theweatheroutlook

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VIRTUAL STORMCHASER
16 January 2014 09:54:13


Hi all, can someone direct me to a website that explains what things like:
Outliers
Slack air
Sliders
And other such descriptions/nuances mean??
Thanks in advance!
VSC

Originally Posted by: Chiltern Blizzard 



hmm, I doubt there is any website that provide answer for Slang terms, but ill give it a go. IveBolded terms which you will find info on the internet.
Outliers
on the ensembles ther tends to be trends to follow, milder or colder, or even stable. Usually an outlier is unique ensemble that trends very differently to the rest of the ensemble members.

Slack air
My best interpretation of this - would be slack areas of Low pressure- or even High pressure. Systems either between two larger systems that have all the energy within them... or simply a decaying area of pressure. Typical weather you would expect is decaying or less severe weather phenomena. ie Less wind, less intense rainfall, perhaps less intense temperature gradients.

Sliders
When we refer to Slider Lows we usually mean Low pressure which split from the usual course from mid atlantic up to iceland, and rather diverge from the mother low and reconnect with Low pressures usually over the med. Usually asscociated with Scandinavian basedHigh pressure systems.

http://rgsweather.com/tag/slider-low/ 
This gives diagramatic detail.

These can produce alot of snowfall to the UK (if you remain on the cold side)

Last winter was dominated by such features, with weather systems running up to cold air over the uk stalling then falling south over to France leaving the uk in the colder air, a pretty much perfect weather scenario for widespreadsnow to the uk.

If you have the time, suggest you have a look at the GFS archives to see them develop and move.

Originally Posted by: Russwirral 


If I had time I'd like to create a glossary of weather-nerd slang.... There's loads of it and it must baffle the uninitiated (as it used to me a few years ).... I've listed as many as I could think of in the couple of minutesI have to write this: The Beast, faux-cold, Barlett High, and its slang-slang derivative Uncle Barty, Murr sausage, toppler, Euroslug, Fantasy Island/FI, WAA etc.

Originally Posted by: VIRTUAL STORMCHASER 



Hi Chiltern Blizzard;

I think a page or three including a glossary of the main references, weather terms and slang descriptives would be a great topic for this community to have on this forum. I know a few people that have hovered on this forum and given up because they did not understand most of the info discussed. . I persevered, because I have a very real phobia of thunderstorms (well lightning) and have gleaned lots of info on this subject and as a side effect have taken a much more indepth interest of weather in general... perhaps a "sticky" explaining the rudimentary stuff for people who want to learn to a level a bit higher than "TV Forecasts"
Cheers
VSC
blizzard of 78
16 January 2014 09:59:56
Depending on your outlook the current modelling is either mind numbingly boring or incredibly fascinating, perhaps due to having had to learn patience through the mainly atrocious winters of the 1990's, I now fall into the latter category.

To my mind the most important feature of the the models at the moment is that none of them, ( even the normally ultra progressive GFS) want to remove the the block to our east. Sure they play about with the exact positioning but in the end they all keep it there and as others have pointed out any progged returns to zonality have been continually put back.

Having done an immense amount of model watching over the years, this suggests to me that longer term it is the block which will have more influence on our weather. It is a case at the moment of very very slowly slowly catchey monkey, but I do think at some point we will see a quite sudden movement in the model output towards outcomes favouring the block to our east.
Quantum
16 January 2014 10:00:15

I see little of interest this morning. A weak easterly flow might affect Newcastle for 20 minutes next week but apart from that the output is pants. ECM FI is horrible and not to be looked at over breakfast. Mind you it's all better than this time last year when Penrith was the only town in the uk where it wasn't snowing! Fed up with this miserable weather so feeling grumpy this morning. Andy

Originally Posted by: Andy Woodcock 


I don't know what is up with ECMWF FI but I'm tempted to bin it, it is one of the most unnatural solutions I have ever seen (at least on ECM), that amplification of the polar vortex is just not believable imo. 

