johnholmes

Just looking at my usual charts to see if there are any signs of a major change in upper wavelength Monday (27 Nov) and a marked shift in the NOAA 8-14 chart issued Sunday evening. On Saturday(Friday evening) and it continued with the 6-10 meridional output. Last evening, Sunday, and it had totally changed, see chart. It is only one output and I always like to see at least 2 showing a similar pattern before suggesting it will be a valid chart. It is also supported to some extent by the ECMWF output for 2 nd- 6 th with a developing ridge bringing a less cold airmass over the UK by about day 3. The 850’s for example show the -5 C retreating north of Scotland in that time frame. Climate Prediction Center - 6-10 Day 500mb Outlook WWW.CPC.NCEP.NOAA.GOV

Raining with temperature on 3.8 C; rainfall total since midnight 8.4 C

Dry and with a lot of cloud, white patchy frost, cars and roofs with the current low on -0.8 C

Saturday 25 November and a look at the 500 mb outputs from NOAA and ECMWF Taking ECMWF first for a change and quick summation seems more trough managed than ridging at 500 MB with the -5 C 850 MB covering much of the country for the first 3 days retreating to approx sw Scotland to Kent by day 3(4/12) NOAA 6-10 and the marked meridional that has developed over the past 4-5 days is very well pronounced. Contour heights have lowered over the UK, a touch below normal I would say for all, with the trough over Europe also quite a marked feature. Upwind we have a fairly strong mainly westerly flow out of America rounding the main trough, still rather distorted ESE-WNW over ne Canada, back to the much flatter pattern off the west coast. A week agao this was a marked trough/ridge pattern. I suspect this had something to do with how the flow developed in our area of interest. So a rather cold pattern seems likely for the next 6-10 days with not much change showing on the NOAA 8-14. Detail of actual weather will keep most of you on your toes as the synoptic models try to deal with the finer detail. Also interesting to watch the ECMWF-graphcast interplay over similar short and longer time scales. Climate Prediction Center - 6-10 Day 500mb Outlook WWW.CPC.NCEP.NOAA.GOV Original post: https://community.netweather.tv/topic/99428-model-output-discussion-mid-autumn/?do=findComment&comment=4958766

Saturday 25 November and a look at the 500 mb outputs from NOAA and ECMWF Taking ECMWF first for a change and quick summation seems more trough managed than ridging at 500 MB with the -5 C 850 MB covering much of the country for the first 3 days retreating to approx sw Scotland to Kent by day 3(4/12) NOAA 6-10 and the marked meridional that has developed over the past 4-5 days is very well pronounced. Contour heights have lowered over the UK, a touch below normal I would say for all, with the trough over Europe also quite a marked feature. Upwind we have a fairly strong mainly westerly flow out of America rounding the main trough, still rather distorted ESE-WNW over ne Canada, back to the much flatter pattern off the west coast. A week agao this was a marked trough/ridge pattern. I suspect this had something to do with how the flow developed in our area of interest. So a rather cold pattern seems likely for the next 6-10 days with not much change showing on the NOAA 8-14. Detail of actual weather will keep most of you on your toes as the synoptic models try to deal with the finer detail. Also interesting to watch the ECMWF-graphcast interplay over similar short and longer time scales. Climate Prediction Center - 6-10 Day 500mb Outlook WWW.CPC.NCEP.NOAA.GOV

Dry with a lot of clear sky, has been an air frost with a low of -0.2 C, currently 0.8 C

Seems fairly cloudy, dry with a low of 5.4 C, higher than predicted

Wow, did not understand a good deal of this but it appears to be a possible 'jump' in forecast accuracy at most time scales. I'd love to be able to chat, (as I used to be able to), with the senior person on duty at Exeter on how they see this developing in the future! From the UK Met website Artificial Intelligence for Numerical Weather Prediction WWW.METOFFICE.GOV.UK Artificial Intelligence (AI) is rapidly advancing and being utilised widely across society, fundamentally changing the way we live and work. well worth reading sorry to interrupt the flow in the model thread. Original post: https://community.netweather.tv/topic/99428-model-output-discussion-mid-autumn/?do=findComment&comment=4956992

Wow, did not understand a good deal of this but it appears to be a possible 'jump' in forecast accuracy at most time scales. I'd love to be able to chat, (as I used to be able to), with the senior person on duty at Exeter on how they see this developing in the future! From the UK Met website Artificial Intelligence for Numerical Weather Prediction WWW.METOFFICE.GOV.UK Artificial Intelligence (AI) is rapidly advancing and being utilised widely across society, fundamentally changing the way we live and work. well worth reading sorry to interrupt the flow in the model thread.

