Winter Model Discussion 18Z 19/2/13 onwards.

[Mucka]

Some interesting ppn charts showing up on NAE the little blue square is over my house as it has been all winter

[Panayiotis]

So the 12z has updated to the crucial part and its much cleaner than the 06z (however that was also cold) with no shortwaves around,we now want that low to dig SE as much as it can, dragging in those cold uppers.

[snowking]

Whilst March could well turn out below average temp wise the ECM 32d day certainly doesn't suggest a mega March freeze.

Any low level snow i feel would be reserved for North England upwards, maybe on the odd occasion over the highest hills of Southern England. March could also turn out be wetter than average (the wetter further South you go).

Those are tmax values

Average temps here:

http://www.weatherxchange.com/unzippedmonth/Coleshill_monthts_Tmean_21022013_D+XX.png

Certainly below average

SK

[SMU]

Cheers CC

Yes that was the one

March 1962

Steve

[No Balls Like Snow Balls]

Those are tmax values

Average temps here:

http://www.weatherxc...022013_D XX.png

Certainly below average

SK

Thanks, still no mega freeze but better than the Tmax I was looking at lol, I class a mega freeze as 0c and below by the way.

Edited February 22, 2013 by No balls like Snow Balls

[Tom Jarvis]

typical gfs goes back to defalt zonal in low res

[Beaufort12]

Has it gone t1ts up?

[LomondSnowstorm]

UKMO looks very nicely teed up for a northerly at +144:

[Summer Sun]

Nothing majorly cold from GFS tonight looking fairly zonal from later next week

UKMO offers the best chance at t144 for a northerly

Edited February 22, 2013 by Paul

[LomondSnowstorm]

Nothing majorly cold from GFS tonight looking fairly zonal from later next week

http://www.jp2webdes...o.uk/ds/gfs.htm

UKMO offers the best chance at t144 for a northerly

I wouldn't call it zonal, the northerly reaches Scotland then a weak ridge forms over us and ridges towards Scandi with the fronts to the west failing to make any progress eastwards. Bit of an odd run synoptically.

[legritter]

Any thing is possible Fellow Posters .this is the weather and if mother nature wants to give us in the uk the coldest march on record or documented with raging blizzards and sub zero days she will .anyhow modells looking mouthwatering at the moment ,with hints of a cold start to march .plenty of cold air to our north we just need that door to open in our favour .tonights run i hope keeps the interest going .cant complain here dry day forecast ,now light snow falling ,nothing on radar but only very light .

[nicknacknoo]

Gavin., on 22 February 2013 - 16:47 , said:

Nothing majorly cold from GFS tonight looking fairly zonal from later next week

I'm in agreement with LS here, certainly not my definition of zonal. T300+ maybe.

[mushymanrob]

I'm sure that I can remember ice-days (usually combined with blizzards) several times, in March: 1965, 1970, 1979...On April 11th 1978 it was only up to about 3 or 4C...

Anywho, we're meant to discussing the models, not 'Marches throughout history'...

cant comment on 65, 70 was the biggest fall and took several days to go. the rest were 24 hour wonders, oh and there was heavy (but temporary) snow in april 68. on those statistics we get one snowy spell in march (of any note) every ten years....

well.... the 12z completely downgrades any cold chances, no northerly, no cold uppers to speak of. i dare say that this run isnt a trend setter but an outlier, so i for one will not be breaking open the champaigne to celebrate the coming of spring just yet, dispite it being right up my street! itll take several more runs plus anomaly chart confirmation before i start getting more confident of anything springlike coming.

just goes to show though, that northerly was not nailed, it wasnt certain, those who were sceptical were right to be so. mind you, that doesnt mean to say that there wont be a northerly, just that yesterday was too far off for it to have been certain.

[Chris W]

well.... the 12z completely downgrades any cold chances, no northerly, no cold uppers to speak of.

I disagree, not as potent but still a cold north/northwesterly by Sunday 3rd:

[nicknacknoo]

cant comment on 65, 70 was the biggest fall and took several days to go. the rest were 24 hour wonders, oh and there was heavy (but temporary) snow in april 68. on those statistics we get one snowy spell in march (of any note) every ten years....

well.... the 12z completely downgrades any cold chances, no northerly, no cold uppers to speak of. i dare say that this run isnt a trend setter but an outlier, so i for one will not be breaking open the champaigne to celebrate the coming of spring just yet, dispite it being right up my street! itll take several more runs plus anomaly chart confirmation before i start getting more confident of anything springlike coming.

just goes to show though, that northerly was not nailed, it wasnt certain, those who were sceptical were right to be so. mind you, that doesnt mean to say that there wont be a northerly, just that yesterday was too far off for it to have been certain.

