Model Output Discussion

[Eugene]

although for alot of people, it will be dull and wet and windy which is not too inspiring.

Next week once the low moves through on GFS 00Z would give some lovely crisp sunny weather with wintry convective possibilities.

GFS 00Z not a run for the mushyman

[mushymanrob]

Next week once the low moves through on GFS 00Z would give some lovely crisp sunny weather with wintry convective possibilities.

GFS 00Z not a run for the mushyman

why?.... oh yeah itll be rather wet at times, nope i dont relish working in the wet i suppose, but in all the 00z is much warmer then previous runs with and wintriness being downgraded. but its still 'normal' albeit less pleasant then recently, i dare say though that between the rain/showers next week itll be rather nice in the sun :lol:. its still only march so i for one am not expecting real 'warmth' yet for another month or so.

[towbar0]

Has there been a downgrade this morning?

[The PIT]

ECM 00 oz has flipped back to the milder solution in FI while GFS brings back winter. UKMO fax charts follows the GFS basically. Nothing yet from Morning forecasts about cooling down which for me indicates a lack of confidence in the models.

So next week could average to slightly above or below average if the GFS is right.

[NorthantsSnow]

Has there been a downgrade this morning?

Perhaps ever so slightly. The 00z certainly was, but then the 06z has produced something more akin to last night's outputs:

http://charts.netweather.tv/gfsimages/gfs.20100325/06/141/h850t850eu.png

Still looking good to me for a final flirt with winter. Those upper temps are crucial though, if they get watered down much more then forget it.

[snowmadchrisuk]

Perhaps ever so slightly. The 00z certainly was, but then the 06z has produced something more akin to last night's outputs:

http://charts.netweather.tv/gfsimages/gfs.20100325/06/141/h850t850eu.png

Still looking good to me for a final flirt with winter. Those upper temps are crucial though, if they get watered down much more then forget it.

We would also get some wild winds and Snow or rain precipitation will be heavy .

Nice charts still a little bit to far away to take them seriously though . Will be a shock to the system as I have become very use to the mild temps and spring like conditions.

Edited March 25, 2010 by snowmadchrisuk

[SP1986]

I would probably personally back the ECM, I think although the GFS has shown the pattern for a while, some stuff doesn't quite add up. -5C 850hPa with excessively strong evaporative cooling at the surface (predictions of 0C in the day) in a band of rain, forgive me for being sceptical.

[Nick F]

Quite a divergence after t+120 between ECM and GFS to have too much confidence that the cold and wintry 06z GFS north/northwesterly will come off. ECM doesn't build a ridge upstream over the Atlantic like GFS - as the low moves in from the SW on Monday, it keeps a much less amplified flow with shortwaves preventing colder air to the north getting south like GFS.

However there is strong support from 06Z GEFS members of t850s tumbling to around -5C on the 31st for London, with the flow from the N and NW. The UKMet 6-15 dayer today suggests: "... a risk of the rain turning to snow, particularly on northern hills, but there is a smaller risk of snow at lower levels and also further south." But I don't buy GFS until ECM comes on board with less shortwave activity upstream and more ridging like GFS over the NW Atlantic.

[Thundery wintry showers]

A close look at the GFS 06Z also suggests a lot of cold cloudy wet windy weather, since the low stalls just to our east with slow-moving fronts draped around it, and strongly mixed-out air coming around the depression from the NE. Snow can't be ruled out in that setup but it does remind me a lot of the first week of March 1999, when in Tyneside it was dull and raw with outbreaks of rain and sleet all week.

For widespread snowfall we will need that low to drift further east allowing polar air to attack with relatively little mixing from around the top of the depression, which would give the mix of sunshine and wintry showers shown on many earlier GFS runs.

Another potential issue shown by ECM is very strong winds, the ECM is not known for vastly overdeepening lows and if Monday's low comes off as shown there could be some structural damage from gales towards the SW.

[Tim Bland]

Very good ensembles from the 06z for snow lovers! 12z keeping the theme going with most places at least seeing some wet snow at the begining of next week. I expect the pennines and Noth york moors etc are the only ones to see anything significant. For others it will be brief slushy coverings at best.

[Thundery wintry showers]

GFS 12Z does continue the wintry theme but the outcome from this would be rather different to the 06Z because of the low being much further east. Apart from a brief bout of frontal rain in the extreme south next Monday the emphasis would be on sunny spells and increasingly wintry showers for all if this run was to come to fruition. Temperatures higher by day than on the 06Z- highs of 5 to 8C for most into next week- but also colder by night due to clearer skies/lower dewpoints.

So we certainly can't write it off just yet, but we need UKMO/ECM to show some movement towards GFS if there is to be any confidence on the outlook not simply turning wet, windy and fairly cool as shown by this morning's ECM.

[MR EXTREMES]

dunno about cold returning just had a lovely storm here.

brillant lightning im hoping for more of the same.

but on the other had bit cold with wintry showers would be nice aswell.

strong possibility that the ecm tonight will trend colder.

how cold is another question but its been fairly cold cool few months so any low dew points would be pretty effective if you ask me.

Edited March 25, 2010 by badboy657

[StewieEatWorld]

dunno about cold returning just had a lovely storm here.

brillant lightning im hoping for more of the same.

but on the other had bit cold with wintry showers would be nice aswell.

Surely the weather you are having right now doesn't define the weather for the future?

But back on topic, when does the UKMO come out?

[MR EXTREMES]

Surely the weather you are having right now doesn't define the weather for the future?

