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Stormchaser
08 December 2014 17:31:24


Yes Beast, interesting to see where/ what would happen to that low at mid latitude coming off the Eastern seaboard. With the North Western Atlantic looking completely blocked on Christmas Eve, it leads the imagination into all sorts of territory.


http://jpwxcharts.blogspot.co.uk/2014/02/blog-post.html


Originally Posted by: White Meadows 


It's a good jump towards a weaker jet and more blocked outcome beyond day 10 from the GFS 12z op run when compared to previous runs.


The GFSP 12z op run manages to be a bit more amplified out to day 14, but then phases the southern and northern jet arms to pile energy NE, which is a shame as a low dropping west of the Azores in similar fashion to the GFS 12z op run would have taken the northerly to the next level rather than blasting it aside.


The suggestion of high latitude blocking starting to develop seems stronger on the GFS run compared to the GFSP.


As the latter is the first run of the parallel in several days, the inherent variability between runs can't be accounted for using trends and such, so we can only sit back and see if the trend starts to become evident over the coming days, while keeping an eye on Ferguson's snippets of insight into the Met Office thinking and MOGREPS/EC ENS signals.


 


MJO Update


Latest MJO modelling shows phase 8 being reached at around 0.5 amplitude and then the solutions diverge. ECMF actually makes it to phase 1 before it all fades away, though only just. UKME and GEFS have it crashing in phase 8 (unusually close agreement at that point) but GEFS follows this up with significant amplification in phase 1/phase 2 but that's way too far off to give much consideration too.


Compared to yesterday GEFS and UKME have changed little, but ECMF has continued a trend that it's followed all week, taking the MJO a bit further along the phase 7-8-1 journey with each new update.


I hope to sort out an issue with my cut/paste function shortly, after which I can resume posting charts and/or links on this matter 


If you have any problems or queries relating to TWO you can Email [email protected]

https://twitter.com/peacockreports 
2023's Homeland Extremes:
T-Max: 30.2°C 9th Sep (...!) | T-Min: -7.1°C 22nd & 23rd Jan | Wettest Day: 25.9mm 2nd Nov | Ice Days: 1 (2nd Dec -1.3°C in freezing fog)
Keep Calm and Forecast On
idj20
08 December 2014 17:37:03


 


 


Me to ive learnt a lot from this forum still don't quite understand the dam lines though! 


Originally Posted by: John Tempest 



 In a nutshell, in the winter season, the 528 DAM line is where the parameters are ideal for snow production/falls - something to do with the "thickness" of the atmosphere. Values higher than that (546 DAM) and precipitations are likely to be of rain. We would get most excited if the 510 line is sitting over Southern England and accompanied with a north east wind.

However, it is a really rough guide and is a small part of a wider forecasting tool (850 hpas which is air temperature and pressure at the 1,500 metres level, etc).

At least that's what I know of.


Folkestone Harbour. 
Matty H
  • Matty H
  • Advanced Member Topic Starter
08 December 2014 17:40:46


 


 


Me to ive learnt a lot from this forum still don't quite understand the dam lines though! 


Originally Posted by: John Tempest 


These may be of use to you


 


http://www.theweatheroutlook.com/twocommunity/default.aspx?g=posts&t=2206


http://www.theweatheroutlook.com/twocommunity/default.aspx?g=posts&t=2207


nsrobins
08 December 2014 17:41:49

My interest is just starting to be tweaked by the possibility of something later on Saturday. The last few runs have developed a circulation on the clearing cold front as it exits into the Channel, and with circa -4 to -5 uppers pushing under the trough and nocturnal cooling, some areas inland in the South may get a wintry mix Sat evening. Worth watching for as we wait for the MOGREPS induced HLB later in the month.


