Model Output Discussion - May and Early Summer!

[Frosty.]

There's potential for it to warm / hot up again at the end of next week with very warm and humid continental air drawn up across the uk, especially further s / e  according to the GEFS 6z mean..and operational..and FV3!!

Further ahead indicates a chance of some changeable cooler spells across the far NW but for the majority it looks a predominantly slack warm pattern with a mixture of dry and sunny weather and also a chance of thundery showers, especially further south where the warmest conditions would also be!

Edited May 30, 2019 by Frosty.

[Methuselah]

18 minutes ago, Flash bang flash bang etc said:

I guess the argument is that just 1 storm will end the drought, but is it enough to make up for the lack of convective activity in general?

Also, I’ve noticed even the heaviest downpours are relatively brief (round our way anyway). They cause localised flooding but by the next day you’d be forgiven for thinking it never even happened!

A hot and fairly wet summer is what’s needed, ideally

Aye FB, spot-on -- that's exactly what we need!

[stainesbloke]

2 hours ago, Alderc said:

Lol if ever there was a chart that sums up the uk weather that’s it. Makes you feels left out!

Chin up, that sort of chart rarely occurs without much of England, at least sharing the warmth. 

[Methuselah]

The 06Z ensembles are here:

Rain!                                     

[MATTWOLVES 3]

25 minutes ago, Ed Stone said:

The 06Z ensembles are here:

Rain!                                     

Personally Pete I would rather see the water shortfalls being topped up during autumn, rather than in summer. I understand your requirements for rain in that neck of the woods. The cumulative rainfall for the past 12 months has been the fourth lowest for East Anglia since records began in 1910. Other parts of the uk are fairing much better though.. Ie folks in the NW currently are probably hoping they don't witness another drop for the rest of the summer! Hopefully a more settled 2nd half of June coming up. Perhaps we should get used to these shortages, in 20/30 years down the line, the uk will probably be no longer known as the water country. Eyes down for the 12z and something better...

Edited May 30, 2019 by Mattwolves

[Frosty.]

The latest cfs 0z isn't all bad!

[MATTWOLVES 3]

CFS looks good even beyond that timeframe Karl, it's mainly high pressure dominated! 

[Frosty.]

The cfs further into FI looks even better!

[Tamara]

On 28/05/2019 at 10:13, Tamara said:

Such support and uptick having the effect of re-orbiting the GWO back through Phase 4 towards the Nino attractor Phase 5....the signal to lift out the trough and pressure rise from the south (likely as suggested yesterday that the boundary of the heat will still be fairly close by and conceivably ready to advect back northwards and westwards). It remains something to keep watching in ensemble suites in the coming days, as this story is far from complete....

What could go wrong?

The importance of re-energising of westerly momentum across the Pacific to neutralise the trade increase is a vital key here to support AAM and prevent a deeper slide. Any shortfall would add incentive for a more durable trough solution and retain a more amplified ridge profile in the Atlantic to lock the longwave trough in.

What can quite conceivably go right (aka AAM forecast)

Its also true though that if the atmosphere just stays as it is, then summer seasonal wavelengths on their own should work in our favour and increasingly means that just a persistence of the present GWO orbit regime inclines the trough to edge back westwards the closer we get towards the later part of June and into July. Any ideal scenario of repeated vigorous westerly wind bursts however, that pushes the GWO into higher phase Nino attractor orbit 5,6 and 7 starts to flag up the possibility of 2006 and 1983 type scenarios with prominent Western European heat ridges duelling with thundery cut-off lows to our west and south west....But that is for another time perhaps...

Reference paragraph 1 :

Clearer signs have emerged from NWP related to this suggestion - one that previously had first been flagged up last weekend related to possible tight margins of error related to this dividing line between the cooler Atlantic air and the increasingly hot and very humid air consolidating over the continental mainland. Hence the reference, however clumsy it might have been to interpret, to the void where low pressure 'seems' to gravitate no further eastwards.

Remaining paragraphs:

The final outcome of this scenario remains predicated on the technical factors outlined already in considerable detail - under the pros and cons influencing it.

I think some are perhaps getting sucked too far prematurely into the 'against' argument rather than keep an open mind at least about the 'for' argument, or perhaps they have other reasons for the apparent pessimism for no obvious reason - other than using thesnapshot of an unsettled spell being extrapolated outwards for concocted periods of time by specially selecting NWP operational charts to try to prove the points.  Operational charts which so often chop and change each and every 6 to 12 hours.

