Model output discussion - summer rolls on

[MattStoke]

GFS 12z for this time next week. Blowtorch incoming.

 

[Mike Poole]

GFS 12z following UKMO and ICON, here for comparison at T180, if anything this run going for the plume even more:

GEM at same time, off the rails and into a disused quarry, for the bin, given other output.

Edited July 29, 2018 by Mike Poole

[Weather-history]

Sunday roast

[Summer Sun]

A scorcher from GFS 12z 100F territory in the SE

 

[I remember Atlantic 252]

8 minutes ago, Summer Sun said:

A scorcher from GFS 12z 100F territory in the SE

 

Ay, certainly modelling a plume, short lived though (kinda thankfully) does turn cooler from the south on Tuesday

few days before the best around 26C

[Mike Poole]

I've been mainly posting charts tonight at T180 to give easy comparison, here's the GEFS ensemble mean at that time, and it is significant I think:

The shape and angle of the high on the mean pressure chart is strongly suggestive of some time of plume scenario by next weekend. Leading maybe to this, purples in the UK who'd of thunk it. And GFS under does temperatures, 'tis often said!

Models definitely firming up on next weekend!

Edited July 29, 2018 by Mike Poole

[SMU]

The threat of the record going this year has been very real & the dates earmarked 5th / 6th havent really changed in the last few days - we could still do with more of a southerly component - but we are homing in on a possible shot at 39c. 

Last week we missed due to the upper air being far east & timings - this time around availability of heat looks more significant & the source certainly 4-5c hotter....

[Singularity]

 

During the crucial period around this coming Friday, the upper westerly flow is a bit weaker on this run - hence the 'heat low' takes longer to move NE - but it's still flat, with the upstream Atlantic trough slightly sharper but not digging any further south toward the Azores.

Still plenty of time for corrections to both of those factors. My 'dangerous heat threat level' has increased a bit since this morning.

At the least, there's a good chance that this summer will bring yet another run of at least a few days widely hitting the high 20s to low 30s. A big contrast to today's cool, wet and windy conditions that's for sure!

[Mike Poole]

ECM T96 digs a much bigger trough in the Atlantic than UKMO, this could get interesting, charts ECM first:

Edit: T144, could get more interesting I would suggest ?

Edited July 29, 2018 by Mike Poole

[Captain Shortwave]

   

   

Well then, only five days away and the ECM says the 16C isotherm makes it into southern England. Sunny for pretty much everyone and becoming hot in the south from Thursday onwards. To be fair the UKMO and GFS are pretty close to this.

For comparison, the GFS actually looks almost identical at this point whilst the UKMO has that more developed albeit shallow Atlantic trough.

   

The ECM develops a heat low and drifts this north to the west of the UK with the intense heating drifting ever closer. Any extra depth on that weak trough early on would push the heat up faster though so certainly worth looking out for.

Edited July 29, 2018 by Captain Shortwave

[Mike Poole]

So why is the ECM T144 interesting? here it is

 It is backing other runs, ops or ensembles, for a UK high shaped which is highly likely to draw up a plume of hot air from the south. Let's see what happens as the rest of run dribbles out!

[mother nature rocks]

ECM 12z @ 168 hrs, looking pretty impressive especially compared to last 0z run. Good set of runs this evening.

MNR

 

Looks very similar to GFS 12z which is fantastic considering they seem to argue about absolutely everything. Roll on next week/end!!!

Edited July 29, 2018 by mother nature rocks

[Mike Poole]

Them plumes, them plumes, they push on through, certainly on as the ECM's take on things,but what's following on after? ECM at T192:

Edited July 29, 2018 by Mike Poole

[Mike Poole]

ECM at T 240, what a complete mess, I'm not getting it here's the charts

whichever direction we're headed, I don't think its this one, happy to be proved wrong as always. 

Edited July 29, 2018 by Mike Poole

[mother nature rocks]

3 minutes ago, Mike Poole said:

ECM at T 240, what a complete mess, I'm not getting it here's the carts

whichever direction we're headed, I don't think its this one, happy to be proved wrong as always. 

With gentle breezes and ok uppers I think it would bring a lot of usable weather and generally warm so (if it materialises) it gets the thumbs up from me. Not a bad run all in all.

