Model output discussion 10/02/21

[knocker]

We are looking at a dry, rather cool, weekend adter widespread morning frosts, with variable cloud. The exception being the far north west where there will some rain by Sunday as the high cell slips south

By Monday the Atlantic fronts are slowly making inroads in the west but it is over the next couple of days that some rapid changes occur with frontal waves undergoing rapid cyclogenesis near the left exit of a pumped up jet. Thus heavy rain and  very strong winds across the countryt by Weds

And this heralds the start of some unsettled weather

 

Edited March 6, 2021 by knocker

[IDO]

As expected we are seeing that after this westerly Atlantic rush, the repeating El Nino pattern of heights building in our region. The gfs op seems progressive, as its way when spotting a new theme:

That is more amplified than the mean, as you would expect, but heading in that direction of a more settled period post d8/9:

GEM at d8 also heading in that direction, ecm slower but looking in the ball park by d10. So issues of timing and how the pressure rise will manifest itself. Four drier days IMBY before the unsettled spell, but hopefully shortlived!

[Sky Full]

An unsettled and possibly stormy look to the weather next week, as referred to by Knocker above, but at 10 days out (+240hrs) there is a hint of a possible return to more settled weather again (emphasis on the word ‘possible’ at this distance):

                                            +144hr                                                +240hr

ECM        

GFS        

GEM       

Overall, temperatures should be near average under these conditions so growers will be pleased that no hard frosts are in the charts for the next two weeks.

[knocker]

The general theme in the ext period is for the main tpv lobe to consolidate near northern Russia which facilitates, to some extent, subtropical high amplification in the eastern Atlantic. There is no agreement on this so a watching brief at the moment regarding detail

Similar indications with the spv in the lower strat

Edited March 6, 2021 by knocker

[Frosty.]

The Gfs 0z operational becomes anticyclonic during the mid month period and the GEFS 0z mean also indicates a gradually improving picture across southern u k during that timeframe with a number of anticyclonic members emerging...so, yes, next week does become unsettled from Wednesday but the second half / last third of March could see a marked improvement?  

 

[Tim Bland]

After this coming weeks stormy spell it is still looking good for a settled spell mid month.   ECM has the high to our west but would probably drift north east with time. 

[minus10]

Yes after this 'stormy' spell a period of relative calm looks increasingly likely. However still not clear imo how warm or indeed cool it will be. Both gfs and ecm dont show it being overly warm imo although that can be mitigated by increasing strength of the sun now. Potential for frosts for gardeners/growers i would have thought . Also ecm out to 240 hr does not appear that settled.....and the blue cold air to the NE is still showing on both..

[mushymanrob]

16 hours ago, Tim Bland said:

Some consistency for a settled spell mid month starting to show now though...

Id love that to become reality, trouble is, all winter the GFS has produced some stunning cold charts in FI that only seldom verify. Until the noaa charts support these charts then im not getting any hopes up.

[Frosty.]

Looking at the ECM 0z ensemble mean longer term, there are clearly the green shoots of recovery from around mid month onwards following the very unsettled spell during the second half of next week...I’m actually quite positive about our prospects for the final third of March, no guarantees of course but it’s a recurring theme from the mid / longer term models to gradually settle things down!

Edited March 6, 2021 by Jon Snow

[knocker]

The 0600 ecm

[Frosty.]

Jeez it’s so dead in here, it must be spring..right?..anyway the Gfs 6z op delivers a late wintry blast although I admit it’s hard too get ice days in late March, cough cough..anyhoo..here’s some charts..this is model discussion isn’t it..hmmm?  

[lassie23]

4 minutes ago, Jon Snow said:

Jeez it’s so dead in here, it must be spring..right?..anyway the Gfs 6z op delivers a late wintry blast although I admit it’s hard too get ice days in late March, cough cough..anyhoo..here’s some charts..this is model discussion isn’t it..hmmm?  

I think everyone thinks winter is over and the cold lovers are now in hibernation. It is too early for the heat seekers so it is limbo land with a few posts a day until the heat builds and fries us all like bacon.

[minus10]

Once again the gfs going totally off script for later March after the spell of HP weather for 4 or 5 days. Little chance of it happening but it does illustrate how volatile the spring weather pattens can be. Models maybe picking up on this volatility. The 12z will probably have a blowtorch southerly..

