Winter Model Output Discussion 01/02/2013 12z onwards

[chionomaniac]

I wasn't the one promising that deep cold was coming, when it was as plain as the nose on your face it wasn't. Low heights to our NW have been constant throughout this winter and not once have they looked like receding, a point I have often made.

No - you promise nothing and deliver just that.

Please find a post where I have promised​ deep cold. Please recognise the difference between a forecast ( as expected with previous climatology) and a promise.

I feel that it is easy to keep firing shots off, SI, but less easy to provide some sort of analysis and subsequent forecast. Perhaps if you had spent a lot of your own time voluntarily researching and constructing forecasts for the benefit of others (with no gain to yourself) you may not be quite as keen to knock.

[Snowman.]

Turned out to be nothing but we now know we need LP system to track SE into Europe this will allow heights to build NE.

[IDO]

Yep, it amazes me how some people didn't spot the backtrack earlier on in the run!

I think most of us spotted that, but with the current synoptics, our thoughts were, so what, it will only flatten out a few days later. With the PV continuing to sit over west Greenland the best we can hope for are some topplers and cool temps with transient sleet, cold rain (more so IMBY).

[Severe Siberian icy blast]

Point taken, sometimes I can be a little brutal with my assessments. Apologies all round.

I no it's frustrating buddy as its been for us all, my passion is so great that I wake up and sometimes after viewing the models I feel literally angry , this year promised so much , but that's the weather, and I have no control , that's the hardest part , but any hoo , this month can and will deliver ! . .

[UV-RAY]

No - you promise nothing and deliver just that.

Please find a post where I have promised​ deep cold. Please recognise the difference between a forecast ( as expected with previous climatology) and a promise.

I feel that it is easy to keep firing shots off, SI, but less easy to provide some sort of analysis and subsequent forecast. Perhaps if you had spent a lot of your own time voluntarily researching and constructing forecasts for the benefit of others (with no gain to yourself) you may not be quite as keen to knock.

It wasn't a dig at yourself and I do apologise if it came across as such, a lot of my angst is borne out of frustration at how a synoptic pattern which should have been conductive of cold has failed to deliver. I retract my earlier post Chion and hopefully we can draw a line under this and move on. Edited February 1, 2013 by Sceptical Inquirer

[Snowman.]

We need that Westward correction on the GFS.

This is the ECM

The low on on the eastern seaboard has a better tilt and further south keeping us in a NNE.

The GFS on the other hand has it further north causing the high to topple faster and trying to break through over the top, causing the winds to swing NW.

We need something like the ECM to get us in a better position for heights north.

Until I see more models going the GFS route I believe nothing,

GFS has lost my respect this year when all models pointed towards cold this one said no until it came to the correct time frame and made a U turn it had support from the GEFS ensembles that it would turn mild.

In December UKMO was the model that didn't match what the ECM and GFS was saying. UKMO then joined the 2 before switching back along with the GFS and ECM.

UKMO this year has done very well indeed with ECM then GFS following behind.

Edited February 1, 2013 by SN0WM4N

[Severe Siberian icy blast]

All in all a better gfs , the scandi high built , which has to be a positive , but then it all fell apart in fi , but when doesn't it? Think we have saw a backtrack tonight by the gfs, we have a good week coming up , with some snow for many, but maybe short lived , then we have signs of the scandi high , the ECM develops this well, and the gfs tonight has also produced one , but it never effected our island , but good to see both models picking up on the trend, and I'm hoping we can see a first class ECM .

[chris55]

I think I quite like the UKMO tonight, it is hard to judge as I'm no expert. But we have a few things that interest me, first is the significant area to the north and north east that is simply a filling trough, with no real defined pattern, there is also no eastward push of energy from the Canadian PV, if anything the main thrust of energy from the Canadian PV is heading around it's western side digging into the far North East US/Newfoundland. Now this is not a bad upstream pattern and with the filling trough to the north east maybe there is a possibility off the heights to the far north east backing West into the gap? But maybe we need more energy slipping down the eastern side of the Azores high between us and it, I'm not to sure really, a hard chart to read, maybe Steve M can enlighten us.

