Model Discussion - 27th July

[damianslaw]

Models painting a different picture compared to yesterday with a much more settled and warm end to the week for southern and central and eastern parts thanks to stronger ridging of heights from the south ahead of a stalling trough to the west - are we seeing the hallmarks of a spanish plume event will have to wait and see.

Hoping we can squeeze at least one good day from the weekend but my fear it is going to be a classic NW/SE divide with the NW either wet or simply overcast whilst the SE rejoices in warmth and sunshine.

Still the charts are making for rather uninteresting viewing - but if we do see a spanish plume we may well have some thunderstorms to be looking out for..

[William of Walworth]

If any NW/SE divide over the weekend leaves the South West on the benign side of the line, then I may have to try quite hard to restrain my happiness/irrelevant joy at current prospects!!

Our last weekend-long 'excursion' of the summer may well end up with synoptics being properly kind to us (= no rain in/near Exeter over the w/e?) for the first time since 2006 ....

Nothing like this looked likely to be on the cards for the Saturday 20th w/e this time last week. Just emphasises how quickly models can alter.

ETA : Not had time to check very latest updates, but fingers crossed that Gibby won't bring discouraging news in this morning's update ...

Edited August 16, 2011 by William of Walworth

[mushymanrob]

well.... theres still an decent chance of a breif hot spell from saturday to monday next. as per usual the southeast are in line for the best of it. beyond that the ecm and gfs differ greatly, the ecm suggest a more seasonal theme with the atlantic dominating whilst the gfs into fi keep alot of potential for heat and thunderstorms with a couple of biscay lows. nice to see even if it has very little chance of varifying.

[shedhead]

My initial take on the overnight stuff is 'been there, seen that, got the t-shirt'. Whilst some drier, warmer weather looks likely across the next week or so, the pattern is still inherently unsettled for most

parts of the country, with any possible heat again likely to be confined to the SE corner. Little to be either optimistic or exited about as far as a protracted nationwide spell of fine weather is concerned in my opinion, but for those looking for a cold start to Autumn the T+384hr is chock full of potential, with the -5c 850mb line already getting close to the Faroes on Sept 1st.

[Gibby]

Good morning.

GFS shows a couple of quiet days with light winds and pleasant weather with some sunshine away from Southern England where a waving trough in the English Channel throws a canopy of cloud across and even some rain tomorrow and Thursday. By Friday and the weekend a ridge builds in giving several days of very warm and bright weather in the south and east, more short lived if at all in the North and West with cloud and breeze from an Atlantic depression giving the risk of rain here later in the weekend. Through the early days of next week a trough from this will give a spell of rain as it moves east cooling things down as it goes. A new ridge then dries things up behind with sunny spells and somewhat cooler weather for midweek. In FI this morning things become more unsettled with time from the south with the whole of the UK joining in with rain at times by the runs end with Low pressure in close proximity and high pressure over Greenland once again.

UKMO follows a similar route through the rest of the week with some very warm conditions developing for the south and east while the North and West come under the influence of an Atlantic Low bringing occasional rain there. It would stay warm in the south and especially the southeast with the risk of a few thundery showers late in the period.

The Fax charts today show a push Northward of the English Channel trough on Thursday with the risk of some heavy rain in the south for a while. Thereafter very warm air engages with the south in response to a ridge over the SE over the weekend.

ECM also follows the route of GFS and UKMO up to the weekend with a potentially thundery trough moving east early next week. There would then be a period of quiet, slightly cooler conditions before a further thundery depression moves North from the continent over the UK with heavy rain for all and much fresher air by Friday.

No major changes in the shorter term pattern shown last night. the bullet points being the sharp rise in temperatures at the weekend although I feel the very highest temperatures will be kept the other side of the channel as cloud amounts could be quite large even in the south if there is a SW component to the flow. The second bullet point is the cold front early next week and its interaction with the potentially hot air and the following evolution of Low pressure from the south shown by both ECM and latterly from GFS too.

