Model Output Discussions 12z 08/03/17

[Frosty.]

From next midweek onwards the Gfs 18z looks increasingly settled as the azores high ridges up and across the uk..low res becomes pleasantly warm by day with sunny spells but nights look a bit chilly with a touch of frost and mist / fog patches but as with the 18z last night, again it looks very spring like during late March, at least for the southern half of the uk and the warmth eventually extends further north for a time..Nice trend, at least I think so!

Edited March 14, 2017 by Frosty.

[jvenge]

Move along, nothing to see here, other than typical Spring weather. Attached are the 850 anomaly temperatures for GFS and GEFS. No real clear signal after day 7 or so on the GEFS.

 

[knocker]

A familiar story with the GFS this morning with HP continuing to influence the southern half of the UK whilst the rest comes under the auspices of major low pressure systems tracking west -east to the north of Scotland. Thus the UK remaining in a moist westerly airstream with the odd ingress of showery rain, particularly effecting the north. Temps continuing above average.

By midday Monday the next major upper trough has arrived west of Ireland with associated surface low 995mb over the borders with fronts orientated SW to Cornwall.

This is roughly the time when the GFS started to differ from the ecm and it is still disrupting the trough as it moves east and phasing with the low pressure to the south forming yet another cut off low over Iberia as the Azores again ridges NE.and heralding once more a not unfamiliar surface pattern

This morning's GEFS anomalies suggest support for this scenario but as usual the detail will depend on the strength and orientation of the HP as to just how far south the troughs will venture

 

 

 

Edited March 15, 2017 by knocker

[knocker]

The ecm is still differing vis the treatment of the upper trough next week and has it slightly further west and more organized before it slides south and facilitates the Azores to ridge NE thus delaying the ridging a little although  it gets there in the end

Edited March 15, 2017 by knocker

[Summer Sun]

ARPEGE is still showing the further south and east you are the longer you'll stay dry on Friday some snow for high ground in Scotland and for a time the Pennines

Saturday continues to show a mostly dry day for many with just the odd shower during daylight hours

By Sunday morning we have some more persistent rain moving into the northwest of Scotland with some heavier showers for NW England too drier to start with for the south and east

I think Sunday could well be the windiest day of the weekend as the low close to Iceland tracks a bit further south with Saturday probably the better day of the two if you don't mind the breeze certainly some usable weather to be had

Temps over the weekend ranging from 9c in Scotland to around 14c in the south though these will be tempered somewhat by the wind more so on Sunday if that low does track a bit further south

 

Edited March 15, 2017 by Summer Sun

[feb1991blizzard]

The GFS 6z looks like it could be a snowfest for even moderately high ground and Not just for the far North either.

 

and a certain amount from EPS mean as well, hopes hanging by a thread but still just about alive.

[feb1991blizzard]

Just for the record - my post last night was referring to what is possible at this time of year, it wasn't suggesting that a 360 chart was proof it was going to verify, it was proof it was possible, these models do take into account the hours of sunlight, if you want more proof of wintry conditions being possible in spring, look no further than late April 1981.

[Man With Beard]

Being firmly in spring-mode this week, the GFS 06Z would be quite a shock for next week if verified:

     

[Frosty.]

Even a chance of snow for the south from the Gfs 6z Sidney won't be pleased!

Edited March 15, 2017 by Frosty.

[Sky Full]

GFS and ECM now broadly in agreement predicting low pressure over the UK at +168 (March 22) bringing colder conditions for all:

ECM:

   

GFS:

   

Yesterday the GFS was suggesting that the Azores high would be more dominant but backtracking today.  Will it swing the other way again by tomorrow??  Perhaps March will have a kick in its tail after all....

 

 

 

[Frosty.]

As mentioned, the Gfs 6z shows a wintry snap next week with a risk of snow early / mid next week followed by high pressure building in with frosty nights and fine days with sunny spells. Temperatures start to recover by day and night and eventually we are into a very pleasant spell with warm sunshine under high pressure during late march.

Edited March 15, 2017 by Frosty.

[knocker]

Sidney  isn't concerned as he has the family coming down for Easter. Although he does wonder why people didn't mention the ecm run in this context as it is all about how the models handle the upper trough deconstruct and track which will possible give two of three days of cooler unsettled weather before further ridging from the Azores. As mentioned earlier the ecm drops the trough down further west a tad and brings some quite cool weather the Agadir. Nothing new to get excited about

 

Edited March 15, 2017 by knocker

[NO LONGER POSTING]

Interesting model watching imo it's a case of what next.. Cooler conditions or continue with spring.. 

GFS is doing its usual thing and going from one extreme to the other.. 

One thing is for certain though, why the he'll would you wanna swap this for cold and snow? 

[Frosty.]

4 minutes ago, Surrey said:

Interesting model watching imo it's a case of what next.. Cooler conditions or continue with spring.. 

GFS is doing its usual thing and going from one extreme to the other.. 

One thing is for certain though, why the he'll would you wanna swap this for cold and snow? 

That's what I love about March, the 6z has it all, frost, snow and then warm sunshine and high pressure..very interesting model output. 

[Summer Sun]

Op and control on the colder side of the mean for the aforementioned period in posts above - for balance they are also on the warm side towards months end

More runs needed

[Frosty.]

We are on track for a quieter spell later this month according to the GEFS 6z mean with high pressure or at least ridging bringing chilly nights with frost / fog but with the ever increasing strength in the sunshine, days look generally bright or sunny and feeling pleasant in the strengthening late march sun..still a risk of frontal zones bringing rain and strong winds but mainly across northern uk.  Into April there are still weak signals for blocked, slow moving weather patterns with a lot of fine weather with temps milder than average by day but with on going risk of night frosts.

Edited March 15, 2017 by Frosty.

[Summer Sun]

ARPEGE has done quite well for Friday's rain it's consistently shown the south and east would stay drier longest and that now appears to be the case

[Summer Sun]

UKMO extended looks pretty unsettled for mid next week

[skifreak]

I wonder how high the temperature roller coaster could climb tonight in NE Scotland!  

[cheshire snow]

5 hours ago, Frosty. said:

Even a chance of snow for the south from the Gfs 6z Sidney won't be pleased!

And the GFS  12z continues the above theme,thanks but no thanks five weeks to late.

C.S. 

[Summer Sun]

Saturday still looks the 'better' day of the weekend once the rain band clears away most parts will be left with just a few showers and breezy the showers seem more likely in the west

Sunday sees the winds strengthening virtually UK wide with some more persistent rain in the west the south and east will again see the best of the drier weather - gusts widely at or above 40mph

The unsettled theme continues into next week

[mb018538]

Looking unsettled into mid-late next week before we perhaps see high pressure settling things down again. Nothing overly destructive, just bog standard spring wind, rain and showers. Best weather in the SE.

[Frosty.]

The Gfs 12z turns into a cracking run from the end of next week through to the end of March with increasingly settled and warmer weather, especially warm for the south with temps into the low to mid 60's F..wouldn't mind that!

[cheshire snow]

ECM showing it turning colder Tues through to Thursday with some wintry PPN about

Turning milder Friday but possibly still cold in the far south at day nine.

C.S. 

[Summer Sun]

Settled later next week but temps down compared to this week if ECM is right

 

Edited March 15, 2017 by Summer Sun