Model Output Discussion - 23rd Jan - 12z onwards

[chionomaniac]

We may just need that nudge from the MJO. currently the UKMO have heading towards low amp phase 7 - ECM better with even reaching low amplitude phase 8 - will be interested to see where they head today.

 

Has anyone seen the ECM ens  - if there are no easterlies here then the form house would be a trepeat of the current pattern as ido suggests. It wouldn't take much of a westwards shift from the GFs at T+168 to have the country flooded in -10 850's.

 

On another note longer range strat 10hPa forecasts are fluctuating between keeping the displaced vortex over Siberia or returning it to Greenland

[Neilsouth]

With all the discussion about the "No Easterlies" are we unlikely to see any wind change to the nne/ne during the weekend,next week?

[Severe Siberian icy blast]

Looking at all 21 runs available from GFS/GEFS on the panel maps, 9 out of 21 at 168 still show what I would call a decent easterly. By decent I mean potential for snow, especially along the east coast. All charts look cold...

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=168

Blooming eck that's a fairly decent set of ens there .

Easterly certainly been sniffed at by the models . Just would love a week of freezing easterlies and a front moving up against it from the south . That has to be on the table at least for now one would of thought with low pressure over Europe set to remain in situ it's got to be even split between 3 options

: easterly

: mid lat high with our name on it .

: re amplification of the pattern to our west as Nick Sussex has shown us .

Which would keep the door open to our north/northeast ?

Edited January 30, 2015 by Severe Siberian icy blast

[bluearmy]

Not made too many posts recently as the signals remain a tad unconvincing to make any judgement.

If the GEFS were showing MLB centred just to our South or decent euro ridging through week 2 then I would be more attentive to the extended ecm which builds heights over the South of the uk with an discreet upper ridge Iberia.

I am taken by the 06z gefs memebers in week 2 in respect of how many retain trouging close to our se or s.

I wouldn't discount a repeat of the current pattern where the trough dives se. The spread on ecm day 10 is building a deep system in the Iceland locale and it's not clear where the direction of travel lies thereafter.

I just wonder if the NWP is adjusting to a very different hemispheric set up for the second half of feb. Hopefully, the extended ens will come into some agreement soon. In the meantime, I'm left waiting to see an op run diving that trough into Europe in the 10/12 day timeframe.

[Jason M]

not really, theres pretty good agreement , its shown currently on the models, so whilst might not happen its fair game for comment.

 

Entirely fair to comment, absolutely   . Been a bit more tolerance on here the last couple of days, which is good to see.

 

That said, the 06Z GEFS are very good IMHO. At 180 there is now quite a strong easterly signal and even at 240 hours its still there (albeit watered down by then).

 

Clearly for the next 5 days we need to assume the opps are leading the way. From day 6-10 though the ensembles cannot be ignored. I, for one am not calling it beyond day 8 (happy to say cold to day 8   ), but I think there is a danger to read too much into what are a couple of opp runs.

 

Either way, I have a feeling we will know where were headed by early next week. If we do go back to a westerly regime though, then I would agree that anything major thereafter is unlikely (not impossible).

 

Good to see IDO posting again. Was getting worried!

Edited January 30, 2015 by Jason M

[Tamara]

But WC, that's been the point...none of them have come to fruition.  No matter how detailed or good they are, the good signs have always thus far been overridden, shame as some of the thought process has been convincing.  Been the story of this winter thus far slapping many in the face.

I Fs update in short term is quite a good outlook for next week, so lets have that first and see what is shown come Tues/Wed?

 

BFTP

I think you made a very similar point before very recently

 

As repeated several times, the main problems (the enigmatic drivers as popularly described) with regard to arriving at any sustained cold patterns this winter have been covered equally several times - so as far as looking for good signs are concerned within more upbeat posts, these still have attempted to be kept entirely within that sober perspective from the start of the season to the present.

