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Stratosphere Temperature Watch 2013/2014


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Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.

Do not agree with regard to the warming not propagating down through the strat to

the trop. This will become increasingly obvious  in the NWP charts over the coming

days. If the warming that is showing towards the end of the GFS runs does verify

then with a pre-condiitioned strat this could lead to extensive northern blocking.

 

 

Possibly but its surely going to have to be a further strat warming to turn the weakish blocking on the later frames of the h500 GFS charts over greeny into a stonking big long ridge and surely looking at 5th March at the earliest by then?? could still deliver a massive easterly and I aint giving up just yet but clock ticking, certainly think a below average March on the cards though but for most people in here it would have to be record breaking to salvage anything.

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Lets recap all this in a orderly fashioned way. I will just give you my interpretation (which has not changed since my last posts) using the "list" I made. Anyone can use it and fill in his/hers own view. 

 

This year, do we have a significant stratospheric warming?                           Not really.

Is the warming propagating downwards?                                                        No.Fixed above 20mb.

 

While I don't fully agree with the second point, the first is overwhelmingly the case. The graph below shows the trends of average polar cap temperature (60-90°N) from 150mb to 10mb for 29 SSW in the MERRA data. The composite runs from -70 to +30 days, SSW is day 71 

 

post-2779-0-87038300-1391770400_thumb.gi

 

Compare this to the chart for this winter, day 1 is December 1st.

 

post-2779-0-95728400-1391770560_thumb.gi

 

The obvious thing to notice is the lack of warming higher up at 10mb - as much anticipated it started in early January but really wasn't very strong and struggled to get over 220K. The average at SSW is over 232K - some may suggest that well this is higher but then so are the starting temperatures, however when choosing colder vortex preconditions closer to this winter the average value at SSW is even greater, above 235K.

 

In both graphs, the warming can be seen first at 10mb as expected then trickles down to the lower levels. In the SSW cases the stratosphere becomes warmer with height or at least isothermal in the lower layers whereas this year it struggled to get below 50mb.

Ironically now the lower levels are just starting to warm quite well and for 30 and 50mb the closest 30 day analogue trends to 05/02 result in SSW within 18 days (the end range of today's GFS) in about 40% or more of cases, and up to 50% within 30 days.

Meanwhile the 10mb trend is just bumbling along, and only 1 of the closest 100 analogue periods is from the months December-February being more reminiscent of late October, November or March (15% followed by negative 10mb winds within 18 days).

So it appears to be more a case of lack of warming above 20mb rather than downwelling and I expect there will be further 'promising' charts on the horizon until there is a final surge of warming higher up.

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Posted
  • Location: Lincolnshire - 15m asl
  • Weather Preferences: Frost and snow. A quiet autumn day is also good.
  • Location: Lincolnshire - 15m asl

Feelings of possible La Niña towards the end of year.

 

JB tweeting today of the opposite. Weak El Nino is his early call for next winter.

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Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl

Can anyone explain why we have such low heights covering such a large area from the great lakes through to west Russia - with no ridge in sight! whereas we have a strong ridge over Siberia - a shallow trough over sea of japan/okhost followed by another large high over north pacific and a low to sw of Alaska and then another ridge over north Canada.. the ridge trough pattern is evidence on one half of the northern hemisphere but not this side- its an unusual state of affairs it has to be said.......

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Posted
  • Location: Portrush. (NI) UK
  • Location: Portrush. (NI) UK

Can anyone explain why we have such low heights covering such a large area from the great lakes through to west Russia - with no ridge in sight! whereas we have a strong ridge over Siberia - a shallow trough over sea of japan/okhost followed by another large high over north pacific and a low to sw of Alaska and then another ridge over north Canada.. the ridge trough pattern is evidence on one half of the northern hemisphere but not this side- its an unusual state of affairs it has to be said.......

I'm no expert, my best guess would be the combination of the PV and the warm AMO. PV spawns the low and warm upwelling of water in Atlantic supercharges the lows. Ridging cannot force its way through the conveyor belt. Question if anyone knows ? Can slight wave /warming at the 10 hPA level, allow a way to forecast high pressure ridges and placement in the lower Troposphere. Where we see slight warming/waves and not the stronger waves that go all the way up to the 1 hPa level . High pressure ridges seem to form in those areas. Edited by KyleHenry
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Posted
  • Location: @scotlandwx
  • Weather Preferences: Crystal Clear High Pressure & Blue Skies
  • Location: @scotlandwx

Without referring to Triton data, I would reckon the next MJO cycle is going to ramp up Nino prospects.

