Model Output Discussions 12z 03/05/2016

[Man With Beard]

10 hours ago, Polar Maritime said:

 

5 minutes ago, knocker said:

The Saturday and Monday depressions according to the ecm. I confess I remain puzzled as to why people are still talking about the Scandinavian ridge as I don't see one. Plus there is a 100kt jet stream just the south of the UK next weekend.

That second trough is a horror! Is that really 70 knots into western Ireland or do I need my eyesight testing?

It really was the good the bad and the ugly from the ECM. Good stuff away from the east coast the next 3, possibly 4(if lucky) days with warm or hot sunshine and perhaps a thunderstorm or two. Bad for the coming weekend as the next Atlantic low aims straight at us now. And the low on Monday is just downright ugly. Still time for track or intensity of the storms to change, but that bloke who asked on here about using his convertible next weekend - I'd switch back to the other car sharpish.

[knocker]

1 minute ago, Man With Beard said:

 

 

That second trough is a horror! Is that really 70 knots into western Ireland or do I need my eyesight testing?

It really was the good the bad and the ugly from the ECM. Good stuff away from the east coast the next 3, possibly 4(if lucky) days with warm or hot sunshine and perhaps a thunderstorm or two. Bad for the coming weekend as the next Atlantic low aims straight at us now. And the low on Monday is just downright ugly. Still time for track or intensity of the storms to change, but that bloke who asked on here about using his convertible next weekend - I'd switch back to the other car sharpish.

Yes not looking that clever but I think next weekend and after is a fair way from being nailed down, Certainly worth watching over the next day or two. don't forget those winds are at the 850mb level.

[damianslaw]

Some of the models are showing a very unsettled weekend ahead, good job its not bank holiday weekend, indeed some charts look reminscent of august bank holiday 1986, with a deep low and gales.

[ANYWEATHER]

Good evening all. A great start to this week all starting to go downhill from Tuesday onwards.

[Nouska]

That's quite a vigorous low latitude, for time of year, jet stream being shown on the ECM at 96.

IMO unusual to see the procession of strong lows coming in from the SW as is being modelled in the next 8 days.

Now there's a blocked Atlantic showing at day 10 and maybe a couple of tropical cyclones in the mix.

Edited August 14, 2016 by Nouska

[knocker]

The 6-10 anomalies are more or less in agreement with the deep low over the Pole and trough adjacent to the UK with HP NE Europe. Looking more closely at the beginning of the period the HP is still ridging west over north Scandinavia which I suspect is influencing the first surface  low to track further north. This ridging retreats as the period progresses and with less amplification the upper flow veers more WSW and with brief transient ridging following the passage of the first low appears to not  agree with the appearance of a second low as indicated by the det. run at the beginning of next week.

Edited August 14, 2016 by knocker

[Man With Beard]

Highlights this morning so far - the GFS escapes from the ECM's super-low scenario for early next week by finding another one of its 35C plumes. Unlikely, but nice.

Though it is supported by several ensembles (and several near misses). Some of them are monstrous. Is it a case of cry wolf or right second time?

Edited August 15, 2016 by Man With Beard

[knocker]

Today (and tomorrow)

High Pressure in charge and a fine sunny day. Temps ranging from 17C to 23C.

The GFS this morning has the Atlantic front impacting the far west early Wednesday morning and it makes slow progress eastwards through the day and Thursday although mainly effecting the west and south as a shallow low forms on it. This eventually dissipates and clears away to the east in time for the next depression and associated fronts to arrive on Friday bringing some wet, and possibly windy weather for the weekend aided and abetted by the next frontal system arriving on Sunday. The low associated with these fronts initially tracks more NEN before swinging east over Scotland.

[coldcomfort]

Well all I can say this morning is make the most of the coming 2 or 3 days. Thereafter and despite the GFS op we appear to be staring down the barrel of a really disappointing spell of late summer weather, indeed that description is probably being very charitable as things currently stand, with charts that wouldn't look out of place in late Autumn

[knocker]

The ecm has the low 12z Friday just off the tip of south west Ireland 982mb with associated front orientated N/S down the west of the UK. It slowly moves ENE and fill to be Edinburgh Sunday midnight. So a pretty wet and windy weekend before it completes it's travels to be over southern Norway by 12z Monday. Brief ridging as the next low moves more NEN and the associated fronts impact the NW midday Tuesday.

[Summer Sun]

Some hot runs starting to show again towards months end on the London ens

[northwestsnow]

Very nice 3 or 4 days this week before the Atlantic moves in, all the models pretty much agree on this, the only question now is the duration of this more unsettled weather. Hopefully we will see a slowing down of the jet in the medium term and the re-emergence of some ridging.

[northwestsnow]

6Z continues on from the 0z with the unsettled spell really quite brief - ridging re asserting itself in the medium term with some very useable late summer weather on offer.

 

[stainesbloke]

2 hours ago, northwestsnow said:

Very nice 3 or 4 days this week before the Atlantic moves in, all the models pretty much agree on this, the only question now is the duration of this more unsettled weather. Hopefully we will see a slowing down of the jet in the medium term and the re-emergence of some ridging.

GFS looks quite a lot better than yesterday's output. A poor weekend to come but then high pressure asserts itself, could hold on for the BH weekend with any luck. Though the usual caution required of course.

[MR EXTREMES]

well 6z does not really show bad weather for the south the low from the west will more and likely go n to ne than south southeast.

so id expect the south will be not to bad after maybe a few storms.

northern blocking be a pretty strong feature through this summer so far can we get to winter with more blocking.

been watching solar activity closely and pacific la nina formation with interest.

tbh i dont think the rest of summer will be to bad in the south certainly heights trying to block the zonal train.

although the lows approaching are very well formed could be some fairly wet weather further north and west you go.

