Model Output Discussion - 1st February Onwards 12z--->

[Midlands Ice Age]

Afternoon from a snowy Austria. Just for a bit of fun to break up the rather uninspiring forecast models for the UK at the moment. Can you readers of the various models predict the temperature and surface wind flow at Gatwick Airport for (12Z) Thursday 17th February 2015? You may remember a couple of weeks ago, I was going for a Easterly by then. More than likely off the mark, but I will stick with my prognosis and predict 3C and ENE. Remenber the models from a few days ago had a pressure of 1040mb over the UK for the end of this week, could be 35 mb lower in places now !

Will be interesting to see some of your various interpretations of your model assessments for this date. Good luck.

C

 

Is it the tuesday or the thursday. Not that it matters as the models seem totally random for this part of the world at the moment!

I think I might be nearer the mark if I go for Tuesday even if it is for Thursday.!!!!      

 

MIA

Edited February 9, 2015 by Midlands Ice Age

[Midlands Ice Age]

this evenings UKMO chart is not to bad at +144h it may be a long shot but the HP may just move further west if it went further out those lows diving SE in to europe may be the triger to pull it west on the other hand the GFS looks nothing like it winter is not quite over yet there is still a very slim chance left

 

 

 

The UKMO shows the trough coming up from the wsw rather than the NW as per the other models.

I think I prefer the positioning of the UK low just to the west of Southern Ireland on the BBC graphics.

 

MIA

[Frosty.]

GFS 12z op run shows quite springlike weather next week, especially midweek with a flow from the Azores and the best of the sunshine across the far south and far north. In the meantime, settled up to and including Thursday with some clear / sunny spells but also a lot of cloud floating around, the high is shunted away by Friday with an Atlantic low moving in, a brief ridge is followed by another low.

[carinthian]

Is it the tuesday or the thursday. Not that it matters as the models seem totally random for this part of the world at the moment!

I think I might be nearer the mark if I go for Tuesday even if it is for Thursday.!!!!      

 

MIA

Sorry Tues 17th Feb !

[Polar Maritime]

The GFS shows a cool unsettled spell from around the 16th from the N/W, With bands of rain crossing the UK off the Atlantic it will feel raw in the wind. Towards the end of the run/Month High Pressure again set's up shop over the UK, With the possibility of some below average temps.

 

[carinthian]

1050mb over Ireland. Wow that would put the lid on a thoroughly miserable winter for most. Reminds me of the worst of Euro High over here, thankfully not had for two winter seasons.

 C

[Frosty.]

The GFS 12z op run ends on a 'high' note with a powerful anticyclone bringing plenty of fine weather with variable cloud and sunny spells with temperatures around average by day but cold enough for slight frosts at night where skies clear.

[chris55]

ECM trying to build the Scandi high seen on yesterdays GFS

 

 

UKMO for comparison

 

[SMU]

A brief return post-

 

ECM shows a rain to snow event for the midlands & poss NE

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015020912/ECM1-144.GIF?09-0

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015020912/ECU1-120.GIF?09-0

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015020912/ECU1-144.GIF?09-0

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015020912/ECU0-144.GIF?09-0

 

best

s

[JoeShmoe]

GFS 12z op run shows quite springlike weather next week, especially midweek with a flow from the Azores and the best of the sunshine across the far south and far north. In the meantime, settled up to and including Thursday with some clear / sunny spells but also a lot of cloud floating around, the high is shunted away by Friday with an Atlantic low moving in, a brief ridge is followed by another low.

 

13c here, if the Sun is out that will feel like spring! might get out and cut the grass !

[Frosty.]

Taking a snapshot at T+240 hours on tonight's GEFS 12z mean shows high pressure to the south and low to the north west but among the 12z perturbations there are about 50 percent going for an anticyclonic spell during that period, however, by the end of the run there are quite a few colder and more unsettled solutions but in the mid range, temperatures look around average with some milder and cooler days and nights but the mean does trend rather colder later on with temperatures dipping just below average.

[Frosty.]

Tonight's Ecm 12z is not a mild run, indeed there are some rather chilly feeling days, none more so than this chart. Overall it shows our current anticyclonic spell crumbling later this week as per the other 12z output and it then turns more unsettled from the west...a nice bubble of 522 dam @ T+192.

[ANYWEATHER]

Evening, well just a few days ago the models had endless high pressure across the nation, and now low pressure is more dominant from late week onwards! Still sucks for anything Wintry though!    

[polar vortex]

I am still hopeful that with continued MJO forcing and ridging on the pacific side we will see a fairly 

dramatic switch in the mid to longer range output  over the coming days. The strat forecasts are 

showing a split of sorts from 10mb on down around t240 mark. If the MJO forcing is stronger than modeled 

then the likely hood of a full blown split and HLB's is greatly increased. 

There is strong tropical convection about 170 degrees west, ideally we would like to see this move further 

east into a more favorably phase 8 position ( if anything it has moved a little west the last couple of days 

though it has kept its intensity). This is the key  I feel to the AO turning negative and producing the pattern 

change that most on here are looking for.

Edited February 9, 2015 by polar vortex

[pureasthedriven]

Model output continues to bore me.

 

I have to be honest even the GFS attempts at an E,ly flow do nothing for me. When it comes to a classic E,ly the synoptics prior to this developing are just as important as the actual synoptics that bring the E,ly. I shall explain this below with some archives.

 

Take this chart below from Feb 1991 which shows the Scandi HP in the perfect position and the corresponding upper temps.

 

http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00119910207.gif

http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00219910207.gif

 

However do get into this position you need to rewind back many days. Look at the chart below and you will see the very cold airmass sinking S.