Neil
Fareham, Hampshire 28m ASL (near estuary)
Stormchaser, Member TORRO
Gooner
08 December 2014 17:42:31

As someone who lurks on these pages often, I have to say just how valuable and educational this page is for me and others like me who don't know of the technicalities of what the charts are showing or predicting. SC and Gibby provide a perfect ballance between the technical explanations of what's being seen, and language that your everyday man in the street like me can understand. I also enjoy Gooners JFF's and try not to take them too literally.
At this time of year I particulary look forward to hearing from Steve Murr, as there always seems to be a chance of something more wintery occuring when he wakes from his slumbers!
You might think you are just talking between yourselves, but there are those who watch and listen from the outside who very much appreciate what is said in this forum. Thank you.

Originally Posted by: andykinch 


Thanks Andy , though they really are for fun .


Hopefully many to come in the weeks ahead


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


Jive Buddy
08 December 2014 18:05:36


 


 


Me to ive learnt a lot from this forum still don't quite understand the dam lines though! 


Originally Posted by: John Tempest 


I've been on the forum for around 13 years, and all I've learnt is that there are lines, dam lines, and statistics


It's not over, until the fat Scandy sinks.....

Location: St. Mary Cray, S.E. London border with Kent.
Osprey
08 December 2014 18:05:46

As someone who lurks on these pages often, I have to say just how valuable and educational this page is for me and others like me who don't know of the technicalities of what the charts are showing or predicting. SC and Gibby provide a perfect ballance between the technical explanations of what's being seen, and language that your everyday man in the street like me can understand. I also enjoy Gooners JFF's and try not to take them too literally.
At this time of year I particulary look forward to hearing from Steve Murr, as there always seems to be a chance of something more wintery occuring when he wakes from his slumbers!
You might think you are just talking between yourselves, but there are those who watch and listen from the outside who very much appreciate what is said in this forum. Thank you.

Originally Posted by: andykinch 


Couldn't agree more!


Nobody likes a smartass, especially another smartass...
If it ain't broke, don't fix it!
Essan
08 December 2014 18:16:12


 I've been on the forum for around 13 years, and all I've learnt is that there are lines, dam lines, and statistics


Originally Posted by: Jive Buddy 




Damned if I know!


Andy
Evesham, Worcs, Albion - 35m asl
Weather & Earth Science News 

Anyone who is capable of getting themselves made President should on no account be allowed to do the job - DNA
Retron
08 December 2014 18:25:44


It is, but at the same time he left because he was annoyed by someone's (remain nameless) summer LRF forecast. To be honest I've no time for either. It's just a weather forum.


Originally Posted by: Matty H 


Actually it was someone who said "it's going to be X degrees on suchandsuch a day", when all the models were showing something like 5 degrees lower as the max. They didn't offer any substantiating evidence for their claims and when they fluked it and it really was that warm in a few places, quite a few people suggested they deserved praise for getting it right. I disagreed, as it was purely a lucky guess.


That, added to the mild-ramping which was going on regarding March in general, was enough to make me leave for "a few days". As it happened, I carried on reading posts on the site from time to time, and Netweather too, but rather enjoyed having some time away from it all during my least favourite time of year.


I'm still around but have to admit it's much more relaxing taking a back seat from it all!


(And just to bring this on topic, if you look through the 12z GEFS runs you'll see all sorts of "interest" going on to the NE in many of the members. I reckon something's brewing, but it's out in low-res land (ie day 10+) and at the moment it's like chasing a mirage... and indeed, the majority of runs both in GEFS and ECM continue to show a mobile "sine wave" picture, albeit not an especially mild picture overall. Given the various hints, tweets, bits of ensembles we get to see I wouldn't be at all surprised to see some notably cold runs re-appearing in the ensembles by this time next week.)


Leysdown, north Kent
Essan
08 December 2014 18:29:54


 


Actually it was someone who said "it's going to be X degrees on suchandsuch a day", when all the models were showing something like 5 degrees lower as the max. They didn't offer any substantiating evidence for their claims and when they fluked it and it really was that warm in a few places, quite a few people suggested they deserved praise for getting it right. I disagreed, as it was purely a lucky guess.


