Jump to content
Snow?
Local
Radar
Cold?
IGNORED

OCTOBER PATTERN INDEX (OPI) MONITORING WINTER SEASON 2014-2015


Riccardo

Recommended Posts

Posted
  • Location: Sunderland
  • Weather Preferences: cold
  • Location: Sunderland

The better the 12z, the bigger fall you're setting yourself up for- it's all a trap!

But seriously, it does look like another sub -2.5 run, just hoping for the next 10 days it can hold steady around here. Landing range between -1.5 and -2.5 I'd say.

Link to comment
Share on other sites

Posted
  • Location: Brighton (currently)
  • Location: Brighton (currently)

The UKMO is much more mobile and pushes the Arctic high away pretty quickly! It is similar to its 0z output so maybe it is slow at picking the new signal. Let's see what the ECM says later.

Link to comment
Share on other sites

Posted
  • Location: leicester
  • Location: leicester

The UKMO is much more mobile and pushes the Arctic high away pretty quickly! It is similar to its 0z output so maybe it is slow at picking the new signal. Let's see what the ECM says later.

pretty strong Greenland high though to maybe balance things out? Edited by shaky
Link to comment
Share on other sites

Todays OPI of -2.52 continues to cement the thoughts on where the landing zone is going to be.

 

Heres a nice statistic & very simple.

 

If we have 4 more days after today at -2 which looks likely-

 

This takes us out to the 25th,

 

After that even if the last 6 days averaged Only Neutral we would deliver -1.65.

 

Nearly there folks....

 

S

  • Like 6
Link to comment
Share on other sites

Posted
  • Location: st albans
  • Location: st albans

GEM has backed off its cut off arctic hgh and subsequent high anomolys spread across the arctic. now finds an aluetian ridge and general nw canadian/alaskan blocking in contrast with its earlier run. at least gfs is showing a modicom of consistency though tbh, no model currently covering itself in glory with its arctic modelling post day 6 at the moment.

 

cant really see any way that a sub -1.5 OPI cannot be returned, though whether it could get below -2 remains in the balance.

 

thereafter, we await riccardo's teams analysis.

  • Like 4
Link to comment
Share on other sites

Posted
  • Location: Batley, West Yorkshire
  • Weather Preferences: Heat and Snow
  • Location: Batley, West Yorkshire

Todays OPI of -2.52 continues to cement the thoughts on where the landing zone is going to be.

 

Heres a nice statistic & very simple.

 

If we have 4 more days after today at -2 which looks likely-

 

This takes us out to the 25th,

 

After that even if the last 6 days averaged Only Neutral we would deliver -1.65.

 

Nearly there folks....

 

S

 

So it will be a super duper -AO then? :yahoo:

 

get ready folks...a repeat of winter 2009/10 looks likely :bomb:

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: South Gloucestershire BS35
  • Weather Preferences: Severe weather enthusiast
  • Location: South Gloucestershire BS35

So it will be a super duper -AO then? :yahoo:

 

get ready folks...a repeat of winter 2009/10 looks likely :bomb:

 

That is if the correlation between a negative OPI and a higher chance of a weak polar vortex/mean -AO pattern during winter holds true of course...

 

Either way, it will certainly make watching this winter unfold even more interesting/heart palpitation inducing and it will be a good test for the model.

Edited by Chris K
  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Stoke Gifford, nr Bristol, SGlos
  • Location: Stoke Gifford, nr Bristol, SGlos

I hope these OPI stats turn out right for a cold winter in the UK, otherwise the Samaritans will be busy in a few months time.

  • Like 4
Link to comment
Share on other sites

Posted
  • Location: Solihull, WestMidlands, 121m asl -20 :-)
  • Weather Preferences: Cold and Snow -20 would be nice :)
  • Location: Solihull, WestMidlands, 121m asl -20 :-)

I hope these OPI stats turn out right for a cold winter in the UK, otherwise the Samaritans will be busy in a few months time.

I've held back up to now, but i'm genuinely starting to get a little excited.... Let hope it delivers the goods tongue.gif

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Batley, West Yorkshire
  • Weather Preferences: Heat and Snow
  • Location: Batley, West Yorkshire

2.19   looking very good

 

If it was 2.19 I'd be crying right now

  • Like 4
Link to comment
Share on other sites

Posted
  • Location: North East Cotswolds, 232m, 761feet ASL
  • Location: North East Cotswolds, 232m, 761feet ASL

I feel a bit disappointed by that, however it's still sub -2 which is good. If the OPI theory is correct anyway!!!!

Link to comment
Share on other sites

Posted
  • Location: Batley, West Yorkshire
  • Weather Preferences: Heat and Snow
  • Location: Batley, West Yorkshire

Fixed that for you. :wink:

 

Thanks.

 

get ready folks...a repeat of winter 2009/10 looks unlikely, because were getting 1962/63 repeat.

  • Like 6
Link to comment
Share on other sites

Posted
  • Location: Yatton, South of Bristol
  • Location: Yatton, South of Bristol

I can't help feeling we would not be in the current position with the OPI if it were not for us being in an Easterly QBO phase.

Indeed...but an Easterly QBO is no guarantee of a colder winter either.