If it went further would not be surprised to see much warmer uppers pushing up from the south again. Rinse and repeat summer!!

MNR

[Frosty.]

Nice to see the warmth / heat (564 dam) returning following this cooler atlantic blip, I like these Ecm 12z charts, plenty of high pressure with temps back up to the high 20's / low 30's celsius across the south and very warm for most other areas.

[Craig84]

What I find fascinating is that normally, following any modelled plume, the jet quickly ramps up and blasts it all away. The 216 and 240 charts while being a bit of a mess, shows this just isn’t happening. Certainly not normal service this year!

 

 

 

[Frosty.]

Following this cooler unsettled weekend, the week ahead will improve considerably with high pressure building in and for the south, the recent very warm / hot conditions return. The GEFS 12z mean looks very nice in a week's time doesn't it.☺

[johnholmes]

I would not put too much credence on that evolution, certainly the last runs of the 500 mb anomaly charts do not support that outlook.

Will post the charts and more comment tomorrow.

[Singularity]

With the ECM 12z along such similar lines to the GFS 12z, having also reduced the pace with which the heat low moves east, I'm led to the conclusion that the Nino forcing now places us at a medium level of risk of seeing some severe high temperatures next weekend.

I would say high if it wasn't for the fact that the heat low could potentially come together further east, counteracting the further slowdowns to the eastward movement (assuming they occur).

Even if we do escape this weekend, I can see a continued risk the following week, as I can see background support for the main Atlantic trough to become more of a factor while out west of the UK, potentially coming up against the mega-plume as it tries to take a boat trip from Portugal out into the N. Atlantic. GFS has yet to even begin to capture this next stage, but ECM's had a go at it this evening - it just needed to offer more upper-level support to the trough that spends four days visiting the Azores.

Brace yourselves - we're going to be living dangerously this August.

[Mike Poole]

The ECM ensemble mean looking good for UK high to be re-established T144:

Signal weaker at T240:

As you would expect given uncertainty, we do need to wait for more runs regarding the week after next!

Edited July 29, 2018 by Mike Poole

[chapmanslade]

I think there are far better chances of heat records going next weekend because this time France is properly hot rather than just late 30C's. There is a very real risk of the French record high (44.1C) going either Sunday or Monday according to the GFS around the Bordeaux area with 850's of 28C or more. The big question is how much this advects North and the timings.

[damianslaw]

Various options on the table this evening, as we move into August, but all with the theme of further very warm/hot conditions. One of three scenarios for next weekend:

1. UK ridge builds over the UK trapping very warm uppers underneath, resulting in widespread mid 20's - low 30's maxima, but also chance of one or two thundery outbreaks thanks to the cold frontal feature set to move SW on Friday also being trapped within

2. A heat low disturbance builds out of Biscay and to our SW shores, its orientation will mean the difference to possible mid 30s maxima in SE hotspots, or generally just high 20's with cloud invading from the east

3. A southerly plume airflow, bringing chance of localised downpours but generally very warm/hot humid conditions, could be quite cloudy which will suppress temperatures

Longer term - a probable rinse and repeat pattern, with the atlantic trough stuck out to our west sharpening to produce another plume scenario, but then wouldn't be surprised to see another repeat of this weekend again, with the jet having a bit more vigour about it next month compared to recent months.

We had a similiar pattern I think in August 1997 one of the hottest on record but also very wet, with plume events galore, however, the trough managed to break through the UK on many occasions, and was a very sharp feature hence pulled in long drawn southerlies, reason why it was very wet and thundery, this August we are likely to see it further west more, hence more drier conditions than then.

 

 

[Mike Poole]

It's pub time folks , ICON 18z reinforces what we think we know,  heat returning, and quickly.  T120 the end of this run:

It's not this run, it's the trend!

[95 Degrees]

Exciting times for heat fans. A real potential for a repeat of last Thursday to take place late this week and into next week, but with much hotter air over Spain and France, 36-37c possible in the London area if things stay as projected. Not sure I agree about the French record going as that was sustained over an exceptional summer (2003) but certainly 40-42c is possible with 45c in Spain. Still more runs needed until this can be concluded though.

Edited July 29, 2018 by 95 Degrees