Model Output Discussion 1st January 2014-06z onwards.

[BLAST FROM THE PAST]

I think a step forward again overall, look where we were just a few days ago when even a chance of colder solution wasn't on the cards.  The models have improved the chance of a cold outlook from no chance to 'within a shout'.  I wouldn't mind betting they will move from 'within a shout' to shouting over next couple of days.

The trough holding to our NW instead of being/moving further east has imo prevented a colder solution  to come in quicker....but of course pattenr changes are generally slower than 'overnight'.

I am happy with developments as long as we see more progress tomorrow and Saturday then I think we're getting in the game.

 

BFTP 

[draztik]

Yesterdays 12z op from ecm on left, todays 12z on right (height anomalies day 6-10)

All i can ascertain from this is that the models, in general, are struggling big time with where we go within this time range. So as ever, more runs. However, important to note that the 12z op from today looks similar to its own extended ens from the 0z update earlier.

Day 6.5-11.5 ecm ext. ensembles 0z

[Summer Sun]

Positive signs from the GFS ensembles again this evening with rainfall easing significantly across the UK during next week it could also turn cooler towards mid month so any precipitation could be wintry especially on higher ground for the south and maybe lower levels the further north you go at times

 

Edited January 2, 2014 by Summer Sun

[Steve C]

now come on, a quick check through out to 240h on the Extra gfs output shows possibly 4 days out of the 10 when maximum values are suggested in double figures in areas away from Cornwall, so your term is, as often is the case, a touch OTT. Why oh why can some of you not be factual from the computer runs instead of making your own spin on it?Don't believe me Purga or anyone else, then simply look at the 12z outputs on the Extra part of this site or if not then the basic GFS run

Good post John. I'm neither a proper cold, or hot weather aficionado. Ramping posts, or even those that might be conceived as the same, shouldn't be posted here, without a caveat, IMHO.Not having a proper go at the poster, I just feel this thread should be fairly objective, (mostly)

[shedhead]

Another very familiar run from ECM this evening (bar the couple of recent blips), with the Atlantic continuing to throw system after system at us, albeit rather more slowly and with slightly less vigour post T+144hrs. So still plenty of wind and rain to come, especially during the first half of the period, with mean temps holding up a little above the seasonal average overall. 

 

[johnholmes]

another pdf on the elusive probability using 500mb anomaly charts

 

update on 500mb anomaly charts 2 jan.pdf

[phil nw.]

Come on people let's stop this sniping against members who have a different pov.

Some posts have been removed because of this.

You all have choices of PM's,ignore or report.

 

Thanks all.

[Frosty.]

The GEFS 12z mean shows an increasingly colder trend locking in beyond T+168 hours with an increasing chance of the rain turning more to sleet and wet snow, on hills initially and then lower levels...this is looking very good for my fellow coldies, bolstered by the more wintry met office further outlook for the second half of January, this winter looks like waking up at last..

[ANYWEATHER]

Happy New Year Folks and this is my first post of the year [And hopefully not the last!!!] Models both Ecm and Gfs right out too T+240 show the unsettled weather to continue with no real cold to tap into. although Ecm has recently showed some blocking to our North East!!    I think models are really struggling with this scenario ,but what I do think is that there is a probable to cold by Mid January, as the models keep hinting, but Patience is needed ,  

[shaky]

Hopefully ian ferguson can inform us off what the high resolution models are offering on the potential snow event saturday!!

[bluearmy]

Wrt to the 12zECM op run, of course it won't verify like that past day 7 but it is worth noting that in its latter stages, the neg AO is bringing a chunk of p/v ex Siberia from east to west south of Svalbard which meets the strong northern arm and they then phase together. This won't be an easy situation for the model to resolve. I think a fair bit of chopping and changing around the detail re the blocking to our north will be the theme for e next few days.

[johnholmes]

From my reading of the charts I would imagine not much in terms of reality for those under the heaviest rain. At most some wet flakes but I would be surprised, with what any of the models are currently suggesting,much if anything more than that.