Twitter: @QuantumOverlord (general), @MedicaneWatch (medicane/TC stuff)
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.
The Beast from the East
16 January 2014 10:21:46

bitter ridging on the 06z. and the slider may produce snow over northern hills


http://modeles.meteociel.fr/modeles/gfs/runs/2014011606/gfsnh-0-150.png?6

"We have some alternative facts for you"
Kelly-Ann Conway - special adviser to the President
Russwirral
16 January 2014 10:25:07
If i remember correctly - last years cold spells started off in similar fashion. with each chart inching its way to a cold scenario - though we never really saw deep deep cold - we were often 'just' inside the cold air boundary for heavy snow.

I remember excitement building with a few charts in January showing HP to the east, but the charts kept demolishing them with Atlantic front after front, though as we got closer to T+0 the weather fronts started to appear to stall on the charts - then the famous Slider lows started to appear.

Looking at the charts - there has been a few slider lows appearing, but i think the models struggle modelling them, so theres a bit of chaos theory thrown in instead.

If any cold spell develops - it will probably develop very quickly within a very short timescale.


Weather station:
https://www.wunderground.com/personal-weather-station/dashboard?ID=IWIRRAL24#history 
Charmhills
16 January 2014 10:25:23

Its generally unsettled and it stays unsettled well into FI with close to average temps.

Loughborough, EM.

Knowledge is power, ignorance is weakness.

Duane.
The Beast from the East
16 January 2014 10:26:10

http://modeles.meteociel.fr/modeles/gfs/runs/2014011606/gfsnh-0-162.png?6


quite a few changes to the 00z. Still all up for grabs

"We have some alternative facts for you"
Kelly-Ann Conway - special adviser to the President
sriram
16 January 2014 10:26:14
All eyes on Candlemas 2nd February

Candlemas be dry and bright - winter is back with another fright so the folklore goes
Sriram
Sedgley, West Midlands ( just south of Wolverhampton )
162m ASL
The Beast from the East
16 January 2014 10:29:06

http://www.wetterzentrale.de/pics/Rtavn1681.png


not bad

"We have some alternative facts for you"
Kelly-Ann Conway - special adviser to the President
The Beast from the East
16 January 2014 10:30:27

cold but shame no cold pool to tap into


at least it will feel wintry


 http://www.wetterzentrale.de/pics/Rtavn17417.png

"We have some alternative facts for you"
Kelly-Ann Conway - special adviser to the President
Gooner
16 January 2014 10:30:30

http://www.wetterzentrale.de/pics/Rtavn1681.png


If verified I am expecting the CF forecast to have a wintry feel

Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


The Beast from the East
16 January 2014 10:32:19

sadly the renewed jet streak off the east coast will screw us


http://www.wetterzentrale.de/pics/Rtavn18014.png

"We have some alternative facts for you"
Kelly-Ann Conway - special adviser to the President
The Beast from the East
16 January 2014 10:37:19

a poor mans cold snap, Steve Murr's "faux cold"


but better than nothing

"We have some alternative facts for you"
Kelly-Ann Conway - special adviser to the President
Gooner
16 January 2014 10:42:07


a poor mans cold snap, Steve Murr's "faux cold"


but better than nothing


Originally Posted by: The Beast from the East 


Indeed

Remember anything after T120 is really Just For Fun



Marcus
Banbury
North Oxfordshire
378 feet A S L


warrenb
16 January 2014 10:55:18
I actually believe we have an SSW underway right now, and the confusion in the models is reflecting this.

UserPostedImage
Tonbridge 45m 
Quantum
16 January 2014 11:04:24

A bit more amplification on that mid atlantic high and we are looking at a potentially significant cold spell. 

Twitter: @QuantumOverlord (general), @MedicaneWatch (medicane/TC stuff)
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.
Saint Snow
16 January 2014 11:10:40


sadly the renewed jet streak off the east coast will screw us


http://www.wetterzentrale.de/pics/Rtavn18014.png


Originally Posted by: The Beast from the East 


 


You & me both know a strong Jet isn't automatically a bad thing - it depends on its amplification, track & latitude. I remember the Jet being strong in a couple of recent cold/snowy spells.


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
Rob K
16 January 2014 11:18:16



sadly the renewed jet streak off the east coast will screw us


http://www.wetterzentrale.de/pics/Rtavn18014.png


Originally Posted by: Saint Snow 


 


You & me both know a strong Jet isn't automatically a bad thing - it depends on its amplification, track & latitude. I remember the Jet being strong in a couple of recent cold/snowy spells.


