Model Output Discussion - 21st - 28th November

[Mark Neal.]

Can someone explain what this is showing in FI? Newbie here. Thanks

High Pressure over the uk, bringing settled conditions by the looks of that, im new to this and could be wrong though.

[summer blizzard]

GFS18z is brilliant - if you like frost.

There is a chance of snow to about 500 feet i would say around the 3rd December although for the most part it would be frosty.

GFS18z then builds the upper high over the UK with a strong inversion, very similar to Novermber 2005 (minima well below 0C, maxima about 5C)..

http://www.wetterzentrale.de/pics/archive/ra/2005/Rrea00120051122.gif

[cheshire snow]

Hmm, a nice 4 day cold spell thrown in there by the GFS from December 3rd.

First low level snow perhaps?

Indeed,probably have gone by morning though LOL

C.S

[Alex]

Can someone explain what this is showing in FI? Newbie here. Thanks

Settled with a big high over the UK, cold at night under clear long nights under light winds but perhaps low cloud and fog/mist in southern areas under a slight easterly flow off the north sea

[Paul]

Fully detailed and in depth version of the winter forecast now online:

http://www.netweather.tv/index.cgi?action=winter-forecast-detail-2011;sess=

Discussion thread:

[nick sussex]

Latest ECM ensemble maps upto 168hrs:

http://www.ecmwf.int/samples/d/inspect/catalog/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!168!pop!od!enfo!enplot!2009112700!!/

The majority of the members look very unsettled with some very deep depressions.

Perhaps some good news at last for the European ski resorts, for fear of jinxing things it looks like the eastern Alps look most favoured.

In terms of where the pattern goes after this flirtation with more seasonal conditions this depends on the amplification upstream, putting aside the GFS 18hrs run lower resolution output if the pattern flattens out the Azores high is likely to push east into Europe, if theres enough upstream amplification then the jet may cut se near the UK for a while longer.

[wolvesfan]

Can someone explain what this is showing in FI? Newbie here. Thanks

Its a mid atlantic high,it's formed south of the polar front jet so would be filled with relativly mild air and i would say cloudy as moisture is fed into it from the atlantic.night time minimums or around 0c daytime maxima around 5-10c but dependant of cloud cover.

[summer blizzard]

Its a mid atlantic high,it's formed south of the polar front jet so would be filled with relativly mild air and i would say cloudy as moisture is fed into it from the atlantic.night time minimums or around 0c daytime maxima around 5-10c but dependant of cloud cover.

If you look at the chart i posted at the bottom of the previous page you can see that it actually has a cold surface layer prompting strong inversions.

[snowlover2009]

That UK high above would produce fog and frost and be very seasonal. Any fog lingering would keep temperatures well below 5c, with maxes around 4 to 9c, north to south. Progressively getting colder, the longer it hangs on, as that is the tendency with those type of highs.

[phil nw.]

Fax Charts Wed/Thurs next week

http://www.meteociel.../fax/fax96s.gif

http://www.meteociel...fax/fax120s.gif

That little secondary low running NE across the UK could produce a fair bit of snow over the higher ground in the north and depending on it`s track maybe on some lower levels too.

http://176.31.229.22...fs-2-108.png?18

It`s only a kink in the isobars on 12z raw outputs but developed on 18Z GFS and now drawn on the UK fax.

Edited November 26, 2011 by phil n.warks.

[Cheese Rice]

I think you're really clutching at straws here mate. I don't see anything away from high ground.

Wait until the end of the run, then you'll probably see a decent toppler in FI, but it's not gonna verify.

We're running out of straws to clutch at, and it's going to be a while yet until we get any low lying snow.

I would say the brief northerly (if you can call it that), is conclusive for low level snow. Probably not on the coasts mind.

850's -5/-6

Dew point -1.c

Precipitation

Freezing level been the only fly in the ointment.

Anyway a great GFS run, i'm really pleased to see plenty of frosts, some deep lows, below average temperatures, northerlies and an increasing risk of snow.

[Aaron]

This would produce wet snow in the North West. even to places like Manchester (in the form of showers)

Edited November 26, 2011 by Aaron

[Cheese Rice]

That UK high above would produce fog and frost and be very seasonal. Any fog lingering would keep temperatures well below 5c, with maxes around 4 to 9c, north to south. Progressively getting colder, the longer it hangs on, as that is the tendency with those type of highs.

To further add..

What we saw early Jan 2009.

Edited November 26, 2011 by Cheese Rice

[kold weather]

Pattern past 240hrs is pretty good for a developing Euro High and the 18z GFS is abit of an outlier in that respect, so we need to hope that its spotted a trend. It can happen, even in poor winters, i'm sure December 2006 had a blocking high for a week or so giving decent cold due to inversions?

Anyway very long way to go till then and several NW shots that could well produce hill snow and give the mountions a decent amount of snow.

[snowlover2009]

Also to add a about 5 or 6 runs showing heights building over scandi or Greenland. The majority of the other runs keep resetting the very unsettled northwesterly incursion or west to east movement. A good deal of runs show some major storm systems coming up, so some lively weather indeed and with the wind directions and strength of wind, it won't feel pleasant to be out in! To add the temperatures are generally looking average to below, particularly for us in the north. No deep cold, but I like the fact of the wind making it feel very raw, which in some ways is better than dry continental cold.

