Model Output Discussions 12z 01/09/2016

[Frosty.]

In the meantime, the models show more hot and humid conditions to come across England and Wales during today and tomorrow with 32c  likely across the southeast and 29-30c tomorrow along with plenty of sunshine but decent cape as yesterday with some big T-Storms breaking out. Yesterday was an extraordinary day with 34.4c 94f..the highest september temperature in over 100 years..hopefully the rest of september will bring more fine and warm weather!

Edited September 14, 2016 by Frosty.

[summer blizzard]

GFS attempts another warm shot in around ten days while the Euro has a much cooler outcome..

[Frosty.]

The Gfs 00z shows a decent weekend coming up across the south of the uk due to a ridge of high pressure and temperatures around 70f but cooler and changeable across the north. Into next week and really the south gets a good deal with high pressure or at least ridging bringing predominantly fine and warm conditions with temps into the low 20's celsius whereas the north and especially the nw look cooler and more unsettled due to lower heights to the northwest but for the south this is a good run overall.

[Gordon Webb]

yep even after this warmth ends it still looks pleasant for more southern areas , on a more now weather still battling with a little mist and fog think the suns going to win out though

[legritter]

Just popped in to look at charts gang ,I,V had a look at charts for about a weeks time and looks like many southern and central areas will see it summery for a while yet ,possibly Low pressure rattling in after that ,Five minutes ago full on sunshine ,we now have thick mist  and last night was probably for me the warmest september night for sleeping i can remember , cheers gang .

[Frosty.]

The Gfs 6z op run ends  glorious with high pressure dominating towards the end of september with power to add into early october and temperatures look great for the time of year too..something to hope for!

In the meantime, enjoy the current very summery weather across southern uk as it then looks like turning cooler and fresher from Friday but for the south of the uk, apart from some rain for a time on friday, the weekend looks fine with sunny spells under a ridge of high pressure but then a band of rain slides south on sun night but is then followed by a largely fine and warm start to next week but across the north / northwest of the uk throughout most of this period it looks cooler and more changeable / unsettled but across the south, apart from a few changeable blips it looks predominantly fine and pleasantly warm and then all parts of the uk become anticyclonic.

[Methuselah]

17 hours ago, CreweCold said:

I thought this reading was questionable? Even so, it seems to have been used by the Metoffice.

And if that were to materialise, it'd give us (with favourable winds) a shot at the all-time record for October?

[Frosty.]

Another thing to note about tomorrow is a higher chance of scattered T-Storms breaking out across the south but again, a hot and humid day with highest temps reaching 30c..this week will be one to remember for all the right reasons, especially for those of you in the s / se but then a band of heavy rain with embedded thunderstorms working across from west to east on friday heralding a cooler and fresher weekend but also a fine one further south.

[phil nw.]

Yes Frosty this week has certainly been one to recall for heat ,and storms in some places.Of course not everywhere has seen the notable max's seen on recent days with a big difference between parts of Scotland and N.Ireland and areas further south and east.

Looking ahead tomorrow sees the last of the real warmth before a change to fresher Atlantic air moves right across during Friday.

temperatures much closer ot normal for mid-September.

The pattern then looks like reverting to the more usual north south split with the Azores high still ridging across the south but more changeable from occasional low pressure further north although nothing untoward yet on the horizon it must be said.

London ens show reasonable temperatures and quite low rainfall. 

 

[Man With Beard]

Another possible warm spell showing on the GEFS 06Z

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=216

Lots of runs with - of course! - stalling trough to the west and heights building to the east. Perhaps 60% of the runs with a variation on this?

Doubt there will be the level of heat we've got currently, but 22C-25C still possible out of many of members, which is still very, very good for late September. Let's hope it co-incides with a weekend for once, if it happens!

[Matthew.]

The 12z GFS shows higher pressure than normal taking Main theme in the reliable timeframe

Edited September 14, 2016 by Matthew Wilson

[Frosty.]

The Gfs 12z shows a pleasant weekend across the south of the uk under a ridge of high pressure but more unsettled and cooler further towards the n / nw but then a weakening band of rain eventually slides southeastwards across the south during the early hours of Monday and early next week looks bright and largely dry but fresh across the south. This run, as with the earlier runs today shows the south having the best of the weather but the Atlantic cranks up more and this brings the more generally unsettled weather further SE at times which would make it feel more autumnal.

[damianslaw]

ECM and UKMO showing azores high ridging northwest to produce mid atlantic heights forcing low pressure to attack from the NW as we move through next week, resulting in a much cooler trend. GFS toying around with this scenario. Until then, one more day of summery conditions, then a cool down for all, generally unsettled in the north, drier and still very pleasant in the south with high teen/low 20 maxima- which is very respectable for mid September.