Edited February 1, 2013 by chris55

[legritter]

Yes there are some interesting possibilities out there but it keeps getting put at arms length.im hoping for a little bit of wintryness next week just to get my adrelalin going .it looks to me that something is around that corner, perhaps thats why met office seem only half commited .ECM will be one to watch tonight and later faxes for any features next tues /wed .i think tonight or tomorrow will be the crunch time for ECM to bring in high over scandy ,and perhaps maintain it .it as been a frustrating winter for coldies we are shown plenty of promise then it vanishes ,although we did get some .just been thinking about SSW and with it being a very new science iv a hunch that perhaps we meteorologists scientists pick up the signalls when its nearly complete and the impact on blocking comes sooner than later ,but thats my thoughts .still plenty of time for a major cold spell yet ,and some could get lucky next week .

[phil nw.]

Considering this is quite a mobile Atlantic pattern with only modest amplification in the flow we still manage to get a couple of decent Arctic incursions in the next few days.

The one for the weekend is quite brief but the second go for mid-week is more noticeable.

We can see a snapshot here at T90hrs.

The cold air diving south late on Monday as deep low moves down the N.Sea bringing some snowfall widely for higher ground and with freezing levels dropping as the cold air digs in snow could fall anywhere during the following 72hrs.

Edited February 1, 2013 by phil nw.

[Suburban Streamer]

a lot of my angst is borne out of frustration at how a synoptic pattern which should have been conductive of cold has failed to deliver

hi si

did u miss the snow we had or were u expecting something more...um...canadian?

we've had a two week cold spell that delivered plenty of snow for much of the uk. a fair number of people got more snow than they did in dec 2010!

i've sat through plenty of winters that failed to deliver even a flurry let alone 15cms of lying snow!

If you are one of the few unlucky ones who didnt get any lying snow last month then i understand your frustration, but even then, u really cant suggest that it didnt deliver snow, regardless of synoptics

Edited February 1, 2013 by Suburban Streamer

[rotation]

Indeed. Last several winters have blurred what is the norm and influenced expectations. Perspective is the key. I used to be happy with a flake lol. And looking at the model output even here down south a few marginal flakey surprises may occur next week.

[phil nw.]

I think we are getting the best we can out of this setup if the models verify as shown.

Considering the amount of energy still coming from the Atlantic and the mobility of the flow the UK stays quite cold in the next week or so.

I have seen many a North Westerly modified by that Azores High when it set up even closer to the UK and the UK received more modified polar air with the real Arctic cold pushed further east.

Granted it`s not ideal and it`s unfortunate that the High shows continued reluctance to move west as we hoped.

Mean 00z outputs suggest the 500hPa pattern will look similar in week 2 with a Euro trough just to our east so i think we will have to continue to look north west and hope that Canadian vortex relents somewhat.

It could make a world of difference to our chances of enhancing our cold prospects.

[Captain Shortwave]

The ensembles looks pretty interesting, the Russian heights for the most part look to come into play. Some Scandi ridges, the majority of the runs do causes some trough disruption with lows going south east through the UK or there abouts. Very few show full on zonal throughout.

[UV-RAY]

hi si

did u miss the snow we had or were u expecting something more...um...canadian?

we've had a two week cold spell that delivered plenty of snow for much of the uk. a fair number of people got more snow than they did in dec 2010!

i've sat through plenty of winters that failed to deliver even a flurry let alone 15cms of lying snow!

If you are one of the few unlucky ones who didnt get any lying snow last month then i understand your frustration, but even then, u really cant suggest that it didnt deliver snow, regardless of synoptics

I did see a little snow, but it's not that though more a case of hoping for heights to our NW becoming established, everything pointed to this happening, but sods law dictated otherwise. Anyhow next week I could see a little more snow from a brisk W/NW direction, it looks a rather cold and unsettled week IMBY and these sort of setups can deliver a surprise or two normally.

[phil nw.]

The ensembles looks pretty interesting, the Russian heights for the most part look to come into play. Some Scandi ridges, the majority of the runs do causes some trough disruption with lows going south east through the UK or there abouts. Very few show full on zonal throughout.

The 850hPa graph showing not bad either for C.England -5C mean line.

http://modeles.meteociel.fr/modeles/gens/graphe_ens3.php?x=262&ext=1&y=102&run=12&runpara=0

underlining the cold outlook throughout with few mild members.

[bluearmy]

having thrown in the towel on next weeks cold lasting through till mid month, the 12z ncep suite backs the mean trough west and had this been the 00z run, i would have probably kept my powder dry until the 12z ecm ens were out later. so there's a swing back of the prndulum and all eyes at 8-30 on the ecm ens.

[Hotspur62]

Have looked at latest GFS and although there is some improvement on previous run i just feel that those hoping for prolonged cold spell(by that i mean 7-10 period with widespread cold/snow) is looking less likely and although next week looks coldish with some snow in the NW,those South of Midlands will be unlikely to see much in the way of snow.

