Model output discussion pm 13/01/2016

[smith25]

I'm not going to pretend I'm an expert but I have been a member for well over 10 years and have seen plenty of model drama at times.  The last few times I've seen output this confusing was when what I would class as special cold events was occurring.  Don't panic over any perceived down grades this morning as its just the models trying to get to grips with the difficult synoptics and will play out various scenarios until they agree on a result.  I would recommend sticking to the fax charts and now casting until after the weekend!.

[radiohead]

GFS shows of a band of snow turning to rain on Monday morning.

Which could lead to very icy conditions as temperatures hover around 0 in places later that night.

[Djdazzle]

It's hilarious in here. All I can see is what has been present for the past few days - huge uncertainty in the models. And just because a couple of op runs shorten the cold spell, that doesn't guarantee it will happen like that.

I think what annoys folk is when others look at a chart, then comment as though that will definitely happen. Yes, I agree that the models are hinting that the cold spell will end earlier. But there is enough spread in the outputs, ensembles etc to keep me interested.

There may well be another swing back later. As others have said, that subtropical storm will cause the models an even greater headache than they are already suffering. So I'm expecting some wild swings. Hold on tight . . .

[Day 10]

Differences again this morning for what seems like an age (which can only be a good thing for wanting the cold to last). At 120 we still have the UKMO showing the strongest high slap bang over the UK, the ECM trying to dig energy SE but doesn't succeed (let's hope the high get's that bit further north) and the GFS still trying to blast through! It is still all to play for but just not as good as yesterday going by the big 3. I wouldn't mind a snowy break down and then hit reset and go again, the polar vortex isn't exactly organised right now so I'm sure there will be further cold spells if this one doesn't last.

[Polar Maritime]

A few off topic posts have been hidden, Can we just use this thread to sensibly discuss what the models are 'actually' showing please, There is a maoning thread open if emotions run high.. Thanks.

[Hammer]

I am sure I read thoughts are the sub-tropical storm will aid the block. However I am also sure from model perspective it's certainly a spanner.

Edited January 14, 2016 by Hammer

[TEITS]

Interesting discussion this morning with regards to the models. Whether you feel they have upgraded or downgraded depends on what you seek i.e snow or frost.

The UKMO synoptically speaking is a downgrade if you seek snowfall because gone is the wedge of high pressure to our N/NW with the chance of any disturbances running to our S. However oddly enough if you seek cold temps and frost then actually its an upgrade because the UKMO would bring very cold max/min temps especially min.

My own personal thoughts is this. I am not convinced we shall see the high sink S allowing milder W,lys. However I do not believe we shall see any form of blocking to our N to allow further snowfalls. A high pressure remaining centred over the UK is our best option and then hopefully changes will allow a colder outlook to develop. I will add I do not believe in the GFS snowfall prediction for Monday either as I feel only the far SW will see any preciptation.

[phil nw.]

So differences by day 3.

I haven't much time this morning but compare the latest fax at T84 with the Gfs and we can see how fast the latter is to push the Atlantic in.I would trust that forecasters fax in in maintaining the high over the UK.

 

 

[blizzard81]

1 minute ago, Hammer said:

I am sure I read thoughts are the sub-tropical storm will aid the block. However I am also sure from model perspective it's certainly a spanner.

Yes, I am not sure if that storm is aiding the block. You would think so with the waa up the western side of the block but I also feel it is putting pressure on the block. This may have contributed to the downgrades this morning.

[nick sussex]

Jeez what a poor turnaround in the outputs.

Even the undercut looks hard to achieve, after lauding the UKMO that's backtracked but still much better than the GFS/ECM.

The ECM ensembles are going the wrong way and that poor looking cluster last night seems to have grown, theres not even agreement now within T72hrs with the GFS most progressive.

Very bizarre goings on but it does look like the cold will have a difficult job hanging on given the GFS/ECM spill a lot more energy eastwards.

Its amazing just what a mess the models can make of undercutting scenarios, overall after a decent trend yesterday its all gone rather pearshaped so far today.

[johnholmes]

Looking at the anomaly outputs over the past 3 days and they have slowly moved from the block idea to a less settled theme. The ridge is now centred from SW of the UK with the 500mb flow from S of W into the country and originating from well south over N America. Just what effect the predicted Sub Tropical low will have is not at all clear. They usually upset things for several days and I cannot recollect one this early.

So a cold spell into next week then a breakdwon to milder air from the Atlantic in the 6-14 day time scale. Beyond that, who knows, not me for sure.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

http://www.cpc.noaa.gov/products/predictions/610day/fxus06.html

[radiohead]

ECM ENS mean chart backs up the trend we've seen this morning.

[Snowman.]