Agree with this... though strange because while looking at the run things looked a lot more promising up to circa T174 with a better uninterupted flow heading towards the north. Can someone with considerably more expertise please explain the reason for the divergence between the models (GFS 06Z and 12Z) from this point on?

Edited February 22, 2013 by nicknacknoo

[mushymanrob]

I disagree, not as potent but still a cold north/northwesterly by Sunday 3rd:

it is a much less potent then the previous 24 hour runs, isnt that a downgrade of the cold? what the 12z shows is normal early march weather, a mix . true the -5c upper crosses the country on march 3rd, but its gone by monday 4th! 24 hours of a cold upper is considerably less then what the previous 3 runs displayed.

Edited February 22, 2013 by mushymanrob

[NorthernRab]

it is a much less potent then the previous 24 hour runs, isnt that a downgrade of the cold? what the 12z shows is normal early march weather, a mix . true the -5c upper crosses the country on march 3rd, but its gone by monday 4th! 24 hours of a cold upper is considerably less then what the previous 3 runs displayed.

I think he's more being critical of the fact that you said that there were no cold uppers to speak of on the 12z run, which judging by the chart he posted in support of his claim, he was right to be critical.

[J10]

The main problem with the Northerly is there is no real trigger to push the cold south.

As such most runs have kept the cold locked up well to the south of us, so far.

[johnholmes]

Some interesting ppn charts showing up on NAE the little blue square is over my house as it has been all winter

at least we now know where you are talking about!

[Frosty.]

Met will not mention colder northerly, easterly etc unless it is virtually sitting in their laps,

Well one thing is for sure, the latest Gfs 12z op run won't encourage them to talk up a northerly as it's a long way away from last night's 18z freezathon, the gfs seems to be backing further away.

[Frosty.]

The main problem with the Northerly is there is no real trigger to push the cold south.

As such most runs have kept the cold locked up well to the south of us, so far.

did you mean to the north?

[itsnowjoke]

Some interesting ppn charts showing up on NAE the little blue square is over my house as it has been all winter

shall be coming for tea now i know where you are

[mushymanrob]

I think he's more being critical of the fact that you said that there were no cold uppers to speak of on the 12z run, which judging by the chart he posted in support of his claim, he was right to be critical.

yep, 'none to speak of'... meaning what there was is basically hardly worth a mention. if id said 'no cold uppers' then he would have been correct.

anyway, i expect the next few runs to revert to being much colder as i think the 12z was an outlier and not a trend setter, which will make this bickering over trivia obsolete.

[AWD]

yep, 'none to speak of'... meaning what there was is basically hardly worth a mention. if id said 'no cold uppers' then he would have been correct.

anyway, i expect the next few runs to revert to being much colder as i think the 12z was an outlier and not a trend setter, which will make this bickering over trivia obsolete.

Wouldn't say its an outlier, but on the milder side in FI, yes.

Interesting that its a cold outlier for a small period in later high res.

[Altohumorous]

Feb/March 2001 northerly blast - heavy snow in many areas. We had blizzards for 24 hours here.

http://www.wetterzentrale.de/topkarten/fsreaeur.html

Feb/March week 2000 had topplers. First week march 1999 had this:

http://www.wetterzentrale.de/topkarten/fsreaeur.html

Feb/March week 1998 (mentioned above I think?) had a northerly blast period but it had alot more potential than it delivered here. It was one of a few I can recall from late winter/start of spring where the forecast was for polar low and very heavy snow that didn't turn out so, especially away from the north and northwest.

Here's Feb 28, 2002:

http://www.wetterzentrale.de/topkarten/fsreaeur.html

Feb 27th, 2004:

http://www.wetterzentrale.de/topkarten/fsreaeur.html

Later ones have been mentioned. This all illustrates my point about what a typical set-up it is for this week of the year, going back at least 15 years. The difference from all of those to this year's current situation is that we currently have a cold and very settled anticyclone over north/northwest Europe, whereas in almost all those other scenarios we had low pressure/polar vortex into Scandinavia and north urope, though some may have started with high pressure over these islands. Northerly out breaks earlier in feb and later in march and in April in many years have begun this way.

Currently that anticyclone over northwest Europe looks too stubborn to allow a proper northerly, or rather alternatively, the vortex isn't really getting strongly down across Scandinavia into north central Europe (or it is too weak)