Model Output Discussion

[BLAST FROM THE PAST]

Fred i'm just curious, are you expecting something similar to what the GFS 18z showed last night, i.e. a screaming Northerly with a good pressure rise to the northwest and a deep scandi trough in the mid range?

..

Hi Karl

I didn't see the 18z but synoptically yes that sounds right...about very start of Feb. This HP will drift east SE into Scandi and will be around most of the month.

BFTP

Personally I feel the pattern is becoming clearer with less uncertainity.

At first we see it turning colder with a flow from the continent. We then see it turn milder with NW,lys which ride over the top of the Atlantic HP. Due to the Atlantic HP being unable to move further NW due to the lowering heights to our N and the increasing PFJ we then see this HP sink S over the UK or slightly further S.

After viewing the 06Z GFS I really think last nights 12Z ECM was on the right track. This mornings 0Z GEM at +240 best represents the likely pattern at +240.

http://www.wetterzentrale.de/pics/Rgem2401.gif

I would love to see a return of colder, wintry weather but if I was honest the model output this morning is about as bad as it can get. At times using instinct I can see how certain patterns may trend more favourably. However this morning I cannot see any possible way this could happen.

WE I can class relatively mild NW/W,lys as boring. Unlikely to even see a good storm in this pattern because the deep LP systems will be to the N of us!

With the sudden changes that have occurred with the models how come they have become on the right track and that the storms and positioning of the HPs are correct. Yes they are correct in looking W and NW as the block to our east will be gone between 25-31, always was the plan. I think some good developments will come into play on models come early next week. Feb for sure is not decided

BFTP

[karyo]

Hey Karyo

very interesting what you and some others post over here in this topic

where can I find some more information for the correlation between the phases of MJO and positioning of high pressure in our neighbourhood?

thanks!!

sebastiaan

hi Sebastian,

In this case, we need the MJO to enter phase 8 to amplify the pattern so that the forecasted high pressure can extend further north into more northern latitudes. If that happens, we have a good chance to get a northerly rather than a west/northwesterly flow midified by the Atlantic. Please refer to the posts by GP this morning.

This link: http://www.cpc.noaa.gov/products/precip/CWlink/MJO/forca.shtml has some good info as well as the forecast. As you can see, the forecast doesn't look that hopeful for this wave to enter phase 8, but I have to say the forecasts have been rather inaccurate over the last few months, so worth watching.

I also find satellite watching quite useful, as you can see the latest flare ups of convection in the tropics.

I hope that's a start!

Karyo

[Frosty.]

..

Hi Karl

I didn't see the 18z but synoptically yes that sounds right...about very start of Feb. This HP will drift east SE into Scandi and will be around most of the month.

BFTP

Thanks Fred,

That should give us something to look forward to beyond the weak E'ly projected for next week with a good old arctic blast. Also, good news from GP earlier with the stratospheric warming likely to impact probably late feb and into march, we could squeeze 2 or 3 very cold spells between now and spring, it will make it easier to endure the milder dross knowing late winter/early spring will bring more snow.

I've just look at this and thought exactly the same thing. So everything still confused a the moment hopefully we can get some concensus in the next couple of runs.

The 6z run was probably wrong and i'm expecting the 12z to be better.

[Matt12]

I reckon to get a 'sustained' cold spell we will need a strongly negative AO like late December/early January. The AO then was even lower than those of the famous winters of yesteryear, even if this winter hasn't been anywhere near as cold as, say, the famous winter of 1962/3. It seems that to get truly cold winter spells that last beyond a week and a half/few weeks, reminiscent of previous eras, we now need exceptional synoptics. The good news is that late dec/early Jan proved that this is still possible, if less likely.

I can't really get excited at the mo because the weather in the next few weeks looks like being not particularly cold on the whole, but not that mild either. Unless the AO is forecasted to drop significantly, I think we will be left with what we have at the moment.

Edited January 21, 2010 by Matt12

[BLAST FROM THE PAST]

Thanks Fred,

That should give us something to look forward to beyond the weak E'ly projected for next week with a good old arctic blast. Also, good news from GP earlier with the stratospheric warming likely to impact probably late feb and into march, we could squeeze 2 or 3 very cold spells between now and spring, it will make it easier to endure the milder dross knowing late winter/early spring will bring more snow.

