Model Output Discussion - 1st February Onwards 12z--->

[ANYWEATHER]

FroM Retron over on TWO;

 

The ECM 32-day control run shows a zonal spell setting in from 240 to 444, then high pressure surges NE'wards and a monster (>1060) Scandinavian High sets up. This then eventually retrogresses westwards, all the while with lows barrelling along close to the UK.

 

We can only look at it retrospectively if we don't subscribe to Weatherbell or similar. From what I can make out on the verification page, it has performed well this winter.

 

All to play for. I'd say.

With the Ecms performance as of late ...forget it!

[Timmytour]

GFS for 5th Feb

7th Feb 1956

Similarities?

Wouldn't mind a similar evolution into this

..ended up one of the three coldest Februarys of the last 60 years and colder than any we've experienced in nearly thirty years

Edited February 3, 2015 by Timmytour

[mcweather]

With the Ecms performance as of late ...forget it!

Your getting your models mixed up Anyweather. THe Ecm 32 dayer as opposed to daily Ecm has performed well this winter, just ask Fergie.

Edited February 3, 2015 by mcweather

[ANYWEATHER]

Your getting your models mixed up Anyweather. THe Ecm 32 dayer as opposed to daily Ecm has performed well this winter, just ask Fergie.

Ok I respect your point, But don't Agree

[legritter]

The threat of snow over east Anglia, and southeast England Wednesday night into Thursday looks to be diminishing 

all the time. Also the threat of another northerly reload was never really there in the first place, just another ECM 

poor run to add to the growing list. Certainly not much in the way of wintry weather to look forward to in the mid range 

( day 5 to 10) beyond that who knows. 

It certainly looks as though the vortex this winter is  far more robust than we thought judging by the latest runs and 

despite posts throwing everything into the equation for this winter ie GWO,QBO, MJO, Enso, solar and strat and  

covering all angles searching for answers the weather does what it wants to do.

Frosty at night and dry but rather cold perhaps by day looks the order of the day as we go through next week.

only just popped in to have a quick look, as busy with elderly relatives ,you say the threat of snow coming in from the east is now diminishing for later wed /thursday is this to a lack of any troughs or an opening out of any pressure ,i will check back later for an update .looks like the cold will keep going for a while yet, by tonights models , cheers all .

[knocker]

Tonight's anomalies are all much the same with the vortex over the Pole and HP dominating the UK but centred probably to the west. The ext GEFS and ECM out to T360 maintain this analysis except the ECM has the ridge to the SE of the Uk and the GEFS to the SW. with the HP tending to mid Atlantic.

Charts weatherbell

Edited February 3, 2015 by knocker

[A.J]

Statistically speaking, I don't think we're in that bad a position going forward if you're of the colder persuasion.......The differences between the current output and last winter is stark.....Last winter it was a raging PV in the worst possible place, with a zonal train to give the most thick skinned coldie nightmares of the 'Im on a derelict spaceship with only a mars bar and a ravenous 10ft tall xenomorph for company' degree!....with basically nowhere to go until spring

 

The current output going forwards is quite different, High pressure dominating the pattern bringing benign weather, and well, the HP can eventually go in one of a few main directions.....south is not good, a sinking high could lead to thoughts of Bartlett Highs and other such insane nightmares....northwards and we get an easterly feed, much better.......westwards, and I guess we'd have troughing with a Pm air mass, and back east, either benign conditions a possible euro high giving a relatively mild southerly feed.......or the holy grail, HP north east over Scandanavia with an easterly blast.........50/50?....not bad odds, statistically, I'll take them!

Edited February 3, 2015 by ajpoolshark

[bluearmy]

Ok I respect your point, But don't Agree

The ec32 clusters and ens perhaps (tough to tell from week 3 and 4 means/anomolys) but the control run? Can anyone really take any detail from a control run in the 15 to 32 day period?

Having said that, according to matt's tweet, the second half of the EC 32 run members are buliding a scandi height rise so the control may be barking up the tight tree in general terms.

Edited February 3, 2015 by bluearmy

[East_England_Stormchaser91]

Looking like we will be seeing very calm, still and relaxed conditions with the big high right over us. 

I do like the fog, and calm, still atmospheres. Very nice and peaceful to walk in and also for me to be working in. The flip side to my coldie enthusiasm comes at a price for having to work in it!! Wouldn't fancy working in a 1987 style blizzard thats for sure   

Nevertheless, still the back end of Feb and early March to go for a last dig shot at a cold attempt. Then all eyes will be on pumping some warmth up as we enter the first stages of spring 

[Carlrg]

FI I know but if this verifies and sticks then we can all assume this winters fubared.