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Posted
  • Location: Carryduff, County Down 420ft ASL
  • Location: Carryduff, County Down 420ft ASL

Time to close this thread down for Winter 13/14 I think.

A decent shout I think for no SSW this Winter in the early forecasts has born out although I don't think anyone forecast such a pronounced Eastern Canadian PV for the whole Winter.

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Posted
  • Location: Irlam
  • Location: Irlam

Time to close this thread down for Winter 13/14 I think.A decent shout I think for no SSW this Winter in the early forecasts has born out although I don't think anyone forecast such a pronounced Eastern Canadian PV for the whole Winter.

Why?Still a lot can be learnt and studied. Edited by Weather-history
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Is it worth repeating this table of SSW in westerly QBO years?

1979	22/02/791981	04/03/811984	24/02/841986	19/03/861988	14/03/881989	21/02/891991	01993	01994	01995	05/02/951996	01998	29/03/982000	20/03/002001	11/02/012003	18/01/032005	12/03/052007	24/02/072009	24/01/092011	02012	0

Average date 25th February, >40% in March - unless pinning all their hopes of a cold winter in the UK or Europe on this, not sure what people were expecting but the stratosphere has not been particularly out of the ordinary this winter.

 

 

 

Sadly point two is clearly in fruition,  for those on the hunt for a repeat of recent years. The key point for me was around the time fergie and snowballz were hinting at things on Glosea5 when it caught hold of propagation of warming, seeing wave activity as x having a result as y. 

 

Well as posted before, I really don't think you can read too much into the Met Office systems as being significantly more advanced than the CFS or GFS for example. Here are notes from the Report on the 1st SPARC Stratospheric Network for the Assessment of Predictability (SNAP) April 24-26 April 2013 -

 

An invited talk on the predictability of the stratosphere and associated teleconnections was given 

by Adam Scaife. He showed a series of monthly forecasts of the stratospheric sudden warming of 
January 2013. These showed that a signal of the SSW started appearing on December 21, 2013 in 
the operational forecast model and that Met Office forecasts were modified to include the potential 
effects of this event. This was an example of the importance of what Adam called ‘actionable 
information’ for forecasters which SNAP should bear in mind when considering the impact of 
stratospheric variability on surface weather. Adam also discussed a number of case studies of 
recent cold winter events and discussed experiments which highlighted the role of stratospheric 
variability in the predictability of these events. He estimated that of the mean time over which SSW 
events could be predicted in the current version of the Met Office model was around 12 days and 
also showed experiments which highlighted the role of drivers of variability in the extra-tropical 
stratosphere including ENSO, the QBO and the solar cycle. Finally, he presented results from the 
most recent version of the Met Office seasonal forecasting model, GloSea5. Excitingly, these 
results show a much greater skill than previous models in predicting the wintertime NAO, with 
correlation between DJF mean NAO and November forecasts of around 0.6 over a series of 
hindcasts.
 
GloSea5 predicts NAO with a modicum of skill but an average range of 12 days to forecast SSW is the same or less than claimed by the American models. It's interesting comparing archives of 10mb GFS charts from December 2012 (not the erroneous 2013 quoted above!) to recall how clear an SSW appeared likely to be.
This presentation slide gives an idea how it appeared in the Met Office data (source http://www.wmo.int/pages/prog/arep/wwrp/new/documents/S2S2_day1_9_SH.ppt)
 
post-2779-0-63793300-1391854321_thumb.jp
 
 
 
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Posted
  • Location: hertfordshire
  • Location: hertfordshire

While others are happy to dismiss the effects of the strat warming down onto the troposphere

which may benefit our locale I am not. I would still expect to see better amplification and blocking

to the north/northeast for the last third of February and into the first third of March even more so

if it is followed fairly quickly by another warming,which the GFS runs are doing although not to any

great extent at the moment.

I am not saying we are going to see the sort of blocking we have seen like last winter or some of

the previous winters(the warming although significant was not sustained for long enough) but there

should be sufficient height increases to bring something of a much more wintry flavour.

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Posted
  • Location: Slovenia, Central Europe 1050m ASL
  • Location: Slovenia, Central Europe 1050m ASL

@CC, not taking anything away from your post, but are you really that focused on the temperature to ignore the heights? :)

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Posted
  • Location: Catchgate, Durham,705ft asl
  • Location: Catchgate, Durham,705ft asl

It all looks great at 10 hpa at the moment with a split vortex and warming in a great place (nice to see one of those charts verify)....

 

  http://earth.nullschool.net/#current/wind/isobaric/10hPa/orthographic=-2.93,84.73,512

 

 

.....trouble is,the vortex reforms quickly after only a couple of days and is looking strong and

in the wrong place in the medium term.