  • Like 1
Link to comment
Share on other sites

Posted
  • Location: Drayton, Portsmouth
  • Location: Drayton, Portsmouth

Another angle on this ... one thought in my mind has been that, though the PV has taken time to get its act together, it hasn't been far off at any point and now as the end of October approaches all the PV cards might fall into line, at least if some recent model runs are to be believed:

 

ECH1-192.GIF?21-0

 

... also, some others on here have wondered if the state of the atmosphere at the end of October is more important than at the beginning - after all, why should the OPI limit itself to being a straight average across the 31 days of October?

 

So I dug out the NH charts for the end of October for some of the recent "super negative" OPI years:

 

archivesnh-2012-10-31-0-0.png

archivesnh-2009-10-31-0-0.png

archivesnh-1984-10-31-0-0.png

archivesnh-1976-10-31-0-0.png

So all of the previous years had a far more scattered PV come the end of October, I'd sure you'd agree from the above - and therefore I suggest the daily OPI readings at the end of these months were still contributing to the overly negative OPI score - whereas with this year, the OPI might be holding on based on "gains" from earlier in the month (though of course the chart for 29th October 2014 is merely a forecast that could be wrong).

 

Something to think about if this year's AO does not match up to previous years with -1.5 OPIs or less.

Edited by rjbw
  • Like 6
Link to comment
Share on other sites

Posted
  • Location: Brighton (currently)
  • Location: Brighton (currently)

Having viewed the 12z output it appears that the GFS is the most promising in terms of blocking! The ECM unfortunately sides more with the UKMO and sinks the Arctic high quite quickly. We just need this sinking process to slow down as much as possible! Quite a frustrating evening for me...

 

Karyo

Edited by karyo
Link to comment
Share on other sites

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

Another angle on this ... one thought in my mind has been that, though the PV has taken time to get its act together, it hasn't been far off at any point and now as the end of October approaches all the PV cards might fall into line, at least if some recent model runs are to be believed:

 

 

 

... also, some others on here have wondered if the state of the atmosphere at the end of October is more important than at the beginning - after all, why should the OPI limit itself to being a straight average across the 31 days of October?

 

So I dug out the NH charts for the end of October for some of the recent "super negative" OPI years:

 

 

 

 

So all of the previous years had a far more scattered PV come the end of October, I'd sure you'd agree from the above - and therefore I suggest the daily OPI readings at the end of these months were still contributing to the overly negative OPI score - whereas with this year, the OPI might be holding on based on "gains" from earlier in the month (though of course the chart for 29th October 2014 is merely a forecast that could be wrong).

 

Something to think about if this year's AO does not match up to previous years with -1.5 OPIs or less.

 

I've deleted the charts in your post for economy of space.

 

As far as I understand, the pattern needs to be looked at in terms of geopotential height anomalies - these charts do not show that and as far as I can see not available in archived data. Probably can do it in reanalysis if important.

 

What the anomalies of the month to date show, is that it will take very negative poleward heights to make inroads on what we have already 'banked'.

 

89uqx1P.gif

Edited by Nouska
  • Like 3
Link to comment
Share on other sites

Posted
  • Location: Glasgow, Scotland (Charing Cross, 40m asl)
  • Weather Preferences: cold and snowy in winter, a good mix of weather the rest of the time
  • Location: Glasgow, Scotland (Charing Cross, 40m asl)

I wouldn't say there's that much in it rbjw - 76 in particular was significantly more organised and in a much worse position than our current one.

While heights over the Arctic are maybe a bit lower generally than some of those other charts it still doesn't look particularly organised. Also worth remembering Interitus' comments on this too - the -ve value this time actually comes from the angle bit of the equation rather than just the heights.

  • Like 3
Link to comment
Share on other sites

Posted
  • Location: Gillingham, Kent
  • Weather Preferences: Snow, Thunderstorms,
  • Location: Gillingham, Kent

Another angle on this ... one thought in my mind has been that, though the PV has taken time to get its act together, it hasn't been far off at any point and now as the end of October approaches all the PV cards might fall into line, at least if some recent model runs are to be believed:

 

 

... also, some others on here have wondered if the state of the atmosphere at the end of October is more important than at the beginning - after all, why should the OPI limit itself to being a straight average across the 31 days of October?

 

So I dug out the NH charts for the end of October for some of the recent "super negative" OPI years:

 

So all of the previous years had a far more scattered PV come the end of October, I'd sure you'd agree from the above - and therefore I suggest the daily OPI readings at the end of these months were still contributing to the overly negative OPI score - whereas with this year, the OPI might be holding on based on "gains" from earlier in the month (though of course the chart for 29th October 2014 is merely a forecast that could be wrong).

 

Something to think about if this year's AO does not match up to previous years with -1.5 OPIs or less.

 

Whilst I agree that the last quarter of the month obviously factors into the overall OPI score, I think it's the pattern as a whole throughout the month that counts. So even if the last week of October had all positive values, once averaged over the entire month the final score could still be negative. 

 

The PV is by no means organised at the moment and whilst models are toying with the idea of it becoming slightly more organised, it's still no where close to where we were last year. 

 

In fact, i'd be a little surprised if the PV didn't get it's act together as we moved towards the end of October, it'd be very unusual.

 

The important thing is that the overall OPI score now is very, very likely to be negative. Factor in the -QBO and the Wave Breaking we're already seeing in the Statosphere I don't think we need to be too concerned at this juncture. 

  • Like 2
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • 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...