Model Output Discussion - 3rd May Onwards 00z--->

[Captain Shortwave]

It does look like turning fairly dry and pleasant, at least for the south after mid-week as the Azores high starts to become more influential to our south west. In fact the bank holiday weekend looks quite usable for many.

 

Some weak frontal systems could be a pain here for some as the high cannot ridge fully across the UK, but apart from that there should be a lot of dry weather around and where the sun does come out then the low twenties is possible.

 

Beyond this, the models seem to want to keep the Azores high in a similar position, so the drier than average conditions prevailing beyond the first half of this week. Temperatures near or slightly above normal (again after the first half of this week).

 

GFS suite largely agrees with this outlook, though the GFS operational does build a more UK based high in week 2 which would bring sunnier and warmer conditions if it verified.

[coldcomfort]

Without question the outlook is far better than what we're currently experiencing, but given the initial position of the main high centre I'm reluctant to get too far ahead of myself regarding the outlook. All too often in the past the models have been keen to build pressure eastwards 3 or 4 days hence from this kind of set up, but as time goes by this proves increasingly difficult to do, with winds remaining N of W and weak systems continuing to move down across eastern areas in particular. 

[Frank Trough]

Without question the outlook is far better than what we're currently experiencing, but given the initial position of the main high centre I'm reluctant to get too far ahead of myself regarding the outlook. All too often in the past the models have been keen to build pressure eastwards 3 or 4 days hence from this kind of set up, but as time goes by this proves increasingly difficult to do, with winds remaining N of W and weak systems continuing to move down across eastern areas in particular. 

on the flipside to that, how many times do we a trough predicted to drop down across or just east of the country and introduce a northerly only for it to end up further east at verification? that scenario seems to happen quite often but mainly gets noticed in winter. Maybe it's more common in winter! don't know.

 

I just want Saturday to be reasonable day - a whole day free to pursue outdoor interests so dry and not too windy are what I would order (don't really care about temps or sunshine). at present I will definitely bank any of the big three given how it was looking a few days ago!

[coldcomfort]

Fair point CKOF, but even the 06 GFS illustrates quite well what I was trying to say, with a fairly active set of fronts still bringing rain southeastwards across many parts of the UK on Sunday....almost a week away. Whether this then proves to be the trigger for a more robust and sustainable pressure rise into next week remains to be seen, but I will remain sceptical about that for now, with my 'most likely' option being more of the same.

Edited May 18, 2015 by coldcomfort

[Captain Shortwave]

Fair point CKOF, but even the 06 GFS illustrates quite well what I was trying to say, with a fairly active set of fronts still bringing rain southeastwards across many parts of the UK on Sunday....almost a week away. Whether this then proves to be the trigger for a more robust and sustainable pressure rise into next week remains to be seen, but I will remain sceptical about that for now, with my 'most likely' option being more of the same.

Maybe the precipitation charts are being a little deceiving, the GFS has rainfall totals for the next 10 days generally being in the 15-20mm range (away from the usual wet spots in a westerly pattern). The majority of this rain is forecast to fall in the next 3 days. With pressure fairly high I suspect any rain would be moderate at most and most likely light. 

 

That said cloud amounts could be an issue throughout the forecast period given the Azores high isn't in the best position, of course with us being in late May then the strength of the sun could compensate somewhat with sunny spells breaking through the cloud, especially in central and eastern areas.

[mushymanrob]

and the actual chart for 6-10 below.

To me it does support the idea that the anomaly charts are trending away from the trough dominated flow north of west to a more westerly type with +ve heights edging nearer the UK. It is only the first day that all 3 have suggested this trend but it does look a feasible one to me. So after a coolish and rather changeable few days then prospects of it starting to settle down a touch from the WSW?

Of course my summary of the anomaly charts might be wrong, indeed they might be wrong but that is how it looks to me this evening.

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

 

 

my interpretation john, and i might well be wrong of course, viewing both the 6-10 and 8-14 noaa charts are that there might be a slight relief from the cooler northerly sourced, northern trough, showery regime as the western high does nudge in closer to us (as per the 6-10 day chart), but fails to track over us and retrogresses back leaving us with the trough to our north again (as per the 8-14 day chart).

but i might be wrong, they might be wrong or more likely might change (esp the 8-14 day chart).

either way im far from confident about more pleasant settled weather winning out (as per some op runs).

