Model Outlook Thread: January 2010

WolfeIRE · 13-01-2010 3:16pm

jambofc wrote: »

lol,defo need to get one of them.

hill of ward is 9 miles to the north of me only 390ft high and hill of tara 9 miles east of me at 590ft,surely they would be to low to really impact snowfall considering the amount of rain that falls in this area?
sea level maybe,but a lot of other places at sea level saw snow out of some of these system's.
ta for the input

In a case where there is wind driven snow, snow will not settle as much on the leeward side of your house as much as on the side of your house facing the wind. The same effect can be applied to a 590ft hill close to you, although as you say nine miles is quite a distance away. Would be interesting to see what the experts say.

Deep Easterly · 13-01-2010 3:17pm

jambofc wrote: »

lol,defo need to get one of them.

hill of ward is 9 miles to the north of me only 390ft high and hill of tara 9 miles east of me at 590ft,surely they would be to low to really impact snowfall considering the amount of rain that falls in this area?
sea level maybe,but a lot of other places at sea level saw snow out of some of these system's.
ta for the input

Like yourself, I am on the central plain with no with little or no high ground within my horizon. Snow as a result always stuggles to fall here, but I have to say, despite the severity of the recent cold, I have seen much greater snowfalls and snow depth in other less cold winters than this one. Frost certainly was the big story here during this spell, and while snow did fall on many days, it was light and often wet which is no use to anyone really.

maquiladora · 13-01-2010 3:53pm

Any else notice that the 06Z GFS wants to introduce the cold/snow risk again about this time next week?

It will probably be gone on the 12Z run. We'll, we will find out soon. :pac:

WolfeIRE · 13-01-2010 4:22pm

maquiladora wrote: »

Any else notice that the 06Z GFS wants to introduce the cold/snow risk again about this time next week?

It will probably be gone on the 12Z run. We'll, we will find out soon. :pac:

yes maq. Building from scandanavia again

Deep Easterly · 13-01-2010 4:24pm

WolfeIRE wrote: »

yes maq. Building from scandanavia again

GFS 12z rolling out soon, will be interesting to see if a trend is emerging.

Snowaddict · 13-01-2010 4:52pm

The crucial element to this possible evolution is the presence of a very strong Siberian High - which is itself originated from the various blocking that we saw to our variable North over the past several weeks.

The key to this evolution is the stalling of a deep upper trough over the Atlantic, allowing a renewed phase of Warm Air Advection, this time Northeastwards.

This is somewhat similar to the evolution that occured into December & the one which resulted in our first real cold outbreak of the winter season. The alignment is not due North this time around, but with the SH to our Northeast, this makes a link up much more possible.

There are also increasing signs of a warming at the 30mb Level, which would correlate with these medium term synoptics. Perhaps NWP Guidance is being a bit too progressive at the moment in bringing in the evolution a little early but has the overall largescale idea correct?

SA

WolfeIRE · 13-01-2010 5:04pm

GEM, ECM and JMA models all agree on the idea of cold uppers (850Hpa) attempting to push over Ireland from the NE at +144.
EXAMPLE
http://91.121.94.83/modeles/gem/run/gem-1-12.png

maquiladora · 13-01-2010 5:17pm

12Z GFS rolling out. -10 850 temps coming near the UK with high pressure drifting off to the NW as early as next Tuesday. Hmmm. Wonder what the rest of the run will be like...

Snowaddict · 13-01-2010 5:21pm

maquiladora wrote: »

12Z GFS rolling out. -10 850 temps coming near the UK with high pressure drifting off to the NW as early as next Tuesday. Hmmm. Wonder what the rest of the run will be like...

Indeed Maq,

The most striking point is that even by T+144 the evolution is set in place.

Very interesting indeed.

SA

opr · 13-01-2010 5:22pm

Looks like GFS 12z continues with the same theme in FI.

Opr

maquiladora · 13-01-2010 5:25pm

Yep, could be looking at snow showers as early as Tuesday night if this run came off.

I dunno if I want the cold back so soon! :pac:

WolfeIRE · 13-01-2010 5:25pm

By the looks of things, it is a very gradual process according to the GFS.

What is most noticeable is the warming of near Polar Regions caused by the easterly high pressure squeezing warmer air masses north of us. Wonder what effect would that have on our weather.
http://charts.netweather.tv/gfsimages/gfs.20100113/12/159/h850t850eu.png

Deep Easterly · 13-01-2010 5:25pm

Snowaddict wrote: »

Indeed Maq,

The most striking point is that even by T+144 the evolution is set in place.

Very interesting indeed.

SA

Snowaddict · 13-01-2010 5:27pm

opr wrote: »

Looks like GFS 12z continues with the same theme in FI.

