Model Output Discussion 19th January 2014-18z onwards.

[IDO]

Slight differences with the ens from the GFS 12z. We still have the UKMO (or close to) in the mix, along with the op (and Control) showing full on zonal, however the third cluster is now the Atlantic ridge linking with the sinking (now Scandi) Arctic high.

 

This is that cluster at T144: 

 

  

 

   

 

Even split between the three clusters, so uncertainty remains with that googly thrown in for good measure. This link cluster means by T180 there is a MLB with lower height in S.Europe (mostly cut off) with the PV running west to east thru Iceland.

 

More runs needed.

Edited January 23, 2014 by i'm dreaming of...

[Panayiotis]

Well member 14 on the GEFS ensembles shows where we can go if we can get enough heights to the north:

http://www.meteociel.fr/modeles/gefs_cartes.php?code=14&ech=6&carte=0&mode=0

[nick sussex]

I think theres some cross wires in here re Ian F's post because what maybe viewed as zonal by the UKMO isn't perhaps what this means in here, a nw/se jet axis with troughing near the UK may still be viewed as zonal by the UKMO, unless the UKMO are ignoring the ECM ensembles, perhaps they're going with MOGREPS because the De Bilt ensembles do not have an overwhelming signal for a westerly driven pattern in that region.

[weather eater]

 

Edited January 23, 2014 by weather eater

[Biggin]

Good to hear reports about the snow falling in various areas considering the mild (compared to next week) weather at the moment. Wonder why the models cant pick this up this close, and no mention on weather forecasts. Spose we have to take the "no chance of snow" opinions with a pinch of rock salt. Re the models, any of them predict the snowfall today ??

[shedhead]

Posted Today, 16:32

fergieweather, on 23 Jan 2014 - 16:20, said:

Correct - and I've just come of a conference with UKMO who remain confident on that ultimate outcome (and they aren't expecting any issues re lowland snow across southern England next week, as everything currently sits model-wise, but I think we'd all gathered that from the models ourselves). The rain issues, on the other hand, are top of the agenda. Tomorrow offers e.g. 10-15mm 30%PROB 20mm Somerset Levels; same area Sunday 15-25mm with to 35mm possible locally. EA have raised to Amber there too.

 

 

Glenn W

Hmmm.. How does one have high confidence circa 10 days in advance to a return of Zonal & no issues regards lowland snow, but a 30% probability of 10-15mm of rain for the next day?

 

I would take it with a pinch of salt re snow issues next week, especially amounts/quantities. I can count a lot of times the forecast has been "Little snow" and turned out to be quite a lot.

 

In view of responses to Ian F's professional input I think we are very lucky indeed that he continues to post in here...some people seem hell bent on arguing with just about anything and everything that doesn't scream snowmamadden...

 

 

Edited January 23, 2014 by shedhead

[weather eater]

Snow in Bolton - some heavy ppn passing to the SE over Lancashire and Yorkshire - clearly not forecast. 

 

 

https://pbs.twimg.com/media/BeriTJgCUAAF953.jpg

 

https://pbs.twimg.com/media/BerhIRmCYAIkVG3.jpg:large

Actually last night’s forecast did mention the possibility of some winteriness today and we have seen some wet snow, sleet and hail but it’s not laid even on the hills, just added to the soggy wet mess. Big lightning flash just now as well and a bit of a hail/sleet laying on the ground in the last few mins.

[winterof79]

You know all of this talk about a bit of rain down South for Sunday we have taken our eyes off of the ball for what's happened today in the last hour, between this thread and the met office I feel let down, not a single warning about the blizzard I have just had to battle through to get home.. I can also confirm to shedhead that they weren't "wet snow flakes" as he alluded to earlier. Maybe Frosty can confirm if Wakefield experienced anything like we just received in Huddersfield ? Wrt whatever the models shows next week if it's westerly bring it on because if this is the mild Atlantic it ain't that mild

Affirmative Captain.It was actually thunder snow.Sorry mods

[Captain Shortwave]

Right then, I look at the charts tonight and feel a great sense of dread, a situation which could quite frankly go down to the wire here.

The models all agree on a substantial low moving south east through the UK and will stall and fill somewhere south east of the UK. At this point there is a fine line between a lot of snow and a lot of rain.

The upstream pattern and the positioning of polar heights are crucial to what side of the line we fall. If the pattern becomes more amplified than it is now then the chances of heavy snow increase and we get a better surge of cold air along the northern flank of the low, if not then we might just not be able to get the level of cold (dew points etc) to get snow to low levels.

More runs needed but if this goes the way of the pear, many in my area of the world could suffer greatly, this is 100mm+ levels of rainfall if that low stalls in a location where we can't get the cold air into the system. This is very high risk we need a more amplified pattern up the western Atlantic to clear that low quickly and get the most robust easterly we can.

