Model Output Discussion - Spring Has Sprung

[joggs]

 Mike Poole could it be to do with the massive undersea volcanic eruption bear Tonga a couple of years ago,going on.?

Read one or two things on this.

Might have thrown the models a curve ball?.

Edited February 22 by joggs

[Mike Poole]

 joggs Yes, it is certainly a possibility that has done something, it did spew a whole load of water vapour into the strat.  However, it is not clear cut, because that would as I understand it make the strat colder and the vortex stronger, and we’ve had a weak vortex all winter, just one that would not deliver for UK coldies.

[raz.org.rain]

 joggs I assume it could be locally affected by higher SSTs too. I remember seeing some early predictions of heavy rainfall and stormy weather due to the SST heatwave.

[damianslaw]

Both GFS and now ECM hint at pressure rise by first weekend of March, with a signal for heights to ridge east.. something absent all winter, but probably more likely to verify as it will be spring!

In the meantime a changeable outlook, northern half of UK may well see a good 3 day spell Sat- Mon as low pressure anchors further south, odd wintry shower, frost, fog and quite cold. Further south rather wet then dry by Monday. Tomorrow looks a cold blustery day, plenty of rain/ hail showers, sleet and snow on high ground, quite low levels in the north.

February set to end unsettled with another deep trough feature moving into the UK.

 

[Rain All Night]

13 hours ago, Rain All Night said:

0z deterministic runs, Thu 22nd to Thu 29th (day 7)

Nothing new here really, though I note from other posts that there's some interest in whether the low on Sunday could miss us to the south entirely. Regardless, pressure contours looking slack over much of Britain for a while on Saturday and Sunday.

0z ensemble means, Thu 22nd to Fri 8th (day 15)

It feels like we're learning ever so slowly at the moment. We've known about the next trough attack around 29th Feb/1st Mar for days, but still have little signal beyond that. My one concern, based on the raised heights to the east that have been showing up on some of the ensemble means into the first week of March, is that we could end up with troughs getting stuck over, or just to the west of, the UK with no way to exit.

I hope the upcoming stratospheric event can do something to get rid of the tedious TPV to the northwest.

12z/18z deterministic runs, Fri 23rd to Thu 29th (day 7)

12z/18z ensemble means, Fri 23rd to Fri 8th (day 15)

Seeing more of that signal for heights to build to the east or even northeast after that next trough comes in at the turn of the month, kind of interesting.

 

[feb1991blizzard]

Record breaking reversal anyone?

[feb1991blizzard]

Repeat.

[feb1991blizzard]

Stratospheric white hole.

[KTtom]

Well if the day 10 snow charts that have been posted had verified we would all be fed up of the stuff by now! Hopefully, models are a bit more accurate with predicting high pressure...GFS Op hinting we may be able to dry off soon...

[AO-]

Good Morning,

Could be interesting for England if EC verifies. EC as a whole quite interesting with a meridional pattern setting up at the end. Euro block with a slight possibility of expansion towards Svalbard. Far FI of course, but a huge difference between EC and GFS at day 10. 

Edited February 23 by AO-

[RJBingham]

ECM and GFS 

[winterof79]

Cold and  blocked March a distinct possibility

Current Jet profile

Predicted

Signs of a quick Scandi build

[minus10]

Gfs keener to bring in the block from the ene...6z..day 10

...although chilly in.any wind with perhaps frosty nights it should feel nice in the strengthening sun...and best of all..should be dry ..

...ecm still not so keen presently..

[Rain All Night]

10 hours ago, Rain All Night said:

12z/18z deterministic runs, Fri 23rd to Thu 29th (day 7)

12z/18z ensemble means, Fri 23rd to Fri 8th (day 15)

Seeing more of that signal for heights to build to the east or even northeast after that next trough comes in at the turn of the month, kind of interesting.

0z deterministic runs, Fri 23rd to Fri 1st (day 7)

0z ensemble means, Fri 23rd to Sat 9th (day 15)

Still a slow learning process. From 3rd March (day 9), the ensemble means tell us that a lot of member runs feature raised heights to our east, but the means remain too blurry to indicate what pattern might be setting up just yet, and by 7th March (day 13), the signal fades back to noise.

None of the ECM ensemble cluster representative members at day 10 convince me that a strong blocking pattern is emerging, but perhaps there could be some opportunities for drier weather ahead:

Edited February 23 by Rain All Night

[AO-]

 minus10

EC00 and GFS06 not so different at day ten. Shape of the through is better on GFS than on EC, but those are details at that time frame. If it is to be a trend, then later in March an interesting pattern can come to existence. Maybe the Polar high is coming into play this time. Two months late, but I like Polar air flow any time of year. 

[Met4Cast]

The lack of posts in here in recent days tells the story I think. No sign of anything remotely cold or snowy in the forecast with modelling overwhelmingly favouring a return to milder conditions right out into the extended. 

No real urgency in the downwelling of -ve anomalies from the strat.

Edited February 23 by Met4Cast

[MJB]

JFF So don't jump down my throat 

Control has the right idea 

[damianslaw]

Looking further ahead into March, as many appear to be doing so, it is a very unclear picture. GFS notably is playing around with heights building over the top of a sinking trough and expanding and advecting east to become a significant block, but at the same time the PV lurks strong to the NW, and I doubt in such a scenario heights will be able to build so easily. ECM played around with such an evolution yesterday but today it shows the atlantic trough being the greater influence with any ridge development weak, preety much more of the same.

In the meantime it finally feels like February, only 3 plus weeks late!

[Dennis]

Good friday all

EC ideas 

 

[Dennis]

gfs 1 march

[Dennis]

BOMM MJO

[Dennis]

deeply east in the strato chamber, will the downwelling happen?

 

 

Edited February 23 by Dennis

[Dennis]

icon12z 1 march

Edited February 23 by Dennis

[AO-]

 Dennis

I wouldn't be too excited about a blocking scenario as it is too far east. In fact it is a block, but in the wrong place with the wrong history. Even with a retrogression scenario of the Russian/European hp it will not deliver. If we want anything close to substantial cold, we need a pressure rise West of Norway followed by tilting to the East. Of course in March a northerly can deliver plenty of snow showers, but we (I) need more than that. The tpv is just too strong and that makes it an odd winter which was forecasted to have the highest possibility of cold weather/a blocked pattern in February. Well, the opposite is true with the warmest February on record (also in Holland). Plenty of lights are/were green but the cold in Western Europe and Britain were hard to find. The winter of missed opportunities. 

Edited February 23 by AO-

[nick sussex]

The GFS and UKMO on the same page at day 7 . 

The low over the UK fills and pressure building to the ne and east . This looks like a response to the falling zonal winds . The GFS then keeps high pressure in charge .

Shame there’s no cold to latch onto at this point .

The GEM wants to keep a more windy and unsettled spell with low pressure in charge . Although it could eventually turn colder as the jet sinks further south.