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Model Output Discussion - 31/10/2014 and Beyond


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A Lot of misunderstanding come about by people using feel like temperatures and Actual temperature, It may feel mild, and indeed what it feels like is probably the most important part of how someone interprets the weather around them, but for discussion about is it or is it not average then surely using actual statistics is the bes way forward.

Yes the atmosphere is all interlinked, but IMHO I think if we are discussing temperature at ground level then we should use the most relevant data, rather than extrapolated data from another series, for the examples that you give (Inversions etc).

Either way there are no cold charts to be found in the reliable......... In that you are 100% correct.

 

ive found over the course of several years that using the uppers is a pretty good guide to what the surface gets, but hey, we are drifting off topic .

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post-1206-0-71443800-1415810861_thumb.gi

 

Further to my last post heres the UKMO T144hrs, the thing to note is how much amplification is there upstream before  the pattern eventually flattens out.

 

The more amplified that is the more dig south of troughing in the Atlantic to the west of the UK, an area to look out for is southern Greenland aswell as the tilt of the troughing, you want this more negatively tilted as the UKMO shows for newbies running more nw/se.

 

In term of Greenland how much ridging has extended there from the east, the more you have there the better as this puts some forcing on that low.

 

There is little midway solution here, as the low heights exit the ne USA if the energy just spills ne then its game over, if the energy splits more ne/se then you have a chance to get high pressure centred further north.

 

Some of that energy will then head under the ridge to reinforce it.

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what i see in the current runs is mild atlantic air sweeping across the uk and into western europe. we might get this easterly, but the air originated from a mild scource, and not a cold northerly.

 

 

Mushy - not sure I totally agree (although I might have mis-interpreted what you're saying?) - it's really only after t144 that we see the atlantic come in - at least on the GFS.

 

From Sat until then it's fairly cool and dank on all the models.  After that point - we may get a surge of atlantic air but it's not certain IMHO - not from the latest UKMO and GEM anyway.  

 

http://www.meteociel.fr/modeles/geme_cartes.php?&ech=192&mode=0&carte=1

 

I agree that any easterly flow in the interim is not going to be especially cold though.

 

Worth adding that GFS is notorious for being over progressive with the a split vortex and pushing the Canadian part eastwards too soon from my experience. The strat model output this morning was interesting - so even if the atlantic does sweep in after day 6, we might get away with a fairly short lived zonal spell - and not the dross we had last year.

Edited by beng
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o dear o dear its all going rather pear shaped or should i say heights are all but gone from the pole.

just goes to show the power of the polar vortex possibly losing the chance of the strat warming to.....

 

with any luck the azores heights might save us from a 2013/14 repeat winter from hell.

looks pretty dire wet windy and rather disturbed.

 

perhaps this will prove that even with OPI index and even the east based QBO that winter here is a very hard to pin down funny that most of the big forecasting authorities have suggested nothing exciting really to look forwards to.

 

so lesson of the day dont bother getting excited about the ecm past 144 because its love for over cooking heights and easterly is rather a pain in the butt.

 

from now on im certainly not even going to ramp until where at least 72hrs away.

Those that were rather confident on the mid to end of the month cold myself including where taken right up the garden path.

 

gfs nothing but a repeat of last november 

gfsnh-0-192.png?12

ukmo

looks to have a better angle perfect if heights were able to build into greenland better but im sure this to will show a complete melt down of height into the arctic in future runs.

UN144-21.GIF?12-17

the gem to looks like it could be good but the major swings recently in its output would certainly lead me to ignore its latter runs

gem-0-192.png?12

the gfs

jet stream says it all although it looks like it exits the states bit futher south than normal but direct hit for us 

gfs-5-192.png?12

rather messy from the models tonight but i expect the ecm will throw a spanner in the works with heights there to give us some excitement but can it be trusted id say up till t144 then after that forget it.