 

 

 

 

 

[492]

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=186&code=code&mode=0&mode3h=0&runpara=0&carte=1

 

An omega block in the vicinity of the UK by around T+174. It could do with being a bit further north but nevertheless a rare sight.  

[pdiddy]

an odd looking jet profile...

...and can't be easy for the models to decipher.

Edited February 3, 2015 by pdiddy

[Great Plum]

Grim...

[Jason M]

Gotta see the funny side tonight really. Might as well have a blowtorch SWester as a UK high.

This caught my eye from the GEFS. Now this is the perfect example of a UK high. No part of the mainland UK escapes its evil grip.

http://www.meteociel.fr/modeles/gefs_cartes.php?code=20&ech=120&mode=0&carte=0

[Paul_1978]

Grim...

What? Show me a 13 day chart that verified.

[Jason M]

Interestingly at 180 hours most of the gem ensembles are actually full on westerlies. Maybe are UK high will be back on its more usual position sooner than we thought.

Let's see what tommorow brings.

Always got the bitter easterlies to look forward to on Thursday and Friday. What with daytime temps of 6c it should be freezing :-)

[Tamara]

I can't really see any HLB's forming over the next 10 days, but I think that it is a bit early to rule it out for the second half of February, and we know that March can still deliver impressive snow despite the longer days.

 

I think that the pattern that will start to show is hinted at by tonights ECM days 9-10 and it is one that we have become very familiar with this winter. That is recurrent depressions recurving over the top over the Azores high leaving the UK in a predominantly NW airflow with predominantly -5ºC 850's flowing in from the Atlantic. We see some support stratospherically with this pattern with further hints that the stratospheric polar vortex will maintain a Siberia displacement trend as highlighted by the latest GFS in FI.

 

viewimage.png

 

The MJO forecasts keep the suggestion of a more meridional Atlantic pattern as we have seen with the longest lasting toppler ever - in fact it never really toppled properly as the jet stream chart I posted earlier shows. Moreso, the eastern section of the toppler jet stream buckled completely, without the jet stream ever taking an undercutting more southerly flow, close but no cigar there!

Check out the latest ECM and GFS MJO forecasts - there is no hint of a return to phases 4/5  -more a lock in to the current phased pattern.

 

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

 

 

So again it will be no surprise to see another set of toppling type lows start to develop, dragging down colder 850's each time until eventually we see another northerly, which wil be possibly colder than the one just passed, and if this coincides with a strong MJO event, then we could just see that undercut occr and snap things into position.

 

I for one haven't given up on this winter just yet - each cold spell has been progressively longer lived and more potent than the previous and just perhaps the best will be saved for last?

 

I suspect that the ensembles will start to head in that direction - already signs.

 

get_orig_img.gif

Yes, that increasingly meridional pattern leading to something strongest, latest in the season, that you describe very well mirrors my own summaries of late.

 

Never the same as the deepest part of the winter but hopefully still time to see some proper wintry conditions not punctuated with warm sectors and higher dew points. The longevity of this toppler has been synoptically impressive, but it has been a source of frustration in terms of getting a clean arctic flow. Of course one could argue that a clean arctic flow in an Atlantic ridging scenario would not have lasted as long as this one.

 

The displaced vortex has held it in position for far longer than usual, but on the other hand the close presence of the upper trough has prevented a more direct and less cyclonically mixed arctic sourced air mass

 

I admit that rather than what is evolving this week (and in the absence of true HLB) I for one find myself thinking about something like this - as a hoped for parallel in 'toppling Atlantic ridging' - which occurred during one of the colder winters in a relatively unremarkable stretch of 90's winters (post Feb 1991)

 

http://modeles.meteociel.fr/modeles/reana/1996/archivesnh-1996-2-20-0-0.png

 

http://modeles.meteociel.fr/modeles/reana/1996/archivesnh-1996-2-20-0-2.png

 

A very similar broad scale pattern, and very similar displaced vortex signature to now. The clear difference though - a clean undiluted recurve of CAA from the NE with the High at a better amplitude to supply strong snow shower convection.

