed an order for P6 GEFS 6z..extremely wintry!

[winterof79]

1 hour ago, bluearmy said:

There is an eps cluster that’s isn’t too far from that NAVGEM evolution - been there for the past three suites on the spreads mi Lord

Edited blue 

[bluearmy]

you know the old saying .....

the posting of individual gefs members is inversely proportional to the likelihood of widespread snowfall and deep cold

[Youcan'tbecirrus]

24 minutes ago, Catacol said:

Ignore my comment on MJO phase 7 because I hadnt filtered it properly... but the gist of the Nina February composite lagged by 1 month into March suggests a continental air flow which would be cold. However the composite is a lot less useful than it should be because of my duff filtering.... :-(

Thanks Catacol I've a lot to learn,not least on the terminology,but when people like yourself get interested then I sit up and take notice.  

[Deep Snow please]

I mean, I don't think this cold spell will actually materialise it's constantly being pushed further and further back, just sitting in fantasy island. By the time it actually arrives we'll be looking at a few wet and windy storms.

[Frosty.]

1 minute ago, bluearmy said:

you know the old saying .....

the posting of individual gefs members is inversely proportional to the likelihood of widespread snowfall and deep cold

I'm getting more confident about posting great charts, especially as Exeter is firmly on-board!

[Youcan'tbecirrus]

36 minutes ago, tight isobar said:

A locked in blocking scenario..

And deep cold into eurasia-nw europe!!!

Edit; an'out of date below chart...but echos very much the likely prognosis.

Thanks tight isobar. Very limited understanding of all this unfortunately but could we basically expect ground temps of something around 3 degrees colder than average for this time of year if the chart verifies ?

 

Edited February 14, 2018 by Youcan'tbecirrus

[ICE COLD]

5 minutes ago, Deep Snow please said:

I mean, I don't think this cold spell will actually materialise it's constantly being pushed further and further back, just sitting in fantasy island. By the time it actually arrives we'll be looking at a few wet and windy storms.

It won't matter to you . Remember you was ramming it home yesterday that up there you have had the best winter for ages ?. Anyway it's all still on the table according to these . 

oh at the METO . Have you got hump because the MO update says potential snow for the SE , East and central England and not up North ? This forum so biased to up north ?

[Duane S.]

25 minutes ago, Badgers01 said:

I am curious as to whether this warming is the final warming , will the pv reform or is it simply too late now ... of course when they do happen earlier we often have had memorable cold spells . It is a reminder also that when Catacol says its a shame it’s not the 1st Jan nothing is to be taken for granted....!

I suspect, even though it is going to be a very pronounced warming/reversal, it will still have occured too early for the vortex not to reform once it wanes. Happy to be wrong on that though!

[Duane S.]

Another fantastic set of GEFS ens for my area. Just keeps getting better and better...

Could it really happen??

[Deep Snow please]

3 minutes ago, ICE COLD said:

It won't matter to you . Remember you was ramming it home yesterday that up there you have had the best winter for ages ?. Anyway it's all still on the table according to these . 

oh at the METO . Have you got hump because the MO update says potential snow for the SE , East and central England and not up North ? This forum so biased to up north ?

Whilst we have had the best winter for a good few years, the potential cold spell that a SSW has the ability to produce would simply dwarf the events of this winter, which have mainly been short-lived and small snow depths (under 4 inches) - I was banking on the SSW providing a proper cold event but it keeps hovering in Fantasy Island - if it remains there it'll never happen, even if it is brought forward it'll end up being cold rain - about the worst weather you can get. 

I've given up caring what the MetO says - there wrong more often than not; told us it would rain this morning - ended up with a few hours snow even if it didn't settle; pushing us to around 20-25 days of falling snow (I haven't been counting).

[Catacol]

OK - last post on composites - there are only 3 years in the dataset where the MJO state is anything close to the high orbit 6/7/8 that will characterise this month allied to weak or moderate Nina conditions. Doesnt paint a dramatically different picture compared to the bare Nina composites - signal still pretty good. 

[Snowman.]

3 minutes ago, Deep Snow please said:

Whilst we have had the best winter for a good few years, the potential cold spell that a SSW has the ability to produce would simply dwarf the events of this winter, which have mainly been short-lived and small snow depths (under 4 inches) - I was banking on the SSW providing a proper cold event but it keeps hovering in Fantasy Island - if it remains there it'll never happen, even if it is brought forward it'll end up being cold rain - about the worst weather you can get. 

I've given up caring what the MetO says - there wrong more often than not; told us it would rain this morning - ended up with a few hours snow even if it didn't settle; pushing us to around 20-25 days of falling snow (I haven't been counting).

The SSW has already happened. It's affects will be felt just the timing is what is being discussed.

The vortex's days are numbered, this SSW is a record breaker so rather it being a matter of IF it's a matter of WHEN.