[Tim Bland]

Beyond mid month cold from the north or mild from the south / south west?  GEFS are split..either way no sign of anything zonal / unsettled for week 2 

[Cambrian]

Lovely bit of convergence between ECM and GFS for the gale midweek, subtle differences in timing now the main difference for the merging of the two low pressure systems between Iceland and Scotland.  ECM still bringing the secondary low in more quickly to Northern Scotland by 0z Thursday, while the GFS keeps with the N-S troughing to the West of Ireland by that point, and brings it through to Scotland by 06z Thursday. Big similarities with ECM for 0z just running it in 6 hours later. 

ECM +120 00z

 

GFS +114 06Z ; GFS +120 06z

Irrespective of the timing, several hours of coastal and inland gales, arriving in Ireland some time Wednesday pm, transferring east across Wales to most of England, easing later on Thursday. Not so severe in Scotland early Thursday due to the slacker pressure gradient of the trough, but picking up right enough there too later on Thursday.

[Frosty.]

Oh my, the GEFS 6z mean is even more bullish about what I was talking about earlier regarding the 0z mean..i.e..eg..whatever..pfft..a more settled longer term trend!..

Edited March 6, 2021 by Jon Snow

[Tim Bland]

Something for everyone on the 12z GFS. High drifts north and then it ends with an easterly and snow flurries into the east...

[minus10]

17 minutes ago, Tim Bland said:

Something for everyone on the 12z GFS. High drifts north and then it ends with an easterly and snow flurries into the east...

It seems that the stormy period is more or less nailed on while the period after is 'pick and mix', very volatile, changeable and typical spring...

[Dancerwithwings]

59 minutes ago, Tim Bland said:

Something for everyone on the 12z GFS. High drifts north and then it ends with an easterly and snow flurries into the east...

Woulda/coulda .....maybe...hints of 2013 again

[SqueakheartLW]

The GFS 12z shows more or less the two opposite extremes of March weather at 384 hours away

The coldest option     Members 16     2m Temp 3.0

High pressure out to our west means a cold Arctic flow down from the north here and with low pressure playing a significant part over the UK itself then snow is a major possibility here, especially further north

The warmest option     Member 12     2m Temp 19.1

What could be a bigger contrast than Member 12 with warm air pushing in from the S and W and in the stronger late March sunshine temperatures are at 19.1 in Scunthorpe but in the SE 20c is very likely to be breached here

Two examples here of how different things can be in March with warmer air threatening 20c whilst colder air masses can still remind us of how areas to the north have yet to warm up and can suddenly stick us back into winter very quickly

[stodge]

Evening all

A calm but chill day in lowland East London but more "dramatic" weather is on the cards next week with a spell of Atlantic-dominated unsettled weather but not last ing long with clear signs of renewed heights just after mid month on last evening's output.

As for tonight, let's open the box and look inside.

T+144 and T+240 charts to start from GEM, ECM, GFS OP and GFS Parallel respectively.

T+144 (March 12th)

T+240 (March 16th):

At T+144 there's strong agreement on a mobile and strong W'ly pattern across the British Isles. Strong winds in the north but breezy elsewhere with fast moving showers or longer spells of rain. From there, Parallel builds heights to the south and west but keeps a strong Atlantic with a deep LP near Iceland by T+240. The other models develop HP close to the British Isles (or even over the British Isles in the case of GFS OP). GEM looks to build a ridge into Scandinavia and has a N'ly over eastern England while ECM also has a weak N'ly. 

Moving on to T+312 and T+384 from GFS OP, Parallel, Control and CFS:

T+312 (March 19th):

T+384 (March 22nd):

Not much to go on there - GFS OP would be fantastic for coldies and Control not too bad but Parallel seems the most keen tonight to maintain the Atlantic influence while CFS builds and HP close to the British Isles. 

Looks like a stormy spell next week followed by heights rising from the south west by T+240 but from there nothing as yet resolved (as you might expect).

[Mike Poole]

ECM clusters here T192-T240:

Any which way?  All interested in some kind of ridge for the UK by T240.  

T264-T360:

While cluster 1 suggests a northerly, it is close to 50/50 between them 28/23 to be exact, I favour cluster 2, the UK high for the reasons I suggested yesterday.  Welcome to a warm settled spring...

Edited March 6, 2021 by Mike Poole

[Sky Full]

ECM thinks it’ll be a bit breezy in many places next Thursday morning...

Other models are also showing a similar picture at present.  

[minus10]

 

Yes the gfs also showing a 'brisk breeze'. Inland speeds of 50 to 60 mph. This is going to be such a drastic change....

[feb1991blizzard]

GFS 18z is a stonker.

A stonker for any time of year but seriously good for late March.

 

Edited March 6, 2021 by feb1991blizzard