That, added to the mild-ramping which was going on regarding March in general, was enough to make me leave for "a few days". As it happened, I carried on reading posts on the site, and Netweather too, but rather enjoyed having some time away from it all during my least favourite time of year.


I'm still around but have to admit it's much more relaxing taking a back seat from it all!


(And just to bring this on topic, if you look through the 12z GEFS runs you'll see all sorts of "interest" going on to the NE in many of the members. I reckon something's brewing, but it's out in low-res land (ie day 10+) and at the moment it's like chasing a mirage... and indeed, the majority of runs both in GEFS and ECM continue to show a mobile "sine wave" picture, albeit not an especially mild picture overall. Given the various hints, tweets, bits of ensembles we get to see I wouldn't be at all surprised to see some notably cold down runs re-appearing in the ensembles by this time next week.)


Originally Posted by: Retron 



I dont believe you are the real Retron.  I think you are Bren masquerading as MVH pretending to be Retron


Andy
Evesham, Worcs, Albion - 35m asl
Weather & Earth Science News 

Anyone who is capable of getting themselves made President should on no account be allowed to do the job - DNA
Solar Cycles
08 December 2014 18:32:41


 


Actually it was someone who said "it's going to be X degrees on suchandsuch a day", when all the models were showing something like 5 degrees lower as the max. They didn't offer any substantiating evidence for their claims and when they fluked it and it really was that warm in a few places, quite a few people suggested they deserved praise for getting it right. I disagreed, as it was purely a lucky guess.


That, added to the mild-ramping which was going on regarding March in general, was enough to make me leave for "a few days". As it happened, I carried on reading posts on the site from time to time, and Netweather too, but rather enjoyed having some time away from it all during my least favourite time of year.


I'm still around but have to admit it's much more relaxing taking a back seat from it all!


(And just to bring this on topic, if you look through the 12z GEFS runs you'll see all sorts of "interest" going on to the NE in many of the members. I reckon something's brewing, but it's out in low-res land (ie day 10+) and at the moment it's like chasing a mirage... and indeed, the majority of runs both in GEFS and ECM continue to show a mobile "sine wave" picture, albeit not an especially mild picture overall. Given the various hints, tweets, bits of ensembles we get to see I wouldn't be at all surprised to see some notably cold runs re-appearing in the ensembles by this time next week.)


Originally Posted by: Retron 

All the same please stay around Retron, I don't offer praise all that much  ( I'm  grumpy sod must off the time )but I would welcome you back with open arms as your analysis  is up there with the best of them. 

Whether Idle
08 December 2014 18:35:31

 



 


Actually it was someone who said "it's going to be X degrees on suchandsuch a day", when all the models were showing something like 5 degrees lower as the max. They didn't offer any substantiating evidence for their claims and when they fluked it and it really was that warm in a few places, quite a few people suggested they deserved praise for getting it right. I disagreed, as it was purely a lucky guess.


That, added to the mild-ramping which was going on regarding March in general, was enough to make me leave for "a few days". As it happened, I carried on reading posts on the site from time to time, and Netweather too, but rather enjoyed having some time away from it all during my least favourite time of year.


I'm still around but have to admit it's much more relaxing taking a back seat from it all!


(And just to bring this on topic, if you look through the 12z GEFS runs you'll see all sorts of "interest" going on to the NE in many of the members. I reckon something's brewing, but it's out in low-res land (ie day 10+) and at the moment it's like chasing a mirage... and indeed, the majority of runs both in GEFS and ECM continue to show a mobile "sine wave" picture, albeit not an especially mild picture overall. Given the various hints, tweets, bits of ensembles we get to see I wouldn't be at all surprised to see some notably cold runs re-appearing in the ensembles by this time next week.)


Originally Posted by: Retron 


Great to see you back posting Darren!  I hope this is not a flash in the pan, as I for one have missed your input.  Your comment regarding what may happen is a possibility whereas last year the equivalent  felt like an impossibility.