As others have said,those of us in SE were spoilt by snowmeggedan in December 2010 and that has i feel increased expectations when the models have subsequently showed Easterlies etc only for them to be taken away again(a la Dec2012).

But back to GFS,the Vortex over NE Canada just looks too stubborn to move away Westwards which would allow AH to move further North and West and this has just overidden other factors when it looked good for us in the UK over last 6 weeks(excluding period 12th-25th Jan).I have looked at latest UKMO Fax of 120 and 144 and the direction of Low over Newfoundland seems to be moving NEastwards to West of Greenland which i think will be a good thing moving forward(Apologies for not posting these frames but not too hot on PC stuff!!).Am i right at thinking this as do get a bit confused when trying to analyse things?

[Snowman.]

Not a single ECM post?

T168

0z 168

Hmmmm

Edited February 1, 2013 by SN0WM4N

[Snowman.]

Lift off at 192

0z T192

Edited February 1, 2013 by SN0WM4N

[snowking]

Not a single ECM post?

T168

0z 168

Hmmmm

I suspect two reasons

1) people are slowly realising to wait for a whole run to appear before commenting so we can analyse the exact movement of various dynamics, rather than predicting them mid run

2) the ens will be more eagerly awaited given the range we are looking at timeframe wise as opposed to a single op run (as demonstrated by the rather different ECM 0z op compared to its ensembles)

SK

[Severe Siberian icy blast]

Not a single ECM post?

T168

0z 168

Hmmmm

More amplification , not sure where it will go , big low over the states pushing north , will it sink the high and come over the top? Or will it carry on north and go through west Greenland? Looks like our high may ridge northeastwards .

Lift off at 192

0z T192

No way just as I said , brilliant. GAME ON

[Snowman.]

Very cold over Europe

Light winds

[Panayiotis]

Wedge of high pressure to the north (however it has weakened compared to the 0z) at 192hrs on the ECM also SW of the low (to the SE of Greenland) is another low with a perfect orientation to ridge the Azores north combining these that should force the low (to the SE of Greenland) SE ...

Edited February 1, 2013 by Panayiotis

[J10]

As usual early on a Friday evening, here is the synoptic snippet taken from the Alps forecast to be published later.

Starting with the synoptic charts as at 12 noon today.

Sat 2 Feb

There is a deep area of low pressure (960mb) centred over North America, and covering the North Atlantic. Further south the Azores High has ridged north over the southern Atlantic, and has starting to ridge just west over the UK. Low pressure also for much of Europe, running down from Scandinavia, Eastern Europe and an area to the SE of the Alps. A cold northerly wind over the UK and over much of Scandinavia, cool over much of Northern mainland Europe including much of the Alps. Mild over SE parts of Europe.

Sun 3 Feb

Remaining rather unsettled over much of the North Atlantic with low pressure dominating. The Azores High has ridged further North East, with West to North west winds over the Atlantic and over the UK, where there is a mild flow. Remaining cold and unsettled over Scandinavia, cold over much of the Alps with a NE winds and the eastern edge of the Azores High.

Monday 4 Feb

Not that much change in the general pattern with low pressure over the North Atlantic and into Scandinavia. However further south west the Azores High ridges to the North West giving a NW feed over the Atlantic and into the UK and the Alps, feeding in a Polar Maritime airflow, cool to start of the UK and the Alps, turning colder in the UK later

Tuesday 5 Feb

A surface High develops over Greenland and with the Azores High ridging north gives a temporary block over the Atlantic. There is low pressure over North America and also over much of Europe, this will give a cold NW flow over the UK, with the potential of wintry or snow showers over windward coasts, this airflow moderated by the time it reaches the Alps, but still cool here.

Wednesday 6 Feb

Wednesday sees the whole pattern edge further east, a cold northerly flow still over the UK, with still the potential for wintry or snow showers over the UK over windward coasts. The cold air is likely to have pushed further south into Europe and into the Alps with low pressure to the east. Low pressure still over America, with the Azores High starting to ridge closer to the UK from the south west.

Thursday 7 Feb to Friday 8 Feb

A little bit of uncertainty towards the weekend, but the general theme is for the Azores high ridging closer to the UK, and introducing a little but less cold or maybe even mild air over the UK. Looking to remain unsettled over Europe and still looking cold over the Alps with a wind direction probably from a general northerly direction.

Edited February 1, 2013 by Jackone