Model Output Discussion - 16th Jan 12z onwards - Smile While You Post!

[Woollymummy]

Is this a fault or a real thing - a wiggle in all the isobars along the Greenwich meridian up from us towards the Arctic - how odd!

[ANYWEATHER]

The see saw temperatures look very likely in the days ahead with both ecm and gfs, with snow potential to mainly higher ground, even in the south. Later in the stages towards the end of the month both models show an amplification in the Atlantic with low pressure digging into Scandi.....bringing some potent Artic air to the uk.....

[chris55]

Is this a fault or a real thing - a wiggle in all the isobars along the Greenwich meridian up from us towards the Arctic - how odd!

 

 

Its a kink in the Isobars, slightly to pronounced on that chart, but it represents a front within the flow.

 

Actually on second inspection, it just looks like a fault with the grid lols

Edited January 21, 2015 by chris55

[ANYWEATHER]

Is this a fault or a real thing - a wiggle in all the isobars along the Greenwich meridian up from us towards the Arctic - how odd!

Basically means little troughs or disturbances, along the main flow of air....

[Nick L]

Is this a fault or a real thing - a wiggle in all the isobars along the Greenwich meridian up from us towards the Arctic - how odd!

 

Considering it follows the meridian perfectly, I would assume it's something to do with the model itself! Whether it's a bug or just the way it's calculated regarding grid points I have no idea.

[fergieweather]

Considering it follows the meridian perfectly, I would assume it's something to do with the model itself! Whether it's a bug or just the way it's calculated regarding grid points I have no idea.

The model (EC) has rendered data just fine for that timestamp on ECMWF site and others. Fault appears to be with whatever host website carried that image. Data corruption apparently.

[Nick L]

The model (EC) has rendered data just fine for that timestamp on ECMWF site and others. Fault appears to be with whatever host website carried that image. Data corruption apparently.

 

Yes it's fine on my work's software too.

[Paul]

Is this a fault or a real thing - a wiggle in all the isobars along the Greenwich meridian up from us towards the Arctic - how odd!

 

Definitely appears to be something in the data we receive, will ask them about it

[stratty]

same pattern as my bakewell tart for tea!

[bluearmy]

interestingly at day 9, the upper spreads indicate the centre of the trough likely to head sw towards north sea coasts before heading se.  that was also evident on the 00z run. the coldest flow will be to the west of the trough centre and that is indicated by the spread on uppers which also show the mean evolution days 8/10 could well be further west.

 

upstream, the mean trough is sinking ever further south over the states. quite impressive and advertised for a while on the ecm ens hemispheric probabllities. the point being that the pattern begins to look less mobile than it has previously. before, this season, we've seen the n american trough sinking and moving east simultaneously. 

 

will be interesting to see if the extended eps tend towards the less amplified GEFS and what the canadian are thinking. back later.

 

EDIT: re the extended eps - as the us trough sinks ever south so a jet streak appears (no surprise i guess) and this is responsible for flattening the downstream pattern in the 11/15 day period. the se euro trough surviving but we are under the jet as it continues to send systems se into it, probably just to our east.  any thought the atlantic ridge had of amplification finished by that streak. of course, the appearance of the deep euro trough was unexpected at this juncture so no guarantee that ecm has the upstream trough right re placement, orientation and depth.

Edited January 21, 2015 by bluearmy

[Long haul to mild]

It seems to me that the best we can hope to achieve at the moment from the likely forthcoming pattern is a couple of transient Northerlies inbetween some PM shots. Good for those in the N\NW but hardly the countrywide cold and snowy spell that many are looking for.

Unless some proper HLB sets up in the models soon, I'm not going to be getting excited about prospects going into February. At the moment it seems a rinse and repeat of earlier patterns. The Azores high always seems to be too close to us and all the ridging of it towards Greenland seems to be always in FI and doesn't verify.

