Model Output Discussion

[kold weather]

Two consec UKMO's - both less promising by T144 and trending that way at T120. now do we ignore that, given the optimistic tones of the meto 15 dayer this morning. on both occasions the T144 isnt a 'dead duck' and the blocking is still there to push back, but at what point do the shortwaves stop coming, or better still, start to head south and undercut ???

I suspect the UKMO won't be far from the truth, it tends to nail these particular set-ups whilst the ECM more often then not is too far west at first. However if you look back at a lot of powerful easterlies of the recent pasts, many have seen a big block to the NE and the Atlantic coming in, high pressure builds from the SW, links to the huge high further NE and within 72hrs you have a powerful easterly coming in from the east, as I said before Feb 91 is utterly the perfect example of how just such an evolution can evolve, but equally shows how it can take quite a few bites of that old cheery to get the goods.

In many ways despie taking longer, the 12z is a better run for the long term prospects...and its worth watching, the models really are keen on big northern blocking to develop 192-240hrs timeframe.

[January Snowstorm]

I cant understand the negativity this evening.

The gfs looks very good imo and is sticking with the overall trend of a monster siberian high extending it's influence over us!

[LomondSnowstorm]

I believe there was always a lot of caution from more senior members of the easterly arriving by the start of February, with the timeframe which is now +200ish hours looking the best bet. Hopefully this will move into a more reliable timeframe soon though.

LS

[JonGill]

Problem is the meteociel charts don't show the bigger picture. The view from the pole would be much better.

see here:

[Tom D]

Two consec UKMO's - both less promising by T144 and trending that way at T120. now do we ignore that, given the optimistic tones of the meto 15 dayer this morning. on both occasions the T144 isnt a 'dead duck' and the blocking is still there to push back, but at what point do the shortwaves stop coming, or better still, start to head south and undercut ???

The UKMO and 12z GFS op are very similar at 120/144 and it's still a good sign with the block building strong in both and slight pressure building over Greenland.

In the UKMO the Azores ridge would push north moving that SW flow away and joining the block eventually giving a potential easterly I can't see any other medium term solution from here.

Can't wait to see the GEFS with an op like this at +264

http://91.121.94.83/modeles/gfs/run/gfs-1-264.png?12

Edited January 29, 2010 by Tommyd1258

[BLAST FROM THE PAST]

I cant understand the negativity this evening.

The gfs looks very good imo and is sticking with the overall trend of a monster siberian high extending it's influence over us!

Indeed the GFS has headed 'towards' ECM 00z and T96 is still FI due to the dealing with the SW. TGhe overall pattern remains with northern blocking and southerly jet to dominate. I am happy with 12z GFS, letys await the ECM 12z and I tend to view UKMO as a WIMSHURST model. Energy IMO is too far east and north.

BFTP

Edited January 29, 2010 by BLAST FROM THE PAST

[Iceberg]

So we have to wait an extra couple of days when it delivers (FI I admit) it really delivers, Feb 8/9th looks brutal on those charts 850's down to -16, widespread at -14C. 40mph winds and snow.

Like always the ENS will tell the true story....

[nick sussex]

Two consec UKMO's - both less promising by T144 and trending that way at T120. now do we ignore that, given the optimistic tones of the meto 15 dayer this morning. on both occasions the T144 isnt a 'dead duck' and the blocking is still there to push back, but at what point do the shortwaves stop coming, or better still, start to head south and undercut ???

The 120hrs UKMO is IMO better than this morning but before hand it develops two features which look very suspect. Whats clear and what I mentioned a few days back is the proper cold upper air cant advect west till the trough fills and disrupts so unfortunately although it's frustrating we're going to have to be patient.

I still think the ECM is going to look different though and for this reason I have little faith in the models past 96hrs.

[Eugene]

Its all going to plan, i was expecting HP to build after the first 3 to 5 days of February which still looks the case, not forecasting an easterly as it silly too at such a long range

[BLAST FROM THE PAST]

The 120hrs UKMO is IMO better than this morning but before hand it develops two features which look very suspect. Whats clear and what I mentioned a few days back is the proper cold upper air cant advect west till the trough fills and disrupts so unfortunately although it's frustrating we're going to have to be patient.

I still think the ECM is going to look different though and for this reason I have little faith in the models past 96hrs.

