Model Output Discussion

[nick sussex]

Great ecm and ensembles this evening.

I note with interest certain members not postig this evening after going into overdrive with the mild charts over the last few days.

Thanks also to nick sussex who pointed out the absurdity of bartlett high rubbish being sprouted in here recently.

WOW i just looked at the ecm ensembles again man they are HOT!!!

Agreed that BH talk was driving me crazy and i nearly lost it several times! I think if we take a middle ground view then at worst it looks like being quite settled with frost and some sunshine for the weekend and into next week so not bad at all, the ECM ensembles also have improved, the London ones are out later so that should give us a better view of things.

Edited January 18, 2010 by nick sussex

[Cecil Hogmanay Melchett]

Agreed that BH talk was driving me crazy and i nearly lost it several times! I think if we take a middle ground view then at worst it looks like being quite settled with frost and some sunshine for the weekend and into next week so not bad at all, the ECM ensembles also have improved, the London ones are out later so that should give us a better view of things.

dave DONT SHOOT THE SEAGULLS!!!!!!!!!!

hehe nick its you teits and a few others who keep me coming back keep up the good wrok.

PS Nick i was nearly crying in Novemeber with all the rain and wind,did you think we'd have a winter like this?

There really was no inkling in the models right up to the beginning of Dec,i do remember seeing john hammond i think it was in early Dec talking of a big pattern change on the way,my goodness what a pattern change it turned out to be.

[billy]

Seems to me there are some interesting similarities between http://www.wetterzen...s/Recm1201.html and Feb 2nd 1991 (and all that followed a few days later) - perhaps the main difference in 91 was that there was a stronger polar vortex in SW Greenland helping drive the WAA, but I'd say we're getting very close to a real Beasterly at the moment.

Hi Beng, I thought exactly the same thing when i saw the 12z ecm.

[Eugene]

http://www.wetterzen...cs/Rtavn661.png - Wow each run pushes the high to our east slightly nearer to us at this rate the atlantic won't move in at all

Thursday looking cold now, upto 8C just yesterday now around 4C.

Edited January 18, 2010 by Eugene

[Matty M]

Its gas, the 18z has those 850hpa temps another 100 miles further west into England at 66hrs.

The Block is still being underestimated.

[Frosty.]

Good signs of something colder again but nothing on the scale of the last 4 weeks. It's fair to assume the worst of this winter is now behind us.

[Thundery wintry showers]

ECMWF in the longer-term has an easterly but not an especially cold one, so probably cool and cloudy with a few sleety flurries in the east would be my guess from that- but on nthe other hand the HP ridges towards Greenland setting us up for northerlies. The "stalemate" around T+144 is distinctly interesting with a very shallow low and cold air, which would certainly support below average temperatures, maybe even some snowfall. I don't think things will come out exactly as ECM FI shows, but with UKMO and ECM both going for fairly cold, settled weather at around T+144 (and with UKMO also verifying better than GFS at the moment) the chances of cold settled weather coming off have to be fairly high.

[nick sussex]

dave DONT SHOOT THE SEAGULLS!!!!!!!!!!

hehe nick its you teits and a few others who keep me coming back keep up the good wrok.

PS Nick i was nearly crying in Novemeber with all the rain and wind,did you think we'd have a winter like this?

There really was no inkling in the models right up to the beginning of Dec,i do remember seeing john hammond i think it was in early Dec talking of a big pattern change on the way,my goodness what a pattern change it turned out to be.

Yes well November was very mild but actually a mild wet November correlates better with average to colder winters, than the other way round. I think its been especially good for you guys up in the NW so has certainly been great to see such a good winter so far, as for long range forecasting I'm not brave enough to do one of those! Theres only so many teleconnections I can cope with, i think I'll leave those LRF's to GP!

[billy]

Good signs of something colder again but nothing on the scale of the last 4 weeks. It's fair to assume the worst of this winter is now behind us.

Thats a bold statement. Who knows whats coming ? We all know how quickly a cold spell can develop

[Matty M]

For those 18z watchers, its really notable that the block is quite a good bit further west at 96hr compared to the 12z.

Certainly a very good trend.

Old fashioned forcasting needed here i think.

[Thundery wintry showers]

Good signs of something colder again but nothing on the scale of the last 4 weeks. It's fair to assume the worst of this winter is now behind us.

I think this is about 95% likely to be true- on the other hand, this assessment is more down to the exceptional nature of the period mid December to mid January rather than the upcoming synoptics. UKMO/ECM have potential to lead into a very cold snowy spell, but equally it could just end up fairly cold and settled.

[andymusic]

Thats a bold statement. Who knows whats coming ? We all know how quickly a cold spell can develop

totally agree - a good two months of this winter yet to run - february still a great month for deep cold

[Frosty.]