 

On the basis of attempting to be objective by identifying the overriding pattern factors to favoured cold weather (as well as those that might support such a pattern) there is surely no logical reason to try and be further convincing to anyone in my opinion

 

The majority on this thread share a joy to want to look for cold patterns. It is a natural bias that we have to attempt to juggle alongside realism and objectivity. That stance clearly cannot ever be expected to offer guarantees to please any given audience though and expectations should be set this way accordingly imo

 

I think the net weather winter seasonal forecast team have already said themselves that producing forecasts are as much about learning where things don't go to plan as much as hopefully trying to identify seasonal cold potential and when that might arrive (in line with the forum seasonal bias) and I wholly endorse and applaud this attitude

 

The information provided via Ian in terms of METO insight to ensembles and model data is very much appreciated by all of us. But that shouldn't override and/or replace any of the opinions of a large number of very knowledgeable members and likeable personalities who are regulars to these threads 

 

We are, largely, unpaid amateur weather enthusiasts on this site and should not be competing for the most successful weekly/monthly or seasonal LRF'S

 

Meantime what prospects for a north easterly next week? Amplified ridging (tapping into some decently cold uppers to our north and east) and heading to Iceland and Scandinavia are not off the map by any means at this stage. The EPS members as posted by nick earlier cite approx a 1/3 cluster that are more amplified towards this solution than the ECM operational. There are others that suggest a holding upstream pattern at the very least to increase further the uncertainties by the end of next week

 

Aside from any technical reasoning, on the basis of these possibilities at t120, I would be treating extended ensemble data suggestions cautiously.

Edited January 30, 2015 by Tamara

[Due South]

If you get the chance. Take a look at weatherbell site. Watch and listen to the SATURDAY SUMMARY. Those of you who understand global patterns, its worth a look & Listen. Especially from 11 mins on, you maybe able to work out the implications for our neck of the woods, further down the line.

[SnowBallz]

Hang on a minute !! Wasn't GS5 and Mogreps showing a strong signal for a blocked pattern 10 days ago ? Very strong signal I seem to remember for mid feb. Goes to show that it's not always right.

 

Hi Shotski,

 

I don't know if the '10 days ago' refers to the last post I made, this one: https://forum.netweather.tv/topic/82300-model-output-discussion-16th-jan-12z-onwards-smile-while-you-post/?view=findpost&p=3135716?  If you are, you'll note that - whilst I recognised that CFSv2 was advertising its now familar blocking nirvana - I also recognised that, at that point in time, no such signal had any such support from GS5.  So, to answer your question: No, GS5 wasn't showing any strong blocked pattern 10 days ago.

 

Broadly speaking, the signal was for average to slightly below temperatures, and perhaps a little drier than average - which is representative of an anticyclonic pattern.  In this regard, not a great deal has changed - indeed, if anything, confidence is a bit firmer, as we're 9 days further forward.  I'm a proud coldie, and would be happy as larry to see some excellent cold synoptics, but - at this stage - February looks fairly benign.

 

But anyway, I've enough to focus on over the next week or so!

 

SB

[Tim Bland]

GFS Op was definately on the warm side of the ensembles. Almost 40/40 for a break through from the west or a beasterly from next weekend. 20% go for a middle ground solution

 

Some of the ensebles (esp south) show the Op to be completely out of sink with the operational, even from the start!  Any ideas on how this can be?

 

[TEITS]

With all the discussion about the "No Easterlies" are we unlikely to see any wind change to the nne/ne during the weekend,next week?

Personally I feel we have a great chance of seeing the flow from the E/NE next week. The uncertainity for me is what will this bring because it could be a dry, chilly E,ly flow or a colder more convective E,ly flow.

 

Have to laugh though at those worrying about the comments from Ian F/Met O. I don't mean any disrespect but these along with the BBC got last night's track of the low wrong along with the snowfall predictions. Yet some of us amateurs got both of these spot on!

 

I have said this many times over the years but why do the professionals over rely on models rather than using observations when it comes to nowcasting. This is one aspect of the BBC forecasting that seriously needs addressing. Even Alex D on BBC at 10.30 was predicting snow for Wales and none for the SE which proved inaccurate even on the 6.30pm forecast!

[Paul]

GFS Op was definately on the warm side of the ensembles. Almost 40/40 for a break through from the west or a beasterly from next weekend. 20% go for a middle ground solution

 

Some of the ensebles (esp south) show the Op to be completely out of sink with the operational, even from the start!  Any ideas on how this can be?

 

t2mIsle~of~Wight.png

 

It's the difference in resolution - ensembles are at 1 degree, gfs at 0.25 degrees, so you're essentially comparing quite different data, particularly when talking at ground level at the moment. The ensembles will be upgraded this year to bring them more into line with the GFS again. 