A long way to go still obviously and I appreciate that some have had some decent snowfall but my fears are growing for this winter for those of us still awaiting an end to this desperately barren spell since March 2013 in terms of proper winter weather.

[phil nw.]

A strong signal for the Euro trough/Azoes high on the day 10 means.

And underlined in today's CPC day 8/14 outlook

http://www.cpc.noaa.gov/products/predictions/814day/500mb.php

http://www.meteociel.fr/modeles/gefs_cartes.php?code=21&ech=240&mode=0&carte=1

http://www.meteociel.fr/modeles/ecmwf.php?ech=240&mode=1&map=1&type=1&archive=0

Not the ideal setup for a nationwide notable cold spell but chances of some short colder snaps from the north west at times.

Signs of vortex disruption in later frames of the op.runs so the hope that this becomes a solid trend based on continuing minor warmings and the gfs mjo outlook suggesting further amplification of the pattern.

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

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

I would prefer though to see the other agencies backing the GFS forecast on this and indeed a plot further away from the centre for better confidence.

For the time being though we are heading for a fairly typical Atlantic pattern with a mix of cold and rather milder days.

With a little more ridging from this set up we could see a short but cold Arctic spell which would give more areas a chance of at least some brief snowfalls.

Edited January 21, 2015 by phil nw.

[nick sussex]

Regarding the MJO this is a good site to look back to 40 years of MJO tracking across all the seasons, its got a drop down menu, just put your year in and what season you want.

 

http://www.bom.gov.au/climate/mjo/#tabs=MJO-phase

 

In terms of tonights outputs a strong signal for that Euro troughing but the MJO forecasts are all over the place so until that's settled then it's difficult to judge how much cold potential there is.

[MR EXTREMES]

Interested to see if these patterns start moving into closer timeframe soon!.

As I see it there seems to be a growing trend towards a colder February and the most interesting thing for me is the plummeting solar activity!!

Both the gefs look pretty similar yesterday and again today the gefs and the ecm want that vortex obliterated.

Good mjo movement and enso.

more amplified patterns to which should aid development of better ridges

[Nick F]

Nick if you don't mind me asking , your talking of the Azores to ridge North slightly given in essence northerly toppers and a more general cold North westerly ? But yet the NAO and AO are to head negative ? That sort of contradicts itself doesn't. It ? Surely a that leads to high lat blocking in the Atlantic which should set up toward Greenland area ? Even sets up a poss cross polar flow with the -AO in place ?

 

Good question, I'm a bit dubious that the NAO will go into -ve territory looking at the day 10 00z ECM deter despite the pressure rises over Iceland by then as the Azores ridge extends north, though there were and are signs of the AO going -ve at the end of the month. But the height/pressure rises over the pole not manifesting on our side of the northern hemisphere by day 10 on ECM, but all too evident -AO signature on the 12z EC:

 

[Catacol]

Regarding the MJO this is a good site to look back to 40 years of MJO tracking across all the seasons, its got a drop down menu, just put your year in and what season you want.

 

http://www.bom.gov.au/climate/mjo/#tabs=MJO-phase

 

In terms of tonights outputs a strong signal for that Euro troughing but the MJO forecasts are all over the place so until that's settled then it's difficult to judge how much cold potential there is.

Excellent site. I always expect to see crystal clear signals when going back to past cold spells... but then realise how more there is still to learn when I flip to Jan 87 only to find that this awesomely cold spell with a long draw easterly from Siberia occurred in a weak phase 3. Feb 91 happened under a near COD phase 5. So makes you wonder what all the fuss is with regards to MJO.

 

Maybe our weather is just totally and utterly random and there is no making sense of it!!

Edited January 21, 2015 by Catacol_Highlander

[Recretos]

The MJO and ENSO will be temporarily put on hold, or to silence, from days 5-12, while the strat does its dance.