Opr

It sure does & the UKMO @ T+144 is not terribly dissimilar either, with a slight Easterly flow into the UK at this time. Notice how between T+120 & T+144 also on the UKMO 12Z Evolution that the cold upper trough does not advance very far westwards at all.

This is what we need to see to support the evolution towards a reneewed Easterly flow.

SA

patneve · 13-01-2010 5:30pm

Could there be a lovely formation of a Azores HP - Russian Hp bridge? Anyway I feel that after a brief easterly this cold will plunge into Southern Europe, the High Pressure isn't far enough West and the Atlantic streaming back in is quite a high possibility!

WolfeIRE · 13-01-2010 5:32pm

seems to breakdown somewhat at 192+ but if those easterlies are in place like the show for the previous 36 hrs then there is every chance that the 192+ scenario will not be the case.

t+300 is very interesting

maquiladora · 13-01-2010 5:32pm

Meh, not great in FI but that'll change anyway. Most interesting stuff starts around 144 which isn't too far away.

ECM should be interesting later!

Duiske · 13-01-2010 6:20pm

WolfeIRE wrote: »

seems to breakdown somewhat at 192+ but if those easterlies are in place like the show for the previous 36 hrs then there is every chance that the 192+ scenario will not be the case.

Thats the thing with situations like this. The models just don't have a grip on it yet. If you think back a couple of days, we were seeing atlantic dominated weather out to the end of both GFS and ECM.

Its just going to be subtle changes over the next few runs, and i would not be surprised to see the models dismiss the idea altogether at some stage during those runs. But the trend is there. Thats the important thing at this stage.

Deep Easterly · 13-01-2010 7:47pm

ECM not so keen in this run to bring the block influence over Ireland, at least up to mid week next:

Deeper lows in the western Atlantic in this run also.

maquiladora · 13-01-2010 7:55pm

Yeah, not a very interesting ECM output...

Birdnuts · 13-01-2010 8:19pm

ECM really sucks tonight with nothing remotley interesting for this part of the world FTFF:(

ninebeanrows · 13-01-2010 11:25pm

lol

Look at the 18z GFS at 144hrs

ECM was a very mild Ensemble btw.

nacho libre · 14-01-2010 1:47am

force eleven wrote: »

We are reaching the pinnacle of this wintertime in the next week or two. In my opinion, if we get an Atlantic influence breaking through properly over the next week, it'll be hard to shift for a few weeks, and may mark the end of any further really cold plunges.

while we may not be able to get the depth of cold in two-three weeks that we can get now, it's far more likely, should we get another cold incursion in Feburary, that the marginal situations we faced in this past spell would work in our favour with the colder sea temperatures. so, in conclusion, i'll take less cold and more snow overall for many, rather than what we've had; very cold conditions, but with snowfall not as plentiful as it could have been.

nacho libre · 14-01-2010 2:04am

Deep Easterly wrote: »

ECM not so keen in this run to bring the block influence over Ireland, at least up to mid week next:

Deeper lows in the western Atlantic in this run also.

unfortunately this would tally with what M.T. Cranium was saying. anyway you'll win either way:)- because either we get a renewed cold incursion or we get a storm to finish off January. if the latter happens i think it's definitely game over for sustained cold from the east. still, i'd be shocked if we didn't get a brief northerly airflow for a day or two, in a renewed atlantic flow, at some point during February.

Deep Easterly · 14-01-2010 11:42am

nacho libre wrote: »

you'll win either way:)- because either we get a renewed cold incursion or we get a storm to finish off January. if the latter happens i think it's definitely game over for sustained cold from the east.

This morning's ECM shows just how uncertain the outlook is really for next week:

The building high over Europe (on that chart it builds up to 1065mb!) extends its influence just a little further east. Still does not reach Ireland though but at this stage it is hard to say that it won't or will. The block remains pretty strong throughout the run over eastern Europe. Whether or not it does effect Ireland is really up in the air at the moment.

Tom Cruises Left Nut · 14-01-2010 1:06pm

Guys can I ask a question on these charts ?

I am presuming that the wind speed from the North East - East would be caused by the high pressure system over scandinavia and the low pressure system below us ?

nacho libre · 14-01-2010 1:42pm

Deep Easterly wrote: »

This morning's ECM shows just how uncertain the outlook is really for next week:

The building high over Europe (on that chart it builds up to 1065mb!) extends its influence just a little further east. Still does not reach Ireland though but at this stage it is hard to say that it won't or will. The block remains pretty strong throughout the run over eastern Europe. Whether or not it does effect Ireland is really up in the air at the moment.

well the fact pressure reaches that high and still doesn't quite make it to us says it all. i now see why mt cranium is so confident of a storm to see out in january. Even a system of modest low pressure value would perhaps be enough to exert the Atlantic's influence once more

by the way out of curiousity what has been the highest high pressure reading ever recorded?

anyway, i hope all this negativity comes back to bite me in the ass by late next week:D