2 minutes ago, johnholmes said:

Looking at the anomaly outputs over the past 3 days and they have slowly moved from the block idea to a less settled theme. The ridge is now centred from SW of the UK with the 500mb flow from S of W into the country and originating from well south over N America. Just what effect the predicted Sub Tropical low will have is not at all clear. They usually upset things for several days and I cannot recollect one this early.

So a cold spell into next week then a breakdwon to milder air from the Atlantic in the 6-14 day time scale. Beyond that, who knows, not me for sure.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

http://www.cpc.noaa.gov/products/predictions/610day/fxus06.html

Interesting that the GEFS wants to build in the russian ridge again and go for a link up. 0z run shows that perfectly with cold never really too far away.

[nick sussex]

1 minute ago, blizzard81 said:

Absolutely Nick. I wonder if you will get as much stick as me this morning for stating the obvious lol.

Lol! Well its  obvious the models have generally shortened the longevity of the cold, bizarrely theres probably a slightly better chance of seeing some snow unless the models add insult to injury.

The problem is now that the snow is more likely to be one of those that has snow to start with changing over to rain.

I'm not saying that its definitely over but overall theres just too much energy spilling east and any lobe of high pressure is currently not forecast to be able to withstand that.

Things may well change again but I'm just calling a spade a spade going off the 00hrs outputs.

[johnholmes]

the link shows the predicted path of the storm from NOAA

http://www.nhc.noaa.gov/graphics_at1.shtml?5-daynl#contents

[Frosty.]

9 minutes ago, nick sussex said:

its all gone rather pearshaped so far today.

West is Best thinks it looks good with potential omega block forming, amazing differences of opinion so far today!

[johnholmes]

6 minutes ago, radiohead said:

ECM ENS mean chart backs up the trend we've seen this morning.

And that is not an omega block

[Bristawl Si]

With the very early tropical storm situ will it 'intercept' GP's 'torpedo' before it has time to detonate?

[Frosty.]

1 minute ago, johnholmes said:

And that is not an omega block

Did I say it was?

[warrenb]

3 minutes ago, johnholmes said:

And that is not an omega block

And that is ENS mean which if as good as a chocolate fireguard.

[nick sussex]

2 minutes ago, Frosty. said:

West is Best thinks it looks good with potential omega block forming, amazing differences of opinion so far today!

Is that in February! lol

If we're going to have to accept yet another disappointment with the PV reforming to the north then as long as that's temporary which should be the case then we're likely to start off on another model drama.

Its all rather tiresome though and by the time any decent spell arrives most in here will be suffering from model exhaustion.

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 09:00 ON THURSDAY JAN 14TH 2016

THE CURRENT GENERAL SITUATION   A cold NW flow will cover the UK through the next 24-48hrs with wintry showers at times across the North and West.

http://www.wetterzentrale.de/pics/Rtavn001.gif

CURRENT SNOW FORECAST AND FREEZING LEVEL OVER THE UK The freezing level across the British Isles will lie around 500m or 2000ft today with precipitation falling as now above levels of 200m or 1000ft today and tonight.

http://www.snow-forecast.com/maps/dynamic/uk

http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow.gif

MODELS-2 WEEK HEADLINE  Very Cold and frosty with the small chance of snow in the South-west for a time early next week then becoming milder for all with some rain in the North.

THE GFS JET STREAM FORECAST  The main theme of the Jet Stream today shows the Jet Stream turning South across the UK over the coming days having crossed the Atlantic on an easterly track around 50deg north. The flow then largely disrupts as far as the UK is concerned next week as it becomes much lighter and less well defined across Europe thereafter.

http://www.netweather.tv/index.cgi?action=jetstream

GFS OPERATIONAL The GFS Operational Run today shows cold conditions lasting across the UK through the weekend and the start of next week as a cold High crosses the UK from the West. This is then shown to collapse away to the SE towards midweek with SW winds for all and some rain at times in the North and West in particular with any drier and chillier conditions more likely to the SE and behind the passage of cold fronts in the North. 

GFS CONTROL RUN The theme of the Control Run shows a very similar pattern to the Operational with a messy transition away from the cold pattern towards the middle of next week to much milder SW winds with rain at times thereafter with temperatures much closer to average and just brief cooler spells behind any cold fronts crossing East in the flow.

http://www.wetterzentrale.de/pics/Rtavn1441.gif

http://www.wetterzentrale.de/pics/Rtavn3841.gif

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=144&mode=0&carte=0

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=384&mode=0&carte=0

UKMO The UKMO model today is again wanting to prevent milder Atlantic air into the UK next week with High pressure remaining the dominant feature centred across the UK from the weekend and into the middle of next week. Conditions nationwide would remain cold or very cold with widespread sharp night frosts and freezing fog in places. Any wintry showers would be restricted to the far East and SE at first.

http://www.wetterzentrale.de/pics/Rukm1441.gif

THE FAX CHARTS The Fax Charts mirror the raw data well with High pressure centred over the UK in Arctic sourced air ensuring a cold, bright and frosty period maintained through the early part of next week.