Hi Karl

Yes timing is the order. I think the coldest part and most actice will be towards mid month. Th HP to our WNW will be initially very close by and so cold and frosty most likely scenario to start with. I 'll give my full forecast tomorrow but the pattern is generally for HP to be close by to WNW then ridge further north and drift east. Trough to set up over Scandi early Feb and get shunted away as we go through the month. Its when it gets shunter willproduce the most 'wintry' weather as the winds become strong n to ne'ly. There is a real danger that the HP could be closer and sit right over us...and get stuck there...just a risk.

BFTP

Edited January 21, 2010 by BLAST FROM THE PAST

[Duane S.]

I reckon to get a 'sustained' cold spell we will need a strongly negative AO like late December/early January. The AO then was even lower than those of the famous winters of yesteryear, even if this winter hasn't been anywhere near as cold as, say, the famous winter of 1962/3. It seems that to get truly cold winter spells that last beyond a week and a half/few weeks, reminiscent of previous eras, we now need exceptional synoptics. The good news is that late dec/early Jan proved that this is still possible, if less likely.

I can't really get excited at the mo because the weather in the next few weeks looks like being not particularly cold on the whole, but not that mild either. Unless the AO is forecasted to drop significantly, I think we will be left with what we have at the moment.

Not too shabby...

[nick sussex]

Its so typical of the models that the gfs which initially was so enthusiastic about the easterly now looks more half hearted than the ukmo which brings in a better looking easterly for the same time at 96hrs.Upto 120hrs now and the easterly looks alot colder than the gfs for the same time. Also much less energy in the jet to the north.Unbelievable at 144hrs the ukmo speeds towards a possible northerly with trough dropping into Scandi! Much more energy in the southern arm of the jet here.

Edited January 21, 2010 by nick sussex

[snowmadchrisuk]

Just to confuse things further the UKMO still has the Easterly on it's +120 chart .

Sorry Nick , Just seen your post above .

Edited January 21, 2010 by snowmadchrisuk

[nick sussex]

Just to confuse things further the UKMO still has the Easterly on it's +120 chart .

Sorry Nick , Just seen your post above .

It really is a model merry go round at the moment with each model taking turns to go cold then backtracking. The UKMO is great this evening but it's hard to know what to believe given recent days.

[cooling climate]

This is the problem with the GFS model it picks up a trend then ditches it and goes on it

merry way while the Euro models then pick the trend up and run with it.

This happens 80% or so of the time and I would not be surprised to see the ECM side

with the UKMO model.

[Severe Siberian icy blast]

The new charts give us high pressure sitting right over the top of us for more or less all the run , a shabby easterly sunday that retreats monday .

They show that northerly again like last night but 300miles to our east .

Every run is different and there is no point in looking past the wkend , it may well be under doin the effect of the scandi high , or it may be bang on for next wk , we wont no untill sunday i feel .

Either way they havent got a clue at min .

And its boring me to be honest

[snowingman]

GFS is 100% a british winter set up

The atlantic roars on with mild SW across most parts - perhaps the odd dry day

No snow except on the tops of northern mountains!!

so the cold spell... drifts into history as a special moment in our weather history....

could we get a bit of snow in March??

[bluearmy]

any thoughts on the occlusion that will pass through the southeast quarter of the country at the back end of the weekend within sub 528 dam air?? will it be squeezed dry by that time?

also, re the ukmo, NOAA rarely take the ukmo model output ahead of the ecm or gfs off the eastern seaboard. if the ukmo is more bullish about the WAA than the other models, i'd be wary.

[snowmadchrisuk]

GFS is 100% a british winter set up

The atlantic roars on with mild SW across most parts - perhaps the odd dry day

No snow except on the tops of northern mountains!!

so the cold spell... drifts into history as a special moment in our weather history....

could we get a bit of snow in March??

I believe we are going into a natural period of Cold winters , I am fully Expecting Next Years first Snow to be in October . Short Summers , Long Winters . Trust me :lol: And Mild Start to Feb followed by a very Cold reload around the middle of Feb is where i'm placing my bets. Every winter even back in the day had mild blips and this is only the second blip since December 1st.

Call that a ramp but have been reading up on the subject and looking back in history . The Gulf Stream has also slowed right down recently

Edited January 21, 2010 by snowmadchrisuk

[Steve Edgefield]

Its so typical of the models that the gfs which initially was so enthusiastic about the easterly now looks more half hearted than the ukmo which brings in a better looking easterly for the same time at 96hrs.Upto 120hrs now and the easterly looks alot colder than the gfs for the same time. Also much less energy in the jet to the north.Unbelievable at 144hrs the ukmo speeds towards a possible northerly with trough dropping into Scandi! Much more energy in the southern arm of the jet here.