The atlantic isn't much of a power horse at the moment, traditionally it cranks into about third gear when we hit the autumn equinox, but its interesting to note how meridional the flow has been recently, and how ex hurricane features have simply fizzled.. I think it may be due to the anamolous warm SST's over the north atlantic, resulting in a weaker temp gradient and consequently less fuel to ignite the jetstream, all suggestive we could see much more in the way of anticyclonic conditions this winter season, with low pressure becoming sluggish and taking about turns, with greater continental and arctic influences.. we shall see.

[mb018538]

Not much change this morning - the NW/SE split continues. John Hammond did mention that there could perhaps be brief warmth/heat incursions into the south at times - no real sign of that at the moment, but nothing desperately unsettled either.

[johnholmes]

mb018538 above is along the right lines with the idea of a NW-SE split.

The anomaly charts below suggest this to me, no complete agreement on placement and intensity of either the upper ridge or trough.

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

[stodge]

Afternoon all

Just a quick glance at the charts from me at the moment.

After today's fun and games have passed, it all looks fairly benign for a large part of England and Wales with the Azores ridge never too far away so while the temperature values of the past two or three days may not be reached again, it will still be largely pleasant for many.

Scotland and Northern Ireland are as usual more at risk from occasional Atlantic incursions but nothing too alarming...

Except from GEM whose 00Z output takes a decidedly autumnal turn next week with a vigorous LP developing south of Iceland and notable secondary features swinging through England on a strongly westerly airflow.

It has to be said the GFS 06Z OP is in a very different place and the majority of the members at T+216 still favour an anticyclonic rather than a cyclonic-dominated pattern.

[Gordon Webb]

looks the usual NW/SE split then and on current events potential for worse weather seems to be shifting SE

apologies for been slightly off topic

 

[Faronstream]

5 hours ago, stodge said:

Afternoon all

Just a quick glance at the charts from me at the moment.

After today's fun and games have passed, it all looks fairly benign for a large part of England and Wales with the Azores ridge never too far away so while the temperature values of the past two or three days may not be reached again, it will still be largely pleasant for many.

Scotland and Northern Ireland are as usual more at risk from occasional Atlantic incursions but nothing too alarming...

Except from GEM whose 00Z output takes a decidedly autumnal turn next week with a vigorous LP developing south of Iceland and notable secondary features swinging through England on a strongly westerly airflow.

It has to be said the GFS 06Z OP is in a very different place and the majority of the members at T+216 still favour an anticyclonic rather than a cyclonic-dominated pattern.

Are you saying that it looks more like the areas with high pressure are winning over the Atlantic low pressures? Beacuse i only see wet weather in the long range models, October is predicted to be wet

http://www.cpc.ncep.noaa.gov/products/CFSv2/imagesInd3/euPrecMonInd1.gif

 

 

[Polar Maritime]

The GFS certainly paints a typical Autumnal picture as we head into next week, With the Jet racing over the Atlantic to the UK giving some pretty stormy weather for the N/W Highlands.

Edited September 15, 2016 by Polar Maritime

[Man With Beard]

A promising UKMO for T144 - signs of another stalling trough - though not a lot of support elsewhere in the models tonight 

ECM not showing exactly the same idea but with the main trough far to the west, always the chance of a late summer southerly again

Edited September 15, 2016 by Man With Beard

[Matthew.]

In the short-term prepare for some big storms. Up to half a months rain might fall in a few hours tonight and tomorrow. 

Edited September 15, 2016 by Matthew Wilson

[damianslaw]

Models continue to show quite an anticyclonic influence affecting the south in the main, with a still preety ineffectual atlantic unable to make its presence felt. Unlike recent very mild dry calm spells in September which have tended to come courtesy of robust blocks of high pressure centred close or over the country, this September has been very different so far, with a highly amplified flow, and warm southerly airstreams and now heights to our NE.. 

Next week looks a classic NW-SE divide, with the SE continuing to see pleasant benign conditions, with sunny spells and very mild temps, the further north and west more average temps, spells of rain but nothing exceptionally wet and often cloudy skies.

Always think September marks the end of the first half of the year weatherwise, a long hangover from summer, October marks the start of the colder and by far more interesting second half. September and March are the hangover Sunday months, April and October the start of new beginning Monday months.

[mb018538]

Morning all

Not much change again from the models today (maybe the most consistent we've had for a while!). Low pressure out to the NW, high pressure establishing in the NE and pushing up at times from the Azores. The ECM turns things warm and settled again by the end of the run, but the GFS isn't quite as keen. Looks like a bit more of the NW/SE split carrying on. Not masses of rain on the cards in the next week:

 

[summer blizzard]

Euro goes for a somewhat settled and warm outlook (though it looks to me like the high may retrogress a to the north west at day 10).

GFS goes for a rather average n/s split with mainly westerlies. 

GEM goes full on Autumn by this time next week. 

[Frosty.]

The GEFS 6z mean shows increasing Azores high influence during late september, the 6z perturbations showing more anticyclonic influence which  easily outweigh the more unsettled scenarios so late sept could become warm and settled..