[Summer Sun]

ECM tonight is looking quite good for settled weather upto 216h before low pressure takes over,

http://www.wetterzentrale.de/pics/Recm961.gif

http://www.wetterzentrale.de/pics/Recm1201.gif

http://www.wetterzentrale.de/pics/Recm1441.gif

Then a breakdown start's

http://www.wetterzentrale.de/pics/Recm1921.gif

http://www.wetterzentrale.de/pics/Recm2161.gif

http://www.wetterzentrale.de/pics/Recm2401.gif

[bluearmy]

looking at the NOAA cpc update, still managing to hold the upper long wave trough just to the west of the uk with mean surface trough similarly placed. promises a mean s/sw flow with plumes close to the se from time to time. we do run the risk of events such as we will see this thursday though. all this with a mean upper block over greenland - still !!

[damianslaw]

Short term - developing trough feature from the south on Thursday. Expect models to continue to struggle with this feature - its exact path is far from certain.

In this context I remain very cautious with the weekend prospects - developments on Thursday will dictate just how strong any ridging from the south becomes thereafter.

I can't see temps in the 30's as some are suggesting, far too much cloud and the uppers don't look warm enough. Also we will be in a southerly/southwesterly drift. East Anglia best place for any spanish plume. It could easily be a blink and you miss it affair with places orth and west of a line from Southampton to the wash saying what plume whilst being plagued by low cloud and those in the north rain or drizzle.

Next week whilst a long way off isn't promising much in the way of settled warm sunny weather - all models keen on pulling in the trough from the NW and renwed strong heights developing to our north.

I'm not expecting much from the rest of the summer it has to be said.

[mushymanrob]

looks like its been downgraded....again... the real heat/plume now expected into the near continent. saturady looks like the best for heat, with the northwestern half missing out. from sunday onwards back to changable weather as summer 2011 slips away...

[UV-RAY]

looks like its been downgraded....again... the real heat/plume now expected into the near continent. saturady looks like the best for heat, with the northwestern half missing out. from sunday onwards back to changable weather as summer 2011 slips away...

Yes it's been a disappointing Summer for widespread heat, around here in the Ribble Valley temps haven't exceeded 23c. This is now the fourth summer we have had, with temps not exceeding 25c. Looking at the MO, and it's fair to assume that Summer will quietly fizzle away into Autumn.

[nodrog]

Good bye Summer 2011. No return to see just yet. You can tell the weather is pantz as no one is posting here... but hey! Is it me or does Greenland look like the 'blue' 850's look like they are now building with a light spill of a -5 moving into Iceland in FI +324. It's only August and I don't remember seeing this last year. (Im happy to be corrected).

What a difference 16 days make... I know it's early and I don't want to cause a FI syndrome topic but as there this nothing else to 'gab' about I thought I would just post this today... and It's unusual for me cause it's on topic! (In future I will just link the images rather than swamp the forum) .

Oh enjoy a wet and windy spell of weather for us here in Blighty. Looks like some heavy showers going for the SW and South Wales over the next few days and a hint of rual areas seeing temps going to 5 or 6oC at night. Next week looks much the same but thats the beauty of the British weather.

[Radiating Dendrite]

Looking toasty in the SE this weekend, with the 20c 850s flirting with the south coast. Temps should be up into the high twenties/low thirties, probably a max of 32c in the favoured locations, such as West London and towards Gravesend in Kent.

Should then all go bang!

[CLH the red dragon]

Can someone explain why the massive dryness for Wales on Sunday has disappeared to be replaced by a monsoon?

[CasMan]

Anyone know if the South West is going to be warm from Saturday onwards, not sure best place to post this question i am going to Perranporth in Cornwall for a week and hoping for some nice warm sunbathing weather :-), please advise if i need to ask this question somewhere else, and if so apologies.

[Radiating Dendrite]

Anyone know if the South West is going to be warm from Saturday onwards, not sure best place to post this question i am going to Perranporth in Cornwall for a week and hoping for some nice warm sunbathing weather :-), please advise if i need to ask this question somewhere else, and if so apologies.

High teens on Saturday and Low twenties on Sunday at the moment.

[ANYWEATHER]

Anyone know if the South West is going to be warm from Saturday onwards, not sure best place to post this question i am going to Perranporth in Cornwall for a week and hoping for some nice warm sunbathing weather :-), please advise if i need to ask this question somewhere else, and if so apologies.

