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Brian Gaze
08 September 2020 08:13:25

If we do get the suggested September heatwave (and ECM 0z is the best yet) then this summer will have had a remarkably regular repeating pattern: weeks of westerly weather with stable temperatures oscillating around the average, punctuated by a few days of intense plume heatwave with high pressure to the East.

Zonal pattern early-mid June, most of July, mid-late August; heatwave late June, late July, second week of Aug, second-third week of Sept.

Really bimodal summer. Very little in between. Very different to our ridiculously monomodal winter (wet and windy) and spring (dry and sunny).


Originally Posted by: TimS 


It reflects our polarised political and cultural environment. Somebody up there is having a good laugh I fear. 


Brian Gaze
Berkhamsted
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"I'm not socialist, I know that. I don't believe in sharing my money." - Gary Numan
GezM
  • GezM
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08 September 2020 08:34:10


Amazing charts for September....what a turnaround from 10 days ago....be interesting statistics for this month if this keeps up.....


Originally Posted by: CField 


Sounds about right. The models started changing as soon as I put my September CET prediction in .... 


Living in St Albans, Herts (116m asl)
Working at Luton Airport, Beds (160m asl)
DEW
  • DEW
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08 September 2020 08:44:55

 September has often been a dry and warm month - there have been lots of years wen I can remember school cricket being rained off all summer only for pitches to be baked too hard for playing rugby in September.


Two-week summary picks up the warmth and dryness for week 1 (some rain in the NW)and the fine weather hangs on at least in the S for week 2 but some cold air sneaks in over Norway whose mountains are showing the first 'blue' (day-night below 0C) in week 2. 


 


GFS - W-ly regime for this week turning SW and then S as trough establishes itself W of Ireland Sun 13th brnging up waem and dry conditions. The trough resolves itself into  a closed circuit depression which patrols up and down off the W coast of Ireland through to Thu 24th, balancing the HP over the UK - though the HP is a bit weaker from time to time (Wed 16th, Mon 21st). Ex-hurricane makes its appearance well to the SW on Sun 20th as before but today's forecast has it moving only slowly in contrast to last couple of days - so expect further updates on that. 


GEFS - after a cool spell,very warm in S, then cooling down, average still above seasonal norm but a lot more uncertainty. Individual runs show a few big rainfall spikes in the S from 17th. Somewhat less warm and wetter in Scotland  (and less certain on both counts) with some very cold outliers later on(some of that Norwegian air failing to keep to its side of the N Sea?)


ECM - Similar to GFS but LP is placed further S, near Iberia on Fri 17th, and the ex-hurricane is also putting in an appearance then, a couple of days earlier.


Enjoy this week for what it is and next week for the fun of chart watching.


War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
Ally Pally Snowman
08 September 2020 12:19:38

Next week could see a couple of 30c days. Next Monday and Tuesday could get close to the date records of 31.1c and 30.6c respectively.


 


Bishop's Stortford 85m ASL.
Jiries
08 September 2020 19:07:09


Next week could see a couple of 30c days. Next Monday and Tuesday could get close to the date records of 31.1c and 30.6c respectively.


 


Originally Posted by: Ally Pally Snowman 


Would be lovely to see some heat and keep our early Autumn at bay which had been plaguing this summer since June bar few hot cloudy heatwaves we got.  I hope this heatwave will contain wall to wall sunshine like we had in May.  

Ally Pally Snowman
08 September 2020 19:34:43


 


Would be lovely to see some heat and keep our early Autumn at bay which had been plaguing this summer since June bar few hot cloudy heatwaves we got.  I hope this heatwave will contain wall to wall sunshine like we had in May.  


Originally Posted by: Jiries 


Well the ECM 12z is another scorcher. Would likely gives us a fourth month in a row where 90f is reached.


Bishop's Stortford 85m ASL.
briggsy6
08 September 2020 23:22:23

brilliant. Just as I've put my bedroom fan away, I've got to get it back out again.


Location: Uxbridge
DEW
  • DEW
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09 September 2020 06:52:21

Jetstream mostly from W to Sun 13th with occasional hiccups sliding round to a more SW-ly flow before going into a rather unstable phase with loops enfolding the UK (i.e. running down to the S of UK before returning N) and breaking up again - repeated on Tue 15th , Sat 19th, Thu 24th. Small differences in the position of the loop dictate whether the jet is running from the N or the S over the UK so confidence for our weather is low.


GFS goes for W-lies this week, weakening and turning SWly Sun 13th (cf above) and throwing up a block of HP with S-lies by Tue 15th (though this is further E than yesterday's forecast). Trough follows before new HP over S Norway Fri 18th; after a confused few days, strong ridge of HP to Iceland with LP out to W Thu 24th. That ex-hurricane? sitting well to the SW and not going anywhere.


