Model discussion - March drawing to a close

[Paul]

Bit of a change this morning from the ensembles. A less settled first week of April on the way than it had yesterday, then instead of a UK (ish) high, it's going for a Scandi one beyond. 

That means, below average temperatures likely until much later on in the run. 

The ECM mostly agrees too.

Early April - low pressure, colder temperatures

End of the run in 10 days - Scandi high

Edited March 29, 2019 by Paul

[BlueHedgehog074]

Would personally love to see this dry, mild, High Pressure dominated spell continue. It has been pleasant so far and has, in some ways, felt kinda more like April. 

However, this mornings 00Z ECMWF’s Northerly incursion mid next week seems cold enough for showers to be of sleet and snow for places. And probably not necessarily for high ground. (Though that still helps).

Probably the best run this morning in terms of the length and potentency of its cold incursion. But if a Northerly like this was to occur, it might as well be potent enough to deliver a bit of that white stuff. Could very well be the last chance the cold and snow fans have at seeing something. At least until next Winter.

Edited March 29, 2019 by DiagonalRedLine

[I remember Atlantic 252]

 

 

18 minutes ago, Paul said:

early May - low pressure, colder temperatures

hope not, didn't think models went that far? only unreliable CFS

[Paul]

Just now, I remember Atlantic 252 said:

 

 

hope not, didn't think models went that far? only unreliable CFS

Hmm yeah, typo - will correct it.

[stodge]

Morning all

Yes, a very much more interesting look to the model output this morning with GFS 00Z OP, Control and Parallel all featuring Easterly wind flows in Fi. ECM gets there a bit quicker but so much depends on the behaviour of next week's trough. GEM 00Z gas the trough just to the east allowing the very strong and displaced Azores HP to throw a ridge back across southern Britain.

On other models, there's time for the Scandinavian HP to build from Eurasia and for the trough to evolve into a European feature maintaining an E'ly or ESE'ly flow. Nothing too cold to be honest and indeed OP is on the warm side and this is the difference at this time of year between an ENE and an ESE - the former draws the air from Scandinavia and can still be quite chilly but the other is drawing air from much further south and this has already warmed. Cold fans need to see the core of heights shift west to sit to the NW of the UK but I suspect that won't happen.  

These are T+192 on GFS 00Z Control, OP and Parallel to illustrate the differing evolutions - all lead to an E'ly but with variations as you'd expect.

ECM and GEM 00Z at the same time for comparison:

Perhaps worth noting GEM holds the trough a little further north and has the Azores HP a little closer. Also worth noting the Parallel evolution doesn't so much build heights west from Scandinavia but east from Greenland.

[Frosty.]

Looking at the latest models makes me wish it was winter, however, even early / mid April can still produce wintry interest and in the case of 1981..April 25 / 26 th!!

[Methuselah]

A slight watering-down of next Wednesday's cold snap? Where have all the -10C uppers gone?

Thursday's looking good for some slow-moving thundery showers, though:

Edited March 29, 2019 by Ed Stone

[shaky]

11 minutes ago, Ed Stone said:

A slight watering-down of next Wednesday's cold snap? Where have all the -10C uppers gone?

On a serious note i cant believe we could actually be talking bout snow come next week cos that is a really cold and snowy chart above!!ecm had lead the way over the last few days with a more colder and wintry outlook!!ukmo and gfs have finally caught up!!shall be a real shocker after this week!!

Edited March 29, 2019 by shaky

[Frosty.]

The Gfs 6z operational looks increasingly cold and cyclonic next week with a cold pool of -7 uppers descending before rising to -5 on thurs and -3 on friday but a cold week for the time of year, especially the midweek period.

Edited March 29, 2019 by Frosty.

[stodge]

20 minutes ago, Frosty. said:

The Gfs 6z operational looks increasingly cold and cyclonic next week with a cold pool of -7 uppers descending before rising to -5 on thurs and -3 on friday but a cold week for the time of year, especially the midweek period.

More like the GEM 00Z but the heights build first from the NE, transfer SW and then start to retrogress so we get to our mid month cold spell (-8c 850s over northern Scotland in deep FI)

[Methuselah]

The end of the 00Z now suggesting an Atlantic ridge with associated northerly outbreak...typical springtime volatility?

