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


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The GFS op at 240z  compared to the 06z mean

 

 

 

 

Yes and once that D10 chart gets to D7 we will see short wave spoilers running across the heights like we had from the D10 charts a couple of days ago, they are no longer showing heights towards Greenland. Even if the short waves don't appear that is transitory as further lower heights will get ejected from the NW. We need a strong block and at the moment we have only the Pacific Ridge, the Russian high and the Azores. We will be lucky to get any cold period from those in the medium term.

Edited by i'm dreaming of...
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Seeing as it's nice and early in the day, perhaps we can see the remainder of Saturday through without the hysterics expressed on the forum yesterday? Critical points of note are simple: 1. Amplifi

Well... good support in new EC Monthly by mid-Feb for GloSea5 signal re increased incidence of blocking. Indeed, by week 4, first output we've seen all winter with NO low MSLP anomalies anywhere on th

??? No warnings have been issued *because areal (and accumulation) continuity has been totally lacking*. Now we are seeing that manifesting in UKV/UKPP and other output, you can expect Ops Centre to

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Yes IDO, i mentioned that a couple of days ago. Any ridging into Greeland should be taken with a large pinch of salt whilst a PV segment remains in that local, as invariably a bit of short wave energy spits of the vortex and cuts off the Northerly flow.

 

The only time I ever believe a proper Northerly is on the cards is when proper upper heights are modelled over the Greenland plateux and the PV has retreated NW away from Greenland.

 

The projected possible lower heights into Europe will not therefore bring any sustained cold as the Azores ridge will continue to be pushed East by the shortwave energy.

Ridging into Greenland was the pre-cursor to this present cold snap with the vortex segment in place

gfsnh-2015011512-0-72.png?12

 

4" of snow has fallen widely in West and South Yorkshire this morning.

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Ridging into Greenland was the pre-cursor to this present cold snap with the vortex segment in place

 

 

4" of snow has fallen widely in West and South Yorkshire this morning.

 

That is because we didn't have a Pacific Ridge squeezing the PV towards NE Canada. The upcoming spell has re-established the Pacific Ridge and therefore the PV is more mobile, especially with the Russian/Siberian high pinching the other side of the PV. In FI we end up with the PV back to his winter home:

 

post-14819-0-07662800-1421859757_thumb.p  GEM at D10: post-14819-0-30096000-1421860023_thumb.p

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Afternoon all.

With a few things like MJO etc looking more favourable in the upcoming period, can a reduction in sunspot activity to around 60 from a high of 146 on the 10/1 help support HLB in the immediate or does the sunspot trend have to be over a longer sustained period? If so, is there a correlation before it's seen in the models?

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Ridging into Greenland was the pre-cursor to this present cold snap with the vortex segment in place

gfsnh-2015011512-0-72.png?12

 

4" of snow has fallen widely in West and South Yorkshire this morning.

Well exactly, snap not spell. The projected cold zonal spell will still bring snow to favoured places. It just won'tbe sustained until the PV is removed from Greenland.

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The Azores high and the Canadian/Greenland vortex look like driving our weather over the next week to 10 days. 

ECM ens for the overall pattern.

http://www.meteociel.fr/modeles/ecmwf/runs/2015012100/EDH101-120.GIF?21-12

http://www.meteociel.fr/modeles/ecmwf/runs/2015012100/EDH101-240.GIF?21-12

 

The amount of Atlantic jet amplification varies from run to run in the operationals but  if we see enough ridging west or north west of the AH then we will likely squeeze some short cold snaps out of it as the flow turns into a cold north west direction.

 

It must be said though no deep cold will establish in this mobile set up so it looks like we will be relying on a similar pattern from earlier in the Winter with a Euro.trough just to our east and sometimes colder polar maritime incursions from the north west.

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As the control shows there will still be opportunities to get some cold uppers off an Arctic or PM flow. Again favouring the north and hills further south:

 

post-14819-0-55446800-1421862033_thumb.p

 

Still some GEFS around D11 showing a more western based trough (about 20%) so not ruling out as this can flip flop for several more days yet. 

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As the control shows there will still be opportunities to get some cold uppers off an Arctic or PM flow. Again favouring the north and hills further south:

 

attachicon.gifgens-0-0-252.png

 

Still some GEFS around D11 showing a more western based trough (about 20%) so not ruling out as this can flip flop for several more days yet. 

