Model Output Discussions 12z 01/09/2016

[damianslaw]

Differences between GFS and ECM - as is often the case when we look towards the medium term, both show a cut off low scenario early next week, and frontal activity disrupts to our west, but in a different way. GFS shows the low developing just off our SW approaches, which would prevent any 'plume' event and build of heights out of europe as we have seen this week, ECM though very keen on a rinse and repeat of this week.

Not sure how things will pan out, should become clearer on Sunday when the trough feature makes its presence felt. GFS though performed very well last week in terms of ex hurricane Gaston, ECM was much slower in this regard.

September isn't though looking like being a very dry one, especially in the west, the next few days could bring quite a bit of rain.

There are some similarities between now and September 2009 - which brought trough disruption and wafts of warm southerlies with heights to our east.. mmm if this continues through October, could be the sign that the atlantic will be weak feature as we enter winter season eventually coming unstuck and we see those continental (and colder) influences (lets hope for a no Nov 2009 repeat though)... dominate.

[Man With Beard]

GFS 18Z ... balmy ... Or just barmy? 3 days above 30C in there. Mid September? More like mid July ... in the south of France!!

[knocker]

Today.

A cold front will cross the country bringing rain to N.Wales, northern England, Ireland and in particular Scotland. It will clear to the North Sea during the day leaving everyone in a much cooler airmass.

The GFS for the next ten days.

A front tracks SE across the UK on Saturday giving way to some temporary ridging before the next Atlantic system sweeps in from the west By Monday 00z and it's this system with the upper trough stretching way down south that disrupts forming a cut off upper low to the south west

This leads ro a rather complicated surface analysis of a large, slack, unstable area to the south which may nudge north during the week and bring some very warm temps once again to the south. On the other hand the HP to the NE and SE may become more influential and form a barrier cutting the LP of at the pass, so to speak. Ot the cut off upper low may be orientated differently........................It's a scenario which can take a number of turns in the interim.

 

 

Edited September 8, 2016 by knocker

[mb018538]

Morning all - both the GFS and UKMO this morning show some very very/hot air being wafted our way by the middle of next week. 850s exceeding 15c once again, and favoured spots should climb into the high 20s and maybe even 30c. After this things get more uncertain...

[knocker]

Tricky business

[Summer Sun]

Warm to very warm for most of next week for the south and SE fresher air for all by the Saturday

GFS get's the blowtorch out again for the south

This heat then extends north for a time

Edited September 8, 2016 by Summer Sun

[mb018538]

ECM keeps the heat in the south for most of the midweek period like the other big two - before a breakdown eventually makes inroads. Looks like another tropical disturbance could come into play by the end of the run, so one to keep an eye on:


 

[Singularity]

Amazing isn't it. GFS, GEM and seemingly UKMO all jump on the exceptionally high temperature bandwagon (we'd leave 2006 in the dust as we passed mid-month), only for ECM to get cold feet and step off... Or at least hang from the side as it almost brings the plume in despite placing the cut-off further east.

You know, it's actually feasible that the sheer amount of heat (above normal) at the lower latitudes forces strong poleward movements of hot air to occur via dramatic buckling of the jet (gravity waves I think I've seen it called). This doesn't make anticipating them any easier but could factor into longer term climate projections of the evidence builds in favour 

Note though that this does not determine where plumes occur - that's where forcing associated with GWO for example comes into play.

Edited September 8, 2016 by Singularity

[NO LONGER POSTING]

One thing is for sure, unless this heat stops being pumped north over us and over to our east, the continent is going to be warm to very warm as we head into Autumn and winter.

 

[mb018538]

20 minutes ago, Surrey said:

One thing is for sure, unless this heat stops being pumped north over us and over to our east, the continent is going to be warm to very warm as we head into Autumn and winter.

 

Well as January-June was globally the hottest ever recorded (since 1880), you have to feel that it's inevitable.

Just look at all the red!

 

The only area that is really below average is a portion of South America. There's a very high amount of much warmer/record temps globally. You have to feel this will impact on our winter weather again - I for one feel it will again be stormy, pretty mild and wet.

[legritter]

7 minutes ago, mb018538 said:

Well as January-June was globally the hottest ever recorded (since 1880), you have to feel that it's inevitable.

Just look at all the red!

 

The only area that is really below average is a portion of South America. There's a very high amount of much warmer/record temps globally. You have to feel this will impact on our winter weather again - I for one feel it will again be stormy, pretty mild and wet.

Morning all ,And January 1881 produced the great southern blizzard , back on topic and looking good for the lions share of good weather for the south in nearer time frame of models ,cheers gang .

[Ben Lewis]

15 minutes ago, mb018538 said:

Well as January-June was globally the hottest ever recorded (since 1880), you have to feel that it's inevitable.

Just look at all the red!

 

The only area that is really below average is a portion of South America. There's a very high amount of much warmer/record temps globally. You have to feel this will impact on our winter weather again - I for one feel it will again be stormy, pretty mild and wet.

And look what happened the following month https://en.wikipedia.org/wiki/Blizzard_of_January_1881

 

[sundog]

16 minutes ago, Ben Lewis said:

And look what happened the following month https://en.wikipedia.org/wiki/Blizzard_of_January_1881

 

But the charts that were shown are from June 2016,they aren't from 1880.