[knocker]

The position of the fronts Friday and Sunday according to this evening's GFS

 

[William of Walworth]

From those charts above from knocker : Utter weekend washout for many parts. Probably a Glasto-level (?) mudbath in the SW (near Exeter) -- where we'll be at our penmulitmiate van/festival outing this season.

I see little if any chance right now of those fronts tracking further North. Is my pessimism for a writeoff weekend nailed on, more or less, by now?

 

Or are 'further runs needed'??

Edited August 15, 2016 by William of Walworth

[knocker]

The ecm has a slightly different take vis timing but apart from brief ridging for the south late Sunday/early Monday the weekend is not looking too clever

[Singularity]

It's funny how the models sometimes behave like an enthusiastic fellow who suddenly gets big ideas into their head.

Here, we have a substantial draw of cool air heading southwest from Iceland and into the mid-Atlantic. To the east is a sizable chunk of warm air (the warm sector of a troublesome low  affecting the UK). Logically, this means there is a steep thermal gradient extending well southwest of the UK, and it appears that this will coincide with the decaying phase of the aforementioned low. This is all the excuse that the models need to start developing a low somewhere to the west of Europe, with a ridge to  the east of it. All too often I have seen these funky scenarios fail to materialise as some complication or other unhinges the whole process - but that's not to say it's bound to happen this time. Just more likely than not - or so I dare to assume.

Anyway, I may as well entertain the possible outcomes being explored by the ECM and GFS det. runs this evening. The earlier warm sector has stagnated over Europe so there's ample heat for the low to the west of Iberia and high over Europe to waft in our direction. The jet stream is very meridional during this period, so the heat goes nowhere fast. The net result is some charts that look capable of delivering mid-30s maximums to parts of England even in late August. ECM gets there by days 9-10, but only for the far south, with the north potentially rather cool and perhaps very wet:

 

...meanwhile, GFS takes several days longer, yet manages to produce a higher magnitude event and with the whole UK getting in on the act eventually - this looks on a par with 2003 until you factor in the shorter daylight hours.

  

That's a pretty outlandish solution really. A 35*C turns up in not one but two grid squares over East Anglia for the peak on 29th, so the actual UK Max would perhaps be over 36*C. France spends five consecutive days widely in the high 30s to low 40s. Oh how I fear the hype if the media latch onto this one.

 

Massive caveats do of course apply here; not least that the kind of cut-off low formation essential to a slow build of (lets face it very unhealthy) heat like this is notoriously difficult for the models to get a handle on, and as I implied earlier, has a habit of not quite coming off.

That's why I've felt safe entertaining myself with this output; it's not giving anything at all away 

Edited August 15, 2016 by Singularity

[Matthew.]

Another settled fine day to come tomorrow:

[knocker]

The 6-10 anomalies tonight indicate little apart from quite changeable weather for the UK with around average temps in general.

Intense low over the Pole still with HP NE Europe and some positive anomalies Iceland area. Some ridging in the western Atlantic and the proverbial trough in the east a steady 70-80Kt jet stream blowing straight over the UK during this period. Ergo any Atlantic systems probably tracking NE and no sign of any significant ridging from the Azores.

In the later period with the pattern becoming quite flat the percentage play is quite familiar with LP to the NW and HP to the SW the general tendency will be for a N/S split with the usual caveat that the phasing of this mobile pattern could well allow some dry and quite warm weather in the south albeit the overal temps around average.

Edited August 15, 2016 by knocker

[northwestsnow]

Personally im seeing some positive signs in the NWP this evening, i have a feeling the unsettled weekend may be followed by some ridging again,and potentially some warmer southerly based air being transported north across the British Isles as the next low to the sw stalls..

Time will tell, fingers crossed..

Edited August 15, 2016 by northwestsnow

[summer blizzard]

I'd urge caution in the long term since both the Euro and GFS are showing the hurricane season becoming more active. 

[Evening thunder]

2 hours ago, William of Walworth said:

From those charts above from knocker : Utter weekend washout for many parts. Probably a Glasto-level (?) mudbath in the SW (near Exeter) -- where we'll be at our penmulitmiate van/festival outing this season.

I see little if any chance right now of those fronts tracking further North. Is my pessimism for a writeoff weekend nailed on, more or less, by now?

 

Or are 'further runs needed'??

You may get away with it not being too bad mud wise, the ground is very dry down here at the moment. July was very dry with no significant falls of rain, and August has seen no rain since the one significant fall on the 1st.

I guess it will depend how much rain we see but I'd have thought it would have to be significant to get really muddy, and looking at the precip charts we may not get quite enough if you're lucky.

[knocker]

Today

Another fine warm day unless you happen to be in Clacton.

And the GFS this morning

The weakk front early tomorrow stalls over the west of the UK and the shallow low that forms tracks SE into Belgium leaving most of the country with another fine day. Thereafter it's downhill all the way.

Friday 06z sees the frontal systems from the depression tracking NE arriving in the SW  The depression follows suite and fills slowly to be 1004mb over Yorkshire by midday Sunday. So a pretty wet and windy weekend, possible gales in the south west.

This depression eventually clears east but fronts associated with another depression to the west quickly arrive early Monday to bring showery outbreaks perhaps more likely to effect the north wrest.

The aforementioned depression tracks east and is over Thurso by 12z Wednesday but a shortwave has formed in it's southern circulation and has also tracked east bringing some quite wet weather to all.

No point in looking further ahead but just to mention a tropical depression appears on the scene at the end of the run.

Sidney was so angry at this he attacked a stick