Model output discussion 10/02/21

[Jeremy Shockey]

Jetstream for March 4th on GFS 12z

wow ....can you imagine if the jet actually did this in a couple of weeks time !

[Timmytour]

20 minutes ago, Tim Bland said:

Wow what a  beast!!

LATE JAN 2021  ME:   That looks like it would be absolutely fantastic! We'll be buried in snow!

MID FEB 2021  ME:    I suppose there's a chance we might get a dusting from that.......

[I remember Atlantic 252]

2 minutes ago, Timmytour said:

LATE JAN 2021  ME:   That looks like it would be absolutely fantastic! We'll be buried in snow!

MID FEB 2021  ME:    I suppose there's a chance we might get a dusting from that.......

Aye, certainly not that excited about an E'ly, been hopeless here the 2 we've had

[Daniel*]

Any other time with that GFS run this thread would be rocking that would offer snowiest weather of winter down here in spring. There are reasons to believe there’s an avenue here for a cold weather pattern MJO remains in amplified phase 7 that is yet to filter in model output really, GFS in FI will be first to catch on perhaps it is doing so, there looks to be a secondary downwelling of reduced zonality in trop meaning high lat blocking might be more likely in early March. And climatology support in spring where north and east winds are most frequent. And, as we progress into spring in NH there’s unusually expansive exceptionally cold air, so this demonstrates to me we do have a chance of significant cold spell if we’re lucky, even if it is later than what we would like.

Edited February 18, 2021 by Daniel*

[Frostbite1980]

36 minutes ago, Battleground Snow said:

Snowfest in deep FI on the OP, para is a bit meh though.

 

Where have i heard that before lol

[Frosty.]

For sure this is very impressive stuff from the Gfs 12z operational, even more severe than the recent very cold spell! ...for what it’s worth, I do think there is a window of opportunity during the first half of March for another wintery outbreak..who knows, maybe even BFTE 2.0 

 

[Anthony Burden]

GFS continued runs in fantasy island with winter return and possibly colder with more snow 

than previous U.K. spell.Beginning to raise eyebrows will March roar in,after we all thought spring 

was coming.very keen eye on GFS to see if it continues with this scenario.

[MATTWOLVES 3]

11 minutes ago, Daniel* said:

Any other time with that GFS run this thread would be rocking that would offer snowiest weather of winter down here in spring. There are reasons to believe there’s an avenue here for a cold weather pattern MJO remains in amplified phase 7 that is yet to filter in model output really, GFS in FI will be first to catch on perhaps it is doing so, there looks to be a secondary downwelling of reduced zonality in trop meaning high lat blocking might be more likely in early March. And climatology support in spring where north and east winds are most frequent. And, as we progress into spring in NH there’s unusually expansive exceptionally cold air, so this demonstrates to me we do have a chance of significant cold spell if we’re lucky, even if it is later than what we would like.

Rally the troops on twitter Daniel....let's reel this Bad boy in

[Chasbrown]

11 minutes ago, Anthony Burden said:

GFS continued runs in fantasy island with winter return and possibly colder with more snow 

than previous U.K. spell.Beginning to raise eyebrows will March roar in,after we all thought spring 

was coming.very keen eye on GFS to see if it continues with this scenario.

Would it be possible to have less snow?! 

[Interitus]

Talk of a March easterly and 'downwelling' - where is this downwelling from?

Sometimes have to face the fact that tropospheric disruptions may follow an SSW but might not actually be directly caused by one.

[ICE COLD]

With runs appearing like this I’m definitely being drawn back in . One last beast for everyone with widespread snow please

[ICE COLD]

The control going for height rises too

[chris55]

6th March booked for a Snow day ......forget the fact its a 384h GFS Operational run chart in isolation.... its deffo a snow day

Edited February 18, 2021 by chris55

[Tim Bland]

[Frostbite1980]

18 minutes ago, ICE COLD said:

The control going for height rises too

Too far ne though....couldnt make it up and that would just be our luck

[Stav]

54 minutes ago, I remember Atlantic 252 said:

Aye, certainly not that excited about an E'ly, been hopeless here the 2 we've had

But isn't it the only pattern that will keep deep cold in place now we are a bit later in winter?

[BLAST FROM THE PAST]

1 hour ago, Jeremy Shockey said:

Jetstream for March 4th on GFS 12z

wow ....can you imagine if the jet actually did this in a couple of weeks time !

Every chance.  Winter isn’t over imo. We are going through the 10 days of milder stuff but signs are there for blocking to return .  The sun has been blank for 2 weeks again, this current minimum won’t give up yet with cycle 25 struggling to get off the ground as it were.  I think a Scandi block in early March is a reasonable call.