Looks as though there will be a fair bit of high cloud out West, [Cirro Stratus] associated with that cold front slowly moving East/SouthEast. High teens I expect, but perhaps some thundery downpours developing later into Sat/Early Sun,,,,

[Geordiesnow]

ECM has a warmer/thundery set up showing on tonights run and with the high a bit further West for Saturday, it could mean the front is also further Westwards allowing for more heat to build in. Be interesting how the models handle this as its a pretty fine line regarding a thundery breakdown is concerned.

ECM does tend to show quite a few warmer scnarios whilst the UKMO and sometimes but not always the GFS goes for an less warm set up so be interesting to see who is right? Is there a chance that the ECM has a slight warm set up bias to its output like the GFS seemingly have a cold bias in winter?

[Gordon]

I suspect they'll be a few more twists and turns before Sunday so we'll have to wait and see

although the thundery aspect does not please me but like has been said above , a fine line between that and something completely different occuring

[Gibby]

Hi Folks. Actually managing to get a wifi signal tonight at Brean in West Somerset so here's a go at looking at the 12zs.

GFS tonight shows a waving front over Southern England tomorrow moving away NE later to leave us under a ridge of high pressure before further Low pressure encroaches from the NW over the weekend. Heavy rain is likely tomorrow in the south with heavy showers further north before a dry day develops for many on Friday. Then over the weekend things become quite warm for the south and east before showers break out everywhere on Sunday, heavy and thundery in the SE. Through the early and midweek sections of next week Low pressure to the NW dominates with further outbreaks of rain, some heavy and thundery likely almost anywhere with things remaining a little warm and humid especially in the SE. Through FI low pressure remains in control of the weather either centred near to or over the UK delivering outbreaks of rain and showers almost anywhere with temperatures close to normal.

UKMO shows a trough over South Britain tomorrow moving away NE later but not before delivering some copious rainfall for many during the day. Further North a slack showery airflow looks likely with thunder locally. A ridge is then shown to cross east on Friday ahead of falling pressure as Low pressure from off the Atlantic moves closer and very warm, sultry air interacts from the south making Sunday disturbed and showery with some heavy thunderstorms likely in the southeast. Then as we move into next week things slowly cool down somewhat as winds turn more westerly for a while with sunny spells and showers more likely towards the North.

ECM also looks very disturbed tonight mirroring the other two models up to Sunday. Then over the following 4 to 5 days further Low pressure engaging with warm continental air continues to give the potential for some very wet and thundery weather at times next week.

In Summary after tomorrows rain and showers the weekend looks like warming up, (very much so in the SE for a while). However Low pressure quickly follows with all models looking distinctly disturbed as we move through next week with the potential for further surges of thundery weather from the south at times as well as Atlantic systems close by too.

If I continue to get a signal will be back online tomorrow but back home later Saturday so whatever else happens the reports will return to normal then. Sorry to those who missed my reports from the last day or so.

Edited August 17, 2011 by Gibby

[damianslaw]

Looking toasty in the SE this weekend, with the 20c 850s flirting with the south coast. Temps should be up into the high twenties/low thirties, probably a max of 32c in the favoured locations, such as West London and towards Gravesend in Kent.

Should then all go bang!

Mmmm not sure where you are getting these low 30's from... high twenties at the very very best I suspect - too much cloud, and there won't have been enough time for the heat to properly build..

Will wait and see but I suspect the warmth will be downgraded further - the low pressure to the west quickly squeezing away any plume with winds turning quickly to the southwest/west not due south/south east which is where they need to be for low 30's to occur.

Back to the models - GFS keen on pushing the trough further eastwards this weekend compared to ECM and UKMO who are suggesting stronger ridging ahead of the trough. All eventually pull the trough eastwards early next week with a very disturbed atlantic dominated outlook thereafter.

Summer 2011 has been very dissapointing in the warm stakes for the northern half of the country yet again. We have only seen 25 degrees on one occasion in late June - very very poor indeed, much like the last four summers. If London only recorded one day all summer reaching 25 degrees - people woud be screaming summer 2011 the worst ever... but for us in the north we've become used to it..

