Spring Model Discussion 18Z 9/3/13 onwards....

[cooling climate]

The ECM 0Z and the GFS 06z are really not that dissimilar synoptically

except that the ECM is a colder version.

Therefore next week we could see it turning colder again with some snow

around then briefly milder for a couple of days before becomming colder

again with an easterly digging in as the low to the west of the UK disrupts

sending some of the energy eastwards again with the risk of possible snowfall.

[Nick F]

06z ensembles are certainly more promising for milder weather

A return to milder conditions later next week a lot more evident for the south though, the north perhaps hanging on to the colder air. The earlier 00z GFS v ECM ens comparison suggests that both ops were at the milder end of the members too late next week onwards for London, though mean rising a little too, but less markedly:

http://www.weatherca...e-forecast.html

However, there is model uncertainties before then over how far south the cold air will get early-mid next week, the 00z Euro ops are backing the whole of the UK returning to the freezer for a few days, while the GFS keeps the cold confined to the north.

Given all models show the expansion south of a strong arctic ridge next week coupled with WAA over Greenland ... I would give low confidence for now on the exact position of the meandering PFJ over the Atlantic and western Europe which will decide the position of lows and thus quantifying any hopes that milder air will win out - particularly as we have a large mass of dense, deep cold air just to the north and northeast.

Though it's quite clear that the 06z GFS operational is a cold outlier in FI.

Edited March 14, 2013 by Nick F

[mushymanrob]

I think Mushy will be happy with the 06Z run with temps predicted to be around 13/14C during late next week.

http://www.wetterzen.../Rtavn18017.png

So are we looking at bitter E,lys or mild S,lys?

Personally I feel a swing towards the milder outcome is now becoming more likely and we will eventually see the outlook change from the likes of Met O etc.

...and ill not be the only one dave, however, its still in fi so im not holding my breath just yet. nothings in the bag.

The 06Z then continues on to make me look a fool.

http://www.wetterzen...s/Rtavn2401.png

Probably a good job im not applying for the part time job Paul is advertising as I can hardly say my forecasts are based on instincts.

i wouldnt say that, its fi....

funny how gfs fi showing mild = ignored by some, whilst gfs showing cold in fi is something to watch! (not having a go at teits here, just saying). but it is spring, even today its pleasantly warm in the sun, spring might struggle to establish this year but establish it will so these synoptics currently being suggested by both the gfs and ecm are likely to eventually become reality. temps in double figures would be easy to achieve once we get some higher uppers.

so the gfs 06z continues the theme of a cool, wet period gradually getting milder, but not particually drier.

[Mucka]

I do believe you are mis-reading that UKMO chart 120z brings heavy snow to its northern boundary and 144z is a cracker. Wind direction not from a warm source.

You misread my post or I didn't make clear that the UKMO 120/144 charts were very cold for March.

Perhaps you will see if you reread it.

Once again we have a battle of the models with the Euros wanting to bring back the cold uppers and wintry conditions for the North while the GFS and its ensembles are quite firmly in the "No" camp though I should add it isn't mild.

Edited March 14, 2013 by Mucka

[Methuselah]

Is it just me, or has the ECM been predicting an imminent cold blast throughout the entire winter? And the CFS likewise?

[Summer Sun]

The ECM ensemble follows the trend today of a milder hint for later next week for Birmingham we can see the highest temperature goes to

10c on the 22nd

23rd to 26th holds steady at 11c

before another rise on the 27th and 28th to 13c (this is just above the seasonal average of 12c)

Edited March 14, 2013 by Gavin.

[nick sussex]

Is it just me or has the winter just felt like its gone on for a very long time. Perhaps its seeing every single model output since November that major model fatigue has set in.

I've got just enough reserves to see how this possible wintry interlude plays out for the UK before going into my spring/summer semi hibernation.

Looking at all the outputs so far today its really the relatively small detail rather than the NH set up that's uncertain,all the models agree on northern blocking, troughing near the UK but the matter of the orientation of any troughing and how far south it gets is still open to revision.

This will dictate the actual weather on the ground for the UK so you have a spread of outcomes, because of the close proximity of some colder air to the ne possibly engaging a front over the UK that makes the chances of some appreciable snow still possible, this more especially for northern areas.

A few things to look out for if you're still hoping to see some more snow is the start point in terms of where the low centre is located and a shortwave possibly developing in Iberia, this shortwave is important because as it develops and runs ene it helps any troughing near the UK to pivot in an anti-clockwise motion, it also helps to stretch the troughing and draw some energy away from the main low, at the same time forcing from the block to the north edges the main low centre over the UK a little further south.

This then helps pull some colder air in from the east/ne into the UK. If you look at the UKMO 00hrs run between 96 and 120hrs you can see those factors working together.

That's what you need to look out for, elongated troughing= better cold potential,more football shaped= not good as that implies a lack of energy disrupting into mainland Europe.

At that point the issue will be how far south the pattern is as to where the cold/milder boundary will set up.

Edited March 14, 2013 by nick sussex

[Stu_London]

Is it just me or has the winter just felt like its gone on for a very long time. Perhaps its seeing every single model output since November that major model fatigue has set in.