[Catacol]

35 minutes ago, Badgers01 said:

I am curious as to whether this warming is the final warming , will the pv reform or is it simply too late now ... of course when they do happen earlier we often have had memorable cold spells . It is a reminder also that when Catacol says its a shame it’s not the 1st Jan nothing is to be taken for granted....!

Unknown as to FW or not - but timing is fairly obvious in terms of longevity of cold potential. However some sub plots to that to point out - oceans are at their coldest in March..... continent is still cooling in February.... and spring weather in the UK in March only arrives if the flow is from the S or SW. Anything with an easterly vector in it will be cold for a few weeks yet. No panic. 

[Badgers01]

1 minute ago, Catacol said:

Unknown as to FW or not - but timing is fairly obvious in terms of longevity of cold potential. However some sub plots to that to point out - oceans are at their coldest in March..... continent is still cooling in February.... and spring weather in the UK in March only arrives if the flow is from the S or SW. Anything with an easterly vector in it will be cold for a few weeks yet. No panic. 

Thank you for that - I am pretty sure a cold spring is now highly likely whether we get the winter cold or not...

[Catacol]

1 minute ago, Badgers01 said:

Thank you for that - I am pretty sure a cold spring is now highly likely whether we get the winter cold or not...

Yep - or at least a slow start to Spring. At this stage it would be difficult to be sure what April might bring - but the chances of a balmy March look long odds to me.

[stodge]

Interesting to have a look at the temperatures which seems of particular interest and concern to some. Today a range of 3-7c would represent mid-afternoon values for many so chilly but not especially so.

The GFS 06Z keeps most of the country close to or below average until the end of the weekend with Monday getting to double figures in some areas.

No especially low minima either at this time.

By Thursday only Sidney's environment remains on the milder side while much of the rest of the country has slipped back below average:

The maxima for Friday 23rd about where we are today followed by a sharp overnight frost.

So the sequence, as reflected in the 500 and 850 numbers, is a cool/cold spell through to Friday and then a warming over the weekend peaking on Monday with some places getting to double figures followed by a gradual cooling through next week with the really cold area not present until the following weekend.

For those looking at March temperatures, the epic Monday March 11th 2013 is the yardstick - many places had an ice day with -12 uppers widely across the country. In London, we crawled up to freezing point with significant wind-chill. On that basis, if you're looking for an ice day at the end of February into the first week of March, you're going to need -10 to -12 uppers in my view so something like this perhaps:

That's an ice day chart and no whingeing and whining about "marginal" from that. You don't get days of that even in midwinter unless you get something like an anticyclonic inversion in the south. Further north is quite different and for Scotland in perhaps the charts offer a prolonged spell of colder weather going into the new month.

[Deep Snow please]

18 minutes ago, SN0WM4N said:

The SSW has already happened. It's affects will be felt just the timing is what is being discussed.

The vortex's days are numbered, this SSW is a record breaker so rather it being a matter of IF it's a matter of WHEN.

However the later it arrives the less interesting any event it produces from it's effects will be, the air it drags in potentially being slightly warmer and even if it drags in cold weather it could be melted instantaneously. 

[karlos1983]

1 minute ago, Deep Snow please said:

However the later it arrives the less interesting any event it produces from it's effects will be, the air it drags in potentially being slightly warmer and even if it drags in cold weather it could be melted instantaneously. 

If the cold pool to our east is this cold, it's irrelevant if it's February 1st or March 20th!

 

[bluearmy]

2 minutes ago, Deep Snow please said:

However the later it arrives the less interesting any event it produces from it's effects will be, the air it drags in potentially being slightly warmer and even if it drags in cold weather it could be melted instantaneously. 

Maybe you could change your username to ‘slush likely’ ??

Exeter clearly are of the belief that snow is possible back end Feb/early March 

forty mins before we know the direction of travel on the ICON and shortly after to see if ukmo can slow the Altantic and amplify the first ridge 

 

[The Beast From The East]

4 minutes ago, karlos1983 said:

If the cold pool to our east is this cold, it's irrelevant if it's February 1st or March 20th!

 

Just to add to that, Shirley  ☺ if the sea temp is a little warmer come March that could beef up the snow showers as they come in from the bitter East? 

Edited February 14, 2018 by TheBeastFromTheEAST

[tight isobar]

51 minutes ago, Youcan'tbecirrus said:

Thanks tight isobar. Very limited understanding of all this unfortunately but could we basically expect ground temps of something around 3 degrees colder than average for this time of year if the chart verifies ?

 

Hard to pin-point max/mins atm...

On any given geographical quaters.

By the emphasis 'firmly' on cold....

The operational outputs gfs/ecm/ukmo/gem/icon/jma/navgem/gem... should now begin to act more solidly on evolutions...lag -ssw effects imo well within-modeling-data range now.

Via raw outs- ops...

Edited February 14, 2018 by tight isobar