GEFS shows warm/very warm spell nailed on Fri 11th - Wed 16th in S descending back to norm or a bit below amid considerable uncertainty after 16th. Some rain around after that date with a few runs showing big spikes, dry until then. Scotland warms up more slowly (not until 13th)and has better defined clusters of rainfall spikes ca THu 17th and Wed 23rd.


ECM has nothing much to add (still 12z for THu 17th at time of posting)


 


 


 


 


War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
Saint Snow
09 September 2020 12:06:13

Can someone please open a 'Winter Discussion' thread for Tally?


This thread's becoming so clogged one has to trawl back 3 or 4 posts to get to the lone MO-related post of the day (which is DEW's excellent daily summary)



Martin
Home: St Helens (26m asl) Work: Manchester (75m asl)
A TWO addict since 14/12/01
"How can wealth persuade poverty to use its political freedom to keep wealth in power? Here lies the whole art of Conservative politics."
Aneurin Bevan
tallyho_83
09 September 2020 14:00:52


Can someone please open a 'Winter Discussion' thread for Tally?


This thread's becoming so clogged one has to trawl back 3 or 4 posts to get to the lone MO-related post of the day (which is DEW's excellent daily summary)


Originally Posted by: Saint Snow 


 


I agree - and yes would be nice to have a winter discussion thread.


In the south it has felt like summer since the first day of lockdown on 23rd March. 


Home Location - Kellands Lane, Okehampton, Devon (200m ASL)
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DEW
  • DEW
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09 September 2020 20:17:59


 


 


I agree - and yes would be nice to have a winter discussion thread.


In the south it has felt like summer since the first day of lockdown on 23rd March. 


Originally Posted by: tallyho_83 


Your wish is my command


War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
DEW
  • DEW
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10 September 2020 06:26:07

16 dayer staying warm and dry (exc W/NW Scotland) for this week to Fri 18th, much cooler and wetter next week (exc SE England, and not exactly dry there,either)


GFS - W-ly for a bit turning SW with tropical air being brought up from SW Sun 13th by trough of LP off Ireland; warm spell just about hanging on in the E until Fri 18th by which time the LP centre is over SW Scotland.  On that day intense ex(?)-hurricane  975mb off New England gets caught up in W-ly flow of controlling LP near Greenland/Iceland and arrives Cornwall 1005mb Tue 22nd. then more W-lies alternating troughs and ridges. At the tail end of the forecast Sat 26th, a possible repeat with a new deep LP near Greenland dragging the remains of another hurricane across from the US East Coast. But that comes with a caveat about unpredictability of ex-hurricanes.


GEFS - Irregular rise to Very warm Tue 15th after which most runs back to near normby Tue 22nd but a lot of variationin how they get there, some quick, some slow. Some rain in S from Wed 16th, one or two runs with big totals. Similar temp profile further N but if anything with more variability; likewise rainfall but bigger totals and Scotland gets a bonus wet spell on Mon 13th.


ECM (still 12z after Tue 15th, I may update later) - warm and dry spell more prolonged across all UK Sun 13th to Fri 18th; the ex-hurricane shows up Sat 19th in mid-Atlantic as an independent feature, not dependent on the LP near Iceland which  is much weaker. UPDATE Last couple of days for the 0z run quite different from yesterday's 12z. Sat 19th, the ex-hurricane has headed for Greenland and an enormous northern block of HP with significant LP approaching from Brittany.


 


War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
Saint Snow
10 September 2020 09:32:11


16 dayer staying warm and dry (exc W/NW Scotland) for this week to Fri 18th, much cooler and wetter next week (exc SE England, and not exactly dry there,either)


GFS - W-ly for a bit turning SW with tropical air being brought up from SW Sun 13th by trough of LP off Ireland; warm spell just about hanging on in the E until Fri 18th by which time the LP centre is over SW Scotland.  On that day intense ex(?)-hurricane  975mb off New England gets caught up in W-ly flow of controlling LP near Greenland/Iceland and arrives Cornwall 1005mb Tue 22nd. then more W-lies alternating troughs and ridges. At the tail end of the forecast Sat 26th, a possible repeat with a new deep LP near Greenland dragging the remains of another hurricane across from the US East Coast. But that comes with a caveat about unpredictability of ex-hurricanes.


GEFS - Irregular rise to Very warm Tue 15th after which most runs back to near normby Tue 22nd but a lot of variationin how they get there, some quick, some slow. Some rain in S from Wed 16th, one or two runs with big totals. Similar temp profile further N but if anything with more variability; likewise rainfall but bigger totals and Scotland gets a bonus wet spell on Mon 13th.


ECM (still 12z after Tue 15th, I may update later) - warm and dry spell more prolonged across all UK Sun 13th to Fri 18th; the ex-hurricane shows up Sat 19th in mid-Atlantic as an independent feature, not dependent on the LP near Iceland which  is much weaker. UPDATE Last couple of days for the 0z run quite different from yesterday's 12z. Sat 19th, the ex-hurricane has headed for Greenland and an enormous northern block of HP with significant LP approaching from Brittany.