[WINTRY WALES]

Excellent site. I always expect to see crystal clear signals when going back to past cold spells... but then realise how more there is still to learn when I flip to Jan 87 only to find that this awesomely cold spell with a long draw easterly from Siberia occurred in a weak phase 3. Feb 91 happened under a near COD phase 5. So makes you wonder what all the fuss is with regards to MJO.

 

Maybe our weather is just totally and utterly random and there is no making sense of it!!

Yes well pointed out.....does anyone think that eventually all the pieces of the puzzle will be put together to be able to confidentially call say weather patterns correctly on a consistent basis for say a 20-30 day timescale??? Surely if we don't understand how all the pieces fit the models that are programmed as they are (I:e not truly correct by today's understanding) then they are pretty much useless for say a period of 5 day plus?

[Bristawl Si]

Maybe our weather is just totally and utterly random and there is no making sense of it!!

Winner of the "Sentence of the 14/15 Winter" award - no other contenders need apply.

Love these islands. Strategically placed to make our weather v unpredictable week to week.

Edited January 21, 2015 by Bristle boy

[blizzard81]

Interested to see if these patterns start moving into closer timeframe soon!.

As I see it there seems to be a growing trend towards a colder February and the most interesting thing for me is the plummeting solar activity!!

Both the gefs look pretty similar yesterday and again today the gefs and the ecm want that vortex obliterated.

Good mjo movement and enso.

more amplified patterns to which should aid development of better ridges

Very interesting again that a cold spell coincides with a quiet interlude on the sun. This is not coincidence and cannot be ignored imo. Unfortunately, there has been an uptick in activity today and this looks likely to increase over the next few days. This coincides with our cold snap ending!

[Severe Siberian icy blast]

Good question, I'm a bit dubious that the NAO will go into -ve territory looking at the day 10 00z ECM deter despite the pressure rises over Iceland by then as the Azores ridge extends north, though there were and are signs of the AO going -ve at the end of the month. But the height/pressure rises over the pole not manifesting on our side of the northern hemisphere by day 10 on ECM, but all too evident -AO signature on the 12z EC:

Recmnh2401.gif

Thanks for your reply , I guess however the finer detail will be dealt with nearer the time , just really hope your February forecast comes into fruition , really need a good month , it's been a long 2 years of a lot of zonal muck to be honest . Judging by the forecast though you think we need to look East for cold into feb rather than North .

I'm more interested in what comes after this Euro trough rather than with it because a topping ridge just doesn't do it for me to be honest. I suppose it depends on whether we can stay on the northern side of the jet and get some true cold air into the flow , if we can manage -7/8's uppers then given the fact the atlanitc is now colder than what it was 2 wks ago then we may all get something snowy from the northwest .

Feb northwesterlies can pack a righ punch if it's coming from the poles !

Edited January 21, 2015 by Severe Siberian icy blast

[Severe Siberian icy blast]

The MJO and ENSO will be temporarily put on hold, or to silence, from days 5-12, while the strat does its dance.

So your confident in this split then Andrew and do you think it can over ride other signals ? I thought in this instance the MJO was working alongside us benefiting the trop response ?!

[blizzard81]

Winner of the "Sentence of the 14/15 Winter" award - no other contenders need apply.

Love these islands. Strategically placed to make our weather v unpredictable week to week.

I think our weather can be summed up as wet and windy 80% of the time in any season, so quite predictable

[bluearmy]

The MJO and ENSO will be temporarily put on hold, or to silence, from days 5-12, while the strat does its dance.

Now we know how the predicted cold period has actually verified, does anyone have the anomolys for the past week and the current MJO phase charts to see if it is indeed the MJO that has been driving the current trop pattern.

Will be interesting to see if the strat does indeed drive the trop in the 5/12 day period

[blizzard81]

Azores high too influential on our part of the world at T198. This sends everything east! In fact, 18z is an absolute shocker for coldies. Rogue run we hope.

Edited January 21, 2015 by blizzard81