But back on topic, when does the UKMO come out?

just saying the unsettled weather is with us after a rather boring couple of weeks or more.

there is a split in model outputs and there has been for sometime now,

but all of them suggest more unsettled type of weather for the near future.

and as a matter of fact,

it will be similar type of weather to what we have today,

all be it colder in the north,

average in the south depending on what model is correct.

good to see you have set out your thoughts

[Ben_Cambs]

But back on topic, when does the UKMO come out?

UKMO 12z has come out, but has the LP too far west for most areas to see wintry PPN, GFS 12z has it much further east to allow most of the polar air to be unaffected by the LP. Plus UKMO 12z has a glitchy chart at T+144, check this one out!

http://www.meteociel.fr/modeles/ukmo2.php?nh=0&ech=144&carte=1021

[MR EXTREMES]

UKMO 12z has come out, but has the LP too far west for most areas to see wintry PPN, GFS 12z has it much further east to allow most of the polar air to be unaffected by the LP. Plus UKMO 12z has a glitchy chart at T+144, check this one out!

http://www.meteociel...=144&carte=1021

i would say its mighty close to some cold for the north id be suprised if scotland maybe even northern england dont get a snow event of some kind.

[StewieEatWorld]

Haha! I'd settle for the glitchy chart! I think most of us would take lovely sunshine any day

[Thundery wintry showers]

It isn't glitchy on Wetterzentrale:

http://www.wetterzentrale.de/topkarten/fsukmeur.html

I imagine that the UKMO result would be similar to the GFS 06Z- cool, cloudy and wet for most, because low pressure "sets up shop" much further west and will have fronts draped around it. Perhaps the scenario of sunshine and wintry showers would arise if UKMO had a T+168, with the low drifting slowly NE each day.

[frostyjoe]

GFS 12Z does continue the wintry theme but the outcome from this would be rather different to the 06Z because of the low being much further east. Apart from a brief bout of frontal rain in the extreme south next Monday the emphasis would be on sunny spells and increasingly wintry showers for all if this run was to come to fruition. Temperatures higher by day than on the 06Z- highs of 5 to 8C for most into next week- but also colder by night due to clearer skies/lower dewpoints.

So we certainly can't write it off just yet, but we need UKMO/ECM to show some movement towards GFS if there is to be any confidence on the outlook not simply turning wet, windy and fairly cool as shown by this morning's ECM.

met uk have 4c maxes for me and snow on monday night... dont tell me downgrade! i want snow before the end i would love that!

[Eugene]

UKMO 12Z looks pretty fine to me whether i like the outcome or not, whats glitchy about it then?

I notice GFS 00Z was mild and wet for monday now GFS 12Z pushes the mild air much further south completely missing us, shows that we dont yet know the exact track of that LP system yet as that is quite a big change in 12 hours, you could be crazy to write off snowfall as somewhere between GFS 00Z and GFS 12Z coould produce a big snow event in the midlands and south.

[Eugene]

Excellent agreement on a cold spell next week on the 12Z ensembles but some runs show more precip around for early next week than the OP so the risk is there for snowfall, UKMO 12Z and GME 12Z both show cold northerlies mid week so some lovely sunshine and convective wintry showers look possible almost anywhere, GFS 12Z has mins of -2C in a breezy northerly so it will feel very cold indeed for end of March into early April

[frostyjoe]

Excellent agreement on a cold spell next week on the 12Z ensembles but some runs show more precip around for early next week than the OP so the risk is there for snowfall, UKMO 12Z and GME 12Z both show cold northerlies mid week so some lovely sunshine and convective wintry showers look possible almost anywhere, GFS 12Z has mins of -2C in a breezy northerly so it will feel very cold indeed for end of March into early April

we had -7c about 2 weeks ago and snow lying about 4 weeks ago so not long ago.

[Eugene]

lol nowhere did i say in my post that the last cold weather was long ago, just saying it will feel very cold with temps of -2C or lower in a brisk cold arctic northerly wind,

ECM 12Z is one for the cold weather fans.

http://www.wetterzentrale.de/pics/Recm1441.gif

[Thundery wintry showers]

For once we have fairly good agreement from the three main models. To my mind this setup could easily go the way of "sunshine and wintry showers" or "cloudy, raw and wet with snow restricted to high ground" (or some of both, with maybe marginal snow events on the N and W flank of the fronts) and it all depends on the precise track of the low. GFS 12Z has it tracking east-north-east and heading well out to the east, while UKMO and ECM have it tracking north-east and hanging around in the North Sea, and so did the GFS 06Z.

I'm not sure what weather the ECM solution would bring because although it's synoptically similar to GFS 06Z it's clear from the thicknesses that the airmass over the UK is less modified/mixed-ouot than the one shown on the GFS 06Z, and this could imply less in the way of frontal activity and cloud cover. But GFS 06Z certainly looked dull and wet for most.

[phil nw.]

It`s contuing to look unsettled up to the weekend as the Upper trough moves across the UK.

http://www.wetterzentrale.de/pics/Recm721.gif

http://www.wetterzentrale.de/pics/Rtavn721.png

http://www.wetterzentrale.de/pics/Rukm721.gif

Plenty of showers or rain about and temps. below average further North.

The low is modelled to slowly drift East of the UK in the further outlook.

GFS more progressive on this by T120hrs.

http://www.wetterzentrale.de/pics/Rtavn1201.png

bringing the Colder air South earlier and the possibility of Snow/sleet showers with it.

ECM and UKMO more reluctant to do this

http://www.wetterzentrale.de/pics/Recm1201.gif

http://www.wetterzentrale.de/pics/Rukm1201.gif

would still be rather cold with rain at times and snow confined to higher ground further North.

Uncertain then how Wintry it would be after the weekend at this stage but it`s an unsettled outlook and getting somewhat colder further North by Sunday.