[Met4Cast]

It's the difference in resolution - ensembles are at 1 degree, gfs at 0.25 degrees, so you're essentially comparing quite different data, particularly when talking at ground level at the moment. The ensembles will be upgraded this year to bring them more into line with the GFS again. 

 

So in a case such as the ensemble chart posted above - Should we be going with the newly upgraded higher resolution operational, or the ensemble mean? It seems strange to update the operational but not the ensembles

[Mucka]

easterly? what easterly?... placing too much hope on one unsupported run is a mugs game imho...

so yes, its cold, yes theres some snow around, but its going to be far from a decent dumping or big freeze for most of us. and after tuesday whilst it remains cold with hard overnight frosts (and fog i suspect where the breeze dies down) its a pretty normal cold spell.

for those of us (me! lol) who dont like february cold, the outlook this morning is good with strengthening agreement that the cold will fizzle out slowly over days 7 - 10 .

Rtavn2402.gif Recm2402.gif

 

814day.03.gif

yep its currently fi.... and could of course change though i suspect its the timing thatll change more then the outcome. no easterly here.

 

 

If that was a snipe at my comment "Breakdown, what breakdown?" which I expect it was, this is my response. 

 

Not that anyone called an Easterly as you suggest but I'm curious, what one unsupported run was it that this non existent forecast was based on?

Do you mean the JMA or GFS or the majority of GFS ensembles or the cluster in the extended ECM ensembles from last night? 

Maybe you can quote a post of a member who forecast an easterly based on this one run? 

 

I take it from your comment though you are now saying an Easterly is off the table, which run do you base that on exactly?

Wouldn't talking so definitively on one set of output be the mugs game to which you accuse others of playing?

 

Clearly the cold has slowly been extended out several days since early this week as has has been discussed and last nights ensembles, GFS in particular, showed a big move toward extending the cold still further with the large majority showing an Easterly flow at end of high res. That was a big flip toward an Easterly from previous runs.

Have they flipped back this morning?

 

Yesterdays 12z

 

 

Todays 06z

 

 

They are not as impressive as last nights 18z by any means but clearly there is still a big improvement from previous runs with any breakdown being put back several days from around the 5th to the 9th.

So yeah, breakdown, what breakdown? (And a breakdown is not high pressure and cold surface conditions)

There is a breakdown almost perpetually modelled in FI unless there is an extremely strong signal for blocking.

In last nights post I pointed out how GFS had trended right through the day and wanted further improvement on this mornings run before deciding if we were truly onto something Easterly wise which didn't come unfortunately, but is it going the same way today? 

 

 

It looks about 50/50 to me whether we will see a breakdown later next weekend or an Easterly type or perhaps just high pressure over the UK maintaining the cold.

This mornings output is a bit disappointing after last nights JMA,GFS and ensembles no doubt but to suggest saying the breakdown has been put off was unsupported, when the overall output which still shows exactly that, seems rather churlish to me.

 

At least you are not here to win any popularity contests Mushy, I can respect that even if I completely disagree with your "unsupported" version of how things have unfolded. 

 

Clearly there is scope for change either way, especially the crucial period between 72h and 120h where the Atlantic pushes in against the ridge.

It is very finely balanced as to how much the low will disrupt and energy push through the Southern tip of Greenland over the ridge and the upstream keeps chopping and changing. Also downstream is important to see if we can get a decent ridge pushing back NW through Scandi for any potential link up.

 

Because the time-frame is quite near this should all be resolved quite quickly (At least if the breakdown proper with an Atlantic influence really is going to occur next weekend)

We do need to see improvements upstream being modelled soon but all to play for this evening and let's remind ourselves the breakdown was being solidly modelled for next Tuesday not so long ago, we didn't even have a ticket to the raffle. 

Edited January 30, 2015 by Mucka

[Polar Maritime]

Can we try and keep to Model Discussion please, There are other threads for Meto Outlook.

Thanks PM.

[Paul]

So in a case such as the ensemble chart posted above - Should we be going with the newly upgraded higher resolution operational, or the ensemble mean? It seems strange to update the operational but not the ensembles

 

In the particular case of the chart above I'd go with the ensemble as it appears the grid square being used for the isle of wight by the operational is more sea based than land (will see if we can shift it to stop this happening). In most cases, when looking at detail on the ground then the operational will be the way forward. 