Remember though that predicting 500mb winds and even surface wind flow is far far easier than when/where/how heavy/how much will fall of whatever type from the clouds. To predict snow you need at least 6 more variables than for rain and only if 4 of them are 'go' are you likely to get it, assuming of course that the prediction of precipitation in a particular spot is correct.

[PolarWarsaw]

Hopefully ian ferguson can inform us off what the high resolution models are offering on the potential snow event saturday!!

 

The chances are...not alot. It would have been at the forefront of conversation in here if something notable was on the cards.

[phil nw.]

Hopefully ian ferguson can inform us off what the high resolution models are offering on the potential snow event saturday!!

Ian may have different information shaky but the 12z NMM model doesn't indicate any snow for lower levels.

A couple of images for Sat am just to give a basic idea

 

 

Dewpoints above 0c except over some mountainous areas Scottish highlands for example.

Snow risk maps just to show this probability.

[Tim Bland]

NAE shows some snow on the back edge. High ground could see a covering Sat eve

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=nae&MODELLTYP=1&BASE=-&VAR=prty&HH=48&ZOOM=1&ARCHIV=0&RES=0&WMO=&PERIOD=

[Frosty.]

With the GEFS 12z mean turning significantly colder during the second half of the run, it's not surprising to see perturbations as lovely as this small sample, P1 is a stonker....as is P20  I would have that right now if it was offered to me..it sure would feel like winter has arrived!

Edited January 2, 2014 by Frosty.

[Average Joe]

Just to bring us back to the more immediate future.

Some recent images from the NMM model-courtesy fo NW Extra.shows the troublesome amounts of rain and wind expected over the next 3 days

fri r.pngfri 850.png

sat r.pngsat 850.png

viewimage.pbx.pngsun 850.png

 

We can see particularly on Sunday a very active frontal system coming through with the differences in the 850hPa temps. as much as 8C either side of the boundary.

A strong jet streak of 170mph underlining the energy wrapped up in this pattern.

jet.png

 

Note the tightness of the isobars indicating strong winds quite widely at times.

 

Understandably many warnings in force and making the news headlines this evening.

Phil, thank you for posting a chart giving a chart as to what's in store in the short term future as opposed to worrying about the first snowflake. For those of us in flooded areas and with shaky electrical connectivity, an update is appreciated, so thxnk you.

[A.J]

With the GEFS 12z mean turning significantly colder during the second half of the run, it's not surprising to see perturbations as lovely as this small sample, P1 is a stonker....as is P20  I would have that right now if it was offered to me..it sure would feel like winter has arrived!

I totally admire your hunt for cold Karl, and would be more than happy to see some of these perturbations verify, but let's face reality bud, these charts range from T240 - T360 and are just a very narrow sample of the ensembles, so the chances of verification are remote to say the least.......but, if an increasing number of the ensembles show these kind of synoptics over the next few days then interest will certainly grow in here! 

[Frosty.]

I totally admire your hunt for cold Karl, and would be more than happy to see some of these perturbations verify,

They fit with the met office wintry second half of January which is why I think they might not be as unrealistic as you think.

[Gibby]

Good evening folks. Here is the evening report on the 12 midday outputs of the NWP for today Thursday January 2014.

 

All models continue to show a new major storm winding up towards the NW of Britain later tonight and tomorrow with a short spell of rain this evening and tonight giving way to showery and very windy weather tomorrow with gales and severe gales in places. Through Saturday further showers look likely as winds remain SW or West and strong though a drier spell is possible before all models show a new surge of Atlantic energy with wet and windy weather on Sunday before returning all areas to showers and blustery SW winds early next week.

 

GFS then shows Low pressure to the North filling midweek with a lessening in wind and showers for a time. However a further spell of rain looks likely later next week as further Low pressure moves over from the West before High pressure moving up from the SW by next weekend then gives a period of quiet anticyclonic weather with frost and fog problems night and morning and cold bright days.

 

The GFS Ensembles show that the operational was a colder outlier later in the run with most members supporting a change onto drier and brighter conditions at times through Week 2 but with higher temperatures hinting at High pressure being just to the South or SE of the UK.

 

UKMO closes it's run next Wednesday showing sunshine and showers with rather lighter SW winds in association with filling Low pressure to the North and rising pressure to the SE and the mid Atlantic.