??????

[mb018538]

Apologies for going slightly off topic - I made that sound like 1880 was exceptionally hot - the point I tried (and failed!) to make was that the data only began in 1880. So the hottest since records began. I guess it's somewhat model related, as all the heat around is undoubtedly playing havoc with extreme occurrences right around the globe.

[Man With Beard]

3 hours ago, knocker said:

Tricky business

Yes Knocker, if mean pressure to the east was a bit higher e.g. 1025mb or higher, and for a couple of days, I'd feel more confident about there being a block able to stop anything in the Atlantic moving in a bit faster. But what we have to the east looks at great risk of being flattened. Not to say that is what will happen, just I'm a bit more nervy about calling a warm/hot week at the moment compared to some other set-ups we've had this summer.

[knocker]

Well I'm very nervy about calling a hot couple of days MWB looking at this morning's EPS and even that would be confined to the SE. Not unlike the det. run. It's all so dependent on all the pieces falling into place and anything, such as the cut off low being a tad further north,  could throw the analysis out of kilter.

[MR EXTREMES]

13 hours ago, damianslaw said:

Differences between GFS and ECM - as is often the case when we look towards the medium term, both show a cut off low scenario early next week, and frontal activity disrupts to our west, but in a different way. GFS shows the low developing just off our SW approaches, which would prevent any 'plume' event and build of heights out of europe as we have seen this week, ECM though very keen on a rinse and repeat of this week.

Not sure how things will pan out, should become clearer on Sunday when the trough feature makes its presence felt. GFS though performed very well last week in terms of ex hurricane Gaston, ECM was much slower in this regard.

September isn't though looking like being a very dry one, especially in the west, the next few days could bring quite a bit of rain.

There are some similarities between now and September 2009 - which brought trough disruption and wafts of warm southerlies with heights to our east.. mmm if this continues through October, could be the sign that the atlantic will be weak feature as we enter winter season eventually coming unstuck and we see those continental (and colder) influences (lets hope for a no Nov 2009 repeat though)... dominate.

absolutely agree with everything you said.

the gem is just wow! slack heights humid at times i expect very wet at times but theres no doubt the zonal train is not as bullish so far.

the ecm and gfs have been extremely at odds with each other for sometime and id expect the models to be very unpredictable due to a more active hurricaine season.

any way the models do suggest some humid weather to be had at times with slow decline into autumn.

[Summer Sun]

GFS 06z shows increasing heat on Monday and Tuesday for the south and east

By midweek it turns fresher with the SE maybe just reaching the mid 20's

Edited September 8, 2016 by Summer Sun

[Singularity]

Dreadful consistency from GFS - but faster arrival and departure than originally projected seems to be a common theme with these plumes. Here's hoping this time around is an exception and we can get a longer warm spell.

[Summer Sun]

Monday, Tuesday and Wednesday looking very warm for many parts close to hot in parts of the south

By Thursday the heat is more restricted to the SE with fresher air slowly but surely moving in from the west

UKMO looks very warm too possibly some thunderstorms for the south as we pick up more of a continential flow

 

[Captain Shortwave]

Hmm it is interesting to see another spell of warmth or even heat models for next week. 

      

Some hot weather developing by mid-week with temperatures getting to around the 30C mark, a better chance this time of seeing sunnier conditions as we won't drag in the amounts of cloud from the mid-Atlantic as we did this week as the southerly sets up pretty quickly.

 

The UKMO isn't far away either, if anything it puts high pressure in greater control.

      

Low pressure stalls to our south west with the ridge extending to our north east with a south easterly wind. Very warm with sunny spells extending further north and west as the week progresses, though I suspect the far south and south west could see the threat of a few thundery showers.

The GEM is fairly similar to the UKMO in holding the low to our south west for longer but all three pretty much drag the warmest air over the UK by Tuesday onwards so a definite chance of some summer like heat as we move into mid-September.

[Man With Beard]

Now that's a picture from the GEM - warmth penetrating almost all of the UK. And a dose of thunder to follow, perhaps?

   

Edited September 8, 2016 by Man With Beard

[I remember Atlantic 252]

not liking the 13° shown for Thursday, but all FI, generally good charts SS, no doubt the Atlantic will power back in on Thurs (here) Fri (SE) unbelievable trend for this summer, let's hope we can do it again 19th-20th

Edited September 8, 2016 by I remember Atlantic 252

[Singularity]

The high-res ARPEGE has a good setup evolving through Monday day, with the 20*C 850 hPa isotherm closing in on Knocker (now what does Sidney make of that?) by Monday night:

 

Considering UKMO and GEM, the GFS 12z seems a bit too quick to move the low northeast. It would be nice of the quicker solution could turn out to be erroneous for once in a blue moon 

[northwestsnow]

UKMO wanting to extend summer with some lovely warmth pushing into the UK next week

http://old.wetterzentrale.de/pics/Rukm961.html

http://old.wetterzentrale.de/pics/Rukm1201.html

http://old.wetterzentrale.de/pics/Rukm1441.html

Poor sidney !