WI


Dover, 5m asl. Half a mile from the south coast.
haghir22
08 December 2014 18:37:28




I dont believe you are the real Retron.  I think you are Bren masquerading as MVH pretending to be Retron


Originally Posted by: Essan 


Lol. 


YNWA
Matty H
  • Matty H
  • Advanced Member Topic Starter
08 December 2014 18:45:31


 


Actually it was someone who said "it's going to be X degrees on suchandsuch a day", when all the models were showing something like 5 degrees lower as the max. They didn't offer any substantiating evidence for their claims and when they fluked it and it really was that warm in a few places, quite a few people suggested they deserved praise for getting it right. I disagreed, as it was purely a lucky guess.


That, added to the mild-ramping which was going on regarding March in general, was enough to make me leave for "a few days". As it happened, I carried on reading posts on the site from time to time, and Netweather too, but rather enjoyed having some time away from it all during my least favourite time of year.


I'm still around but have to admit it's much more relaxing taking a back seat from it all!


(And just to bring this on topic, if you look through the 12z GEFS runs you'll see all sorts of "interest" going on to the NE in many of the members. I reckon something's brewing, but it's out in low-res land (ie day 10+) and at the moment it's like chasing a mirage... and indeed, the majority of runs both in GEFS and ECM continue to show a mobile "sine wave" picture, albeit not an especially mild picture overall. Given the various hints, tweets, bits of ensembles we get to see I wouldn't be at all surprised to see some notably cold runs re-appearing in the ensembles by this time next week.)


Originally Posted by: Retron 


 


I have no idea who this imposter is 


Evening Darren. Welcome kind of back 


Charmhills
08 December 2014 18:48:11


 


 


I have no idea who this imposter is 


Evening Darren. Welcome kind of back 


Originally Posted by: Matty H 


Good to see you posting again Darren.


Loughborough, EM.

Knowledge is power, ignorance is weakness.

Duane.
Gusty
08 December 2014 18:50:17


 


Actually it was someone who said "it's going to be X degrees on suchandsuch a day", when all the models were showing something like 5 degrees lower as the max. They didn't offer any substantiating evidence for their claims and when they fluked it and it really was that warm in a few places, quite a few people suggested they deserved praise for getting it right. I disagreed, as it was purely a lucky guess.


That, added to the mild-ramping which was going on regarding March in general, was enough to make me leave for "a few days". As it happened, I carried on reading posts on the site from time to time, and Netweather too, but rather enjoyed having some time away from it all during my least favourite time of year.


I'm still around but have to admit it's much more relaxing taking a back seat from it all!


(And just to bring this on topic, if you look through the 12z GEFS runs you'll see all sorts of "interest" going on to the NE in many of the members. I reckon something's brewing, but it's out in low-res land (ie day 10+) and at the moment it's like chasing a mirage... and indeed, the majority of runs both in GEFS and ECM continue to show a mobile "sine wave" picture, albeit not an especially mild picture overall. Given the various hints, tweets, bits of ensembles we get to see I wouldn't be at all surprised to see some notably cold runs re-appearing in the ensembles by this time next week.)


Originally Posted by: Retron 


Good to have you back posting Darren. I'm glad you are noticing things to the NE in la la land at the moment.  Lets hope it makes the rocky journey into high resolution.


Steve - Folkestone, Kent
Current conditions from my Davis Vantage Vue
https://www.wunderground.com/dashboard/pws/IFOLKE11 
Join Kent Weather on Facebook.
https://www.facebook.com/stevewall69/ 



Quantum
08 December 2014 18:53:29

Just a warning to everyone regarding 850s, make sure you take into account the context, when this is done they are great but otherwise wet bulb temperatures are a much safer bet, and Brian has added that parameter to the TWO model! But if you insist on using 850s then here are some adjusted benchmarks.