I agree Nick re T96. I also agree with those saying about easterly flow. Not until beginning of second week earliest and 9-14 to be coldest period but ridge from arctic to exert its influence early next week holding back Atlantic energy and hence it sliding SE or remaining held to our WSW. Interesting the capture that someone mentions re the 8th always popping up.

[Bobby]

GFS FI probably wouldn't be that snowly actually, pressure is too high and the flow is too SEly. Very very cold though. But no point discussing that far out.

[cooling climate]

Two consec UKMO's - both less promising by T144 and trending that way at T120. now do we ignore that, given the optimistic tones of the meto 15 dayer this morning. on both occasions the T144 isnt a 'dead duck' and the blocking is still there to push back, but at what point do the shortwaves stop coming, or better still, start to head south and undercut ???

The UKMO is not a bad chart at all.

http://www.meteociel.fr/modeles/ukmo2.php?nh=1&ech=6&carte=1021

[Iceberg]

The 120hrs UKMO is IMO better than this morning but before hand it develops two features which look very suspect. Whats clear and what I mentioned a few days back is the proper cold upper air cant advect west till the trough fills and disrupts so unfortunately although it's frustrating we're going to have to be patient.

I still think the ECM is going to look different though and for this reason I have little faith in the models past 96hrs.

I too completely agree, The 96hr chart shows it IMO.

The LP off the seaboard drags up to ridges one to the south and one over greenland, thanks to the advancing siberian high.

Before the energy had an escape route to the north over greenland, but this looks to be nolonger the case.

The low that forms from our northerly however provides a very useful route for any residual energy, preventing the surface high from forming that I mentioned earlier and delaying things a little bit.

I do believe that the northerly escape route is now gone, so the new dates suggested look good.

We arn't talking about buckets of energy here though, more a little bit that just needs to be dissapated.

[Frosty.]

Karl

For the moment forget my method and lets look at the models. Last weekend they didn't show the cold evolution then on Tues they jumped on board, then pulled away [then GFS fancied it] and then look at 00z ECM this morning...that is, IMO, significant. It has happened ALL winter with models umming and arhhing and then hey presto. The Meto 6-15 day outlook reads just like the ECM and no model no matter how hard it tries NEVER gets the Atlantic to push through. Indeed overall it is all backing west. Its still is confsing because next week is FI....so much going on across the pond to deal with yet.

Now on my method the signal is that energy in Feb will not push north BUT MAINLY south or some up west side of Greenland.

BFTP

Hi Fred,

Firstly, the GFS 12z backs up your thoughts nicely with some stunning cold output, retrogressing high and a Northerly and NE'ly coming in the back door which looks like it would be prolonged and severe. The ukmo 12z is starting to cause concern though with 2 poor runs in a row and heading towards a mild spell, very frustrating with both models poles apart and again it's down to the ecm to ease concerns. The gfs 12z is an interesting run with scotland seemingly cold all next week with a risk of snow at times whereas it becomes less cold further south.

Edited January 29, 2010 by Frosty039

[Ben_Cambs]

GFS 12z in FI fantastic, very cold uppers, touching -18C in some areas. IMO UKMO at T+144 is fair enough, as you can see the monster High over Siberia if you look on the Northern Hemisphere charts, interesting to see METO 0z tomorrow, if the high retrogresses westwards. Best to take these slowly though, and as for now, Im looking what might happen over the next 3/4 days

Edited January 29, 2010 by Snowman0697

[Cheese Rice]

I think an easterly is 80% likely, we may not get the coldest air but we are very likely to get winds coming from the east or south east. Not sure why there are some downbeat posts, the easterly has been showing for the past 4 days (?), an although how we will get there is changing the models are still projecting it.

[bluearmy]

The UKMO and 12z GFS op are very similar at 120/144 and it's still a good sign with the block building strong in both and slight pressure building over Greenland.

In the UKMO the Azores ridge would push north moving that SW flow away and joining the block eventually giving a potential easterly I can't see any other medium term solution from here.