 

  

Edited March 29, 2019 by Ed Stone

[Azazel]

As long as we get some decent convection out of this setup, i'm not too bothered about it being rank and cold.

[Frosty.]

The Gfs 6z operational saves the best until last..about as wintry as you can get for the time of year..at least the following day would have been even more wintry!!

Edited March 29, 2019 by Frosty.

[Methuselah]

8 minutes ago, Azazel said:

As long as we get some decent convection out of this setup, i'm not too bothered about it being rank and cold.

If the FV3's on the money, you should get your wish, Azazel: slow-moving heavy, thundery, wintry showers?

 

[MATTWOLVES 3]

Does this current set up surprise me? Not really, a few of us on here have been banging the cold drum for a fair few days regrading colder Conditions..... Firstly it was just GFS that was signalling it, now it appears other models have latched onto it!! What amazes me that so many times I've been shot down for posting 10 day charts.... Because apperantly they don't verify in winter, let alone now!! I've even read posts from the regional thread saying.... The folk on the mod thread keep posting cold charts do my head in... Let me know when they stop posting, so I can visit again.... Well like I've always stated beyond 7 days may not verify.... But sooner or later they will!! And sometimes it's the little signals being picked up at range that lead to a protracted  cold spell In the first place! It's our Job to try and put all the little pieces together.... Not that this cold spell will amount to anything significant, but the signs are there.... And they have been.... For days! Ohh, perhaps a bit of cross model agreement to boot! 

Edit... And just to prove there is know cold bias regarding my post at all... We currently have clear blue sky's know wind, and warming temps here in the midlands right now,,, and tbh I wouldn't mind if this weather held firm till September!! It's basically bloomin glorious out there!!! 

Edited March 29, 2019 by Mattwolves

[Azazel]

5 minutes ago, Ed Stone said:

If the FV3's on the money, you should get your wish, Azazel: slow-moving heavy, thundery, wintry showers?

 

Sounds good! Got a new wide-angle lens I want to try out so patiently waiting for our first convective outbreak. Finally purchased a shutter-release cable so determined to get my first legitimate lightning photograph this year too when summer arrives and we "hopefully" get some nocturnal storms.

[stodge]

If you want to get yourself really upset, run the Parallel from 192 to 384 and imagine it was January rather than April and try to work out how much snow southern England would collect in that week,

[MATTWOLVES 3]

8 minutes ago, stodge said:

If you want to get yourself really upset, run the Parallel from 192 to 384 and imagine it was January rather than April and try to work out how much snow southern England would collect in that week,

Yep stodge I've run that scenario a few times! These  charts have appeared 8 weeks to late as per usual.

[Frosty.]

Dream charts from the 6z parallel if it was winter, especially Jan / Feb when we would have been talking powder snow, drifting and -4c max temps with penetrating pipe busting frosts but even in early to mid April it would still feel bitterly cold in those nithering easterly winds! in other words it would still be brass monkey's!!

[Methuselah]

FV3...Watch it and weep! 

If only it were February!

[Methuselah]

And we still have a broadly easterly scenario presenting itself:

 

But the Op is now on the colder side of the ensemble: 

[Frosty.]

The longer term GEFS 6z mean signal is increasingly blocked and less unsettled.

[Frosty.]

Further to my post above there really is an increasingly strong blocking signal in the mid / longer term GEFS 6z..as to what the surface conditions would be in any particular location is unclear but there are some warm and colder options and the Atlantic looks very sluggish / benign.

[Polar Maritime]

Yes a much colder theme to come into the new working week/Month, Even by Monday there is a risk of Wintry showers for some as mid-day temps hover around 5/6/7c with a nippy wind chill and some sharp overnight frost.

A glorious day out-side today to catch up on the gardening, With temps possibly touching 19c in some spots..Don't miss out!

Edited March 29, 2019 by Polar Maritime

[Frosty.]

Certainly a colder feel to next week, especially the midweek period is indicated by these Ecm 00z ensemble mean charts, increasingly unsettled / cyclonic with a mix of rain (hill snow) at times, wintry showers and some dry and sunny weather but with cold nights, especially where skies clear and winds fall light with overnight frosts.

Edited March 29, 2019 by Frosty.