Model Output Discussion - 15th March onwards

[Guest]

6 minutes ago, MattStoke said:

Aye, by midday, with a few hours of heating to go if/where skies are clear.

Also the UKV is completely uninterested any sort of convective outbreak before this time. Almost completely dry Friday night and Saturday morning. 

[MattStoke]

2 minutes ago, In Absence of True Seasons said:

And weather warnings for 'extreme heat' are/were being released. Laughable really. 

I knew the temps would be downgraded closer to the time, they have been this entire year whenever a hotter spell has been forecasted. It's why I raised a brow when murmurings of "30c!" on Sat/Sun started appearing a couple of days back. No way it was gonna hit 30, the set-up just isn't there for it, especially outside of the West. It's still legitimately cold in the mornings and evenings, and we're struggling to breach 20c most days.

Didn’t realise the weekend had already been and gone (Without 30°C being reached). Must have blinked and missed it.

[Earthshine]

2 minutes ago, MattStoke said:

Didn’t realise the weekend had already been and gone (Without 30°C being reached). Must have blinked and missed it.

I need to find out where these guys get their crystal balls from.  

[Don]

6 minutes ago, Earthshine said:

I need to find out where these guys get their crystal balls from.  

It's top secret!! 

[Cambrian]

Oh my days, another case of to R-word or not to R-word! A cross-model consensus from the ensemble means of the big three at days 4-7 on the 0z runs for the brief Scandinavian high to move west - but not by much, only to directly north of the UK and Ireland, in a bit of a dance with the low heights to the south, inserting a wedge between the two lows. 0z ECM, GFS, GEM

  

Rather than us scratching our heads looking around for something new, it might be worth us considering that the pattern for summer 2023 could well turn out to be a continuation of that of the late winter and the whole of spring - docile Atlantic, northern blocking, phases of high pressure retrogression to the Atlantic (northerly / northeasterly flow) alternating with phases of eastward transfer to Scandinavia (warmer easterly / southeasterly flow that will get progressively warmer as the summer progresses);

sometimes the high pressure transferring through the UK and Ireland (dry periods), sometimes transferring further to the north allowing lower heights to encroach for a while from the southwest (warmer, less settled, scope for thundery spells, wash-rinse-repeat of pulses of heat and moisture for around a week or so, bringing much needed rain), but the transfer never happening to the south of us, so maintaining the broad stop on any Atlantic mobility, thanks to a perpetually stronger southern arm of the jet stream, that stays a long way south. 

Day 12 GFS / GEM mean anomalies 

 

Paradoxically, the real relevance to the developing summer in Western Europe of this type of ambiguous and phasic retrogression is precisely in the way that it doesn’t seem to want to push through to completion by following through to Greenland and opening us up to the north in earnest. 

Next IFS version of ECM 46 weekly pressure anomalies - week 1 vs week 5, base time 7 June, yesterday.

 

Rather, it’s part of a slow east-west-east-west oscillation with built-in day-to-day wobbling, which is pleasing for people who want a properly seasonal summer. Lots of dry weather, bursts of hot and humid air, then thundery as the heights withdraw more fully north for a while, then a cool reset to dry as the heights re-establish further south, then off we go again. 

In some ways, the repeat setup and the globally static nature of it all maybe seeming unusual, but definitely completely fascinating that the same broad pattern seems to be lasting so long, this is the fourth month of it (southerly running jet, static Atlantic, heights to the north), and it does seem for now that the new pattern for the first half of the summer at least could well be…..(drum roll)…..more of the same. 

[DR(S)NO]

14 minutes ago, Earthshine said:

I need to find out where these guys get their crystal balls from.  

Sounds serious . An appointment for the doctor may be required?

[MattStoke]

ICON too shows temperatures reaching or exceeding 30°C in a few spots Saturday to Monday. I don’t normally rate the ICON but was told that it normally does well on temperatures at short range  

[mushymanrob]

15 hours ago, JayAlmeida said:

One thing that has confused my non weather expert brain with regards to the upcoming spell of weather is how are the temps going to be as high as the models are predicting? 

All of that cloud and rain would usually mean suppressed temperatures rather than mid to high 20s.

As i understand it, the sun only needs to come ouit for ten minutes or so to make temps rocket... so 25/6c for a few minutes in an otherwise lower 20c odd.. ? maybe?..