Can't wait to see the GEFS with an op like this at +264

http://91.121.94.83/modeles/gfs/run/gfs-1-264.png?12

a few days ago, we had a 'quick route to an easterly' mapped out. then the gulf shortwave appeared and pushed a load of energy into the atlantic which results in the shortwaves we see on ukmo at T120/T144. now i understand that the siberian block is headed west, but at t144, UKMO has another gulf shortwave entering the sw atlantic. the block could easily retrogress west over the top of the atlantic energy or hopefully, the atlantic will undercut. the point i was making is that until the shortwaves slacken off, or the jet heads se, we are forever looking at T180 for the start of a cold flow. a glass half empty post but relevent.

[Mark Bayley]

Should remain cold with the risk of snow till at least Tuesday. Some sort of easterly looks likely. The GFS 12z does get there in the end. Looks very cold as well. It also seems to agree with GPS idea of the high migrating westwards towards Greenland. That's in deep FI though. A trend to watch for i suppose. Lets hope the ECM sticks with the trend

[nick sussex]

I agree Nick re T96. I also agree with those saying about easterly flow. Not until beginning of second week earliest and 9-14 to be coldest period but ridge from arctic to exert its influence early next week holding back Atlantic energy and hence it sliding SE or remaining held to our WSW. Interesting the capture that someone mentions re the 8th always popping up.

I can understand that many people in here are getting a little impatient but the pattern has to play itself out, by this I mean the Atlantic trough will have a go at removing the block but can't win but this means we have to wait till it weakens, in the meantime theres a chance that a colder se flow will be pulled nw and a battleground situation plays out, eventually the trough will disrupt with shortwave heading se'wards under the block this will help to support the very cold upper air backing westwards,I think in terms of your rough dates I'd go for that in terms of the very cold uppers arriving though i think theres a chance that we'll still see a sufficient cold surface flow before then. By the end of next week I would expect to see some fun and games developing especially towards the east and se before the Atlantic trough finds a life and gets lost!

[bluearmy]

The UKMO is not a bad chart at all.

http://www.meteociel.fr/modeles/ukmo2.php?nh=1&ech=6&carte=1021

that rather depends how long you can wait for the cold to come CC. lets see what UKMO is showing come sunday 12z - hopefully it will have the cold in range by then.

[Kentish Kiwi]

GFS FI probably wouldn't be that snowly actually, pressure is too high and the flow is too SEly. Very very cold though. But no point discussing that far out.

Really? Looks to me as though its pretty much ranging from dead E to at its most northerly a NE, but mainly staying at a direction of around ENE - Have a look on the UK stream charts from around T+228 onwards (unless I'm completely misreading the charts). In fact I personally couldn't find a chart in FI that had a SE flow with the Easterly slowly developing into a northerly in the depths of FI. Certainly wouldn't be dry with such severe uppers and vigorous convection of the North-Sea. Wind direction looking particularly juicy for the SE and East-Anglia, definitely more Northerly tint than a Southerly, although mainly strongly E.

But as you say, not much point in the details that far out, best to just look at the general trend as many are doing - and it seems to me that doesn't look mild

KK

Edited January 29, 2010 by Kentish Kiwi

[Frosty.]

that rather depends how long you can wait for the cold to come CC. lets see what UKMO is showing come sunday 12z - hopefully it will have the cold in range by then.

CC thought the ukmo 12z would be an improvement on the 00z but it looks just as poor @ T+144 with winds sw'ly by then, one of these models is very wrong.

[The Weather Dragon]

Cold is even further into FI now - dissapointing

[karyo]

I still refuse to look at the possibility for the easterly seriously! It is simply to far in FI to invest any effort and attention on it.

However, I am pleased to see the wind veering more northwesterly by the later part of the weekend with widespread snow showers affecting many western areas!

Karyo

[kold weather]

Hmmm the 12z GFS ensembles are very interesting indeed, a surprising amount actually go for a easterly airflow around 168hrs and probably as many as 30-40% take the mentioned fast route to cold. Whilst I happen to think we will need several bites of the cheery, that has interested me I must say!

Oh and by the way, my award for the most extreme easterly EVER on any model probably in the history of net weather...goes to this ensemble member:

http://91.121.94.83/modeles/gens/run/gens-11-1-324.png?12

http://91.121.94.83/modeles/gens/run/gens-11-0-324.png?12

Yep folks, thats -20C at 850hpa just a short distance from the SE!

Edited January 29, 2010 by kold weather