 

http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00119910129.gif

http://www.wetterzentrale.de/pics/archive/ra/1991/Rrea00119910130.gif

 

So basically when the HP orientates itself into the perfect position for the UK it has the colder upper temp airmass to tap into. The Jan 87 E,ly is an even better example of this.

 

http://www.wetterzentrale.de/pics/archive/ra/1987/Rrea00119870109.gif

 

Sadly I am still awaiting a classic E,ly even after all these years of being a member on this forum. It seems not only do we fail to get a Scandi HP in the correct position but we neither get that cold pool sinking S to tap into anyway.

Terrific post, TEITS. Certainly makes one yonder for nostalgic winters of yore. Though to be fair, Dec 2010 was pretty classic, even if not classic easterly.

[snefnug]

Terrific post, TEITS. Certainly makes one yonder for nostalgic winters of yore. Though to be fair, Dec 2010 was pretty classic, even if not classic easterly.

Yonder?

[bluearmy]

ext ecm eps fail to make it three on the bounce and this time maintain the euro high anomoly out to 15 days

[nick sussex]

ext ecm eps fail to make it three on the bounce and this time maintain the euro high anomoly out to 15 days

Yuk! It looks pretty grim in the medium term but the outputs are still dragging out the drama re the weekend, the ECM postage stamps only have minority support for the operational run and with so many having already driven the pattern so far east if the operational is right at T120hrs then about 35 ECM ensemble members at least will bite the dust.

 

This might not effect the eventual return of the high from the sw but could impact the angle of the next low and any colder air associated with that before the Grim Reaper returns.

 

Overall barring a few scraps from the buffet table its looking pretty desperate in terms of proper cold and snow. Once again the eastern USA has won the jackpot whilst western Europe has scraped a tenner on the lottery.

[Smiler1709]

What's peoples thinking then? Is winter drawing it's curtains with maybe a couple if brief colder incursions to come? Must say I've loved the weather last couple of days, I'm sorry if this annoys people but I'm now looking for high pressure for dry and calm conditions. I'm gonna stick winter away till November

[knocker]

A liitle more on SST anomalies and the snowstorm Boston. A tweet from Paul Douglas. I must admit I should have thought about looking on the Earth website. Click on screen for data.

 

Trace of snow MSP, 37" on the ground in Boston, most on record. 72" last 30 days. +11C water temp. anomaly a factor? http://bit.ly/1DzoMvm

Edited February 10, 2015 by knocker

[Ali1977]

A break in the PV at 240 on the ECM with a possibility of some ridgeing to follow, way to far out to think it will happen though.

[Duane S.]

Tough viewing continues this morning with little to no hope of any sustained cold for the next 10 days+

However the GFS Control offers us some hope of a late winter cold spell...

Very plausible in how it forms and still not to late in the season to bring very cold and snowy weather to many.

[JoeShmoe]

Can't post charts but GFS at 240 has HP ridging in again from the Azores, with the Foehn effect giving temps of 15c in NE Scotland

[Timmytour]

What's peoples thinking then? Is winter drawing it's curtains with maybe a couple if brief colder incursions to come? Must say I've loved the weather last couple of days, I'm sorry if this annoys people but I'm now looking for high pressure for dry and calm conditions. I'm gonna stick winter away till November

It can be petty on here at times granted, but I really don't think people are going to get annoyed by what you are looking for and will continue instead to look at the models and see what way they are heading or what direction they could potentially take.

Plenty of time for a change to proper wintry weather and the way stubborn high pressure has now been replaced by much lower pressure over the UK in recent runs highlights the potential for change without any guarantees of what that change will be.

The handling of the low coming off the eastern US here after this weekend coming  I think will end up playing a big part in what we eventually see for the thrid weekend of Feb over the UK. I think the possibilities cover the whole spectrum of warm and cold and I don't expect too much consistency in how the models handle it until next week

 

[BlueHedgehog074]

It can be petty on here at times granted, but I really don't think people are going to get annoyed by what you are looking for and will continue instead to look at the models and see what way they are heading or what direction they could potentially take.

Plenty of time for a change to proper wintry weather and the way stubborn high pressure has now been replaced by much lower pressure over the UK in recent runs highlights the potential for change without any guarantees of what that change will be.

The handling of the low coming off the eastern US here after this weekend coming I think will end up playing a big part in what we eventually see for the thrid weekend of Feb over the UK. I think the possibilities cover the whole spectrum of warm and cold and I don't expect too much consistency in how the models handle it until next week

You raise a good point. Even this week, the models still don't seem totally confident how to handle Friday/Saturday's Low Pressure system for the UK. The UKMO, for example, drops it over Southern UK, where as models like the GFS, want to push the Low Pressure Eastwards through Northern UK. (Perhaps a slight chance of something wintry for hills in the South should UKMO's solution turn out to be correct. Especially with the flow coming in from the South-East).

Example from both the GFS and UKMO to reflect the differences in the handling and positioning of the Low Pressure for Saturday and to show things for that period are still a little uncertain.

Would also certainly agree there's still a good amount of time to see further periods of the white stuff. Admittedly the chances of seeing prolonged lying snow decreases the closer Spring approaches, though March (and even April) can still provide some great snowy surprises.

Before then, it looks as though there will be a mixture of cloudy and *brighter periods (eepecily to the North-East sheltered from Western hills) for the next 2 or 3 days with High Pressure mostly in control. Generally quite calm conditions, and perhaps cold enough for a frost at night where skies clear.

Edited February 10, 2015 by DiagonalRedLine