Any cold blast if it happens has a real chance of having some bite too ....global temps dropped dramatically in December AND January...and in Feb we are currently running 0.1c below the 79-2000 baseline.  The vast cold in the NH continents...It’s impressive considering the ice melt and relative warmth in the Arctic.

 

BFTP

Edited February 18, 2021 by BLAST FROM THE PAST

[Purga]

Once we get through the dreadful next 10 days....

The Op run clearly leading the way in FI

[legritter]

bring it on .

[Mike Poole]

ECM 12z looking promising right at the end for a return of cold, with heights building into Scandi, it is what we’ve seen on GFS in FI, there is reasoning behind why it might happen in terms of belated effects from the SSW if weaker of course by this time:

[Battleground Snow]

4 minutes ago, Mike Poole said:

ECM 12z looking promising right at the end for a return of cold, with heights building into Scandi, it is what we’ve seen on GFS in FI, there is reasoning behind why it might happen in terms of belated effects from the SSW if weaker of course by this time:

That's a really nice chart Mike, you would think the high would drift North on the following days with low heights to the west, south and east

[Anthony Burden]

ECM looking to follow GFS at 9 to 10 days out,looking very interesting I have a feeling this site

will be getting very busy once again,don’t put the sledge away or your fur coat if your lucky

to have one.

[Beanz]

18 minutes ago, Anthony Burden said:

ECM looking to follow GFS at 9 to 10 days out,looking very interesting I have a feeling this site

will be getting very busy once again,don’t put the sledge away or your fur coat if your lucky

to have one.

I’ve put both away now, spring coats are out and in use.  
 

Good looking charts if it was December/January but it’s a little too late to really get me excited now, and it’s FI.  All a bit of a non-event really.  

[phil nw.]

12 minutes ago, Mike Poole said:

ECM 12z looking promising right at the end for a return of cold, with heights building into Scandi, it is what we’ve seen on GFS in FI, there is reasoning behind why it might happen in terms of belated effects from the SSW if weaker of course by this time:

Yes ecm follows a similar path to the gfs and shows the high.It ridges ne from the second ridging attempt around day 7.We can see that on the gefs ens pressure diagram as well,

The gfs op and ecm are both therefore backed up in these ens for a UK high developing but a little progressive for a Scandi.high. A look at the S.Norway pressure ens.indicate this although there is a wide spread of pressure members and many do show some rising pressure up there.

There are certainly signs of increasing ht anomalies building ne from day 10 so we will have to see if future runs add mileage to that trend.

A well supported dry spell well into March though looking at the above graph.

Week 2 is certainly looking more interesting with this change to high pressure which now seems more likely around the UK.It's whether we can get a full blown high over Scandinavia out of this a few days later which would help to develop some colder uppers underneath. 

[stodge]

Evening all

Last night's models emphasised how far we have travelled from the cold of last week - we are now four days into what looks an extended period of milder and generally benign weather probably taking us through the end of the month and into March.

To be fair, most winters are a protracted mild spell with occasional colder interludes. 

There were a few hints of a possible change in the early days of next month with Atlantic amplification allowing heights to rise sufficiently to the north east to create a block to the east.

Let's see if there is any evidence for it tonight.

The new pattern is first the T+144 and T+240 charts from GEM, ECM, GFS OP and GFS Parallel.

T+144 (Feb 24th):

T+240 (Feb 28th): 

Not without a bit of interest this evening. The T+144 charts are variations on the theme of LP to the North West and heights to the South East. From there, a new HP cell builds near the Azores and ridges north east and the question is whether it can phase with the existing heights over the Alps and build further north and east or not. GFS OP is the least successful and GEM keeps the core of heights to the south west but both Parallel and in particular ECM successfully build heights into Scandinavia against what looks a much weaker Atlantic by the end of the month.

Let's see if this promise translates into something more interesting as we go into March:

T+312 is March 3rd and T+384 is March 6th. Charts from GFS OP, Parallel, Control and CFS:

T+312:

T+384:

From an unpromising start, OP produces a wonderful FI for cold fans and yes, those are -12 uppers covering most of the British Isles. From a promising start, Parallel fails completely but it has a much stronger PV over Greenland and NE Canada. Control is a near miss while CFS delivers northern blocking yet without the dramatic uppers of GFS OP.

The models continue to sniff out a colder evolution early next month and events around T+216 are significant. Getting that extra push of heights across north west Europe and building those into Scandinavia looks the catalyst to the formation of a strong Arctic HP which, with heights near the Azores, sets up a very cold trough but a lot has to go right for that scenario to happen. High latitude blocking exists on other models as does mid-latitude blocking so it's all to play for later in the month and in the early days of March.

 

Edited February 18, 2021 by stodge