 

GEM again tonight keeps things very unsettled throughout it's run maintaining the Atlantic progression of rain bearing troughs though the gales of late should of become less marked than of late. Temperatures look like remaining near average.

 

NAVGEM also keeps a West or SW feed going later next week though much lighter than of late. There would be continue to be rain at times for all should tonight's charts verify with temperatures close to normal.

 

ECM also shows maintained unsettled weather as a Westerly flow from the Atlantic is maintained with rain and showers at times. Despite higher pressure values than of late the weather in terms of rainfall will continue to be poor and hardly requisite for flooding levels to fall but at least the wind will be less of a feature as will the temperature values.

 

The ECM 10 Day Mean Chart continues it's theme of recent runs with Low pressure most likely towards the NW of Britain near Iceland and High pressure remaining to the South with a SW flow across the UK with the risk of rain remaining for many. This bias indicates relatively few members offer much in the way of reliable relief from wind and rain let alone cold and snow.

 

http://www.wetterzentrale.de/pics/Reem2401.gif

 

The GFS Jet Stream Forecast keeps the flow pumping quickly across the Atlantic and over the British Isles for the next week or so. Then in line with it's rises of pressure the pattern becomes much more diffuse and unclear with no clear cut signal apparent.

 

In Summary the weather pattern remains largely disturbed tonight. GFS does offer some better weather and High pressure in it's operational and ensembles but the other models bring any rise of pressure too far to the South to prevent rain areas to continue to affect all areas at times in the persistent Westerly breeze which hold temperatures close to average at least for all areas.

Edited January 2, 2014 by Gibby

[A.J]

They fit with the met office wintry second half of January which is why I think they might not be as unrealistic as you think.

I'm more than happy to see them play out, hell, we need a cold/snowy outbreak to lift the spirits in here, but as we all know, nothing is set in stone (even at T48 we've been let down in the past)....My point being, please carry on with what you are doing, we just need to temper it occasionally just so new members don't fall into the trap at taking said FI charts as gospel. Like you've posted though the met office outlook is promising and, as other learned members have posted, there are subtle signs of a pattern change in the mid term, so who knows? 

[Dancerwithwings]

 i admire frosty for he's consistent endeavor to find cold and snow, i'm sure if he found one of these  he would post it

Edited January 2, 2014 by Dancerwithwings

[shedhead]

They fit with the met office wintry second half of January which is why I think they might not be as unrealistic as you think.

The MO are not forecasting a wintry 2nd half of Jan though Frosty....their latest output simply suggests it's a possibility, not a given, so things have to be kept in context here imo. 

 

UK Outlook for Friday 17 Jan 2014 to Friday 31 Jan 2014:

Current indications point towards unsettled conditions persisting through mid-January. Some signals are emerging suggesting that the weather may undergo a change later this month allowing colder conditions to then become increasingly likely. This would increase the risk of some wintry conditions developing during the second half of January. A change to a colder weather type would also increase the potential for more settled conditions leaving a lower risk of wet and windy spells than has recently been the case.

Issued at: 1600 on Thu 2 Jan 2014

Edited January 2, 2014 by shedhead

[UV-RAY]

The MO are not forecasting a wintry 2nd half of Jan though Frosty....their latest output simply suggests it's a possibility, not a given, so things have to be kept in context here imo. 

 

UK Outlook for Friday 17 Jan 2014 to Friday 31 Jan 2014:

Current indications point towards unsettled conditions persisting through mid-January. Some signals are emerging suggesting that the weather may undergo a change later this month allowing colder conditions to then become increasingly likely. This would increase the risk of some wintry conditions developing during the second half of January. A change to a colder weather type would also increase the potential for more settled conditions leaving a lower risk of wet and windy spells than has recently been the case.

Issued at: 1600 on Thu 2 Jan 2014

By the same token they aren't forecasting mild and zonal either, but what they are forecasting is a higher than normal level of confidence in it turning colder during the second half of this month.

[Panayiotis]

The NASA model has been showing snow for the highlighted areas in most of its runs since Tuesday for Saturday, is it these areas Ian you were suggesting at?