[northwestsnow]

50 minutes ago, sheikhy said:

Looks bloomingg brilliant!!dunno what happened with the op it went off on  one around 192 hours!!!!ukmo looks amazing!!!!

I suspect day 7 onwards is still to be pinned down with the movement of high pressure .

Right now the trend,albeit weak,seems to be the high centred to our W/WNW which may allow cooler air to filter in back end of next week.

This Weekend and most of next week looks warm though 

Edited June 8, 2023 by northwestsnow

[chapmanslade]

44 minutes ago, In Absence of True Seasons said:

And weather warnings for 'extreme heat' are/were being released. Laughable really. 

I knew the temps would be downgraded closer to the time, they have been this entire year whenever a hotter spell has been forecasted. It's why I raised a brow when murmurings of "30c!" on Sat/Sun started appearing a couple of days back. No way it was gonna hit 30, the set-up just isn't there for it, especially outside of the West. It's still legitimately cold in the mornings and evenings, and we're struggling to breach 20c most days.

 

43 minutes ago, Alderc said:

Also the UKV is completely uninterested any sort of convective outbreak before this time. Almost completely dry Friday night and Saturday morning. 

So there you have your answer

 

You are looking at raw model data not forecasts. Friday night is already difficult to forecast with considerable variation between models on how much convection there will be. If there is a lot then there will almost certainly be a lot of cloud around on Saturday morning in a very humid airmass which means it could hang around a while and supress temperatures. If there isn't it will probably be scorching in the SE on Saturday. 

Also we are currently NOT in the warm humid airmass and so this explains the cool mornings @In Absence of True Seasons - It is comfortably in the 30's today in France where the air is coming from for the weekend.

 

[sheikhy]

No change from gfs from its 00z run!saturday 25 to 27 degrees!!!sunday 23 or 24 so not the heat of the ukv!!!!but it seems to have upgraded the heat for saturday so i dont believe what the gfs is forecastingfor sunday in terms of temps!!

[chapmanslade]

17 minutes ago, mushymanrob said:

As i understand it, the sun only needs to come ouit for ten minutes or so to make temps rocket... so 25/6c for a few minutes in an otherwise lower 20c odd.. ? maybe?..

3C to 4C per hour is possible with the high sun at this time of year. Humidity will slow it down but then also give it a higher starting point and warmer feel.

[Guest]

37 minutes ago, MattStoke said:

ICON too shows temperatures reaching or exceeding 30°C in a few spots Saturday to Monday. I don’t normally rate the ICON but was told that it normally does well on temperatures at short range  

Could the 13th June enigma about to end? 

[In Absence of True Seasons]

1 hour ago, Earthshine said:

I need to find out where these guys get their crystal balls from.  

Crystal ball? No sir, just the forecasts from Met Office etc. 

[Howie]

06z also pulling the high west but seems to be advecting quite a warm air mass from the east

[DIS1970]

The Beeb/MetOffice only has temps peaking between 24/26C locally on Sat/Sun/Mon, with a high chance of thundery showers/storms thrown in for fun, so not overly hot - except maybe for the east and south-east, despite the country wide warnings this morning.

[MattStoke]

21 minutes ago, In Absence of True Seasons said:

Crystal ball? No sir, just the forecasts from Met Office etc. 

Hmm.

[Tamara]

With very good confidence that the atmospheric circulation is set to remain broadly similar through the bulk of the summer,c/o of repeated westerly wind bursts across the tropics, with a convergence standing wave in the Pacific, and as a consequence +ve AAM wind-flow anomalies propagating through the turning force exhibited by +ve torque eddy mechanisms into the extra tropics  - then we can look to natural summer wavelengths to see how the global patterns may evolve this wind-flow propagation and associated amplified wave breaking.

Under such a regime as described, as June moves closer and closer towards July, and equally closer and closer to the peak period of summer wavelength, anticyclonic wave-breaking should progressively ebb and flow further east and the split flow in the Atlantic giving ever greater influence to cut off thundery lows to pump heat from southern Europe.

The cycle presently underway with Oscar bringing very warm, humid air northwards, is the first of a likely repeated sequence, each one escalating warm air advection processes and with a subtly changed emphasis, with time, of a rather more longitudinal trough/ridge pattern than the persistent to date dominant N/S delineation. This based on a trend for the very defined & strong southward displaced sub tropical jet to evolve a more diffuse split STJ energy, under slackest peak summer wavelengths, which will also give tendency for less blocking NW of UK/ Europe. With the height anomalies tending with time more sustainably into mainland Europe & Scandinavia then (in respect of UK & NW Europe) the inference is that cool(er) air advection around the eastern perimeter of the ridging gets mixed out more and more as westward adjustments incrementally reduce.