 

Hi mate, can you explain why just hills further South from that chart please? Thanks

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Hi mate, can you explain why just hills further South from that chart please? Thanks

 

That was based on my experience from a northerly flow but I had a look at the GFS snow risk and it suggests snow between 300-600m:

 

post-14819-0-22083700-1421862496_thumb.p

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That was based on my experience from a northerly flow but I had a look at the GFS snow risk and it suggests snow between 300-600m:

 

attachicon.gifuksnowrisk.png

Thanks pal, just trying to get my head around northerly`s northerlies and cold uppers. ;-)

Edited by SaffW
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Control run is epic by day 12...split PV with cross polar flow

I would not expect that to last due to the lower heights to our NE being squeezed back towards NE Canada by the Siberian/Russian high aided with a pressure rise from the Pacific ridge.

post-14819-0-57846600-1421862705_thumb.p

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Trends people - not detail.

Pinpointing anything from ens members is fruitless. I appreciate, IDO, that all u are doing is pointing out the evolution of that particular run but what I would take from it is that HLB looks a distinct possibility in week 2 across part (s) of the NH and looking at the fi ens mean and spreads, a west coast American ridge seems likely. Nothing else with any kind of certainty can be gleaned.

 

Yes FI starts at around D7-8, the ECM clusters at D5 had just one member so reasonable certainty with the long wave pattern for the next week or so. Afterwards it looks very complex with possible polar heights, pacific ridge and the Siberian high. Along with the ENSO/MJO composites looking promising for heights to the NE moving NW, strat coupling, solar activity reducing, BK low anomalies possibly easing, etc, I would not rule out too much after D8.

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As the control shows there will still be opportunities to get some cold uppers off an Arctic or PM flow. Again favouring the north and hills further south:

 

attachicon.gifgens-0-0-252.png

 

Still some GEFS around D11 showing a more western based trough (about 20%) so not ruling out as this can flip flop for several more days yet. 

The control run is very good, but the average run is not good.
So far it is better to look the average run http://www.meteoguru.com/pro/ensembles/?latlon=51.51,-0.09
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12z GFS operational rather flat-looking with the upper flow, with a stronger jet than its 06z predecesor, which forces the Euro trough too far east and allows the Azores high to ridge in across western Europe.

 

But the medium to long range outlook into the beginning of February is certainly looking looking rosy for cold lovers looking at the teleconnections and MJO

 

attachicon.gifEC_ao+nao.png

 

attachicon.gifEC_NAO.png

 

MJO - GFS and biased corrected GFS. GFS has, IMO, handled the MJO better through the phases than ECM this month so far:

 

attachicon.gifNCPE_phase_21m_full.gifattachicon.gifNCPE_BC_phase_21m_full.gif

 

But for the days up to the end of Jan, we revert back to a more changeable, unsettled and often windy pattern from this Friday, as a strong Atlantic jet stream buckles and meanders back and forth across the UK, bringing milder air at times and also colder conditions too.

 

Recent NWP guidance suggests that the jet will then migrate south and align NW to SE on a more prolonged basis after the end of next week and perhaps into early February, as a deep trough begins to carve out over central and eastern Europe in the last few days of January. This ties in to the signal for a generally more amplified long wave upper flow pattern setting up upstream too, with a persisting ridge over western North America and deep trough over eastern N America teleconnecting to the Azores high building slightly north and a deep trough over Europe. This would mean we stay in a cold northwesterly pattern for longer in the last few day of Jan and into early February. Any amplification north of the Azores ridge over the Atlantic will increase the potential for cold arctic northerly outbreaks too, as showing from some recent operational runs and clusters of NWP ensembles. Though any northerly outbreaks, bringing potential for much colder conditions and risk of snow, would likely last only a few days, given lack of a signal for high latitude blocking for now.

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 ?

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what is the most troublesome aspect is the lack of any type of blocking in february you would normaly see some form of blocking starting to show in the models but viewing some would say cannon fodder the CFS even out to march its as flat as a pancake it has performed well this season on top of the METS own forecast why are the same people on this forum keep banging on about blocking which looks as likely as a heatwave in alaska

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Apart from that being 8 days away and it will change.

Has that chart happened before very often.

 

 

Yes,has happened plenty of times before when the Polar Vortex gets a shove to our side of the Hemisphere.

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The JMA has the UK turning purple at day 8!

 

attachicon.gifJN192-21.gif

 

 

A shining example of deep troughing.

That chart reminds of January 2014 and is something I'm keen to avoid... Would spawn low after low with a ground frost at best between lows.

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Im liking the signal for the deep Euro trough, if we can get things to fall in out favour then this is a very nice signal to have out at day 9-10. Could Feb be freezing?? hope so!

 

Recm2161.gif

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Im liking the signal for the deep Euro trough, if we can get things to fall in out favour then this is a very nice signal to have out at day 9-10. Could Feb be freezing?? hope so!

Recm2161.gif

The Euro trough is a good trend but we really need that azores high to ridge towards Greenland and link up with the arctic high. If this happens we will have locked in cold - true winter weather. If not, we have a short lived northerly with azores high ridging over us. It is one or the other, probably no room for inbetweens. Edited by blizzard81
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