 

 

 

The GFS does shift it east to a much better position in late FI however,so a stratospheric

straw to clutch!

 

 

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Posted
  • Location: Slovenia, Central Europe 1050m ASL
  • Location: Slovenia, Central Europe 1050m ASL

JB tweeting today of the opposite. Weak El Nino is his early call for next winter.

 

Something like that seems plausible. yes.

 

Posted Image

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Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

It's clear to see on the GFS charts how the forecast vortex orientation continues to underline the Atlantic driven pattern we are in.

Signs however of some changes by day 10-30hPa and 100hPa levels.

 

post-2026-0-78865300-1391942059_thumb.gipost-2026-0-55077100-1391942071_thumb.gi

 

post-2026-0-78671100-1391942103_thumb.gipost-2026-0-79113800-1391942113_thumb.gi

 

The Pacific high disappearance and Atlantic height rises instead.

 

The westerly jet flow starting to show some easing with the opening up of the isobars with hopefully some ridging down the line from the Azores area becoming more probable.

Mean zonal wind forecasts from yesterdays ECM run show an increase again for the coming week,reflected in the 500hPa modeling

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/fluxes.gif

 

but hints of a downturn at the end of the graph which would back up a less angry Atlantic trend beyond day 10.

Early signs that hopefully will grow of a way out of this dreadful prolonged stormy period.

 

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Posted
  • Location: hertfordshire
  • Location: hertfordshire

@CC, not taking anything away from your post, but are you really that focused on the temperature to ignore the heights? Posted Image

Fair point. I have trawled through more upper air charts( gph, temperature and zonal wind) than I care to

remember using the NCEP daily composite charts. On many occasions I found that after a warming and

increase in gph has subsided at the 10 and 30mb level it reappears at the top of the troposphere (200

300mb) on down some two weeks or more later.

I see no reason to believe this will not happen this time with a much colder last third of February and

on into  March due to the location of the warming. Of course this is purely my own take on what I think

will transpire. Cheers.

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Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.

Maybe not a huge warming but the transfer of the vortex back to Siberia at the 10mb level is showing some signs of propagating down to lower levels both on the ECM and GFS. If this was to transpire, could be a really good thing if it was to propagate to the troposphere, late feb - early March Northerly to load up the mid lattitudes with cold and any Greeny hights to topple to scandi for a brutal last blast in Mid March, I would rather go that way than have Euro high ridging North and have nothing to tap into.

 

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2014021000&var=HGT&lev=100mb&hour=384

Edited by Lettucing Gutted
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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

At this point it's still worth pointing out that a warming may not deliver the goods. The AO and CET only correlate 70% of the time.

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Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

Is this warming in the "right" place for us in NW Europe?

http://ds.data.jma.go.jp/tcc/tcc/products/clisys/STRAT/html_e/pole30_n.html

Posted Imagepole30_nh.gif

A warm up at the upper levels there picog currently showing on yesterday's ECM run here

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/eczm.php?alert=1&forecast=all&var=t&lng=eng

 

however it doesn't last or get lower down on the 10 day forecasts on the link above.

The story of our Winter this year so far-lots of warmings higher up but no impact lower down into the trophosphere.

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Posted
  • Location: Port Glasgow, Inverclyde, Scotland. 200m ASL.
  • Weather Preferences: Thundery summers, very snowy winters! Huge Atlantic Storms!
  • Location: Port Glasgow, Inverclyde, Scotland. 200m ASL.

post-21143-0-80350300-1392065262_thumb.p

 

I don't know much about this topic. Is this chart not a cold outlook since the PV is over the UK?

Edited by Ross Andrew Hemphill
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Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.

Posted Imagenpst30.png

 

I don't know much about this topic. Is this chart not a cold outlook since the PV is over the UK?

 

The core is much further North and East, however, that would be a cracking chart IF it propagated, although these charts are for 384 hours so must be treated with caution, we can see that they look very good, that chart you posted IF was replicated at 500mb (18000ft) would be a Northerly wind for the UK.

 

 

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2014021018&var=HGT&lev=30mb&hour=384

 

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2014021018&var=HGT&lev=50mb&hour=384

 

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2014021018&var=HGT&lev=70mb&hour=384

 

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2014021018&var=HGT&lev=100mb&hour=384

 

Patience might be rewarded, we are slowly getting there.

 

EDIT  :  Not strictly a strat chart but just to complete the set

 

Posted Image

 

 

Very solid modelling all the way down, it has to be said.

Edited by Lettucing Gutted
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