http://www.weathercharts.org/ukmomslp.htm#t120

GEM GEM this morning shows cold and anticyclonic conditions from the weekend as High pressure is maintained close to the UK. Then through next week a slow transition towards mild SW winds begins with a messy transition of rain and snow in the SW and South for a time before the milder air accelerates NE over remaining areas late in the week with rain at times towards the North and West.

http://www.wetterzentrale.de/pics/Rgem2401.gif

NAVGEM NAVGEM looks fine and settled this morning but cold. Once the next few days of wintry showers have cleared away East High pressure builds across the UK only receding away slowly East next week, first as a disrupting Low pressure slips SE into France and delivering a risk of snow for the South and West and then more generally as milder SW winds claw there way NE across most Western and Northern areas at least by this time next week.

http://www.wetterzentrale.de/pics/Rnvg1681.gif

ECM ECM today has firmed up again on a return to milder air next week as a messy transitions day or two of rain and snow moves across the UK early in the week following a cold and frosty weekend. by the end of the run all areas are shown to be under fresh and mild West or SW winds with some rain at times in the North and West and High pressure very strong to the South of the UK

http://www.wetterzentrale.de/pics/Recm2401.gif

ECM 10 DAY MEAN The 10 day mean chart is a close replica of the operational chart for the same time so this morning we can evaluate that there is high confidence in this kind of outcome coming to be.

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

NOTABLE TRENDS & CHANGES FROM PREVIOUS RUNS The models continue to show different options towards how long the cold weather across the UK lasts but the end theme for milder weather for all by the end of next weekis maintained and indeed strengthened this morning.

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECM show at 24 hours ECM ahead at 99.6 pts with UKMO  and GFS at 99.4 pts respectively.  At 3 days ECM is leading with 97.5 pts to UKMO's 96.7 pts while GFS lags behind at 96.1 pts. At 5 days ECM leads with 89.7 pts to UKMO at 87.8 pts then GFS at 87.0 pts. Then at 8 Days ECM still leads at 66.1 pts over GFS's 63.2 pts. Finally at Day 10 ECM is ahead of GFS at 48.7 pts to 46.3 pts respectively. 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day1_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.png

MY THOUGHTS   UKMO this morning still looks very isolated in it's stance of maintaining surface cold weather across the UK well into the middle of next week at least while all other output brings milder SW winds across the UK even quicker in some instances than was shown yesterday. For the here and now the weather is settling down for a period of cold and frosty weather especially over the weekend when some very low night temperatures could be achieved under clear skies and anywhere where there is any snow cover. Talking of snow there will be some over the next few days moving South across the UK in the form of showers in the ever weakening Northerly flow though amounts look far from troubling for most. Then as High pressure builds across the UK the coldest weather arrives with widespread frost and some freezing fog. Through the beginning of next week milder Atlantic air will be trying to push in from the SW and after an erratic start most output accelerates this across all areas in the middle days of next week. However, with UKMO still showing a strong High pressure rock solid across the UK next Wednesday I wouldn't discount an extension to the cold not shown by the other output again this morning though on the downside for some due to it's persistence of High pressure any Atlantic attack misses the SW on Monday and and looks some way off still by midweek. So not for the first time of late it's the rest vs UKMO today as this rollercoaster ride of a cold spell continues to baffle the output. For those looking for snow it's not looking particularly likely for many at least not in a meaningful way and if the whiff of snow for the South and SW doesn't materialise in the transitions period early next week it looks likely we could be waiting a good while again thereafter as the Jet stream looks like returning to it's normal axis long term unless the UKMO continues to show a different pattern.  

Next Update Friday January 15th 2016 from 09:00

[Paul_1978]

Are we sure that the models have got a good handle on that sub-tropical storm yet? Storm Alex?

It's just that @fergieweatheralluded to it causing a blocked Atlantic and low pressure tracking south of the UK. Unless the picture has changed overnight and we hear any different today then it's something to keep an eye on. 

[shotski]

8 minutes ago, johnholmes said:

the link shows the predicted path of the storm from NOAA

http://www.nhc.noaa.gov/graphics_at1.shtml?5-daynl#contents

I think this is the most relevant post of the morning . Let's see how it develops in the next couple of days.  

[Bristawl Si]

6 minutes ago, Paul_1978 said:

Are we sure that the models have got a good handle on that sub-tropical storm yet? Storm Alex?

It's just that @fergieweatheralluded to it causing a blocked Atlantic and low pressure tracking south of the UK. Unless the picture has changed overnight and we hear any different today then it's something to keep an eye on. 

Yes i was thinking that. He updated yday eve must 've come from Meto data surely? Can it really change that quickly - like within 12 hours?!

Edited January 14, 2016 by Bristle boy