Edited August 17, 2011 by damianslaw

[ANYWEATHER]

Well I for ,is going to be realistic and put the Summer in the Coffin and hammer the lid tightly with the first nail as I see nothing remotely Summerlike, in fact pretty grim viewing if you want some late Summer weather. Right up to next weekend ,the last Bank Holiday before Christmas!, is looking very disturbed indeed, Ok you can "Hopecast" as much as you want as some have done all Summer, but for me its time to say "RIP SUMMER 2011"!!!

[Radiating Dendrite]

Mmmm not sure where you are getting these low 30's from... high twenties at the very very best I suspect - too much cloud, and there won't have been enough time for the heat to properly build..

Will wait and see but I suspect the warmth will be downgraded further - the low pressure to the west quickly squeezing away any plume with winds turning quickly to the southwest/west not due south/south east which is where they need to be for low 30's to occur.

Back to the models - GFS keen on pushing the trough further eastwards this weekend compared to ECM and UKMO who are suggesting stronger ridging ahead of the trough. All eventually pull the trough eastwards early next week with a very disturbed atlantic dominated outlook thereafter.

Summer 2011 has been very dissapointing in the warm stakes for the northern half of the country yet again. We have only seen 25 degrees on one occasion in late June - very very poor indeed, much like the last four summers. If London only recorded one day all summer reaching 25 degrees - people woud be screaming summer 2011 the worst ever... but for us in the north we've become used to it..

That was after the 6z yesterday, it was showing 28/29c for London (and with a few degrees added on due to the GFS tending to underdo temps) I plumped for 30/31c.

The 0z has downgraded this event quite significantly now, will probably max out at 26c now I would have thought.

[Paul]

Here's the latest forecast from Michael Fish

[johnholmes]

Nothing on the anomaly charts to hold any hope of a very late summer burst, unsettled for most areas, slightly better for the SE'ern quarter, rather worse for the NW'ern quarter. In the nearer time frame and the models are at sixes and seven's over just how to deal with the weekend, muggy for many before the cold front pushes east through the weekend to bring less humid and still unsettled weather for all, merging into the anomaly outlook.

[Gibby]

Good morning. Through the pouring rain at Brean this morning here's a look at the 00zs.

GFS continues to show a changeable period ahead. After todays front has cleared away we move into a period of warm and humid conditions for several days with Low pressure moving in from the west engaging with warm thundery air drifting up towards the southeast. After a dry start to the weekend for many showers will breakout as time passes with Sunday seeing some thundery ones nationally which follows on into Monday and Tuesday too as thundery low pressure remains close to the SE. Through the middle and end of next week the pattern remains locked with Low pressure near to the NW and West with rain or thundery showers at times for all. Through FI and GFS shows some very Autumnal charts today with the air becoming rather cold for the time of year to the North. This means some potent Atlantic depressions which bring rain and strong winds innitially as one such depression sits over the UK before slightly better conditions develop in the South with time as the Azores High throws a ridge or two our way at times.

UKMO also looks very unsettled this morning though warm and humid for many. Todays rain and showers clear to a brief ridge tomorrow and Saturday when temperatures rise into the warm or very warm category in the south and east at least. By Sunday Low pressure develops around the UK with some potent showers and thunderstorms possible almost anywhere as the instability aloft engages the very warm and humid surface air. This pattern remains in place up to the middle of the week.

The Fax Charts show that after tomorrow and Saturdays ridge humid air moves over the UK with a complex structure of troughs and Low pressure developing over the UK with potential for heavy thundery rain in many places from Sunday on.

ECM this morning offers very little cheer too with just variations on a theme of changeable potentially thundery weather for most at times for the next week before a more mobile Atlantic setup develops by next weekend. The one nugget of comfort is that it will feel warm and humid for most of the time and possibly very warm at times towards the SE particularly early in the period.

In Summary today things look decidedly changeable with no fine weather anywhere lasting more than 48hrs from any of the operationals this morning. All three offer potential for some thundery weather in the next 5 -6 days before a more Atlantic based setup developing thereafter. Indeed GFS goes on to show some particularly potent Atlantic depressions in FI which look more akin to October charts than late August.