[shedhead]

No Shed basically we are in a pattern change with cooldown on cue , although it may not be what Zamg projected. The pattern is currently looking at bringing in much cooler conditions than most who are painting a dire picture for winter had thought would happen? Lets see how Dec progresses....please....winter hasn't even begun.

BFTP

Blast, Zamg got it wrong, as C confirmed earlier. As for the current pattern, I don't know anyone who said it isn't going to get much cooler in the near future, it's been almost record breakingly warm of late so no real surprises there.

[Backtrack]

I would say the brief northerly (if you can call it that), is conclusive for low level snow. Probably not on the coasts mind.

850's -5/-6

Dew point -1.c

Precipitation

Freezing level been the only fly in the ointment.

Anyway a great GFS run, i'm really pleased to see plenty of frosts, some deep lows, below average temperatures, northerlies and an increasing risk of snow.

Yes, the toppler around 3rd December would be, otherwise nothing in that run is of interest to me regarding low level snow.

[Ruzzi]

Here you go :

http://www.wetterzen...00120101218.gif

A jawdropper of a chart.

Wow, what a stark contrast to current affairs. Would take that chart in a second! Still we have the whole winter of surprises ahead of us. Thanks alot for all your efforts tonight . . Much appreciated

[A Winter's Tale]

Wow, what a stark contrast to current affairs. Would take that chart in a second! Still we have the whole winter of surprises ahead of us. Thanks alot for all your efforts tonight . . Much appreciated

What a stark contrast to current affairs? Never knew we were back in December 2010!

[Jason T]

What a stark contrast to current affairs? Never knew we were back in December 2010!

!!!!!!!!! and i believe it will just get better,Model output this time next week could be a big WOW. It seems the case that NW is the way to go (or to watch) On a different note anybody know where steve murr gone.,If not he is probably out building an awesome THAMES STREAMER.

[kumquat]

Lets stop talking about "indeeds" and "maybes" . Sick of those. The next week will bring snow to lower levels up north and towards the NW. Not lasting.

After that we'll get a couple of shots after the fronts clear. Again snow, but shortlived.

[phil nw.]

The overnight runs show the Atlantic Westerly Pattern in full flow.

http://www.wetterzen...ics/Rukm721.gif

http://www.wetterzen...cs/Recm1442.gif

Low`s moving across the North one after the other with brief incusrsions of cooler air behind the fronts.

Wet and Windy at times for many.

Temps. never far from average.

GFS Ens.

http://176.31.229.22...ndres&runpara=0

Dutch ECM Ens.

http://www.knmi.nl/e...M_06260_NWT.png

Op Runs never far from the mean lines.

Edited November 27, 2011 by phil n.warks.

[SNOWPLOUGH]

GFS and ECM 00Z are as you were, cool zonality for the +348/+240 hrs. Not much change here, just checked all of the teleconnections and the outlook is bleak for cold and snow. Are we really going to have to wait til late December/early January for a pattern change?

Dan

[nick sussex]

Not much overall change this morning in the model output.

Unsettled weather, a mix of milder and cooler days, chances for the odd glancing blow of PM air, any lowland snow at the moment looks reserved for the far north.

Some very windy weather also looks likely, best watch out for this, still uncertain here as to how deep any depressions could be.

Looking at where the pattern goes after this more typical type early winter weather well generally if the jet flattens out then the Azores high pushes in, there is however one possible variable now appearing and thats pressure rising to the east, this can have the effect of holding some troughing over central Europe.

If you look at the ECM De Bilt ensembles there are very few milder options there, generally they look close to or a little below average:

http://www.weerplaza.nl/15daagseverwachting/default.asp?type=eps_pluim

So these suggest that its unlikely we'll see a strong sw flow into the heart of Europe, if you look at the control run that most definitely brings in high pressure towards the end.

It maybe that the Azores high ridges ne joining up with high pressure developing to the east. Of course the continent can be a lot colder with a Euro high whilst the UK can have that sw flow around the ridge.

There is then some uncertainty in exactly what happens post 240hrs, however for those looking for a winter wonderland I'm afraid theres little chance of that for the timebeing.

If you want to at least keep chances of some relatively colder conditions then look no further than the eastern USA, an amplfied trough there would be good news for that, broad flat trough not good.

Anyway lets see what delights the GFS 06hrs run has for us!

[WhiteFox]

GFS and ECM 00Z are as you were, cool zonality for the +348/+240 hrs. Not much change here, just checked all of the teleconnections and the outlook is bleak for cold and snow. Are we really going to have to wait til late December/early January for a pattern change?

Dan

As far as I'm concerned, this coming week marks a pattern change. The enduring euro high slopes off allowing atlantic depressions to have more influence further south at last. It's been generally settled down south for what feels like weeks with occasional spotty rain and clouds.

A pattern change doesn't have to be a sudden and dramatic shift to the freezer!