Edited January 23, 2014 by Captain shortwave

[nick sussex]

 

Posted Today, 16:32

fergieweather, on 23 Jan 2014 - 16:20, said:

 

 

Glenn W

Hmmm.. How does one have high confidence circa 10 days in advance to a return of Zonal & no issues regards lowland snow, but a 30% probability of 10-15mm of rain for the next day?

 

I would take it with a pinch of salt re snow issues next week, especially amounts/quantities. I can count a lot of times the forecast has been "Little snow" and turned out to be quite a lot.

 

In view of responses to Ian F's professional input I think we are very lucky indeed that he continues to post in here...some people seem hell bent on arguing with just about anything and everything that doesn't scream snowmamadden...

 

 

I don't think anyones arguing Shed, of course everyone appreciates Ians input. That's not the issue at all, just I think perhaps theres more uncertainty than the modelling suggests. And again our terminology in here might be a bit different to the UKMO, zonal in here normally means strong Azores high limpet PV to the north and  west/sw flow for the majority of the time, and that's not what I see from the modelling. So I think the term zonal used probably means the proximity of low pressure rather than the normal terror term that most people associate with that word zonal.

[fergieweather]

Actually last night’s forecast did mention the possibility of some winteriness today and we have seen some wet snow, sleet and hail but it’s not laid even on the hills, just added to the soggy wet mess. Big lightning flash just now as well and a bit of a hail/sleet laying on the ground in the last few mins.

 Indeed... the Chief earlier today advised us "Hail and sleet has been reported 400 m below WBFL, so continued risk of local solid precipitation to low levels under deep convection." 'Twas a good call.

[steelermark]

I don't think anyones arguing Shed, of course everyone appreciates Ians input. That's not the issue at all, just I think perhaps theres more uncertainty than the modelling suggests. And again our terminology in here might be a bit different to the UKMO, zonal in here normally means strong Azores high limpet PV to the north and  west/sw flow for the majority of the time, and that's not what I see from the modelling. So I think the term zonal used probably means the proximity of low pressure rather than the normal terror term that most people associate with that word zonal.

I understood a zonal flow was just a flow from the predominant direction. So for us that is westerly. Whether it's straight westerly, north westerly or south westerly it's still zonal. Obviously very different conditions on the ground.

[Frosty.]

You know all of this talk about a bit of rain down South for Sunday we have taken our eyes off of the ball for what's happened today in the last hour, between this thread and the met office I feel let down, not a single warning about the blizzard I have just had to battle through to get home.. I can also confirm to shedhead that they weren't "wet snow flakes" as he alluded to earlier. Maybe Frosty can confirm if Wakefield experienced anything like we just received in Huddersfield ? Wrt whatever the models shows next week if it's westerly bring it on because if this is the mild Atlantic it ain't that mild

The met office and bbc forecast wintry showers, which is what these are? rain, hail, sleet and snow with gusty westerly winds..met office were spot on.

[Nick L]

I understood a zonal flow was just a flow from the predominant direction. So for us that is westerly. Whether it's straight westerly, north westerly or south westerly it's still zonal. Obviously very different conditions on the ground.

 

Yeah you're pretty much right. A zonal flow is one which broadly follows latitudinal lines (i.e. E-W), and a meridional flow follows longitudinal lines (i.e. N-S). There is a tendency in here to use zonal as an umbrella term for anything mild and wet.

[snowingtequila]

If we are here to look at the models then surely we have the right to question the met office's analysis of those models. It is brilliant to have a professional forecaster on here but I don't think that takes our rights away to post a contrary view. This is a forum after all, if you don't want a discussion maybe we should just post the met office forecast with a warning not to discuss as it is insulting to the pros on here.

Edited January 23, 2014 by snowingtequila

[Paul White.]

The met office and bbc forecast wintry showers, which is what these are? rain, hail, sleet and snow with gusty westerly winds..met office were spot on.

Well maybe I've spent all of my time in here and forgot to check the met lol. But I have checked since the event and nothing except an ice warning.. It was a heavy thunder shower blizzard conditions. From the mild mild west

[nick sussex]

These comments from NCEP might show that perhaps all is not as it seems:

 

FORECAST SPREAD DOES INCREASE BY NEXT MIDWEEK WITH
PACIFIC ENERGY TRYING TO WORK INTO THE WRN PERIPHERY OF THE RIDGE
AND EMBEDDED SYSTEM FLOW SPECIFICS DROPPING THROUGH CANADA TO THE
LEE OF THE RIDGE.  HOWEVER A RECENT TREND HAS BEEN THAT NEWER
MODEL AND ENSEMBLE RUNS HAVE BEEN FINDING WAYS OF MAINTAINING THE
RIDGE LONGER THAN PRIOR GUIDANCE.  THIS WOULD PROLONG THE
ANOMALOUSLY DRY PATTERN THAT HAS BEEN IN PLACE ACROSS THE WRN US
THIS SEASON...ALBEIT EVEN WITH SOME LIMITED PCPN WORKING INTO THE
PAC NW AND NRN ROCKIES.
 