Normal 850hpa benchmark (for convection): -6C


To this add the following adendums:


 


Low pressure (<980mb): +1C


High pressure (>1020mb): -1C


 


Coastal with Sea wind: -1C


Virtually calm winds: +2C


Virtually calm winds and persistent, heavy precipitation: +4C


 


Weak cold front: 0C


Strong cold front: -2C


 


Warm fronts::


Weak: -1C


Strong, with westerly component: +1C


Strong, with no westerly component: +3C


No westerly, subzero temps continuously for 2+ days: +6C


 


Occluded fronts::


Cold weak: 0C


Cold strong: +1C


Warm weak: -1C


Warm Strong: +3C


 


Warm sector: -3C


 


March Onwards: -1C


Cold spell lasting more than a week: +1C


 


 


 


 


2023/2024 Snow days (approx 850hpa temp):
29/11 (-6), 30/11 (-6), 02/12 (-5), 03/12 (-5), 04/12 (-3), 16/01 (-3), 18/01 (-8), 08/02 (-5)

Total: 8 days with snow/sleet falling.

2022/2023 Snow days (approx 850hpa temp):

18/12 (-1), 06/03 (-6), 08/03 (-8), 09/03 (-6), 10/03 (-8), 11/03 (-5), 14/03 (-6)

Total: 7 days with snow/sleet falling.

2021/2022 Snow days (approx 850hpa temp):

26/11 (-5), 27/11 (-7), 28/11 (-6), 02/12 (-6), 06/01 (-5), 07/01 (-6), 06/02 (-5), 19/02 (-5), 24/02 (-7), 30/03 (-7), 31/03 (-8), 01/04 (-8)
Total: 12 days with snow/sleet falling.
Russwirral
08 December 2014 19:15:17
Russwirral
08 December 2014 19:19:14

Low temps on the ensembles for next week for liverpool. Not many snow rows though...so maybe quite dry


 


 



hammer10
08 December 2014 19:43:33
Why is it there are always the same quotes repeated it most annoying sorry if in wrong place but I like to read new stuff not old.
nsrobins
08 December 2014 19:50:20

Why is it there are always the same quotes repeated it most annoying sorry if in wrong place but I like to read new stuff not old.

Originally Posted by: hammer10 


Ah, but some things are worth mentioning twice - or more.


By the way, good to here from you Darren


Neil
Fareham, Hampshire 28m ASL (near estuary)
Stormchaser, Member TORRO
Brian Gaze
08 December 2014 19:55:25


Just a warning to everyone regarding 850s, make sure you take into account the context, when this is done they are great but otherwise wet bulb temperatures are a much safer bet, and Brian has added that parameter to the TWO model! But if you insist on using 850s then here are some adjusted benchmarks.


Originally Posted by: Quantum 


Yes, it's available under GFS - Other+- as a derived variable. It's not a native GFS one. I can't remember whether the GFSP has it.


PS: Welcome back Darren!


Brian Gaze
Berkhamsted
TWO Buzz - get the latest news and views 
"I'm not socialist, I know that. I don't believe in sharing my money." - Gary Numan
David M Porter
08 December 2014 20:13:58


 


Actually it was someone who said "it's going to be X degrees on suchandsuch a day", when all the models were showing something like 5 degrees lower as the max. They didn't offer any substantiating evidence for their claims and when they fluked it and it really was that warm in a few places, quite a few people suggested they deserved praise for getting it right. I disagreed, as it was purely a lucky guess.


That, added to the mild-ramping which was going on regarding March in general, was enough to make me leave for "a few days". As it happened, I carried on reading posts on the site from time to time, and Netweather too, but rather enjoyed having some time away from it all during my least favourite time of year.


I'm still around but have to admit it's much more relaxing taking a back seat from it all!


(And just to bring this on topic, if you look through the 12z GEFS runs you'll see all sorts of "interest" going on to the NE in many of the members. I reckon something's brewing, but it's out in low-res land (ie day 10+) and at the moment it's like chasing a mirage... and indeed, the majority of runs both in GEFS and ECM continue to show a mobile "sine wave" picture, albeit not an especially mild picture overall. Given the various hints, tweets, bits of ensembles we get to see I wouldn't be at all surprised to see some notably cold runs re-appearing in the ensembles by this time next week.)