Thats a bold statement. Who knows whats coming ? We all know how quickly a cold spell can develop

I can't see anything severe on the charts and nothing to suggest it will develop either but I will be happy to be proved wrong. There does appear to be some backtracking in the models but I don't get that same feeling as I did before the recent very wintry spell started back in december. The models are a mish mash with some showing fairly bland set-ups while others show a strongly watered down colder phase approaching.

[Eugene]

OMG that front that struggles through us on friday stalls over the SE saturday morning with cold air just to the east, , maybe just maybe if the runs keep the trend up of easing the high closer to us it could snow in the SE on saturday, best case scenario though this is and leaning on the side of big optimism but you just never know

http://www.wetterzen...s/Rtavn1084.png

http://www.wetterzentrale.de/pics/Rtavn10810.png

http://www.wetterzen...s/Rtavn1141.png

Edited January 18, 2010 by Eugene

[Matty M]

Yea comparing the 12z GFS to 18z at even 96hrs is showing a MAJOR move to the west.

And i mean MAJOR, if the trend continues in future runs a cold outbreak could occur sooner than we think.

[andymusic]

OMG that front that struggles through us on friday stalls over the SE saturday morning with cold air just to the east, , maybe just maybe if the runs keep the trend up of easing the high closer to us it could snow in the SE on saturday, best case scenario though this is and leaning on the side of big optimism but you just never know

http://www.wetterzen...s/Rtavn1084.png

http://www.wetterzen.../Rtavn10810.png

http://www.wetterzen...s/Rtavn1141.png

By sunday on this run the front is moving back and doing just that! - Our next cold spell seems to be developing before our eyes

[J10]

Interesting comment about all of the analysis about the potential snow event with warnings from the Met Office and the fact that most of the analysis been done on here via the GFS.

If we stretch our minds back to the potential Snow event for South Western parts last Tuesday, GFS was having none of it at this range, but there was a Met Office advisory out. In that event it turned out the UKMO was the closest to the mark and indeed the NAE was closer still.

Saying that does the GFS 18Hz give a potential snow event, well IMO a resounding no.

Both thicknesses are not really conducive for snow (sub 528 and 129), are never really over the UK, and these charts for chosen for giving the best thickness levels for us, earlier charts when there was precipitation had higher thicknesses.

However, even though GFS says no, doesn't mean that snow can be ruled out, for the reasons above, although IMO a snow event is not looking that likely and certainly not likely at all for western areas.

I made the above post on Saturday, based on the GFS 18Hz, let's revisit the event for midweek by looking at the current charts.

It is clear that the thicknesses are further wet than they were suggested to be on Saturday, indicating the block is more sturdy than first thought.

Of course , the GFS also has the front not making it that far east either.

[nick sussex]

I think the best that can be said for the gfs 18hrs run is that it's a very interesting mess! the thing that stands out though is the troughing over the western Atlantic, that should provide some good WAA and build pressure to the east and ne.

Edited January 18, 2010 by nick sussex

[Tom D]

Wow two real monsters on the 18z run, deep low in the Atlantic, massive block to the east... with us in between!

http://charts.netweather.tv/gfsimages/gfs.20100118/18/159/h850t850eu.png

Looks like a cold win in this run, but could all change in the 00z.

The change around over us from the 12z is remarkable at +168, a strong westerly flow turns into an easterly flow. Really can't say this outcome is more likely based on the sudden change.

Edited January 18, 2010 by Tommyd1258

[Cloud 10]

18z NAE for wednesday.

snow for cardiff?

[Jayfromcardiff]

18z NAE for wednesday.

snow for cardiff?

No, misses us lol....BBC going for 7c so i doubt it.

[PubliusEnigma]

Interesting kunundrum, out in FI GFS this evening is calling for Raging zonailty, and a fat juicy bartlett, yet the ECM plays the complete opposite with HP dominating

to the NEast before sinking south, only to be replaced by a new HP centre forming over Iceland so all the while we remain in an easterly of sorts. Whats your hunch this evening.? Raging rain and gales and mild. Or cold raw, dull and very cold, with snizzle sleet and snow ? Any takers ?

[snowbob]

And London by the looks of that or am I way off .

[Matty M]

Below that 850hpa temperature graph is a much deeper cold pool lower down.

Look at those dewpoints on the continent heading this way.

Remember this chart is fantasy just for illustrative purposes

Edited January 18, 2010 by Matty M

[Skyhi]

Interesting kunundrum, out in FI GFS this evening is calling for Raging zonailty, and a fat juicy bartlett, yet the ECM plays the complete opposite with HP dominating

to the NEast before sinking south, only to be replaced by a new HP centre forming over Iceland so all the while we remain in an easterly of sorts. Whats your hunch this evening.? Raging rain and gales and mild. Or cold raw, dull and very cold, with snizzle sleet and snow ? Any takers ?

The latter for me.....bring on those blizzards and bone chillin temps and be done wiv it!!