[nick sussex]

First output of the evening the GME brings in an easterly, not one of the major models but still nice to see:

 

SLP:

 

 

850's:

 

 

The deepish low in northern Italy helps to drive the cold air westwards along the southern flank of the high.There is some sub -10 850's waiting to moving westwards and if they arrive the set up is more condusive to the convective type easterly, the question at this stage is really how long that strong easterly can last. I think theres a decent chance of an easterly flow but longevity and cold pool to tap into still quite uncertain.

Edited January 30, 2015 by nick sussex

[Johnp]

Cracking GME to start the 12 z's

http://www.meteociel.fr/modeles/gmee_cartes.php?&ech=132&mode=0&map=0&archive=0

[ItNeverSnowsInWindsor]

Cracking GME to start the 12 z's

http://www.meteociel.fr/modeles/gmee_cartes.php?&ech=132&mode=0&map=0&archive=0

Wow that's some leap of faith from T84 to T108!

[Tamara]

It might not be considered reputable, but the GME 12z fits the NE Atlantic ridge theme discussed today with a nice convective NE'erly

 

Heavy snow showers I think would be driven inland from eastern coasts off the North Sea especially as  -10 uppers arrive

 

http://modeles.meteociel.fr/modeles/gme/run/gmenh-0-132.png

 

http://modeles.meteociel.fr/modeles/gme/run/gmefr-1-132.png

 

Edit: All sing together

 

Yes nick, in the context of the evolving pattern it gives that extra credibility. It reflects well that 1/3 % of EPS members who suggest similar this morning

 

UKMO t96

 

http://www.meteociel.fr/ukmo/runs/2015013012/UN96-21.GIF?30-17

Edited January 30, 2015 by Tamara

[nick sussex]

It might not be considered reputable, but the GME 12z fits the NE Atlantic ridge theme discussed today with a nice convective NE'erly

 

Heavy snow showers I think would be driven inland from eastern coasts off the North Sea especially as  -10 uppers arrive

 

http://modeles.meteociel.fr/modeles/gme/run/gmenh-0-132.png

 

http://modeles.meteociel.fr/modeles/gme/run/gmefr-1-132.png

It used to be that the GME was quite a good early pointer towards the ECM output! That output is certainly possible, hopefully we do see the other outputs go for this tonight.

[Met4Cast]

It used to be that the GME was quite a good early pointer towards the ECM output! That output is certainly possible, hopefully we do see the other outputs go for this tonight.

 

It'd be quite a big win for the JMA if we did end up in an Easterly pattern, it was the first model to pick up a stronger Easterly I believe - 6z out to 84 shows a fair amount of amplification so we can assume it stuck with yesterdays 12z thoughts. 

[NoTraction]

Sorry if off topic

 

can i ask a question, i have searched but not found what i am looking for and there are alot of knowledgable posters on here!

 

I have heard that the rainfall radars we all look at are not live but a prediction based on the model runs and current observations, it was mentioned on few posts recently, is that correct? Or is the precipitation radar live but wether its rain, sleet or snow is what the prediction factor is?

 

Thanks

[Skullzrulerz]

Well Guys and Girls we now await the 12z run of the GFS. I am hoping for upgrades for this run.

 

Its likely we have a 'better' run compared to the 0z run.

Edited January 30, 2015 by Skulltheruler

[Paul]

Sorry if off topic

 

can i ask a question, i have searched but not found what i am looking for and there are alot of knowledgable posters on here!

 

I have heard that the rainfall radars we all look at are not live but a prediction based on the model runs and current observations, it was mentioned on few posts recently, is that correct? Or is the precipitation radar live but wether its rain, sleet or snow is what the prediction factor is?

 

Thanks

 

It is off topic, but the radar is live from the UK's radar network, the precip type detection is based on model data/observations. Feel free to pm me if you would like further info.

[Nick L]

Sorry if off topic

 

can i ask a question, i have searched but not found what i am looking for and there are alot of knowledgable posters on here!

 

I have heard that the rainfall radars we all look at are not live but a prediction based on the model runs and current observations, it was mentioned on few posts recently, is that correct? Or is the precipitation radar live but wether its rain, sleet or snow is what the prediction factor is?

 

Thanks

 

Precip type radars use the model data to determine what the most likely type of precipitation is falling. It is a good guide but may not necessarily represent what is actually happening.

 

The actual precipitation intensity shown is live and not model derived.