Jump to content
Snow?
Local
Radar
Cold?
IGNORED

Stratosphere temperature watch - 2016/17


Paul

Recommended Posts

Posted
  • Location: st albans
  • Location: st albans
27 minutes ago, chris55 said:

Is the kink to our north east the ridge? Or am I looking at the wrong charts/wrong interpretation?

IMG_1788.GIF

That's about it Chris - these charts don't show the anomoly but its bigger on the latest 00z run 

maybe nothjng, maybe something 

Link to comment
Share on other sites

Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)
2 hours ago, bluearmy said:

The ec 50hpa charts at day 8/10 develop a high anomoly to our north which migrates ne.  Presumably this is earlier than you are looking at 

 

Thanks for the info. It's sooner as I'm thinking about early-mid Feb, but we already have a lesser displacement in place so it could be that the decelerating zone at the higher levels is currently more toward the Arctic, with those 50 hPa changes being a response. 

  • Like 1
Link to comment
Share on other sites

20 hours ago, summer blizzard said:

Interitus, i remember a while ago that you were looking at analogies and concluded no SSW for at least 51 days. I was just curious whether this beats that.

Using the MERRA data, the two closest analogue periods for 30mb 60°N wind over the 30 days up to and including 10/12/16, were 05/12/09 and 13/12/00. The closeness is seen in this graph to the left of the black vertical line. How the analogue years progressed, and this year up to Jan 27th GEOS-5 forecast in the MERRA data is on the right of the line -

30mb.png

Where the 51 days came in is given the analogue dates 05/12/09 and 13/12/00, both these years saw a reversed polar temperature gradient 51 days later. In this instance, the reversed gradient is the difference in temperature between 80 and 50°N, averaged over six pressure levels (10, 30, 50, 70, 100, 150mb). Usually it is colder at 80°N with a strong vortex - a reversal is a sure sign that the vortex is weakening or breaking down with a high probability of a SSW around that time.

51 days from 10/12/16 will be 30/01/17, here is how the temperature gradient is progressing -

5080t.png

Not bad!

  • Like 4
Link to comment
Share on other sites

Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)
56 minutes ago, Summer Sun said:

 

I'd sure like to know how he figures a split may manifest. Sometimes a daughter vortex can peel away from the main one as part of the vorticity tail but that's not associated with the dramatic top-down changes brought by a wave-2 converging on the pole. I suppose, though, a secondary feature in the vortex tail can make for a secondary area of regionally very anomalous conditions - from what I've seen of the 1991 event, it looks to me that such a feature bedded down over W. Asia or thereabouts and contributed to that unusually intense easterly that managed to reach the UK.

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: st albans
  • Location: st albans

The upper strat stretched a long way on yesterday's ec op run as depicted this morning on the Berlin charts.  Big zonal reversal at the very top which results in the vortex at 1hpa s Greenland/Iceland region whilst at 20hpa it sits just ne of Svalbard. heights below that drift it further towards Siberia. I wonder if this potential stretching of the vortex could cause a split between the upper and lower parts or simply cause the vortex to break apart quite markedly if  reversal gets far enough down.   there is some continuity  from the the previous runs re this stretching high up. 

 

Edited by bluearmy
  • Like 2
Link to comment
Share on other sites

Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)
4 hours ago, bluearmy said:

The upper strat stretched a long way on yesterday's ec op run as depicted this morning on the Berlin charts.  Big zonal reversal at the very top which results in the vortex at 1hpa s Greenland/Iceland region whilst at 20hpa it sits just ne of Svalbard. heights below that drift it further towards Siberia. I wonder if this potential stretching of the vortex could cause a split between the upper and lower parts or simply cause the vortex to break apart quite markedly if  reversal gets far enough down.   there is some continuity  from the the previous runs re this stretching high up. 

 

The polar vortex will be more lopsided than a Friday night drunk at this rate!

What you describe sounds like a reversal slicing through the tilted column?

Link to comment
Share on other sites

Posted
  • Location: Surrey and SW France.
  • Location: Surrey and SW France.

The ECM 00Z run prolongs the opportunity for seeing nacreous clouds if clear skies permit. Overhead 30mb temperatures as low as -86C on some of the time stamps - not all shown in gif - just a sample to give idea of movement of the coldest core.

58e04e0403b2f94be2e45fa1a2ad32bb.gif

  • Like 6
Link to comment
Share on other sites

Posted
  • Location: st albans
  • Location: st albans
1 hour ago, Singularity said:

The polar vortex will be more lopsided than a Friday night drunk at this rate!

What you describe sounds like a reversal slicing through the tilted column?

http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/index.html

It's available to see for free 

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: Warsaw, Poland. Formerly London.
  • Weather Preferences: Four true seasons. Hot summers and cold winters.
  • Location: Warsaw, Poland. Formerly London.
11 minutes ago, knocker said:

 

Judah being cryptic again! He says "if" so what are the chances in your opinion knocker? 

Link to comment
Share on other sites

Posted
  • Location: st albans
  • Location: st albans

Had Judah referenced the parallel rather than the op, his tweet would have been rather different.  all, ifs, mights and maybes at the moment

EDIT : looks like the 12z op follows suit 

 

Edited by bluearmy
Link to comment
Share on other sites

Posted
  • Location: Surrey and SW France.
  • Location: Surrey and SW France.

Remarkable similarity between what is being modelled for the 30mb temps/heights and what actually was in place at the end of January 2016.

January 31st 2016                      gsm025_nhem_gh30_t30_2016013112_006.png

January 28th 2017 forecast      gsm025_nhem_gh30_t30_2017012000_204.png

A lot of layers to get through before we see what the impacts will be on surface conditions.

  • Like 4
Link to comment
Share on other sites

Posted
  • Location: st albans
  • Location: st albans
12 minutes ago, Interitus said:

GFS 12z very different, no SSW zonal winds recovering quickly from a minimum around 10 m/s -

umedel60_17012012ed.png

NH_HGT_10mb_384_17012012.gif

and possibly not dissimilar to gfsp 00 z and 06z

the gefs mean maintains a displaced vortex and higher temps warming across the pole

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Heckmondwike, West Yorkshire
  • Location: Heckmondwike, West Yorkshire

Must admit I am confused about the mixed messages this evening with regards to the strat. Sounds like there has been a downgrade. How much of a downgrade is this?

  • Like 2
Link to comment
Share on other sites

Posted
  • Location: Clayton-le-Woods, Chorley, Lancs
  • Weather Preferences: Snow
  • Location: Clayton-le-Woods, Chorley, Lancs
Just now, blizzard81 said:

Must admit I am confused about the mixed messages this evening with regards to the strat. Sounds like there has been a downgrade. How much of a downgrade is this?

Me too. 

Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
  • UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-29 07:13:16 Valid: 29/03/2024 0600 - 30/03/2024 0600 THUNDERSTORM WATCH - FRI 29 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather

    Difficult travel conditions as the Easter break begins

    Low Nelson is throwing wind and rain at the UK before it impacts mainland Spain at Easter. Wild condtions in the English Channel, and more rain and lightning here on Thursday. Read the full update here

    Netweather forecasts
    Netweather forecasts
    Latest weather updates from Netweather

    UK Storm and Severe Convective Forecast

    UK Severe Convective & Storm Forecast - Issued 2024-03-28 09:16:06 Valid: 28/03/2024 0800 - 29/03/2024 0600 SEVERE THUNDERSTORM WATCH - THURS 28 MARCH 2024 Click here for the full forecast

    Nick F
    Nick F
    Latest weather updates from Netweather
×
×
  • Create New...