Originally Posted by: The Beast from the East 


But on this run it does indeed flatten everything. The latter part of the 06Z is rather different from the 00Z!


But of course with such big uncertainty in the near term, FI is pretty pointless. It's like trying to predict the position of a car in 5 minutes' time when you don't know whether it's going to turn left or right at the next junction...

Yateley, NE Hampshire, 73m asl
"But who wants to be foretold the weather? It is bad enough when it comes, without our having the misery of knowing about it beforehand." — Jerome K. Jerome
Russwirral
16 January 2014 11:35:04

I actually believe we have an SSW underway right now, and the confusion in the models is reflecting this. UserPostedImage

Originally Posted by: warrenb 


 


Its quite possible


 


The whole saga that developed last year - no one could say at any point in time that yup - we are now officially seeing SSW generated weather.  well - after a few weeks they could, but its difficult to tell where the switch happens, or impact begins.


 


Therefore your point about models acting up, and behaving slightly strangley may have a point.


Weather station:
https://www.wunderground.com/personal-weather-station/dashboard?ID=IWIRRAL24#history 
Saint Snow
16 January 2014 11:37:14

It's like trying to predict the position of a car in 5 minutes' time when you don't know whether it's going to turn left or right at the next junction...


Originally Posted by: Rob K 


 



 


Nice analogy


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
blizzard of 78
16 January 2014 11:42:26
From Ian Fergusson over on Netweather

fergieweather, on 16 Jan 2014 - 11:10, said:

Actually as of last night, 50% of MOGREPS members heralded an easterly by next Fri and that suite is currently exhibiting near record high levels of Shannon entropy out through day 10 onward. Given some support (albeit still minority) in EC ENS for cut-off low to SE and easterly feed, UKMO urging caution on being too prescriptive end of next week onwards, despite majority westerly solutions. In short: nothing yet discounted.
johnm1976
16 January 2014 11:44:49
I really don't...gulp..think the 6z is too bad. We get a brief cool (not real cold) incursion, the zonal train is somewhat moderated and we end with evidence of HP building over Greenland and Azores high migrating into the mid atlantic and linking up.

Fair assessment? No chance to look GEFS yet.
roger63
16 January 2014 11:45:02

The 06H GFS op , on the face of it,is a very slight swing back to the Atlantic.


However it looks to be an outlier because the Ens on GFS have shifted.


Between 102h and 192 hours roughly 40% of ens have some form of easterly.Also there is evidence of some HP build to the north and some very wintry looking runs.


I won,t get too excited at present.But if the proportion of easterly ENS gets over  50% then there might be room for some optimism.


Have a look at ENS 3,9,11,12,13,17 as examples.

Russwirral
16 January 2014 11:47:03

From Ian Fergusson over on Netweather fergieweather, on 16 Jan 2014 - 11:10, said: Actually as of last night, 50% of MOGREPS members heralded an easterly by next Fri and that suite is currently exhibiting near record high levels of Shannon entropy out through day 10 onward. Given some support (albeit still minority) in EC ENS for cut-off low to SE and easterly feed, UKMO urging caution on being too prescriptive end of next week onwards, despite majority westerly solutions. In short: nothing yet discounted.

Originally Posted by: blizzard of 78 


 


 Record levels of Shannon Entropy = Models trying to make sense of the SSW?


Weather station:
https://www.wunderground.com/personal-weather-station/dashboard?ID=IWIRRAL24#history 
Arbroath 1320
16 January 2014 11:48:59

From Ian Fergusson over on Netweather

fergieweather, on 16 Jan 2014 - 11:10, said:

Actually as of last night, 50% of MOGREPS members heralded an easterly by next Fri and that suite is currently exhibiting near record high levels of Shannon entropy out through day 10 onward. Given some support (albeit still minority) in EC ENS for cut-off low to SE and easterly feed, UKMO urging caution on being too prescriptive end of next week onwards, despite majority westerly solutions. In short: nothing yet discounted.

Originally Posted by: blizzard of 78 



I'd say that's a pretty decent assessment from UKMO. it will be interesting to see if the uncertainty is evident in todays long range forecasts.
GGTTH
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