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

[Mucka]

GFS 144 better to our North/Northeast re the Arctic high but fails to clear energy SE and is quite flat behind so the next low pressure phases with our trough. Let's hope it is too flat and progressive upstream which is a known bias of GFS.

 

 

UKMO a little better but we're not going to hold the atlantic back from there. It wouldn't by typical zonal by any stretch but it wouldn't be cold and blocked for the foreseeable either.

 

Edited January 21, 2014 by Mucka

[fergieweather]

 

Further to my previous posting here.

 

http://forum.netweather.tv/topic/79144-model-output-discussion-19th-january-2014-18z-onwards/?p=2902364

 

This is the GFS 12z's reaction to our state of affairs come Sunday showing the snow risk which extends into Monday, albeit largely a west based event by then, but most certainly an interesting event just about within the reliable timeframe now.

 

 

GFS 12z 210114 UK Snow Risk and NH T850s & SLP at t+126.jpg

...although (and ignoring the ongoing concerns over GFS handling of all this in any case) it's the rainfall issues that are much more the focus of interest and concern. As I said earlier: grim, not least coming on top of the Fri-early Sat totals. Any transient wintry stuff almost insignificant by comparison, frankly.

[Mark Bayley]

 At present, the more progressive solutions running the low faster to SE are preferred (GFS not favoured by Exeter on this one), but 12z EC will be instructive on this issue. Either way, looking grim re rainfall amounts Sunday, let alone possible wind issues, should they emerge as threatening.

Yes some models certainly not looking good with ground still very saturated and river levels high, especially for those areas prone to flooding. A further 30-50mm of rain in western regions (by Sunday end) if the GFS is anything to go by!

[warrenb]

Yep, flooding again going to be an issue. Especially now with the block to the east stalling the fronts, so not just transient rainfall, but continuous, this is what brought the issues just before christmas.

[Panayiotis]

UKMO @144hrs looking nice with a +PNA and an Arctic high splitting the PV, with the NE US remaining brutally cold. As for us we need to see the Arctic high move south into Scandi so it shift that low SE. But all in all great!

[karyo]

I suppose the 12z is giving us good shots at cold zonality thanks to the heights to the northeast and the orientation of the jet. No deep cold but an improvement to yesterday's 12z.

Karyo

[nick sussex]

The GFS 12hrs run is wildly different to the earlier 06hrs run and so its hard to put too much faith in its output given the lack of consistency, the UKMO is okay but its touch and go upstream with phasing issues likely.

 

Both the models develop a shortwave but too late and nothing like the ECM 00hrs run  which develops this deepens this and phases this much further west with the PV  and not over the ne USA.

[warrenb]

That is an interesting UKMO chart, energy going south into Europe, only problem being the AH and the jet out of the US, hold on, that has been the problem all winter.

[Bobby]

 ...although (and ignoring the ongoing concerns over GFS handling of all this in any case) it's the rainfall issues that are much more the focus of interest and concern. As I said earlier: grim, not least coming on top of the Fri-early Sat totals. Any transient wintry stuff almost insignificant by comparison, frankly.

 

Looks like a lot of rain from those two systems, possibly western hills could see close to 100mm in a worst case, 50-75mm more generally? Not good anyway with everything a bog.

[Cecil Hogmanay Melchett]

I suppose the 12z is giving us good shots at cold zonality thanks to the heights to the northeast and the orientation of the jet. No deep cold but an improvement to yesterday's 12z.Karyo

Yes K,

GFS 12Z gives hope fo something wintry mid term for those in the north with altitude.

Looks better than the 06z in that regard..

[gottolovethisweather]

 

At present, the more progressive solutions running the low faster to SE are preferred (GFS not favoured by Exeter on this one), but 12z EC will be instructive on this issue. Either way, looking grim re rainfall amounts Sunday, let alone possible wind issues, should they emerge as threatening.

 

I've deliberately highlighted the more pertinent part of fergie's post above as we do need to account for all possibilities moving ahead whilst the majority of us in here, continue our search for the rarity of a Winter 2013/14 snowflake.  Tis fascinating stuff and may yet become a forecasting nightmare for all manner of reasons, both long-term and shorter-tem.

Edited January 21, 2014 by gottolovethisweather

[Severe Siberian icy blast]

Bad early on as the low pressure next week doesn't detach from the vortex like it did on the 06 but roll it forward a few hours and the second one middle of next week does and we have a favourable profile picture and week hights to the north across Iceland . Think we will see a good fi coming up.