 


Originally Posted by: DEW 


 


 


Thanks, DEW - interesting MO, with the uncertainty brought by the ex-Hurricanes. Be nice to get a last hoorah of warmth... assuming it comes off



Martin
Home: St Helens (26m asl) Work: Manchester (75m asl)
A TWO addict since 14/12/01
"How can wealth persuade poverty to use its political freedom to keep wealth in power? Here lies the whole art of Conservative politics."
Aneurin Bevan
Ally Pally Snowman
10 September 2020 09:38:14

ECM and it's ensembles look very warm this morning. Looks like we could squeeze 30c again next week.


Bishop's Stortford 85m ASL.
Ally Pally Snowman
10 September 2020 19:49:21

Arpege going for 31c on Monday.


 


Bishop's Stortford 85m ASL.
Heavy Weather 2013
10 September 2020 20:10:40
I was just settling into Autumn mode and this bloody mini heatwave turns up. Irritating.
Mark
Beckton, E London
Less than 500m from the end of London City Airport runway.
DEW
  • DEW
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11 September 2020 06:12:43

GFS - as predicted for a while, W-lies turning SW-ly and bringing in a hot spell early next week but now forecast to be short-lived; peak Tue 15th but LP to the SW develops and there is then the possibility of substantial rain coming to the south on a SE wind (that from BBC longer outlook last night).The LP moves in slowly but is centred in the Channel 1000mb Sat 19th with a long run of SE-lies between it and HP over Norway. Hew ridge of HP from the SW settles over Scotland 1030mb Thu 24th and sticks around with LP never far from the S.  


Ex-hurricanes Fri 18th and Sat 26th both running N to Greenland (the latter 950mb over Newfoundland, can do without that here) and not directly affecting UK on today's forecast, could be different tomorrow.


GEFS - peak temp (10C above norm) on Tue 15th descending to seasonal norm rather bumpily by Tue 22nd - a lot of uncertainty which gets worse after that date. Some rain around in S mostly Wed 16th - Sat 19th, also on isolated runs later. Scotland generally dryer but some runs nevertheless produce big spikes. N Scotland wetter to start with and less of a heatwave though still generally above norm and dryer later.


ECM (mostly yesterday's 12z) looks very like the GFS to Sun 20th though Friday's ex-hurricane less potent


War does not determine who is right, only who is left - Bertrand Russell

Chichester 12m asl
White Meadows
11 September 2020 06:22:25
AJ*
  • AJ*
  • Advanced Member
11 September 2020 08:30:00

I was just settling into Autumn mode and this bloody mini heatwave turns up. Irritating.

Originally Posted by: Heavy Weather 2013 


Yes, it has prompted me to re-work one of Eric Morecambe's finest jokes: "All the right weather but not necessarily in the right order."


Angus; one of the Kent crew on TWO.
Tonbridge, 40m (131ft) asl
Downpour
11 September 2020 09:07:13
Not surprised to see summer weather in summer.

Will be interesting to see if things become more autumnal when autumn begins on 21 September.
Chingford
London E4
147ft
Brian Gaze
11 September 2020 12:03:16

Astonishing GEFS. You do wonder if the rules are being rewritten as we watch.



Brian Gaze
Berkhamsted
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"I'm not socialist, I know that. I don't believe in sharing my money." - Gary Numan
Gusty
11 September 2020 13:12:39


Astonishing GEFS. You do wonder if the rules are being rewritten as we watch.



Originally Posted by: Brian Gaze 


Its out of control Brian.


Steve - Folkestone, Kent
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Saint Snow
11 September 2020 14:21:30

Not just a SE thing, either - this is Liverpool's. A degree less hot and a little more rain in the mix (esp later) but a very similar pattern:




Martin
Home: St Helens (26m asl) Work: Manchester (75m asl)
A TWO addict since 14/12/01
"How can wealth persuade poverty to use its political freedom to keep wealth in power? Here lies the whole art of Conservative politics."
Aneurin Bevan
TimS
  • TimS
  • Advanced Member
11 September 2020 17:36:29
Quite impressive charts. This really does cap off the weirdest of summers.

On the near continent summer has never really gone away.

Macon in Burgundy should be settling into the low 20s with dwindling sunshine and autumn rains by now. Stats for the month so far:

Mean max: 26.9 (+5.0 above average)
Mean min: 13.4 (+1.9)
Rainfall: 0mm
Sunshine: 116 hours (over 10hrs per day).

But it’s only just getting started:

Maxes forecast for next 6 days: 30, 32, 36, 33, 33, 31. No rain forecast until at least next Saturday. Whole of North and Central France already in severe epochal drought.
Brockley, South East London 30m asl
Ally Pally Snowman
11 September 2020 18:18:48

Latest Arpege 30c for Monday 33c for Tuesday. Crazy for mid September.


 


Bishop's Stortford 85m ASL.

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