 

if anything id be more inclined to follow the ukmo as this is by far the best model.

as for any stratospheric influence then id be inclined to reject projected warming or split as this was certainly a feature last winter when there was forecasts for warming but never really came to anything.

 

 

but i can safely say its not going to be blow torch but slightly above is a possibilty if you take model outputs at face value.

Edited by Polar Maritime
To remove off topic Winter Hopes/thoughts.
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GEM similar with fledgling heights to the north and a disrupting low on its travels from the NW to the UK but in the wings a cold pool with UK written on it:

 

D7: post-14819-0-57365000-1415810894_thumb.p

 

And by D10 its about to roll in: post-14819-0-51036100-1415811920_thumb.p

 

This ties in with the cold pool in the US beginning to wane around that time, as the meridional flow slackens, so that would be the trigger for the pattern change.

 

So a disrupting trough for the next 10 days followed by the left overs from the US cold spell washing over us for the following week plus?

 

D16 PV's on the GFS op and P: post-14819-0-00529200-1415812604_thumb.ppost-14819-0-95164800-1415812611_thumb.p

Edited by i'm dreaming of...
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Mushy - not sure I totally agree (although I might have mis-interpreted what you're saying?) - it's really only after t144 that we see the atlantic come in - at least on the GFS.

 

 

 

are we not under atlantic sourced air now? and have been for a while?

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o dear o dear its all going rather pear shaped or should i say heights are all but gone from the pole.

just goes to show the power of the polar vortex possibly losing the chance of the strat warming to.....

with any luck the azores heights might save us from a 2013/14 repeat winter from hell.

looks pretty dire wet windy and rather disturbed.

perhaps this will prove that even with OPI index and even the east based QBO that winter here is a very hard to pin down funny that most of the big forecasting authorities have suggested nothing exciting really to look forwards to.

so lesson of the day dont bother getting excited about the ecm past 144 because its love for over cooking heights and easterly is rather a pain in the butt.

from now on im certainly not even going to ramp until where at least 72hrs away.

Those that were rather confident on the mid to end of the month cold myself including where taken right up the garden path.

gfs nothing but a repeat of last november

gfsnh-0-192.png?12

ukmo

looks to have a better angle perfect if heights were able to build into greenland better but im sure this to will show a complete melt down of height into the arctic in future runs.

UN144-21.GIF?12-17

the gem to looks like it could be good but the major swings recently in its output would certainly lead me to ignore its latter runs

gem-0-192.png?12

the gfs

jet stream says it all although it looks like it exits the states bit futher south than normal but direct hit for us

gfs-5-192.png?12

rather messy from the models tonight but i expect the ecm will throw a spanner in the works with heights there to give us some excitement but can it be trusted id say up till t144 then after that forget it.

if anything id be more inclined to follow the ukmo as this is by far the best model.

as for any stratospheric influence then id be inclined to reject projected warming or split as this was certainly a feature last winter when there was forecasts for warming but never really came to anything.

but i can safely say its not going to be blow torch but slightly above is a possibilty if you take model outputs at face value.[/

It's 12th of November, just because the charts are showing something mild and wet now doesn't mean we're suddenly gonna have a winter like 2013/14. Winter hasn't started yet and already people are writing it off.

Edited by Smiler1709
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We don't get Atlantic sourced air until after day 7, if a cold spell was showing after day 7 we'd all be cautious. So it's certainly not a done deal that the Atlantic will win out, especially since the GFS has a habit of doing this. The ECM and UKMO with some improvements, could still prevent the Atlantic breaking through, and we could be stuck in a cool south-easterly flow. If we maintain this flow long enough, theirs still the potential for cold air to start sweeping in. As long as the Atlantic doesn't win out, we are still in business.