Yes, couldn't agree more. Just wondering which is playing catch up though?

[karyo]

It really is a model merry go round at the moment with each model taking turns to go cold then backtracking. The UKMO is great this evening but it's hard to know what to believe given recent days.

The 12z UKMO is an improvement to it's 0z output! I wonder if it is picking up a new signal for reduced energy in the northern arm. However, it's 144 hours chart looks a bit far fetched to me - not what I would expect to see after the 120 hours chart.

Karyo

[Duane S.]

And then along came the METO! :lol: Interesting run indeed and a lot better a one than I was expecting to see. Certainly ties nicely in with their forecast for next week.

[03jtrickey]

Just to confuse things further the UKMO still has the Easterly on it's +120 chart .

Sorry Nick , Just seen your post above .

GME is also showing quite a potent easterly by +132

http://www.wzkarten3.de/pics/Rgme1322.gif

[snowmadchrisuk]

The 12z UKMO is an improvement to it's 0z output! I wonder if it is picking up a new signal for reduced energy in the northern arm. However, it's 144 hours chart looks a bit far fetched to me - not what I would expect to see after the 120 hours chart.

Karyo

With High pressure tending to want to move NW towards Greenland would signal less energy in the Northern arm . I get the feeling were building up to something and the next Cold spell is not as far away as some may think.

[Tom D]

I believe we are going into a natural period of Cold winters , I am fully Expecting Next Years first Snow to be in October . Short Summers , Long Winters . Trust me :lol: And Mild Start to Feb followed by a very Cold reload around the middle of Feb is where i'm placing my bets. Every winter even back in the day had mild blips and this is only the second blip since December 1st.

Call that a ramp but have been reading up on the subject and looking back in history . The Gulf Stream has also slowed right down recently

We had snow here in October 2008, 3/4cm it was very strange with the trees in leaf still. I disagree with the shorter summers - I think we'll get longer, drier summers in the longer term. Shorter spring/autumnal periods however.

Probably the wrong thread but they're just my ideas.

Edited January 21, 2010 by Tommyd1258

[Duane S.]

The 12z UKMO is an improvement to it's 0z output! I wonder if it is picking up a new signal for reduced energy in the northern arm. However, it's 144 hours chart looks a bit far fetched to me - not what I would expect to see after the 120 hours chart.

Karyo

I quite agree with you there Kayro. The +144 chart is incredible relative to what I was expecting as I was watching its evolution right through the run. If the ECM hints at what the METO is showing at +144 then maybe it is on to something!

[Polar Continental]

Wheres Dave? The Eye

Can some body tell him to go and have a bath, that worked last time and we got 3 weeks of bitter easterlies. Sorry Dave only joking mate.

The 12z GFS stubbornly sticks to its guns and only briefly advects some cold air to the east on Sunday and Monday, even some 10c hpa in the extreme south east of England.

Now the UKMO dishes out its best easterly so far for Tuesday, I really dont know what to believe anymore.

If tonights ECM stays on the same track then the GFS I am sure will apologise on the 18z pub run.

Edited January 21, 2010 by Polar Continental

[Richard Lake]

And its boring me to be honest

Yeah I know the feeling, ppl are always saying that there is 'uncertainty' in the models, this is usually because 2 of the big 3 are at odds, but this time all 3 models have flipped and flopped in the last few days that must be quite a rarity and just goes to show you cannot trust the models in winter.

I still find it really hard to believe the GFS has no AI. Surely computer models should read, learn and be feed previous data experience?!

We had snow here in October 2008, 3/4cm it was very strange with the trees in leaf still. I disagree with the shorter summers - I think we'll get longer, drier summers in the longer term. Shorter spring/autumnal periods however.

Yeah I remember that October, winters have certainly improved over the last few years.

Edited January 21, 2010 by rikki

[Ben_Cambs]

So UKMO is very good tonight, and if there is less energy into the northern arm of the jet and if ECM is similar to UKMO tonight, then a new situation could arise....

[snowmadchrisuk]

We had snow here in October 2008, 3/4cm it was very strange with the trees in leaf still. I disagree with the shorter summers - I think we'll get longer, drier summers in the longer term. Shorter spring/autumnal periods however.

Probably the wrong thread but they're just my ideas.

I agree with you . What I meant to say is Winters extending well into Spring and starting in Autumn .

Onto the Models the UKMO looks like it would give a good Greenland block if it went out any further and with plenty of low pressure to our East a Snowy Northerly would be likely in a very unstable flow .