Originally Posted by: Retron 


Welcome back, Darren!


Lenzie, Glasgow

"Let us not take ourselves too seriously. None of us has a monopoly on wisdom, and we must always be ready to listen and respect other points of view."- Queen Elizabeth II 1926-2022
Gooner
08 December 2014 20:21:20

^^^^^^^^^^^^^^^^^^^^^ who


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 


 



Back for Winter, that can't be a bad thing


Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


Stormchaser
08 December 2014 20:55:22

Good show Darren, good show 


 


Back to the NWP output, and I've just watched the ECM unfold.


The +168 to +192 progression had me leaning in a bit and murmuring 'interesting...' but then the following two charts led to a face-palm 


...not because what it does is entirely unreasonable - just rather unlucky if it does manifest; energy phases in the western North Atlantic much like it once looked to do during the next few days, and that results in trough development west of the UK which brings a close to the wild 'cold day, mild day, cold day...' roller-coaster ride.


There's still some positive signs elsewhere though, and with my copy/paste ability restored I can illustrate this:


No chart available for the selected hour. Many charts start at 3 hours ahead, so if you have 0 hours selected try stepping forward or selecting a later hour.  No chart available for the selected hour. Many charts start at 3 hours ahead, so if you have 0 hours selected try stepping forward or selecting a later hour.


The key developments are a hefty, vortex-troubling blocking high extending right up to Siberia, and a slight drop in the Arctic Oscillation, perhaps back to negative - though only just. The GFS run was actually a little better as far as the latter goes, while the GFSP was a little worse.


 


So what might that Siberian block get up to? Well... alongside the benefits in terms of wave-breaking in the stratosphere, there's always the possibility of a stand-off with the UK stuck under a persistent trough.


Then there's the option of low heights sliding underneath and bringing about a cold blast from the east.


Or in this particular case, if the MJO managed phase 8 before crashing, a more momentous shift in the hemispheric setup could take place, in which the Siberian High transfers poleward and blocking comes to dominate the Arctic with a potentially heavy influence on the UK:



 


Now if you're wondering where exactly I stand on this possible MJO influence, based on trends over the past few days, some level of influence seems increasingly likely, but the models are consistent in keeping the amplitude fairly low, indicating that the impacts are likely to be fairly weak. My own expectations had been shifting towards us needing to wait for the strat. warming to take effect at the end of this month or early next.


Yet the first of this morning's snippets from the Met Office courtesy of Ian Ferguson gave the impression that GLOSEA 5 and the ECM ensembles were trending toward the establishment of a pattern resembling the phase 8 response within the second half of December, as the signs of a -ve NAO were mentioned.


Then came talk of a continental block featuring in around 40% of the ensembles. The fact that it's positioning was not mentioned suggests to me that it's significance is in what it says about the westerly momentum i.e. that it reduces markedly. From that point it's easier to get the high latitude blocking implied by the -ve NAO.


 


So perhaps, then, a 40% chance (based on morning runs though - no word on the evening runs) of the pattern becoming favourable for even a weak MJO to encourage height rises to our NW.


Today's NWP output seems a bit half-hearted on that measure... some hints but not really going for it. I'm left sitting on the fence as far as the MJO goes (let alone a notable UK cold spell this side of the New Year),  but will keep tracking it so that I can get a feel for how well or poorly the models tend to handle it's behaviour.


 


If you have any problems or queries relating to TWO you can Email [email protected]

https://twitter.com/peacockreports 
2023's Homeland Extremes:
T-Max: 30.2°C 9th Sep (...!) | T-Min: -7.1°C 22nd & 23rd Jan | Wettest Day: 25.9mm 2nd Nov | Ice Days: 1 (2nd Dec -1.3°C in freezing fog)
Keep Calm and Forecast On

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