On the basis as described that takes a suggested extended perspective, better to not read too much into hints of any longer term re-set to the entrenched pattern of recent weeks or extrapolating outwards any persistent recurrence factor of the same through any greater part of the summer..

@MattStoke  Yes exactly. Signals drive numerical models. Numerical models do not drive signals.

Edited June 8, 2023 by Tamara

[sheikhy]

Latest ukv 09z!!continues to bring hot conditions for much of england on saturday!!30 31 degrees in many places!also im sure i see an isolated 33 degrees in there near the welsh border aswell!!!not many storms either and whatever storms do break seem very scattered and towards wales!!

[MattStoke]

5 minutes ago, Tamara said:

With very good confidence that the atmospheric circulation is set to remain broadly similar through the bulk of the summer,c/o of repeated westerly wind bursts across the tropics, with a convergence standing wave in the Pacific, and as a consequence +ve AAM wind-flow anomalies propagating through the turning force exhibited by +ve torque eddy mechanisms into the extra tropics  - then we can look to natural summer wavelengths to see how the global patterns may evolve this wind-flow propagation and associated amplified wave breaking.

Under such a regime as described, as June moves closer and closer towards July, and equally closer and closer to the peak period of summer wavelength, anticyclonic wave-breaking should progressively ebb and flow further east and the split flow in the Atlantic giving ever greater influence to cut off thundery lows to pump heat from southern Europe.

The cycle presently underway with Oscar bringing very warm, humid air northwards, is the first of a likely repeated sequence, each one escalating warm air advection processes and with a subtly changed emphasis, with time, of a rather more longitudinal trough/ridge pattern than the persistent to date dominant N/S delineation. This based on a trend for the very defined & strong southward displaced sub tropical jet to evolve a more diffuse split STJ energy, under slackest peak summer wavelengths, which will also give tendency for less blocking NW of UK/ Europe. With the height anomalies tending with time more sustainably into mainland Europe & Scandinavia then (in respect of UK & NW Europe) the inference is that cool(er) air advection around the eastern perimeter of the ridging gets mixed out more and more as westward adjustments incrementally reduce.

On the basis as described that takes a suggested extended perspective, better to not read too much into hints of any longer term re-set to the entrenched pattern of recent weeks or extrapolating outwards any persistent recurrence factor of the same through any greater part of the summer..

I enjoy watching how the NWP projection evolves in relation to developments mentioned in your posts even if some of the terminology goes over my head. A good reminder that NWP models don’t drive the weather. They merely try to figure it out  

[sheikhy]

Hot hot hot ecm 06z for saturday!!!!even better than the 00z and on par with ukv or even better!!!no storms except across wales!!!!still updating for sunday......

[damianslaw]

Alot of talk in here about projected temps.. there is a heatwatch thread for just that, please use it and free up the thread for model discussion, rather than simply saying what models are suggesting temp wise. 

[sheikhy]

Ecm 06z for sunday a hot 27 to 28 degrees east mids eastward!!west mids west 22-24 degrees and thunderstorms!

[Scorcher]

18 hours ago, JayAlmeida said:

One thing that has confused my non weather expert brain with regards to the upcoming spell of weather is how are the temps going to be as high as the models are predicting? 

All of that cloud and rain would usually mean suppressed temperatures rather than mid to high 20s.

Because there won't be that much rain and there will be plenty of sun between very isolated showers (that some will avoid completely).

[alexisj9]

4 hours ago, In Absence of True Seasons said:

And weather warnings for 'extreme heat' are/were being released. Laughable really. 

I knew the temps would be downgraded closer to the time, they have been this entire year whenever a hotter spell has been forecasted. It's why I raised a brow when murmurings of "30c!" on Sat/Sun started appearing a couple of days back. No way it was gonna hit 30, the set-up just isn't there for it, especially outside of the West. It's still legitimately cold in the mornings and evenings, and we're struggling to breach 20c most days.

No weather warnings have been released re heat, a heat health warning, is not a weather warning, it's aimed at the NHS and infrastructure.