[Backtrack]

PLEASE can someone define 'The South' we get this problem every year. But every post I read mentions it! What exactly do you define as the South?! South of Scotland, south of Wales?!

[Nights King]

PLEASE can someone define 'The South' we get this problem every year. But every post I read mentions it! What exactly do you define as the South?! South of Scotland, south of Wales?!

 

 

Everyone knows that everyone north of the Watford gap is a northerner.. 

[SteveB]

PLEASE can someone define 'The South' we get this problem every year. But every post I read mentions it! What exactly do you define as the South?! South of Scotland, south of Wales?!

Anything South of the Midlands is generally considered South

[Frosty.]

The Gfs 6z is trending in the right direction with the Azores high becoming more influential as time goes on, especially through next week and into early June but we get a taste of things to come during the second half of this week with a ridge of high pressure building in from the west/southwest and we see a building and rebuilding of the Azores high through the next few weeks. Having just read the latest met office update it really ties in pretty well with what this run shows with high pressure gaining the upper hand for much of the time with the driest, sunniest and warmest conditions across the southern half of the UK with just occasional short interruptions to the mainly fine picture and even the north becoming settled at times..The end of spring and early summer are looking much better. Early June charts looking very good

[049balt]

Some real warmth on the way for the final week.

 

http://wxmaps.org/pix/prec4.html

[Frosty.]

Spring Bank holiday weekend is shaping up to be a good one according to the ukmo 12z with a strong ridge of high pressure across the whole of the UK bringing plenty of sunshine and becoming rather warm, especially in the south.

[Frosty.]

This evenings Ecm 12z shows a significant change on the way with high pressure replacing the recent/current showery low(s) . There will be a good deal of pleasant late spring weather to look forward to if this run or similar verifies.

[ANYWEATHER]

Evening folks . The projected outlook from the ecm and gfs  is rather poor with the azores high giving way to an Atlantic mid ridge will only introduce dross and boredom. So lets summarize , cool, often cloudy weather....no convective weather, little rain, little wind , Limited sunshine.no thunderstorms, and no beautiful fluffy  clouds ,to be honest No weather from todays weather output     

[049balt]

Evening folks . The projected outlook from the ecm and gfs  is rather poor with the azores high giving way to an Atlantic mid ridge will only introduce dross and boredom. So lets summarize , cool, often cloudy weather....no convective weather, little rain, little wind , Limited sunshine.no thunderstorms, and no beautiful fluffy  clouds ,to be honest No weather from todays weather output     

This is the start of some great weather which will arrive later in the month.

[ANYWEATHER]

Really

[049balt]

Really

Yes.

[Polar Maritime]

Ok, Back to sensible 'Model Output' related discussion please. Thanks. 

Edited May 18, 2015 by Polar Maritime

[knocker]

Tonight's anomalies are looking as if the HP to the SW will edge far enough east to maybe give a fairly good weekend with temps about average or just above. And become more influential from then on.

Charts weatherbell

 

 

[draztik]

This is the start of some great weather which will arrive later in the month.

Great weather as in dry conditions? Possible.

Great weather as in warm conditions? Unlikely

[im not saying it will be cold, before that is suggested. I'm merely saying flaming June may not have any flame burning wildly]

GEFS, ext ecm ens, jma, CFS ens all singing from the same hymn sheet! - negative temp anomaly indicated.

GEFS temp anom days 7-12

CFS ens latest June temp anom

Edited May 18, 2015 by draztik

[summer blizzard]

Warmth rejected on the 18z..

 

[knocker]

Latest EC32 update

 

First of all this weekend has the HP in charge with trough pushed east. Temps about average or slightly above.

 

This scenario continues until June 01st with temps around average.

 

After that a build up of heights to the NE with the Azores HP slipping a tad SW but the HP linkage over the UK remains with temps improving and becoming above average. This until June 9th.