 

ECH1-144.GIF?12-12UN144-21.GIF?12-17

 

It's also only at day 7 that the polar vortex get's going, I believe day 6 tomorrow (day 7 today) will have a much weaker polar vortex than forecast. It will probably be weaker on tonights ECM 12z as well, as the polar vortex has been forecasted to get stronger for weeks now, but never makes it into the reliable time frame. With all the wave 1 in the Stratosphere, I very much doubt the polar vortex will be anywhere near as strong as forecast. UKMO at day 6 tomorrow will be interesting, to see what the polar vortex is like.

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We don't get Atlantic sourced air until after day 7,

 

?

 

todays fax, showing clearly that we are currently in atlantic scourced air

post-2797-0-48529500-1415814856_thumb.gi

 

and for friday, this demonstrates what i meant, atlantic scourced air sweeping into western europe

post-2797-0-72374000-1415814921_thumb.gi

 

and at t120 , sunday, demonstrating the first signes of an easterly fed by the atlantic air that swept into western europe, caught into the circulation of the low and heads westwards over its northern flank.

post-2797-0-63374900-1415815025_thumb.gi

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As you can see from the GEFS for D10, very strong support for the cold pool from the US to get ejected west. A couple of members go for something different. The main question is where will the jet sit:

 

post-14819-0-32623200-1415815071_thumb.p

 

About 33% of members have some sort of pressure build to the south of the UK, the rest sends the low heights over the UK. Looking at the 850s, nothing resembling cold, a few cooler runs, mostly average and some milder:

 

post-14819-0-36843300-1415815237_thumb.p

 

Looking further, D16, and the mean 850s suggests average to above: post-14819-0-48029500-1415815317_thumb.p

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?

 

todays fax, showing clearly that we are currently in atlantic scourced air

attachicon.gifbracka1.gif

 

and for friday, this demonstrates what i meant, atlantic scourced air sweeping into western europe

attachicon.gifbracka1.gif

 

and at t120 , sunday, demonstrating the first signes of an easterly fed by the atlantic air that swept into western europe, caught into the circulation of the low and heads westwards over its northern flank.

attachicon.gifbrack4.gif

 

My point was it's not certain that once we get the Easterly flow that the Atlantic will break through. It's never pure Atlantic air when the flow is coming from the East.

Edited by Barry95
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As you can see from the GEFS for D10, very strong support for the cold pool from the US to get ejected west. A couple of members go for something different. The main question is where will the jet sit:

 

attachicon.gifMeteociel_-_Panel_GEFS.png

 

About 33% of members have some sort of pressure build to the south of the UK, the rest sends the low heights over the UK. Looking at the 850s, nothing resembling cold, a few cooler runs, mostly average and some milder:

 

attachicon.gifMeteociel_-_Panel_GEFS.png

 

Looking further, D16, and the mean 850s suggests average to above: attachicon.gifgens-21-0-384.png

 

Should be south of the cold air so here?

post-12275-0-72705700-1415816199_thumb.p

post-12275-0-65962400-1415816352_thumb.p

Edited by knocker
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As long as the cold sits the over ne usa feeding the jet towards us i fear at least 3wks of this set up.I know the gfs is a pattern flattener but tied in with the mo outlook i just cannot see a wintery spell anytime soon imo.Its not even winter yet and setup is different from last year(re polar vortex) so im hoping a pattern change will aid us coldies about 2nd wk dec im going for.

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GFS 12z ensembles are pretty rank in all honesty, the 0z ensembles had a few interesting runs especially in the latter stages but the 12z suite is fairly solid with it's Atlantic driven weather notion with a powerful jet coming off the eastern seaboard.

However it's out of a reliable timeframe right now. (d7-10) although annoyingly when these horrible sypnotics are shown they tend too happen whereas it's the exact opposite with cold weather.

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Whilst i am an avid coldie and I am praying we don't get a repeat of last year there seems to be an unmistakable attempt by the models to build the vortex around eastern Canada and western Greenland

 

 ECH1-216.GIF?12-0

This is just where we don't want it to be as it will power up the jet and give us 2013-14 x 10!!