Dry and very mild, cloudy and breezy max gust= 24, no rain and a low of 12.4 C=higher than the average November Max!

Cloudy, dry at the moment but the radar shows some rain moving down from the north is very close; a low of 5.3 C

What an improvement in the past hour, from dull dank and rain to blue skies, cold breeze though, dewpoint slowly falling now 7C from 9C

Not correct, best you look at outputs, and also get hold of UK Met predicted some decent time ahead.

Monday Dry with variable cloud, no wind and a low of 6.8 C

Looks overcast, dry after very slight rain in early hours; 0.2 mm since midnight, current low is 11.0C so very mild, seems a bit breezy

Cloudy still with slight rain; total 6.4 mm since midnight and a low of 6.8 C now on 8.2 C

Mostly clear skies, dry after Davis shows 0.2 mm at 0400(?), current low is 3.9 C, actual min was 3.8 C

A long time since last made notes (=Tue 7/11) now Thur 16/11 NOAA first and quite different charts with the ridge in far west reasonably amplified; the main trough out of the Arctic into ne Canada/US also quite marked, east of this a fairly flat flow but with +ve heights around 50N of about 180 DM, then into some indications of troughing into France then to the Med. The 8-14 maintains this pattern neither amplifying or flattening anything really. Turning to the ECMWF (22-26), much same period as NOAA 6-10 and it starts with fairly marked ridging, centre to wsw of UK, changing to a more trough orientated pattern centred over Scandinavia with slight ridging again into UK and running back into troughing out of ne Canada, thus keeping milder air south of the UK. The 850 T with the +5 C briefly into the far west before the zero C again covers much of the UK most of the time. As the 500 ridge edges in by the period end the zero line edges back east to about N Ireland-Wales-Isle of Wight. The two sets of charts suggest temperatures hovering around normal, a bit below for a time. At the surface ridging giving way to a coldish north of west flow for a time, ending with an other ridge from the Atlantic by the 26 th. Standard rather changeable late November fare really? Climate Prediction Center - 6-10 Day 500mb Outlook WWW.CPC.NCEP.NOAA.GOV Original post: https://community.netweather.tv/topic/99428-model-output-discussion-mid-autumn/?do=findComment&comment=4952440

A long time since last made notes (=Tue 7/11) now Thur 16/11 NOAA first and quite different charts with the ridge in far west reasonably amplified; the main trough out of the Arctic into ne Canada/US also quite marked, east of this a fairly flat flow but with +ve heights around 50N of about 180 DM, then into some indications of troughing into France then to the Med. The 8-14 maintains this pattern neither amplifying or flattening anything really. Turning to the ECMWF (22-26), much same period as NOAA 6-10 and it starts with fairly marked ridging, centre to wsw of UK, changing to a more trough orientated pattern centred over Scandinavia with slight ridging again into UK and running back into troughing out of ne Canada, thus keeping milder air south of the UK. The 850 T with the +5 C briefly into the far west before the zero C again covers much of the UK most of the time. As the 500 ridge edges in by the period end the zero line edges back east to about N Ireland-Wales-Isle of Wight. The two sets of charts suggest temperatures hovering around normal, a bit below for a time. At the surface ridging giving way to a coldish north of west flow for a time, ending with an other ridge from the Atlantic by the 26 th. Standard rather changeable late November fare really? Climate Prediction Center - 6-10 Day 500mb Outlook WWW.CPC.NCEP.NOAA.GOV

Cloudy, dry, current low is 6.9 C

Dry after a light shower around 0300=0.2 mm, a current low of 9.1 C, another mild night, trees look to be swaying quite a bit!

Now got 7/8 As type 1 verging on 2 over me with just a gap to the ne with Cu tops showing, T=11.7 C and Td=9 C, no wind which makes a change from yesterday

Dry with some cloud, a low of 9.3 C so far, mild and no wind after yesterday's high winds

Cloudy with rain at times, rather breezy; ran since midnight=1.6 mm and a low of 7.6 C

Sunday starts with thick fog, some patchy ground frost still showing and a low of 0.8 C, and my coldest night since 27 April