 

After the 9th there is more of a disconnect with the HP to the SW and a more W/SW flow but temps remain above average until the 19th. In fact there are a lot of above average temps around including over the Pole.

 

Summary.

A fairly pleasant outlook and warming up in June.

[Summer Sun]

At t144 ECM doesn't have the high as far east as UKMO and GFS, if ECM is correct bank holiday Monday may see the risk of some showers

 

[BlueHedgehog074]

The NOAA 500mb anomaly charts (the 6 to 10 day and the 8 to 14 day versions - issued 18th May) maintain a similar theme to previous versions of keeping areas of High Pressure close-by over Western and South-Western areas of the UK (in a way, quite similar to the 500mb mean charts Knocker posted yesterday). I would perhaps says it has trended the higher than average heights to the West of the UK a touch further East compared to the NOAA's previous anomaly charts. It has also certainly lost some of the influence of Low Pressure areas affecting Eastern areas of the UK, which was evident on the anomaly charts a few days ago. However, I think as someone pointed out earlier on, there still doesn't seem to be much of a signal (yet) to suggest the Azores High Pressure will ridge over to the East of the UK. And it's possible some of the troughing the NOAA shows to the East of the UK could help keep the Azores High Pressure locked away to the West or South-West of the UK (though doesn't mean it can't happen at some point and things could always possibly change for the better for those wanting to see an Eastern UK High Pressure set-up). Does, however, still look to be the case that High Pressure and the higher heights towards Western/South-Western UK could stay close enough to keep the British Isles free from much wet weather - although, again, the best of the driest and brightest conditions would probably be over Western and South-Western areas. While nothing particularly warm, especially with a flow at the 500mb height from the North-West, some reasonably warm conditions could still be achieved via longer sunnier breaks. This perhaps again especially true towards Western areas of the UK.

The anomaly charts above also have support from the ECMWF 12Z 500mb and Surface Pressure Ensemble Mean chart - keeps ridging close by over South-Western UK with the strongest of the highest heights out to our West in the Southern Atlantic. Also has the lower than average heights around the Greenland area to our North like the NOAA anomaly charts have.

Be interesting to see whether the 00Z ECMWF sticks to a similar theme (but I suspect there won't be much difference).

In the meantime, the models show a cool Polar Maritime flow bringing some sunshine and showers for places both today

...and tomorrow

...as Low Pressure tracks towards North-Eastern Scotland drags a cool and showery flow down from the North-West. Temperatures slowly starting to rise tomorrow as well, as the charts above show a ridge of High Pressure towards the South-West of the UK terminating the showery activity. Remaining showers getting pushed off to our East. Temperatures looking to get up to around 14 - 17*C for some Eastern spots.

Both tonight and tomorrow night look to be on the chilly side for most places, too:

Thursday will see the ridge of High Pressure settle over Southern areas of the UK with the best of the brightest and warmest conditions towards the East and South of the Beitish Isles. Low Pressure to the North, though, could bring a spell of rain over Scotland. Will be cooler over North-Western areas, especially to those towards Western Scotland exposed to the wet conditions.

While detail is still liable to change somewhat for the next few days after, does looks as though High Pressure will settle over South-Western and Southern areas with the best of the driest conditions and warmest conditions in these areas. But one or two odd spells of rain could spill over the top of the High Pressure and affect Eastern or North-Eastern areas at times.

And should the anomaly charts be correct with their ideas (although it does have similar support from operational models, such as the 0Z GFS, then High Pressure could remain somewhere close by to the West or South-Western areas of the UK for a little while.

[coldcomfort]

Fair point CKOF, but even the 06 GFS illustrates quite well what I was trying to say, with a fairly active set of fronts still bringing rain southeastwards across many parts of the UK on Sunday....almost a week away. Whether this then proves to be the trigger for a more robust and sustainable pressure rise into next week remains to be seen, but I will remain sceptical about that for now, with my 'most likely' option being more of the same.

Unable to post charts atm, but the overnight runs pretty much confirm my thoughts from yesterday, with the 144 and 168hr ECM in particular proving very resistant to any sustained ridging, let alone HP setting up over or to the east of us.