However, whatever the motive, this is a perilous stance to take based on the fact that the doom-saying summers listed of 2007, 2011 and 2012 (and one or two others maybe such as 2010 which featured a -ve PDO and low angular momentum La Nina state which correlate to a -AO) have some considerable ostensible differences to this summer.

One thing this summer does have in common with those years is the perilous arctic ice situation (and even more perilous than since any of those summers) . But we have also seen other summers in this period, such as from July 2013, some parts of summer 2014, the latter part of 2016 and most especially of all of course last summer where the pressure state of the Arctic has had no influence at all in contributing towards blocking patterns that are detrimental to some highly ideal spells of summer weather. Therefore it once again reinforces the message, and one that I fully subscribe to, that each season should be sensibly taken individually on its merits. How else can one be objective?

One key difference to all those poor summers listed is that this one is being ushered in by a higher than average angular momentum regime feedback circulation. 2007 featured sharply crashing AAM based on a fast emerging strong La Nina (nowhere in sight this year) aligned with the very low sea ice and a strong eQBO to help reinforce the blocked patterns in the Atlantic and over the pole. Likewise both 2011 and 2012 featured low angular momentum Springs heading right into the start of summer -

 

- with the former never recovering from this state during the summer at all until early September (which coincided with some of the hottest weather of the 'summer' during autumn 2011.... 

 

and the latter with a brief rally in angular momentum in late June 2012 into the early part of July which accorded with the spectacular plume seen close to the end of June and hence otherwise associated  poor synoptics.

No coincidence that both 2011 and 2012 both featured, like 2007, extensive periods of blocking in the 'wrong' places and a trough that refused to lift out properly due to the location of the tropical standing wave being in the 'wrong' part of the hemisphere and according with long periods of amplified Pacific and Atlantic ridges and downstream trough..

This summer begins featuring a weak El Nino, w/WQBO and overall we have been seeing a neutral to slightly +ve PDO. I have seen suggested by a very respected and knowledgeable forecaster in another place as something of a cross between 2002 and 2006. In terms of the UK, the former was not especially good though a few short bursts of warmth occurred, but the latter featured some wonderful weather throughout June and July and then a very impressive Indian summer from early September into October 2006 was also a w/QBO year like this year - a good antidote to any -AO patterns. There are other observations to make in terms of SST's and solar forcing here too in respect of both those years - and so again another argument for taking each season on its own merits.

This summer also starts with a supressed phase of tropical convection in the Pacific, temporarily altering the PDO state a little, and already dealt with in huge detail - and which lends itself to some a-typical Nino forcing (aka more La Nina-esque) Hence the displaced and amplified Atlantic ridge and trough axis steered south on a very unhelpful longwave in our vicinity.

But until, or if there are signs this is to become the default, signal (i.e through crashing angular momentum as part of a a longer term change of atmospheric circulation such as happened in the aforementioned poor years) it remains sensible to be suspicious of any NWP which appears to try to match some of the commentary on here by sticking the boxed in pattern for inordinate amounts of time.

It remains to be seen how far any heat advection from the continent might advect this way - but whatever happens in that respect, the chances are higher of this trough lifting out much sooner than in any of the pessimist years. And even if the greatest heat doesn't arrive, there is no reason not to expect a general improvement in conditions more widely SE>NW in the more extended period.  If its not good enough for the likes of someone like me to say this, then look at the METO updates, which essentially are saying the same thing as someone ordinary as me on a weather enthusiast page.

Based on the fact that the polar field is now resembling a state adjusting from the fallout of the strength of the final late warming of the stratosphere, and assuming that angular momentum remains close enough to where it is at present, the pressure will grow according to summer wavelength changes to keep backing the pattern very slowly westwards the further June progresses and most particularly from midmonth towards July.

Keep the pros and cons list handy - but try to remain objective about the possibilities of both, and not skew opinion according to other motives and reasons.

[knocker]

The warm front straddling Scotland and the waving frontal structure just to the west is going to continue to bring rain to N. Ireland, northern England and Scotland through this evening and overnight becoming moderate as dawn breaks. Further south mainly cloudy in the warm moist airstream. but more prevalent in western areas, with some coastal mist in places.

Edited May 30, 2019 by knocker

[northwestsnow]

Thanks Tamara...

I have noticed in the long term there does appear to be an appetite from the models to push the warmer air sourced initially over Russia further and further west.

An inverted winter easterly as we move through June looks plausable to me.

[Frosty.]