 

This is the type of closer scale UK evolution I had hoped for within the possibilities and context of the predicted present macro pattern which has verified quite well

 

Instead.. we see this week a small window on Thursday that gets some proper upper cold in right at the death of the protracted amplification, but with the High too close to the UK to provide and sustain deep convection. This upper cold only extends briefly to southern most parts rather than a greater part of the UK -and seems likely to yield scarce snow even here

 

Very frustrating after a series of occurences that, however impressively sustained synoptically, have always tipped the wrong side of marginal as any trough within the cyclonic airstream that has created a snow event, invariably has not lasted beyond a matter of hours before giving way to rain and sleet  - away from northern most areas and highest hills

 

However, aside from this rare whinge, the continued amplified expectation theme remains the same - and maybe the next amplification will go one closer to that archived one. There have been many more of course in winters that are much more famous than 95/96

Edited February 3, 2015 by Tamara

[Pixel]

Ok so here we are all us amateurs looking at the models and deciding what may or may not come next… all while the models are fed with data from ‘x’ number of scenarios (outcomes) over many years… plus some of the other (dare I say) controversial variables available.

 

This time of year is one of the most exciting as a weather enthusiast, our atlantic driven friend nods off a while, gets distracted up and down and patterns swing wildly in the battle of balance to regain the ‘norm’.  

 

Could it be even slightly plausible that the models are about as confused as us as to what happens next as they enter a phase where a particular scenario doesn’t ‘fit in’ with previous predicted output?

 

T6 to 24 is radar time, T 96+ is interesting but T180.. may be la la land 

[TEITS]

Just a quickie from me.

 

I am surprised nobody has mentioned the potential storm off the NE coast of the US which potentially is only 2 days away. Now the GFS continues to keep this away from the E coast of the US and out to sea.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015020318/gfsna-0-60.png?18

 

However even at this late stage some of the forecasters in the US are not ruling out this storm deepening and tracking much further W and moving N up the coast of the US. Should this occur our HP could still back further W.

 

May seem like a long shot but a sudden flip back to very cold N,lys on the E flank of our HP cannot be ruled out for E parts of the UK. I am not saying this is likely but still remains possible.

 

http://www.accuweather.com/en/weather-news/snow-storm-boston-new-england/41680393

[davehsug]

Pixel, on 03 Feb 2015 - 23:53, said:

 

Ok so here we are all us amateurs looking at the models and deciding what may or may not come next… all while the models are fed with data from ‘x’ number of scenarios (outcomes) over many years… plus some of the other (dare I say) controversial variables available.

 

This time of year is one of the most exciting as a weather enthusiast, our atlantic driven friend nods off a while, gets distracted up and down and patterns swing wildly in the battle of balance to regain the ‘norm’.  

 

Could it be even slightly plausible that the models are about as confused as us as to what happens next as they enter a phase where a particular scenario doesn’t ‘fit in’ with previous predicted output?

 

T6 to 24 is radar time, T 96+ is interesting but T180.. may be la la land 

 

Pixel, the models are NOT fed with historical data. They are pure mathematical calculations from now.

[fergieweather]

Pixel, the models are NOT fed with historical data. They are pure mathematical calculations from now.

GloSea5 does perform simultaneous hindcasts alongside each forecast run. This allows better forecast calibration and clearer skill assessment. Hindcast covers period 1996-2009.

[davehsug]

fergieweather, on 04 Feb 2015 - 00:23, said:

GloSea5 does perform simultaneous hindcasts alongside each forecast run. This allows better forecast calibration and clearer skill assessment. Hindcast covers period 1996-2009.

If only we could see it Ian lol!

[summer blizzard]

GloSea5 does perform simultaneous hindcasts alongside each forecast run. This allows better forecast calibration and clearer skill assessment. Hindcast covers period 1996-2009.

 

In simpler terms, does it compare what happened from a similar starting point in the 96-09 period in order to assess it's confidence interval in effect. 

[knocker]

ECMWF vs. GFS ensemble mean 500mb geopotential height 11-15d pd fcst maps. Bottom Line: Cold look o/the eastern U.S.

 

https://twitter.com/WSI_Energy

[knocker]

Hardly a surprise that HP dominates the morning GFS run. However there is a small feature (won't verify of course) that gives a brief intermission, As the original HP moves east a small low develops to the NW of the UK and travels into the North sea. There follows a weak ridge with Azores HP suppressed by a large low pressure area western and central Atlantic which drifts north initiating a build up of HP from the SW and order is once again established.

Chart weatherbell

Edited February 4, 2015 by knocker