 

It is however only 12/11/14 and that is the one saving grace, I think snow king said to expect a resurgent vortex as we head into late November/December and the experts over in the strat thread fully expect this to happen. I think it will be a matter of riding out this wet and mild upcoming period which I think will last about a month, it is unavoidable. 

 

So if you are a coldie and are worried that you may not have any snow to play in with your kids this year then head over to the strat thread as it may cheer you up!! 

Edited by Continental Climate
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Awful run from the ECM 12z, hopefully they are better tomorrow. With warming in the stratosphere forecasted for day 8-10, I can't see the polar vortex that strong.

Awful in what respect?

It looks standard fayre to me with a cold N/W shot in the latter stages.All set up nicely for early winter.(Grasshopper)

I will post charts when I am home.

Edited by winterof79
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Some interesting comments from NCEP this evening, some bizarre goings on with the amount of warm air forced into the Arctic circle:

 

...UNCERTAINTY ASSESSMENT...

FASCINATING 'SHAKE-UP' OR 'RE-SHUFFLE' IN THE WESTERN HEMISPHERIC

CIRCULATION HIGH-LATITUDE FLOW PATTERN TAKING PLACE---STARTED IN

MOTION BY ENERGY AND MOISTURE ORIGINATING IN THE SOUTHWEST PACIFIC

(TROPICAL SYSTEM 'NURI'). THE ENTIRE AIRMASS HAS PUSHED NORTH OF

THE ARCTIC CIRCLE. BARROW ALASKA WAS WARMER EARLIER THIS MORNING

(UTC TIME) THAN AMARILLO TEXAS.  

 

You'll also see comments re teleconnections below:

 

USING THE WPC TELECONNECTION TOOLS IS INTERESTING---THE POSITIVE

ANOMALY (UPPER-LEVEL HIGH) CENTERED OVER NORTHEAST ALASKA SUGGESTS

MAINTAINING A STEADY DRAW OF CANADIAN ARCTIC AIR INTO

MONTANA...WYOMING AND THE DAKOTAS---SIMILAR TO THE CURRENT

CONDITIONS---THROUGH THE DAY +8/+11 TIME FRAME. CONTRAST THIS TO

THE NEGATIVE ANOMALY---TELECONNECTING THE FORECAST CALLING FOR AN

UPPER-LEVEL LOW OVER SOUTHEAST HUDSON BAY. THE TELECONNECTION

SHIFTS THE ENTIRE COLD 'FOCUS' AT DAY +8/+11 TO THE

MIDWEST...GREAT LAKES AND SOUTHERN PLAINS---ESSENTIALLY THE ENTIRE

LANDMASS AREA EAST OF THE CONTINENTAL DIVIDE. SO THE QUESTION

IS---WHICH ANOMALY TO BASE THE FORECAST ON? OR EVEN BETTER---WHICH

TELECONNECTION IS MORE SIGNIFICANT AND 'UNUSUAL'?

THE UPPER-LEVEL RIDGE IS THERE NOW...AND THE UPPER-LEVEL LOW?

ANOTHER 36 HOURS AWAY AND HARD TO TELL TODAY WITH THE AIR

TEMPERATURES AHEAD OF THE FRONT---ALONG THE EAST COAST

TODAY---UNSEASONABLY MILD.

 

If the models hold the cold back further west in the USA this then would reflect less eastwards movement of the cold pool. Which would impact the eastern USA and downstream in western Europe.

 

 

Those temperature anomalies show up well on the ECM 850mb with a small patch of off-the-scale

+ve values (black area) west of the pole,and of couse the deep negative values over parts of the USA.

 

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This isnt too bad is it? Pretty cold uppers towards the end of the run on ECM tonight. I think I asked this last year and -4 should be enough for some wintryness on high ground at least, as this is going on end of November time?.....

 

ECM0-192.GIF?12-0ECM0-216.GIF?12-0ECM0-240.GIF

 

Unlikely to happen of course anyway :)

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