[pandit-scholar]

The UKMO is the better chart than GFS in the 12z run. Yes it shows a hell of a lot of rain in the short term, but in the medium term it still shows the PV under a lot of strain in Greenland, and colder uppers filtering to the UK. Now on to the ECM tonight.

Edited January 21, 2014 by pandit-scholar

[Cecil Hogmanay Melchett]

Tell you what,that meto update looks spot on looking at GFS12Z.Westerly regime with hill snow in the north .

A concern has to be the ammount  of rain though,worrying for those already affected.

[gottolovethisweather]

 ...although (and ignoring the ongoing concerns over GFS handling of all this in any case) it's the rainfall issues that are much more the focus of interest and concern. As I said earlier: grim, not least coming on top of the Fri-early Sat totals. Any transient wintry stuff almost insignificant by comparison, frankly.

 

Just corrected my original post and as I was typing my own in which reiterated the part about MetO concerns re: additional rain, I see you had commented. A damn lot going on in the coming weeks and all to play for in terms of weather type I guess.

Edited January 21, 2014 by gottolovethisweather

[karlos1983]

nice and warm at 10hpa

 

 

and yes I know normal caveats apply, fl etc...but I'd rather it showed warming than errr not 

[Summer Sun]

Rainfall totals to 18z Sunday based on this afternoon's 12z GFS run

 

 

And the totals to 12z on the 29th

 

 

Worrying amounts for the areas already hit by flooding given the high rivers still and saturated ground

Edited January 21, 2014 by Summer Sun

[fergieweather]

 

Just corrected my original post and as I was typing my own, I see you had commented and I have now reiterated the part about MetO concerns re: additional rain. A damn lot going on in the coming weeks and all to play for I guess.

Yup - and that's before the rest of next week unfolds, with potential rinse-repeat set-ups, or colder passing NE/E phase; or whatever. A total forecasting mare, but merely adding to what's already been a compelling winter of meteorology and model-watching (i.e., unless you are still gasping for snow, obviously!)

[Summer Sun]

GFS 12z  8 day temperature anomaly is another cold run for most though in the west and south west temperatures stay slightly above normal

 

[Wadey]

nice and warm at 10hpa

 

 

and yes I know normal caveats apply, fl etc...but I'd rather it showed warming than errr not 

Karlos what's it's showing on the 31st as this was the date when it was showing warming ? Just wondering if it's been pushed back at all cheers

[Nick L]

nice and warm at 10hpa

 

 

and yes I know normal caveats apply, fl etc...but I'd rather it showed warming than errr not 

 

I think there is some erroneous use and assumptions regarding these charts. Yes, they show stratospheric warming. But even if this does verify (at that range, most likely not) it doesn't guarantee there will be a change to cold to our shores. Even if it does, there would be considerable lag to the point where the effects of this warming wouldn't be felt until pretty much the end of winter.

[chionomaniac]

nice and warm at 10hpa

 

 

and yes I know normal caveats apply, fl etc...but I'd rather it showed warming than errr not 

First complete vortex destruction forcecast at 1 hPa by the end of the run!!

 

Best strat chart of the season - though this is very, very high up!!

 

 

[Downpour]

The high-res shows things more realistically... don't get your hopes up I'd say, only high ground in the N likely to see snow settling, perhaps some wintriness down to lower levels here and there. Perhaps the mountains of Wales too.

 

  I thin

I think the phrase "it will be rain" is apt here...

[karlos1983]

Karlos what's it's showing on the 31st as this was the date when it was showing warming ? Just wondering if it's been pushed back at all cheers

 

I'm not pretending that I understand the Strat, just that it *can affect our weather, although it can take weeks if it does so, but at the same time can be a lot quicker.

 

The Strat is really getting my attention and I really want to get a better understanding of it in the coming winters, I fully intend to do this in the strat thread. (in the background)

Edited January 21, 2014 by karlos1983

[Cecil Hogmanay Melchett]

Well as Fergie has said,yet again,rainfall is the cheif concern for the reliable period.

After that,i guess your location and altitude will play a big part of what you are going to see falling out of the sky.

If your up north and have 200-300m altitude the outlook is potentially interesting,if you live in the south and have little altitude,than the outlook is probably extremely grim from a snow perspective...