Before November even, I seem to recall some of the model output forecasting a wintry spell towards the end of October.

Didn't come to anything in the end, but it did cause some excitement in here.

[Summer Sun]

As you were from GFS so far

[Rollo]

It appears to have gone on forever up in the North-East, hardly ever terribly cold but never to my recollection really mild,not much sunshine and a lot of dull cold days.

I feel ready for some warm sunshine and hope we have similar synoptics to what we have now come December.

[Summer Sun]

UKMO and GFS are almost in agreement at t72 for the uppers, GFS keeps the -4 uppers slightly further west but thats the only difference for the UK

GFS is holding firm to t96

t120 will be interesting tonight will UKMO keep the easterly will GFS follow or will UKMO backtrack we'll soon find out

1060mb high up north at t108

Edited March 14, 2013 by Gavin.

[Summer Sun]

GFS says no to the easterly once more

-8 uppers close to north east Scotland

Never make it much further south

UKMO says yes again to the easterly

All down to ECM now

Edited March 14, 2013 by Gavin.

[Cheshire Freeze]

UKMO holds firm at 120. I wonder if the GFS is going to be pulled kicking and screaming again towards the Euros. If the ECM backs the UKMO later, I'd put my money behind a UKMO/ECM combination any day over the GFS at 120 hours out.

Even the GFS evolutions look bittersweet for those wanting warmth as after a couple of milder days, that Arctic high looks at risk of displacing a wedge of Arctic cold and forcing it towards the UK via a bitter easterly.

Edited March 14, 2013 by CreweCold

[SomeLikeItHot]

Cold night in Scotland next week according to the GFS.

[swfc]

Stunning northern blocking on the ukmo at 144 hours.Not sure where this will go with gfs-ukmo ecm but its getting close so something has to give?

[Mair Snaw]

UKMO holds firm at 120. I wonder if the GFS is going to be pulled kicking and screaming again towards the Euros. If the ECM backs the UKMO later, I'd put my money behind a UKMO/ECM combination any day over the GFS at 120 hours out.

Yep how many times have we been here before this winter? maybe one last cold shot for the UK then some warmth would be welcome by many, its been a long winter and many parts of the UK have seen ok snow and cold, as always some have missed out and for those that have it must be very frustrating to keep seeing the charts promise and not produce the goods.. i would welcome some warm weather after next week as my local coal delivery guy has had more than enough of my cash this winter... one last shot then can we have something hot please!!!

[nick sussex]

UKMO at 120hrs looks like snow along a frontal boundary lying through central areas, the GFS cool and wet!

At 144hrs the UKMO still looks wintry for northern areas, its a complex outlook because of phasing of energies, a bit more energy se at 144hrs from the UKMO and you have even more wintry potential.

A very uncertain outlook because of these disagreements.

The GFS in its later output shows some unbelievably cold air for the time of the year in eastern Europe and Russia.

Edited March 14, 2013 by nick sussex

[Man With Beard]

Before November even, I seem to recall some of the model output forecasting a wintry spell towards the end of October.

Didn't come to anything in the end, but it did cause some excitement in here.

I believe some areas of the South West had 3 inches of snow at the beginning of November. So, so many epic charts this winter, enough to last a decade. Thank goodness a few actually came off!

And there's no let up this afternoon with the UKMO looking like it's set in for another prolonged cold spell at T144. If you compare it with the GFS at that time and then T168/T192, you can imagine the UKMO after T144 sucking the super-cold pool moving west from Siberia

[john pike]

ukmo at 120

gfs 12z at 120

[Cheshire Freeze]

-20 850s into Poland and -15 into Germany

VERY special chart for late March

Edited March 14, 2013 by CreweCold

[Isabellesnanny]

Does this mean spring is on hold again ? I started to feel a bit more confident (and happy) that we were on for a slow build up to Spring over the next week this morning. Has the mild weather been pushed out of the picture again?

[nick sussex]

-20 850s into Poland and -15 into Germany

Yes truly amazing for this late into March, that blocking is something that would have pandemonium breaking out in here in mid winter!

[Cheshire Freeze]

Does this mean spring is on hold again ? I started to feel a bit more confident (and happy) that we were on for a slow build up to Spring over the next week this morning. Has the mild weather been pushed out of the picture again?

It was never really in the picture. Just a few hopecasting type posts reliant upon a GFS operational and the fickle GEFS.

As ever with model watching, this can all change though.

Edited March 14, 2013 by CreweCold

[Summer Sun]

Does this mean spring is on hold again ? I started to feel a bit more confident (and happy) that we were on for a slow build up to Spring over the next week this morning. Has the mild weather been pushed out of the picture again?

The ensembles could have it as a cold outlier yet no need to panic yet

[No Balls Like Snow Balls]

Wasn't the GFS out on it's own predicting the Easterly just gone, and eventually the ECM and UKMO came into line with the GFS. Albeit the UKMO was last to come into line. An Easterly that is showing at 5 days away is a long long long way from bearing fruit.

Edited March 14, 2013 by No balls like Snow Balls