[Paul33]

If we are here to look at the models then surely we have the right to question the met office's analysis of those models. It is brilliant to have a professional forecaster on here but I don't think that takes our rights away to post a contrary view. This is a forum after all, if you don't want a discussion maybe we should just post the met office forecast with a warning not to discuss as it is insulting to the pros on here.

 

^ ^ ^ ^ THIS ^ ^ ^ ^

[MPG]

If we are here to look at the models then surely we have the right to question the met office's analysis of those models. It is brilliant to have a professional forecaster on here but I don't think that takes our rights away to post a contrary view. This is a forum after all, if you don't want a discussion maybe we should just post the met office forecast with a warning not to discuss as it is insulting to the pros on here.

Spot on - it's great having the input but when the METO claim to be so confident of zonal (whatever that is) it can make the discussion of a possible pattern change to colder conditions slightly pointless. But hey, if they are correct about next week spot on to them.

[Frosty.]

Well maybe I've spent all of my time in here and forgot to check the met lol. But I have checked since the event and nothing except an ice warning.. It was a heavy thunder shower blizzard conditions. From the mild mild west

To be fair, the experts and the charts show the uk covered in 528 dam thickness today and they did forecast heavy, squally lines of showers turning wintry with thunder, hail, sleet and snow..which is exactly what we got, bravo to the experts I say. Tomorrow brings heavy rain and further flooding to the southwest. it looks cold and rainy in the east with hill snow and even freezing rain in parts of scotland. a lull on saturday..the calm before the storm and then sunday brings more severe weather with heavy rain and gales, more flooding and damaging winds...then turning colder early next week.

Edited January 23, 2014 by Frosty.

[Chris K]

If we are here to look at the models then surely we have the right to question the met office's analysis of those models. It is brilliant to have a professional forecaster on here but I don't think that takes our rights away to post a contrary view. This is a forum after all, if you don't want a discussion maybe we should just post the met office forecast with a warning not to discuss as it is insulting to the pros on here.

I don't disagree with your post...but if people don't post some evidence to show why they think differently, how is is any question of their analysis meant to be understood and debated? Edited January 23, 2014 by Chris K

[fergieweather]

Well maybe I've spent all of my time in here and forgot to check the met lol. But I have checked since the event and nothing except an ice warning.. It was a heavy thunder shower blizzard conditions. From the mild mild west

 Ah - but that's because 'ice' warning is always used as an umbrella / generic one when the type of solid PPN might vary. It'll only be specified in singular fashion as snow, hail, freezing rain, etc etc in the text when conditions afford high forecasting certainty of such an outcome (and in doing so, also meeting the warning criteria laid-out in the PWS warning matrix).

[EML Network]

Running through the various GFS runs and the overwhelming route post 192 is for a series of deep Lows to run across the UK (YET AGAIN) west to East and then there seems to be support growing for us to end RIGHT back where we started at the beginning of Dec with a Bartlett setting up. 

 

IF it comes to pass this way , then we can kiss goodbye to Winter 2013 / 2014 and I guess it will be hibernation time for the majority of posters on here. 

 

Of course nothing is ever set in stone and anything beyond + 120 is always going to flip flop around, but if it's trends you're looking for this is where things look to be headed. 

 

Tallies up with the Met Office ''Outlook'' as well. 

 

This Winter has been a real let down in just about every regard as it relates to the weather. 

 

I'll be glad to see the back of it tbh and I'm finding myself for the first time ever looking forward to the summer.

[Stuie]

That is one super Scandi brick wall with the ECM.

[R.P. McMurphy]

I don't think anyones arguing Shed, of course everyone appreciates Ians input. That's not the issue at all, just I think perhaps theres more uncertainty than the modelling suggests. And again our terminology in here might be a bit different to the UKMO, zonal in here normally means strong Azores high limpet PV to the north and  west/sw flow for the majority of the time, and that's not what I see from the modelling. So I think the term zonal used probably means the proximity of low pressure rather than the normal terror term that most people associate with that word zonal.

 

Yep thanks for this Nick, didn't see shed's post - due to a neat feature on NW... But to add my stance I wasn't hell bent on anything, just merely asking for clarification, & I have liked Ian's post due to his response, it clears it up well.

 

Ian's posting on here is invaluable, and I do hope he feels like people are not hell bent on disagreeing with him. I'm certainly a fan... Maybe a quick autograph Ian ?

 

Next week is still up in the air, as we all know a week's worth of Model Output does not have the best verification stats, and it's nice to hear 10% of members still going for an Easterly next week, so it;s all still to play for, albeit 90% go for some form of "Zonal" - maybe Ian can clear up what they refer to as Zonal ?

Edited January 23, 2014 by Glenn W