Looking at the ukmo 12h the best of this week's weather is still ahead of us, especially further south where temperatures will continue to rise from today's warm / humid levels, even sunday looks hot and humid across the s / se where the best of the sunshine should be but with an increasing chance of thundery showers being sparked by the heat but it looks progressively less settled and less warm further NW.

Next week we are all in the same boat with an upper trough in control bringing a mixture of sunshine and showers, some heavy, prolonged and thundery but the far south & southeast could have some longer drier and brighter spells, at least for a time with temperatures still reasonably warm but closer to low teens c for the far NW where it's coolest  and mid to upper teens c for most.

Edited May 30, 2019 by Frosty.

[Methuselah]

Next weekend's nae looking too bad, either!

 

[I remember Atlantic 252]

3 minutes ago, Ed Stone said:

Next weekend's nae looking too bad, either!

 

Aye, has appeared on a few runs, plume around 7th-10th June, wonder if it can get further West, see what EC says

[Derecho]

15 minutes ago, I remember Atlantic 252 said:

Aye, has appeared on a few runs, plume around 7th-10th June, wonder if it can get further West, see what EC says

Yup pretty close to what the ECM is showing at a similar time! Some serious heat coming up from Africa over Central Europe but can we tap into it?

If we are looking for a hot summer troughing to the west of Spain is a big help, which seems to be a theme of recent model output...

[Methuselah]

Not a bad end to an all-round good run, IMO; looks like tying-in with the teleconnection-based expectations: slow and erratic, but still a gradual migration from the east?

 

Edited May 30, 2019 by Ed Stone

[Mr Frost]

You just know this will be the story of the Summer...

South East England and parts of the South Coast will sizzle for three months while the rest of us in the UK and Ireland get the leftover scraps on the weather table! 

I know it is very early doors but we all expected a Winter that was going to deliver a grand luxurious feast of tasty treats...instead we got a pot noodle and a pint of watery gravy! 

Hopefully the models, background signals and most importantly the weather start to show us the way to a UK and Ireland wide heatwave/thunderstorm outlook within the next fourteen days - after 48 hours of continuous rain I am praying for some sun and warmth as soon as possible! 

Have a good night all!

 

Edited May 30, 2019 by Mr Frost

[Methuselah]

And even the FV3 (great model BTW) ends on something of a high:

 

[Guest]

28 minutes ago, Ed Stone said:

Next weekend's nae looking too bad, either!

 

Synoptically its very interesting with temperatures easily into the low 30's over in the near continent and dew points mid 20's, extreme heat indices for so early in the summer there and some truly monumental TS activity, in the solution show some heat briefly gets advected into the south but in all fairness its a cloudy, damp and muggy picture for most of the UK. If the solution was nudged east obvs it would be really disappointing but if the cut-off low (more inclined to call that as the upper trough has been displaced north west) remains a touch further south or west it could get seriously interesting. 

[mushymanrob]

personally, im not buying this evolution the gfs is so keen to promote by late next week, referring to the development and current expected track of that deep thundery low to our south. ok, it cannot be ignored, or binned, but it looks a bit far fetched to me. personally im hoping one does develop but stays down there driving up some hot air .
for what its worth, i dont think this summer is following the great washout summers of 07,08,12 either.... imho its looking more like '97, periods of wet and hot/dry ... but im probably wrong, lol.
 

[Methuselah]

More good news, folks: the ensembles are getting better!

 

Edited May 30, 2019 by Ed Stone
No, you weren't seeing double!

[MATTWOLVES 3]

Right folks a little trip down memory lane while we wait for the ECM to roll out. Firstly a snapshot of early June 2018....and secondly a little taster of December 2010....i would happily take a repeat of both, especially 2010...

Edited May 30, 2019 by Mattwolves

[Methuselah]

12 minutes ago, Mattwolves said:

Right folks a little trip down memory lane while we wait for the ECM to roll out. Firstly a snapshot of early June 2018....and secondly a little taster of December 2010....i would happily take a repeat of both, especially 2010...

Not both next week though?

[weathermadbarnsleylad]

@Mattwolves I think even if the ecm shows great ie heat and sunny weather. I still won't trust it until 48hrs away. Been burnt too many times this year Chasing cold in winter and heat in summer. Lol

[MATTWOLVES 3]

Quite a difference for the same time frame with the 12z...just look at the difference with the low pressure area! 

And we end with this... I'm hopeful of a push of heights from the SW towards the end and beyond. 

Edited May 30, 2019 by Mattwolves